58MTB
Deluxe 4–Way Multipoise 2-Stage
Condensing Gas Furnace
Visit www.carrier.com
Installation, Start-up, and Operating Instructions
Sizes 060-120, Series 100
NOTE: Read the entire instruction manual before starting the
installation.
NOTE: This furnace can be installed as a direct vent (2-pipe)
or non-direct vent (1-pipe) condensing gas furnace.
This symbol → indicates a change since the last issue.
A93040
TABLE OF CONTENTS
SAFETY CONSIDERATIONS .....................................................2
CODES AND STANDARDS........................................................3
Safety.........................................................................................3
General Installation...................................................................3
Combustion and Ventilation Air ..............................................5
Duct Systems ............................................................................5
Acoustical Lining and Fibrous Glass Duct..............................5
Gas Piping and Gas Pipe Pressure Testing..............................5
Electrical Connections ..............................................................5
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS........6
INTRODUCTION ..........................................................................6
APPLICATIONS............................................................................6
General ......................................................................................6
Upflow Applications.................................................................6
Downflow Applications ............................................................8
Horizontal Left (Supply-Air Discharge) Applications ..........10
Horizontal Right (Supply-Air Discharge) Applications ........11
LOCATION..................................................................................14
General ....................................................................................14
Furnace Location Relative to Cooling
Equipment ...............................................................................15
Hazardous Locations...............................................................15
Furnace Location and Application .........................................15
Supply Air Connections ....................................................21
Return Air Connections.....................................................21
Filter Arrangement..................................................................21
Bottom Closure Panel.............................................................23
Gas Piping...............................................................................24
Electrical Connections ............................................................25
115-V Wiring.....................................................................25
24-V Wiring.......................................................................27
Accessories ........................................................................27
Removal of Existing Furnaces from Common Vent
Systems ..............................................................................28
Combustion-Air and Vent Pipe Systems ...............................28
Condensate Drain....................................................................42
General...............................................................................42
Application.........................................................................42
Condensation Drain Protection .........................................43
START-UP ADJUSTMENT AND SAFETY CHECK ..............43
General ....................................................................................43
Prime Condensate Trap With Water ......................................44
Purge Gas Lines......................................................................44
Sequence of Operation............................................................44
Two-Stage Heating With Single-Stage Thermostat
(Adaptive Mode)................................................................45
Two-Stage Heating With Two-Stage Thermostat
(Non-Adaptive Heating Mode) .........................................45
Cooling Mode ....................................................................46
Thermidistat Mode ............................................................46
Continuous Blower Mode .................................................50
Heat Pump .........................................................................50
Component Self-Test.........................................................50
Operate Furnace.................................................................51
Furnace Restart ..................................................................51
Adjustments.............................................................................51
Set Gas Input Rate ............................................................51
Set Temperature Rise ........................................................56
Adjust Blower Off Delay (Heat Mode)............................57
Set Thermostat Heat Anticipator ......................................57
Check Safety Controls ............................................................57
Checklist..................................................................................58
AIR FOR COMBUSTION AND VENTILATION ....................16
INSTALLATION .........................................................................19
Leveling Legs (If Desired) .....................................................19
Installation in Upflow and Downflow
Applications ............................................................................19
Installation in Horizontal Applications ..................................19
Air Ducts.................................................................................19
General Requirements .......................................................19
Ductwork Acoustical Treatment .......................................21
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
PC 101
Printed in U.S.A.
Catalog No. 58MTB-1SI
Pg 1
8-05
Replaces: 58MTA-8SI
Tab 6a 8a
AIRFLOW
UPFLOW
HORIZONTAL
RIGHT
HORIZONTAL
LEFT
DOWNFLOW
AIRFLOW
AIRFLOW
SAFETY CONSIDERATIONS
AIRFLOW
FURNACE RELIABILITY HAZARD
Improper installation or misapplication of furnace may require excessive servicing or cause premature component
failure.
Application of this furnace should be indoors with special
attention given to vent sizing and material, gas input rate, air
temperature rise, unit leveling, and unit sizing.
A93041
Fig. 1—Multipoise Orientations
Recognize safety information. This is the safety-alert symbol
.
When you see this symbol on the unit and in instructions or
manuals, be alert to the potential for personal injury.
Understand these signal words: DANGER, WARNING, and
CAUTION. These words are used with the safety-alert symbol.
DANGER identifies the most serious hazards which will result in
severe personal injury or death. WARNING signifies hazards
which could result in personal injury or death. CAUTION is used
to identify unsafe practices which may result in minor personal
injury or product and property damage. NOTE is used to highlight
suggestions which will result in enhanced installation, reliability,
or operation.
FIRE, EXPLOSION, ELECTRICAL SHOCK AND
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in electrical shock,
fire, personal injury, or death.
Improper installation, adjustment, alteration, service, maintenance, or use can cause carbon monoxide poisoning, explosion, fire, electrical shock, or other conditions which may
cause personal injury or property damage. Consult a qualified
installer, service agency, local gas supplier, or your distributor or branch for information or assistance. The qualified
installer or agency must use only factory-authorized and
listed kits or accessories when modifying this product.
The model 58MTB, 2-Stage, 4-way multipoise, Gas-Fired, Category IV, condensing furnace is available in model sizes ranging
in high-stage gas input rates of 60,000 to 120,000 Btuh. This
furnace is CSA (formerly AGA and CGA) design-certified for
natural and propane gases (see furnace rating plate) and for
installation in alcoves, attics, basements, closets, utility rooms,
crawlspaces, and garages. This furnace is factory-shipped for use
with natural gas. A CSA listed gas conversion kit is required to
convert furnace for use with propane gas.
Installing and servicing heating equipment can be hazardous due to
gas and electrical components. Only trained and qualified
personnel should install, repair, or service heating equipment.
Untrained personnel can perform basic maintenance functions
such as cleaning and replacing air filters. All other operations must
be performed by trained service personnel. When working on
heating equipment, observe precautions in literature, on tags, and
on labels attached to or shipped with unit and other safety
precautions that may apply.
These instructions cover the minimum requirements and conform
to existing national standards and safety codes. In some instances,
these instructions exceed certain local codes and ordinances,
especially those that may not have kept up with changing residential construction practices. We require these instructions as a
minimum for a safe installation.
Wear safety glasses and work gloves.
See Fig. 3 for required clearances to combustibles.
This furnace SHALL NOT be installed directly on carpeting, tile,
or any other combustible material other than wood flooring. For
downflow installations, a factory accessory floor base must be
used when installed on combustible materials and wood flooring.
Special base is not required when this furnace is installed on the
manufacturer’s coil assembly or when the manufacturer’s coil box
is used. The design of the 58MTB furnace is not CSA certified for
installation in mobile homes, recreational vehicles, or outdoors.
This furnace is suitable for installation in a structure built on site
or a manufactured building completed at final site.
This furnace is designed for continuous return-air minimum
temperature of 60°F db or intermittent operation down to 55°F db
such as when used with a night setback thermostat. Return-air
temperature must not exceed 80°F db. Failure to follow these
return air limits may affect reliability of heat exchangers, motors
and controls. (See Fig. 4.)
CUT HAZARD
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use care and
wear appropriate protective clothing and gloves when handling parts.
This furnace is shipped with the drain and pressure tubes connected for UPFLOW applications. Minor modifications are required when used in DOWNFLOW, HORIZONTAL RIGHT,
or HORIZONTAL LEFT (supply-air discharge direction) applications as shown in Fig. 1. See details in Applications section.
Have a fire extinguisher available during start-up and adjustment
procedures and service calls.
2
Install this furnace only in a location and position as specified in
LOCATION and INSTALLATION sections of these instructions.
→ Always provide adequate combustion and ventilation air as speci-
→
fied in section Combustion Air and Vent Pipe Systems of these
instructions to furnace.
This furnace is shipped with the following materials to assist in
proper furnace installation. These materials are shipped in the main
blower compartment.
Installer Packet includes:
Installation, Startup, and Operating Instructions
Service and Maintenance Instructions
User’s Information Manual
Warranty Certificate
Loose Parts Bag includes:
Quantity
Pressure tube extension
1
Collector Box or condensate trap extension tube
1
Inducer housing drain tube
1
1/2-in CPVC street elbow
2
Drain tube coupling
1
Drain tube coupling grommet
1
Condensate trap hole filler plug
3
Vent and combustion-air intake hole filler plug
2
Combustion-air intake pipe perforated disk assembly
1
Gas line grommet
1
Vent pipe grommet
1
Combustion-air pipe grommet
1
Power entry hole filler plug
2
Vent Pipe Extension
1*
Combustion products must be discharged outdoors. Connect this
furnace to an approved vent system only, as specified in the
Combustion Air and Vent Piping sections of these instructions.
Never test for gas leaks with an open flame. Use a commercially
available soap solution made specifically for the detection of leaks
to check all connections, as specified in the GAS PIPING section
of these instructions.
Always install furnace to operate within the furnace’s intended rise
range with a duct system which has an external static pressure
within the allowable range, as specified in the SET TEMPERATURE RISE section of these instructions and furnace rating plate.
When a furnace is installed so that supply ducts carry air circulated
by the furnace to areas outside the space containing the furnace,
the return air shall also be handled by duct(s) sealed to the furnace
casing and terminating outside the space containing the furnace.
A gas-fired furnace for installation in a residential garage must be
installed as specified in the Hazardous Locations section of these
instructions.
* ONLY supplied with some furnaces.
→ The furnace may be used for construction heat provided that the
→ The furnace shall be installed so that the electrical components are
furnace installation and operation complies with:
•
•
•
•
•
protected by water.
The furnace is permanently installed with all electrical wiring,
piping, air filters, venting and ducting installed according to
these installation instructions. A return air duct is provided,
sealed to the furnace casing, and terminated outside the space
containing the furnace. This prevents a negative pressure
condition as created by the circulating air blower, causing a
flame rollout and/or drawing combustion products into the
structure.
The furnace is controlled by a thermostat. It may not be ″hot
wired″ to provide heat continuously to the structure without
thermostatic control.
Clean outside air is provided for combustion. This is to
minimize the corrosive effects of adhesives, sealers and other
construction materials. It also prevents the entrainment of
drywall dust into combustion air, which can cause fouling and
plugging of furnace components.
The temperature of the return air to the furnace is maintained
between 55°F (13°C) and 80°F (27°C), with no evening setback
or shutdown. The use of the furnace while the structure is under
construction is deemed to be intermittent operation per our
installation instructions.
The air temperature rise is within the rated rise range on the
furnace rating plate, and the firing rate has been set to the
nameplate value.
•
The filters used to clean the circulating air during the construction process must be either changed or thoroughly cleaned prior
to occupancy.
•
The furnace, ductwork and filters are cleaned as necessary to
remove drywall dust and construction debris from all HVAC
system components after construction is completed.
For accessory installation detail, refer to the accessory installation
instruction.
NOTE: Remove all shipping materials before operating furnace.
CODES AND STANDARDS
Follow all national and local codes and standards in addition to
these instructions. The installation must comply with regulations
of the serving gas supplier, local building, heating, plumbing, and
other codes. In absence of local codes, the installation must
comply with the national codes listed below and all authorities
having jurisdiction.
In the United States and Canada, follow all codes and standards for
the following:
Step 1—Safety
•
→•
US: National Fuel Gas Code (NFGC) NFPA 54-2002/ANSI
Z223.1-2002 and the Installation Standards, Warm Air Heating
and Air Conditioning Systems ANSI/NFPA 90B
CANADA: National Standard of Canada, Natural Gas and
Propane Installation Code (NSCNGPIC) CSA B149.1-05
Step 2—General Installation
•
US: NFGC and the NFPA 90B. For copies, contact the National
Fire Protection Association Inc., Batterymarch Park, Quincy,
MA 02269; or for only the NFGC contact the American Gas
Association, 400 N. Capitol, N.W., Washington DC 20001
• A manufactured (Mobile) home installation must conform with
the Manufactured Home Construction and Safety Standard,
Title 24 CFR, Part 3280, or when this standard is not
applicable, the Standard for Manufactured Home Installation
(Manufactured Home Sites, Communities, and Set-Ups),
ANSI/NCS A225.1, and/or CAN/CSA-Z240, MH Series Mobile
Homes
• CANADA: NSCNGPIC. For a copy, contact Standard Sales,
CSA International, 178 Rexdale Boulevard, Etobicoke (Toronto), Ontario, M9W 1R3, Canada.
3
4
11⁄4"
1"
14 1⁄2"
TYP
1⁄2-IN.
26 15⁄16" TYP
23 1⁄4" TYP
SIDE INLET
SIDE INLET
DIA THERMOSTAT
ENTRY
22 11⁄16"
2-IN. VENT CONN
DIA
GAS CONN
1⁄2-IN.
2-IN. COMBUSTIONAIR CONN
22 5⁄16"
24 1⁄2"
1
26 ⁄4"
26 15⁄16"
17
E
INLET
OUTLET
D
11⁄16"
18 1⁄4"
⁄16"
TYP
9
DIMPLE LOCATORS
FOR HORIZONTAL
HANGING
CONDENSATE
DRAIN LOCATION
(UPFLOW)
30
1⁄2"
CONDENSATE DRAIN
TRAP LOCATION
(DOWNFLOW &
HORIZONTAL RIGHT)
OR ALTERNATE
1⁄2-IN. DIA GAS CONN
⁄ "
13 16
UNIT SIZE
060-12
080-12
080-16
100-16
100-20
120-20
D
15-7/8
15-7/8
15-7/8
19-3/8
19-3/8
22-7/8
Fig. 2—Dimensional Drawing
A
17-1/2
17-1/2
17-1/2
21
21
24-1/2
DIMENSIONS (IN.)
E
16
16
16
19-1/2
19-1/2
23
NOTES: 1. Minimum return-air openings at furnace, based on metal duct. If flex duct is used,
see flex duct manufacturer’s recommendations for equivalent diameters.
2. Minimum return-air opening at furnace:
a. For 800 CFM–16-in. round or 14 1/ 2 x 12-in. rectangle.
b. For 1200 CFM–20-in. round or 14 1/ 2 x 19 1/ 2-in. rectangle.
c. For 1600 CFM–22-in. round or 14 1/ 2 x 23 1/ 4-in. rectangle.
d. For airflow requirements above 1800 CFM, see Air Delivery table in Product Data
literature for specific use of single side inlets. The use of both side inlets, a
combination of 1 side and the bottom, or the bottom only will ensure adequate
return air openings for airflow requirements above 1800 CFM at 0.5” W.C. ESP.
11⁄16"
33 1⁄4"
TYP
32 5⁄8"
TYP
30 13⁄16"
29 11⁄16"
TYP
27 5⁄8"
27 9⁄16"
TYP
24 1⁄2"
5⁄16"
CONDENSATE
DRAIN LOCATION
(UPFLOW)
9 16"
TYP
7⁄
CONDENSATE
DRAIN TRAP
LOCATION
(ALTERNATE
UPFLOW)
DIA
ACCESSORY
POWER ENTRY
7⁄8-IN.
DIA
POWER CONN
7⁄8-IN.
CONDENSATE DRAIN
TRAP LOCATION
(DOWNFLOW &
HORIZONTAL LEFT)
⁄ "
13 16
A
AIRFLOW
A05053
24
BOTTOM INLET
3⁄16"
22 1⁄4" TYP
SIDE INLET
22 11⁄16"
2-IN. VENT CONN
DIA
THERMOSTAT ENTRY
1⁄2-IN.
DIA
POWER CONN
7⁄8-IN.
DIA
GAS CONN
1⁄2-IN.
2-IN. COMBUSTIONAIR CONN
OUTLET
19"
22 5⁄16"
26 1⁄4"
26 15⁄16"
28 1⁄2"
11⁄16"
7⁄16"
1"
39 7⁄8"
5⁄16"
⁄16"
⁄8"
5
13
INSTALLATION
This forced air furnace is equipped for use with natural gas at altitudes 0 - 10,000 ft (0 - 3,050m), except 140 size furnaces are only approved for altitudes 0 - 7,000 ft.
(0 - 2,135m).
An accessory kit, supplied by the manufacturer, shall be used to convert to propane gas use or may be required for some natural gas applications.
This furnace is for indoor installation in a building constructed on site. This furnace may be installed in a manufactured (mobile) home when stated on rating plate and
using factory authorized kit..
This furnace may be installed on combustible flooring in alcove or closet at Minimum Inches Clearance To Combustible Construction as described below.
This furnace requires a special venting system. Refer to the installation instructions for parts list and method of installation. This furnace is for use with schedule-40 PVC,
PVC-DWV, CPVC, or ABS-DWV pipe, and must not be vented in common with other gas-fired appliances. Construction through which vent/air intake pipes may be
installed is maximum 24 inches (600 mm), minimum 3/4 inches (19 mm) thickness (including roofing materials).
Cette fournaise à air pulsé est équipée pour utilisation avec gaz naturel et altitudes comprises entre 0 - 3,050m (0 - 10,000 pi),excepté queles fournaises de 140 taille
sont pour altitudes comprises entre 0 - 2,135m (0 - 7,000pi).
Utiliser une trousse de conversion, fournie par le fabricant, pour passer au gaz propane ou pour certaines installations au gaz naturel.
Cette fournaise à air pulsé est pour installation à l´intérieur dans un bâtiment construit sur place. Cette fournaise à air pulse peut être installée dans une maison
préfabriquée (maison mobile) si prescrit par la plaque signalétique et si l' on utilise une trousse specifiée par le fabricant.
Cette fournaise peut être installée sur un plancher combustible dans un enfoncement ou un placard en observant les Dégagement Minimum En Pouces Avec
Éléments De Construction Combustibles.
Cette fournaise nécessite un système d´évacuation spécial. La méthode d´installation et la liste des pièces nécessaires figurent dans les instructions d´installation. Cette
fournaise doit s´utiliser avec la tuyauterie des nomenclatures 40 PVC, PVC-DWV, CPVC, ou ABS-DWV et elle ne peut pas être ventilée conjointment avec d´autres
appareils à gaz. Épaisseur de la construction au travers de laquelle il est possible de faire passer les tuyaux d'aération (admission/évacuation): 24 po (600 mm)
maximum, 3/4 po (19mm) minimum (y compris la toiture).
For upflow and downflow applications, furnace must be installed level, or pitched within 1/2" of level. For a
LEVEL (0") TO
MIN 1/4" TO 1/2" MAX
horizontal application, the furnace must be pitched minimum 1/4" to maximum of 1/2" forward for proper
1/2" MAX
drainage. See Installation Manual for IMPORTANT unit support details on horizontal applications.
MINIMUM INCHES CLEARANCE TO COMBUSTIBLE CONSTRUCTION
ALL POSITIONS:
*
Minimum front clearance for service 24 inches (610mm).
† † 140 size furnaces require 1 inch back clearance to combustible materials.
DOWNFLOW POSITIONS:
I
† For installation on combustible floors only when installed on special base No. KGASB0201ALL,
Coil Assembly, Part No. CD5 or CK5, or Coil Casing, Part No. KCAKC.
HORIZONTAL POSITIONS::
Line contact is permissible only between lines formed by intersections of top and two sides of
furnace jacket, and building joists, studs, or framing.
§ Clearance shown is for air inlet and air outlet ends.
Ø 120 and 140 size furnaces require 1 inch bottom clearance to combustible materials.
DÉGAGEMENT MINIMUM EN POUCES AVEC ÉLÉMENTS DE CONSTRUCTION COMBUSTIBLES
UPFLOW OR
DOWNFLOW
FRONT
Clearance arrows
do not change with
furnace orientation.
††
0"
A BA C
RR
I EK
RE
*
§
0"
DE
SI ES
OT
POUR LA POSITION HORIZONTALE:
Le contact n´est permis qúentre les lignes formées par les intersections du dessus et des
deuxcôtés de la chemise de la fournaise, et des solives, des montants ou de la charpente du
bátiment.
§ La distance indiquée concerne l´extrémité du tuyau d´arrivée d´air et l´extrémité du tuyau de sortie
d´air.
Ø Pour les fournaises de 120 et 140 taille, 1 po (25mm) dégagement des matériaux combusitbles
est requis au-dessous.
ne change pas avec
l´orientation de la
générateur d´air chaud.
FR
A V ON
AN T
T
C
BOTTOM
DESSOUS
requis au-arriere.
1" Les fléches de dégagement
DE
SI E S
T
CO
E
AC SE
RN A I
F U URN
T
ON
FO
F R AN T
V
A
Dégagement avant minimum de 610mm (24 po) pour l´entretien.
† † Pour les fournaises de 140 taille, 1 po (25mm) dégagement des matériaux combustibles est
pièce nº KCAKC.
HORIZONTAL
This furnace is approved for UPFLOW, DOWNFLOW and
HORIZONTAL installations.
Cette fournaise est approuvée pour l´installation HORIZONTALE
et la circulation d´air VERS LE HAUT et VERS LE BAS.
POUR TOUS
U LES POSITIONS:
POUR LA POSITION COURANT DESCENDANT:
† Pour l´installation sur le plancher combustible seulement quand on utilise la base spéciale, pièce
nº KGASB0201ALL, l´ensemble serpentin, pièce nº CD5 ou CK5, ou le carter de serpentin,
FRONT
TOP/PLENUM
DESSUS/CHAMBRE D´AIR
Pour des applications de flux ascendant et descendant, la fournaise doit être installée de niveau ou inclinée à
pas plus de 1/2" du niveau. Pour une application horizontale, la fournaise doit être inclinée entre minimum
1/4" et maximum 1/2" du niveau pour le drainage approprié. En cas d´installation en position horizontale,
consulter les renseignements IMPORTANTS sur le support dans le manuel d´installation.
Clearance in inches
Dégagement (po).
0"
†Ø
LÈ
0" §
SE
NT R VI
RE
C
TI E
EN
*
24
MIN
3"
Vent clearance to
combustibles 0".
0 (po) Dégagement
d´évent avec combustibles.
328066-201 REV. B LIT TOP
A04110
Fig. 3—Clearances to Combustibles
Step 3—Combustion and Ventilation Air
•
•
In the state of Massachusetts:
US: Section 8.3 of the NFGC, Air for Combustion and
Ventilation
• CANADA: Part 7 of the NSCNGPIC, Venting Systems and Air
Supply for Appliances
Step 4—Duct Systems
•
US and CANADA: Air Conditioning Contractors Association
(ACCA) Manual D, Sheet Metal and Air Conditioning Contractors National Association (SMACNA), or American Society of Heating, Refrigeration, and Air Conditioning Engineers
(ASHRAE) 2001 Fundamentals Handbook Chapter 34.
Step 5—Acoustical Lining and Fibrous Glass Duct
•
This product must be installed by a licensed plumber or gas
fitter.
•
When flexible connectors are used, the maximum length shall
not exceed 36 inches.
•
When lever type gas shutoffs are used they shall not exceed 36
inches.
→•
The use of copper tubing for gas piping is not approved by the
state of Massachusetts.
Step 7—Electrical Connections
•
US and CANADA: current edition of SMACNA, NFPA 90B as
tested by UL Standard 181 for Class I Rigid Air Ducts
Step 6—Gas Piping and Gas Pipe Pressure Testing
•
CANADA: NSCNGPIC Parts 3, 4, 5, A, B, E, G, and H.
US: NFGC; chapters 5, 6, 7, and 12 and national plumbing
codes
5
•
US: National Electrical Code (NEC) ANSI/NFPA 70-2002
•
CANADA: Canadian Electrical Code CSA C22.1
→
0
INTRODUCTION
The model 58MTB 4-way multipoise, Gas-Fired, Category IV,
condensing furnace is available in model sizes ranging from input
capacity of 60,000 to 120,000 Btuh as a direct vent (2-pipe)
application as well as a non-direct vent (1-pipe) application.
APPLICATIONS
MINOR PROPERTY DAMAGE
Failure to follow this caution may result in minor property
damage.
Local codes may require a drain pan under entire furnace and
condensate trap when a condensing furnace is used in an attic
application or over a finished ceiling.
Step 1—General
60
Some assembly and modifications are required for furnaces
installed in any of the 4 applications shown in Fig. 1. All drain and
pressure tubes are connected as shown in Fig. 6. See appropriate
application instructions for these procedures.
Step 2—Upflow Applications
A05004
In an upflow application, the blower is located below the burner
section, and conditioned air is discharged upwards.
Fig. 4—Return-Air Temperature
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS
PROCEDURE
CONDENSATE TRAP LOCATION (FACTORY-SHIPPED
ORIENTATION)
The condensate trap is factory installed in the blower shelf and
factory connected for UPFLOW applications. A factory-supplied
tube is used to extend the condensate trap drain connection to the
desired furnace side for field drain attachment. See Condensate
Trap Tubing (Factory-Shipped Orientation) section for drain tube
extension details. (See Fig. 5.)
UNIT DAMAGE HAZARD
Failure to follow this caution may result in damage to unit
components.
Electrostatic discharge can affect electronic components.
Take precautions during furnace installation and servicing to
protect the furnace electronic control. Precautions will prevent electrostatic discharges from personnel and hand tools
which are held during the procedure. These precautions will
help to avoid exposing the control to electrostatic discharge
by putting the furnace, the control, and the person at the same
electrostatic potential.
CONDENSATE TRAP TUBING (FACTORY-SHIPPED
ORIENTATION)
NOTE: See Fig. 6 or tube routing label on main furnace door to
confirm location of these tubes.
1. Collector Box Drain, Inducer Housing Drain, Relief Port, and
Pressure Switch Tubes
These tubes should be factory attached to condensate trap and
pressure switch ready for use in upflow applications. These
tubes can be identified by their connection location and also
by a color label on each tube. These tubes are identified as
follows: collector box drain tube (blue label), inducer housing
drain tube (violet label or molded), relief port tube (green
label), and pressure switch tube (pink label).
1. Disconnect all power to the furnace. Multiple disconnects may
be required. DO NOT TOUCH THE CONTROL OR ANY
WIRE CONNECTED TO THE CONTROL PRIOR TO DISCHARGING YOUR BODY’S ELECTROSTATIC CHARGE
TO GROUND.
2. Firmly touch the clean, unpainted, metal surface of the furnace
chassis which is close to the control. Tools held in hand during
grounding will be discharged.
2. Condensate Trap Drain Tube
The condensate trap drain connection must be extended for
field attachment by doing the following:
3. After touching the chassis, you may proceed to service the
control or connecting wires as long as you do nothing to
recharge your body (moving or shuffling feet, touching
ungrounded objects, etc.).
a. Determine location of field drain connection. (See Fig. 2 or
6.)
NOTE: If internal filter or side Filter/Media Cabinet is used, drain
tube should be located to opposite side of casing from return duct
attachment to assist in filter removal.
4. If you touch ungrounded objects, firmly touch a clean,
unpainted metal surface of the furnace again before touching
control or wires.
b. Remove and discard casing drain hole plug button from
desired side.
5. Use this procedure for installed and uninstalled (ungrounded)
furnaces.
c. Install drain tube coupling grommet (factory-supplied in
loose parts bag) in selected casing hole.
6. Before removing a new control from its container, discharge
your body’s electrostatic charge to ground to protect the
control from damage. If the control is to be installed in a
furnace, follow items 1 through 4 before bringing the control
or yourself in contact with the furnace. Put all used and new
controls into containers before touching ungrounded objects.
d. Slide drain tube coupling (factory-supplied in loose parts
bag) through grommet ensuring long end of coupling faces
blower.
e. Cement 2 factory-supplied 1/2-in. street CPVC elbows to
the rigid drain tube connection on the condensate trap. (See
Fig. 6.) These elbows must be cemented together and
cemented to condensate trap drain connection.
7. An ESD service kit (available from commercial sources) may
also be used to prevent ESD damage.
6
FURNACE
DOOR
BLOWER SHELF
CONDENSATE
TRAP
CONDENSATE
TRAP (INSIDE)
FURNACE
DOOR
FURNACE
SIDE
4 78
FURNACE
SIDE
4
534
534
4
ALTERNATE DRAIN
TUBE LOCATION
26 1 4
26 1 4
FIELD
DRAIN
CONN
11 2
SIDE VIEW
CONDENSATE TRAP
DRAIN TUBE LOCATION
FIELD
DRAIN
CONN
FRONT VIEW
END VIEW
SLOT FOR SCREW
HORIZONTAL
APPLICATION
(OPTIONAL)
FRONT VIEW
HORIZONTAL
APPLICATIONS
DOWNFLOW AND ALTERNATE
EXTERNAL UPFLOW APPLICATIONS
UPFLOW APPLICATIONS
34
1⁄4 OD
COLLECTOR BOX TO
TRAP RELIEF PORT
11 2
1⁄2 OD
INDUCER HOUSING
DRAIN CONNECTION
34
5⁄8 OD
COLLECTOR BOX
DRAIN CONNECTION
71 8
SCREW HOLE FOR
UPFLOW OR DOWNFLOW APPLICATIONS
(OPTIONAL)
13 4
78
WIRE TIE
GUIDES
(WHEN USED)
21 4
FRONT VIEW
1⁄2-IN.
PVC OR CPVC
SIDE VIEW
A93026
Fig. 5—Condensate Trap
NOTE: Failure to use CPVC elbows may allow drain to kink and
prevent draining.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury
or death.
Casing hole filler cap must be installed in blower shelf hole
when condensate trap is relocated to prevent combustion
products being drawn in from appliances in the equipment
room.
f. Connect larger diameter drain tube and clamp (factorysupplied in loose parts bag) to condensate trap and clamp
securely.
g. Route tube to coupling and cut to appropriate length.
h. Attach tube to coupling and clamp securely.
CONDENSATE TRAP LOCATION (ALTERNATE UPFLOW
ORIENTATION)
4. Install condensate trap into left-hand side casing hole by
inserting tube connection stubs through casing hole and
rotating until tabs snap into locking position.
An alternate location for the condensate trap is the left-hand side
of casing. (See Fig. 2 and 7.)
5. Fill unused condensate trap casing holes with plastic filler
caps (factory-supplied in loose parts bag).
NOTE: If the alternate left-hand side of casing location is used,
the factory-connected drain and relief port tubes must be disconnected and modified for attachment. See Condensate Trap Tubing
(Alternate Upflow Orientation) section for tubing attachment. To
relocate condensate trap to the left-hand side, perform the following:
CONDENSATE TRAP TUBING (ALTERNATE UPFLOW
ORIENTATION)
NOTE: See Fig. 7 or tube routing label on main furnace door to
confirm location of these tubes.
1. Collector Box Drain Tube
Connect collector box drain tube (blue label) to condensate
trap.
1. Remove 3 tubes connected to condensate trap.
2. Remove trap from blower shelf by gently pushing tabs inward
and rotating trap.
NOTE: On 17-1/2 in. wide furnaces ONLY, cut tube between
corrugated sections to prevent kinks from occurring.
3. Install casing hole filler cap (factory-supplied in loose parts
bag) into blower shelf hole where trap was removed.
7
PLUG
PLUG
CAP
CAP
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
COLLECTOR BOX
TUBE (PINK)
COLLECTOR BOX
TUBE (PINK)
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX
DRAIN TUBE (BLUE)
INDUCER HOUSING
(MOLDED) DRAIN
TUBE (BEHIND
COLLECTOR BOX
DRAIN TUBE)
COLLECTOR BOX
DRAIN TUBE (BLUE)
CONDENSATE
TRAP
CONDENSATE
TRAP
INDUCER
HOUSING
DRAIN TUBE
(VIOLET)
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE
COUPLING (LEFT
DRAIN OPTION)
A01031
Fig. 7—Alternate Upflow Configuration and Trap
Location
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE
FIELD-INSTALLED
FACTORY-SUPPLIED
1⁄2-IN. CPVC STREET
ELBOWS (2) FOR
LEFT DRAIN OPTION
NOTE: See Fig. 6 or 7 or tube routing label on main furnace door
to check for proper connections.
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE
COUPLING (RIGHT
DRAIN OPTION)
UPPER COLLECTOR BOX AND INDUCER HOUSING
(UNUSED) DRAIN CONNECTIONS
A01030
Upper Collector Box Drain Connection
Fig. 6—Factory-Shipped Upflow Tube
Configuration
(Shown with Blower Access Panel Removed)
Attached to the UPPER collector box drain connection is a
factory-installed corrugated, plugged tube (blue and white striped
label). This tube is plugged to prevent condensate leakage in this
application. Ensure this tube is plugged.
2. Inducer Housing Drain Tube
a. Remove and discard LOWER (molded) inducer housing
drain tube which was previously connected to condensate
trap.
NOTE: See Fig. 6 or 7 or tube routing label on main furnace door
to check for proper connections.
b. Use inducer housing drain extension tube (violet label and
factory-supplied in loose parts bag) to connect LOWER
inducer housing drain connection to the condensate trap.
Attached to the UPPER (unused) inducer housing drain connection
is a cap and clamp. This cap is used to prevent condensate leakage
in this application. Ensure this connection is capped.
c. Determine appropriate length, cut, and connect tube.
NOTE: See Fig. 6 or 7 or tube routing label on main furnace door
to check for proper connections.
Upper Inducer Housing Drain Connection
d. Clamp tube to prevent any condensate leakage.
3. Relief Port Tube
CONDENSATE TRAP FREEZE PROTECTION
Refer to Condensate Drain Protection section for recommendations and procedures.
a. Connect relief port tube (green label) to condensate trap.
b. Extend this tube (if required) by splicing to small diameter
tube (factory-supplied in loose parts bag).
Step 3—Downflow Applications
In a downflow furnace application, the blower is located above the
burner section, and conditioned air is discharged downwards.
c. Determine appropriate length, cut, and connect tube.
CONDENSATE TRAP FIELD DRAIN ATTACHMENT
CONDENSATE TRAP LOCATION
Refer to Condensate Drain section for recommendations and
procedures.
The condensate trap must be removed from the factory-installed
blower shelf location and relocated in selected application location
as shown in Fig. 2, 8, or 9.
PRESSURE SWITCH TUBING
The LOWER collector box pressure tube (pink label) is factory
connected to the High Pressure Switch and should not require any
modification.
8
COLLECTOR BOX
DRAIN TUBE (BLUE)
CAP
PLUG
PLUG
CAP
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX
DRAIN TUBE (BLUE)
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR BOX
TUBE (PINK)
COLLECTOR BOX
TUBE (PINK)
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR BOX
EXTENSION TUBE
INDUCER HOUSING
DRAIN TUBE
(VIOLET)
CONDENSATE
TRAP
CONDENSATE
TRAP
COLLECTOR BOX
EXTENSION
DRAIN TUBE
INDUCER HOUSING
DRAIN TUBE (VIOLET)
DRAIN TUBE
COUPLING
A01023
A01024
Fig. 8—Downflow Tube Configuration
(Left-Hand Trap Installation)
Fig. 9—Downflow Tube Configuration
(Right-Hand Trap Installation)
1. Remove 3 tubes connected to condensate trap.
b. Install removed clamp and plug into UPPER collector box
drain tube (blue label) which was connected to condensate
trap.
2. Remove trap from blower shelf by gently pushing tabs inward
and rotating trap.
c. Connect LOWER collector box drain connection to condensate trap.
3. Remove casing hole filler cap from casing hole. (See Fig. 2, 8,
or 9.)
(1.) Condensate Trap Located on Left Side of Casing
To relocate condensate trap from the blower shelf to desired
location, perform the following:
(a.) Connect LOWER collector box drain tube (blue
and white striped label) to condensate trap. Tube
does not need to be cut.
4. Install casing hole filler cap into blower shelf hole where trap
was removed.
(b.) Clamp tube to prevent any condensate leakage.
(2.) Condensate Trap Located on Right Side of Casing
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury
or death.
Casing hole filler cap must be installed in blower shelf hole
when condensate trap is relocated to prevent combustion
products being drawn in from appliances in the equipment
room.
(a.) Install drain tube coupling (factory-supplied in
loose parts bag) into collector box drain tube
(blue and white striped label) which was previously plugged.
(b.) Connect larger diameter drain tube (factorysupplied in loose parts bag) to drain tube coupling, extending collector box drain tube for
connection to condensate trap.
5. Install condensate trap into desired casing hole by inserting
tube connection stubs through casing hole and rotating until
tabs snap into locking position.
(c.) Route extended collector box drain tube directly
from collector box drain to condensate trap as
shown in Fig. 9.
CONDENSATE TRAP TUBING
(d.) Determine appropriate length and cut.
NOTE: See Fig. 8 or 9 or tube routing label on main furnace door
to check for proper connections.
(e.) Connect to condensate trap.
(f.) Clamp tube to prevent any condensate leakage.
Relocate tubes as described below.
2. Inducer Housing Drain Tube
1. Collector Box Drain Tube
a. Remove factory-installed cap and clamp from LOWER
inducer housing drain connection.
a. Remove factory-installed plug from LOWER collector box
drain tube (blue and white striped label).
9
b. Remove and discard UPPER (molded) inducer housing
drain tube which was previously connected to condensate
trap.
CONDENSATE TRAP FREEZE PROTECTION
c. Install cap and clamp on UPPER inducer housing drain
connection where molded drain tube was removed.
Step 4—Horizontal Left (Supply-Air Discharge)
Applications
d. Use inducer housing drain tube (violet label and factorysupplied in loose parts bag) to connect LOWER inducer
housing drain connection to the condensate trap.
In a horizontal left furnace application, the blower is located to the
right of the burner section, and conditioned air is discharged to the
left.
e. Connect inducer housing drain connection to condensate
trap.
CONDENSATE TRAP LOCATION
Refer to Condensate Drain Protection section for recommendations and procedures.
The condensate trap must be removed from the factory-installed
blower shelf location and relocated in selected application location
as shown in Fig. 2 or 10.
(1.) Condensate Trap Located on Left Side of Casing
(a.) Determine appropriate length and cut.
(b.) Connect tube to condensate trap.
To relocate condensate trap from the blower shelf to desired
location, perform the following:
(c.) Clamp tube to prevent any condensate leakage.
1. Remove 3 tubes connected to condensate trap.
(2.) Condensate Trap Located on Right Side of Casing
2. Remove trap from blower shelf by gently pushing tabs inward
and rotating trap.
(a.) Route inducer housing drain tube (violet label)
directly from inducer housing to condensate trap
as shown in Fig. 9.
3. Install casing hole filler cap (factory-supplied in loose parts
bag) into blower shelf hole where trap was removed.
(b.) Determine appropriate length and cut.
(c.) Connect tube to condensate trap.
(d.) Clamp tube to prevent any condensate leakage.
3. Relief Port Tube
Refer to Pressure Switch Tubing section for connection
procedure.
→
CONDENSATE TRAP FIELD DRAIN ATTACHMENT
Refer to Condensate Drain section for recommendations and
procedures.
PRESSURE SWITCH TUBING
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury
or death.
Casing hole filler cap must be installed in blower shelf hole
when condensate trap is relocated to prevent combustion
products being drawn in from appliances in the equipment
room.
4. Install condensate trap into left-hand side casing hole by
inserting tube connection stubs through casing hole and
rotating until tabs snap into locking position.
One collector box pressure tube (pink label) is factory connected to
the High Pressure Switch for use when furnace is installed in
upflow applications. This tube MUST be disconnected and used
for the condensate trap relief port tube. The other collector box
pressure tube (green label) which was factory connected to the
condensate trap relief port connection MUST be connected to the
High Pressure Switch in DOWNFLOW or HORIZONTAL
RIGHT applications
5. Fill unused condensate trap casing holes with plastic filler
caps (factory-supplied in loose parts bag).
CONDENSATE TRAP TUBING
NOTE: See Fig. 10 or tube routing label on main furnace door to
check for proper connections.
1. Collector Box Drain Tube
NOTE: See Fig. 8 or 9 or tube routing label on main furnace door
to check for proper connections.
a. Install drain tube coupling (factory-supplied in loose parts
bag) into collector box drain tube (blue label) which was
previously connected to condensate trap.
1. Disconnect collector box pressure tube (pink label) attached to
High Pressure Switch.
b. Connect large diameter drain tube and clamp (factorysupplied in loose parts bag) to drain tube coupling, extending collector box drain tube.
2. Extend collector box pressure tube (green label) which was
previously connected to condensate trap relief port connection
by splicing to small diameter tube (factory-supplied in loose
parts bag).
c. Route extended tube (blue label) to condensate trap and cut
to appropriate length.
3. Connect collector box pressure tube (green label) to High
Pressure Switch connection labeled COLLECTOR BOX.
d. Clamp tube to prevent any condensate leakage.
2. Inducer Housing Drain Tube
4. Extend collector box pressure tube (pink label) which was
previously connected to High Pressure Switch by splicing to
remaining small diameter tube (factory-supplied in loose parts
bag).
a. Remove and discard LOWER (molded) inducer housing
drain tube which was previously connected to condensate
trap.
5. Route this extended tube (pink label) to condensate trap relief
port connection.
6. Determine appropriate length, cut, and connect tube.
b. Use inducer housing drain extension tube (violet label and
factory-supplied in loose parts bag) to connect LOWER
inducer housing drain connection to the condensate trap.
7. Clamp tube to relief port connection.
c. Determine appropriate length, cut, and connect tube.
10
PLUG
CAP
COLLECTOR BOX
DRAIN TUBE
(BLUE AND WHITE STRIPED)
AUXILIARY "J" BOX
CONDENSATE
TRAP
COLLECTOR BOX
TUBE (GREEN)
INDUCER HOUSING
DRAIN TUBE (VIOLET)
COLLECTOR
BOX EXTENSION
DRAIN TUBE
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR BOX
DRAIN TUBE (BLUE)
DRAIN TUBE COUPLING
COLLECTOR BOX TUBE (PINK)
RELOCATE TUBE BETWEEN BLOWER SHELF AND INDUCER HOUSING FOR
040, 060, AND 080 HEATING INPUT FURNACES
A01029
Fig. 10—Horizontal Left Tube Configuration
d. Clamp tube to prevent any condensate leakage.
4. Determine appropriate length, cut, and reconnect tube to High
Pressure Switch connection labeled COLLECTOR BOX.
3. Relief Port Tube
a. Extend collector box tube (green label) which was previously connected to the condensate trap by splicing to small
diameter tube (factory-supplied in loose parts bag).
CONDENSATE TRAP FREEZE PROTECTION
Refer to Condensate Drain Protection section for recommendations and procedures.
b. Route extended collector box pressure tube to relief port
connection on the condensate trap.
CONSTRUCT A WORKING PLATFORM
c. Determine appropriate length, cut, and connect tube.
Construct working platform where all required furnace clearances
are met. (See Fig. 3 and 11 or 12.)
d. Clamp tube to prevent any condensate leakage.
CONDENSATE TRAP FIELD DRAIN ATTACHMENTS
Refer to Condensate Drain section for recommendations and
procedures.
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent unit
operation
The condensate trap MUST be installed below furnace. See
Fig. 5 for dimensions. The drain connection to condensate
trap must also be properly sloped to an open drain.
PRESSURE SWITCH TUBING
The LOWER collector box pressure tube (pink label) is factory
connected to the High Pressure Switch for use when furnace is
installed in UPFLOW applications. This tube MUST be disconnected, extended, rerouted, and then reconnected to the pressure
switch in HORIZONTAL LEFT applications for 060 and 080
heating input furnaces.
NOTE: Combustion-air and vent pipes are restricted to a minimum length of 5 ft. (See Table 12.)
NOTE: See Fig. 10 or tube routing label on main furnace door to
check for proper connections.
NOTE: A 12-in. minimum offset pipe section is recommended
with short (5 to 8 ft) vent systems. This recommendation is to
reduce excessive condensate droplets from exiting the vent pipe.
(See Fig. 11, 12 or 43.)
Modify tube as described below:
1. Disconnect collector box pressure tube (pink label) attached to
High Pressure Switch.
Step 5—Horizontal Right (Supply-Air Discharge)
Applications
2. Use smaller diameter tube (factory-supplied in loose parts
bag) to extend tube disconnected in item 1.
In a horizontal right furnace application, the blower is located to
the left of the burner section, and conditioned air is discharged to
the right.
3. Route extended tube:
a. Behind inducer housing.
b. Between blower shelf and inducer housing.
11
COMBUSTION – AIR
INTAKE
VENT
30″ MIN
WORK AREA
5 3⁄4″
MANUAL
SHUTOFF
GAS VALVE
A 12-IN. MIN HORIZONTAL PIPE
SECTION IS RECOMMENDED WITH
SHORT (5 TO 8 FT) VENT SYSTEMS
TO REDUCE EXCESSIVE
CONDENSATE DROPLETS FROM
EXITING THE VENT PIPE.
ACCESS OPENING
FOR TRAP
SEDIMENT
TRAP
DRAIN
CONDENSATE
TRAP
NOTE: LOCAL CODES MAY REQUIRE A DRAIN PAN UNDER THE
FURNACE AND CONDENSATE TRAP WHEN A CONDENSING
FURNACE IS INSTALLED ABOVE FINISHED CEILINGS.
A93031
Fig. 11—Attic Location and Working Platform for Direct Vent (2-Pipe) Applications
MINOR PROPERTY DAMAGE
Failure to follow this caution may result in minor property
damage.
Local codes may require a drain pan under entire furnace and
condensate trap when a condensing furnace is used in attic
application or over a finished ceiling.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury
or death.
Casing hole filler cap must be installed in blower shelf hole
when condensate trap is relocated to prevent combustion
products being drawn in from appliances in the equipment
room.
NOTE: The auxiliary junction box (J-Box) MUST be relocated to
opposite side of furnace casing. (See Fig. 13.) See Electrical
Connection section for J-Box relocation.
4. Install condensate trap into right-hand side casing hole by
inserting tube connection stubs through casing hole and
rotating until tabs snap into locking position.
CONDENSATE TRAP LOCATION
5. Fill unused condensate trap casing holes with plastic filler
caps (factory-supplied in loose parts bag).
The condensate trap must be removed from the factory-installed
blower shelf location and relocated in selected application location
as shown in Fig. 2 or 13.
CONDENSATE TRAP TUBING
NOTE: See Fig. 13 or tube routing label on main furnace door to
check for proper connections.
To relocate condensate trap from the blower shelf to desired
location, perform the following:
1. Collector Box Drain Tube:
1. Remove 3 tubes connected to condensate trap.
a. Remove factory-installed plug from LOWER collector box
drain tube (blue and white striped label).
2. Remove trap from blower shelf by gently pushing tabs inward
and rotating trap.
b. Install removed clamp and plug into UPPER collector box
drain tube (blue label) which was previously connected to
condensate trap.
3. Install casing hole filler cap (factory-supplied in loose parts
bag) into blower shelf hole where trap was removed.
c. Connect LOWER collector box drain tube (blue and white
striped label) to condensate trap. Tube does not need to be
cut.
12
A 3-IN. MINIMUM CLEARANCE
TO COMBUSTION-AIR INTAKE
IS REQUIRED.
VENT
COMBUSTION–AIR
INTAKE
30-IN. MIN
WORK AREA
5 3⁄4″
MANUAL
SHUTOFF
GAS VALVE
A 12-IN. MIN HORIZONTAL PIPE
SECTION IS RECOMMENDED WITH
SHORT (5 TO 8 FT) VENT SYSTEMS
TO REDUCE EXCESSIVE
CONDENSATE DROPLETS FROM
EXITING THE VENT PIPE.
ACCESS OPENING
FOR TRAP
SEDIMENT
TRAP
DRAIN
CONDENSATE
TRAP
NOTE: LOCAL CODES MAY REQUIRE A DRAIN PAN UNDER THE
FURNACE AND CONDENSATE TRAP WHEN A CONDENSING
FURNACE IS INSTALLED ABOVE FINISHED CEILINGS.
→
A96184
Fig. 12—Attic Location and Working Platform for Non-Direct
Vent (1-pipe) Applications
NOTE: See Fig. 12 or tube routing label on main furnace door to
check for proper connections.
d. Clamp tube to prevent any condensate leakage.
2. Inducer Housing Drain Tube:
Relocate tubes as described below.
a. Remove factory-installed cap and clamp from LOWER
inducer housing drain connection.
1. Disconnect collector box pressure tube (pink label) attached to
High Pressure Switch.
b. Remove and discard UPPER (molded) inducer housing
drain tube which was previously connected to condensate
trap.
2. Extend collector box pressure tube (green label) which was
previously connected to condensate trap relief port connection
by splicing to small diameter tube (factory-supplied in loose
parts bag).
c. Install cap and clamp on UPPER inducer housing drain
connection where molded drain tube was removed.
d. Use inducer housing drain extension tube (violet label and
factory-supplied in loose parts bag) to connect LOWER
inducer housing drain connection to condensate trap.
3. Connect collector box pressure tube (green label) to High
Pressure Switch connection labeled COLLECTOR BOX.
4. Use remaining smaller diameter tube (factory-supplied in
loose parts bag) to extend collector box pressure tube (pink
label) which was previously connected to High Pressure
Switch. Route this extended tube (pink label) to condensate
trap relief port connection.
e. Determine appropriate length, cut, and connect tube to
condensate trap.
f. Clamp tube to prevent any condensate leakage.
3. Relief Port Tube:
Refer to Pressure Switch Tubing section for connection
procedure.
5. Determine appropriate length, cut, and connect tube.
6. Clamp tube to relief port connection.
CONDENSATE TRAP FIELD DRAIN ATTACHMENT
CONDENSATE TRAP FREEZE PROTECTION
Refer to Condensate Drain section for recommendations and
procedures.
Refer to Condensate Drain Protection section for recommendations and procedures.
PRESSURE SWITCH TUBING
One collector box pressure tube (pink label) is factory connected to
the High Pressure Switch for use when furnace is installed in
UPFLOW applications. This tube MUST be disconnected and used
for the condensate trap relief port tube. The other collector box
pressure tube (green label) which was factory connected to the
condensate trap relief port connection MUST be connected to the
High Pressure Switch in DOWNFLOW or HORIZONTAL
RIGHT applications.
CONSTRUCT A WORKING PLATFORM
Construct working platform where all required furnace clearances
are met. (See Fig. 3 and 11 or 12.)
13
CAP
COLLECTOR BOX DRAIN TUBE (BLUE)
COLLECTOR BOX TUBE (GREEN)
COLLECTOR BOX EXTENSION TUBE
COLLECTOR BOX TUBE (PINK)
PLUG
AUXILARY “J” BOX RELOCATED HERE
CONDENSATE
TRAP
COLLECTOR BOX DRAIN TUBE
(BLUE AND WHITE STRIPED)
INDUCER HOUSING
DRAIN TUBE (VIOLET)
COLLECTOR BOX
EXTENSION TUBE
A01028
Fig. 13—Horizontal Right Tube Configuration
•
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent unit
operation.
The condensate trap MUST be installed below furnace. See
Fig. 5 for dimensions. The drain connection to condensate
trap must also be properly sloped to an open drain.
be provided with ample space for servicing and cleaning.
Always comply with minimum fire protection clearances
shown on the furnace clearance to combustibles label.
NOTE: For upflow/downflow applications install furnace so that
it is level or pitched forward within 1/2-in. for proper furnace
operation. For horizontal applications pitch 1/4-in. minimum to
1/2-in. maximum forward to ensure proper condensate drainage
from secondary heat exchangers. (See Fig. 14.)
NOTE: Combustion-air pipe (when applicable) and vent pipe(s)
are restricted to a minimum length of 5 ft. (See Table 12.)
When a furnace is installed so that supply ducts carry air circulated
by the furnace to areas outside the space containing the furnace,
return air must also be handled by ducts sealed to furnace casing.
The ducts terminate outside the space containing the furnace to
ensure a negative pressure condition will not occur within equipment room or space.
NOTE: A 12-in. minimum offset pipe section is recommended
with short (5 to 8 ft) vent systems. This recommendation is to
reduce excessive condensate droplets from exiting the vent pipe.
(See Fig. 11, 12 or 43.)
LOCATION
Step 1—General
FIRE, INJURY OR DEATH HAZARD
Failure to follow this warning could result in fire, property
damage, personal injury, or death.
Do not install furnace on its back. (See Fig. 15.) Safety
control operation will be adversely affected. Never connect
return-air ducts to back of furnace.
This furnace must
•
be installed so the electrical components are protected from
water.
•
not be installed directly on any combustible material other than
wood flooring (refer to SAFETY CONSIDERATIONS).
be located so combustion-air and vent pipe maximum lengths
are not exceeded. Refer to Table 12.
•
•
be located where available electric power and gas supplies meet
specifications on the furnace rating plate.
•
be attached to an air distribution system and be located as close
to the center of the distribution system as possible. Refer to Air
Ducts section.
14
FRONT
LEVEL (0″)
TO
1⁄2″ MAX
FRONT
UPFLOW OR DOWNFLOW
MIN 1⁄4″
TO
1⁄2″ MAX
FRONT
B
A
C
K
HORIZONTAL
BACK
A02146
Fig. 14—Proper Condensate Drainage
FRONT
UNIT DAMAGE HAZARD
This gas furnace may be used for construction heat provided
that:
-The furnace is permanently installed with all electrical
wiring, piping, air filters, venting and ducting installed
according to these installation instructions. A return air duct
is provided, sealed to the furnace casing, and terminated
outside the space containing the furnace. This prevents a
negative pressure condition as created by the circulating air
blower, causing a flame rollout and/or drawing combustion
products into the structure.
-The furnace is controlled by a thermostat. It may not be ″hot
wired″ to provide heat continuously to the structure without
thermostatic control.
-Clean outside air is provided for combustion. This is to
minimize the corrosive effects of adhesives, sealers and other
construction materials. It also prevents the entrainment of
drywall dust into combustion air, which can cause fouling and
plugging of furnace components.
-The temperature of the return air to the furnace is maintained
between 55°F (13°C) and 80°F (27°C), with no evening
setback or shutdown. The use of the furnace while the
structure is under construction is deemed to be intermittent
operation per our installation instructions.
-The air temperature rise is within the rated rise range on the
furnace rating plate, and the firing rate has been set to the
nameplate value.
-The filters used to clean the circulating air during the
construction process must be either changed or thoroughly
cleaned prior to occupancy.
-The furnace, ductwork and filters are cleaned as necessary to
remove drywall dust and construction debris from all HVAC
system components after construction is completed.
-After construction is complete, verify furnace operating
conditions including ignition, input rate, temperature rise and
venting, according to the manufacturer’s instructions.
A93043
Fig. 15—Prohibit Installation on Back
control flow of air shall be adequate to prevent chilled air from
entering furnace. If dampers are manually operated, they must be
equipped with a means to prevent operation of either unit unless
the damper is in full-heat or full-cool position.
Step 3—Hazardous Locations
FIRE, EXPLOSION, INJURY OR DEATH HAZARD
Improper location or inadequate protection could result in fire
or explosion.
When the furnace is installed in a residential garage, the
burners and ignition sources must be located at least 18 in.
above the floor. The furnace must be located or protected to
avoid physical damage by vehicles. When the furnace is
installed in a public garage, airplane hangar, or other building
having a hazardous atmosphere, the furnace must be installed
in accordance with the NFGC or NSCNGPIC. (See Fig. 17.)
→ Step 4—Furnace Location and Application
DIRECT VENT (2-PIPE) APPLICATION
Furnace may be located in a confined space without special
provisions for dilution or ventilation air.
32°F MINIMUM INSTALLED
AMBIENT OR FREEZE
PROTECTION REQUIRED
UNIT DAMAGE HAZARD
Failure to follow this caution may result in minor property or
unit damage.
If this furnace is installed in an unconditioned space where
the ambient temperatures may be 32°F or lower, freeze
protection measures must be taken. (See Fig. 16.)
Step 2—Furnace Location Relative to Cooling
Equipment
The cooling coil must be installed parallel with or on downstream
side of furnace to avoid condensation in heat exchanger. When
installed parallel with a furnace, dampers or other means used to
A93058
Fig. 16—Freeze Protection
15
• Water softening chemicals
• De-icing salts or chemicals
• Carbon tetrachloride
• Halogen type refrigerants
• Cleaning solvents (such as perchloroethylene)
• Printing inks, paint removers, varnishes, etc.
• Hydrochloric acid
• Cements and glues
• Antistatic fabric softeners for clothes dryers
• Masonry acid washing materials
All fuel-burning equipment must be supplied with air for fuel
combustion. Sufficient air must be provided to avoid negative
pressure in the equipment room or space. A positive seal must be
made between the furnace cabinet and the return-air duct to
prevent pulling air from the burner area and from draft safeguard
opening.
18-IN. MINIMUM
TO BURNERS
A93044
Fig. 17—Installation in a Garage
→ NON-DIRECT VENT (1-PIPE) APPLICATION
→
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in peronal injury or
death.
The operation of exhaust fans, kitchen ventilation fans,
clothes dryers, attic exhaust fans or fireplaces could create a
NEGATIVE PRESSURE CONDITION at the furnace.
Make-up air MUST be provided for the ventilation devices, in
addition to that required by the furnace. Refer to the Carbon
Monoxide Poisoning Hazard warning in the venting section
of these instructions to determine if an adequate amount of
make-up air is available.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in intermittent unit
operation.
Do not install furnace in a corrosive or contaminated atmosphere. Make sure all combustion and circulating air requirements are met.
Refer to the AIR FOR COMBUSTION AND VENTILATION
section for details.
The requirements for combustion and ventilation air depend upon
whether or not the furnace is located in a space having a volume
of at least 50 cubic feet per 1,000 Btuh input rating for all gas
appliances installed in the space.
AIR FOR COMBUSTION AND VENTILATION
Provisions for adequate combustion, ventilation, and dilution air
must be provided in accordance with:
•
U.S. Installations: Section 8.3 of the NFGC, Air for Combustion and Ventilation and applicable provisions of the local
building codes.
• Canadian Installations: Part 7 of the NSCNGPIC, Venting
Systems and Air Supply for Appliances and all authorities
having jurisdiction.
→
•
Spaces having less than 50 cubic feet per 1,000 Btuh require
the OUTDOOR COMBUSTION AIR METHOD.
• Spaces having at least 50 cubic feet per 1,000 Btuh may use the
INDOOR COMBUSTION AIR, STANDARD or KNOWNAIR INFILTRATION METHOD.
Outdoor Combustion Air Method
1. Provide the space with sufficient air for proper combustion,
ventilation, and dilution of flue gases using permanent horizontal or vertical duct(s) or opening(s) directly communicating with the outdoors or spaces that freely communicate with
the outdoors.
FURNACE CORROSION HAZARD
Failure to follow this warning could result in reduced furnace
component life.
Air for combustion must not be contaminated by halogen
compounds, which include fluoride, chloride, bromide, and
iodide. These elements could corrode heat exchangers and
shorten furnace life. Air contaminants are found in aerosol
sprays, detergents, bleaches, cleaning solvents, salts, air
fresheners, and other household products.
2. Fig. 18 illustrates how to provide TWO OUTDOOR OPENINGS, one inlet and one outlet combustion and ventilation air
openings to the outdoors.
a. One opening MUST commence within 12″ (300 mm) of
the ceiling and the second opening MUST commence
within 12″ (300 mm) of the floor.
The following types of furnace installations may require OUTDOOR AIR for combustion due to chemical exposures:
b. Size openings and ducts per Fig. 18 and Table 1.
c. TWO HORIZONTAL DUCTS require 1 square inch of
free area per 2,000 Btuh (1,100 mm2/kW) of combined
input for all gas appliances in the space per Fig. 18 and
Table 1.
• Commercial buildings
• Buildings with indoor pools
• Laundry rooms
• Hobby or craft rooms, and
• Chemical storage areas
If air is exposed to the following substances, it should not be used
for combustion air, and outdoor air may be required for combustion:
•
•
•
d. TWO OPENINGS OR VERTICAL DUCTS require 1
square inch of free area per 4,000 Btuh (550 mm2/kW) for
combined input of all gas appliances in the space per Fig.
18 and Table 1.
3. ONE OUTDOOR OPENING requires:
Permanent wave solutions
Chlorinated waxes and cleaners
Chlorine based swimming pool chemicals
a. 1 square inch of free area per 3,000 Btuh (734 mm2/kW)
for combined input of all gas appliances in the space per
Table 1 and
16
→
Table 1—Minimum Free Area Required for Each Combustion Air Opening or Duct to Outdoors
TWO HORIZONTAL DUCTS
SINGLE DUCT OR OPENING
TWO OPENINGS OR VERTICAL DUCTS
FURNACE (1 SQ. IN./2,000 BTUH) (1,100 SQ. MM/KW) (1 SQ. IN./3,000 BTUH) (734 SQ. MM/KW) (1 SQ. IN./4,000 BTUH) (550 SQ. MM/KW)
INPUT
Free Area of
Free Area of
Free Area of
Round Duct
Round Duct
Round Duct
(BTUH)
Opening and Duct
Opening and Duct
Opening and Duct
(in. Dia)
(in. Dia)
(In. Dia)
(Sq. In.)
(sq In.)
(Sq In.)
44,000
22
6
14.7
5
11
4
66,000
33
7
22
6
16.5
5
88,000
44
8
29.3
7
22
6
110,000
55
9
36.7
7
27.5
6
132,000
66
10
44
8
33
7
154,000
77
10
51.3
9
38.5
8
→ EXAMPLES: Determining Free Area
FURNACE
110,000
66,000
88,000
WATER HEATER
30,000
40,000
30,000
+
+
+
=
=
=
TOTAL INPUT
(140,000 divided by 4,000)
(106,000 divided by 3,000)
(118,000 divided by 2,000)
=
=
=
35.0 Sq. In. for each two Vertical Ducts or Openings
35.3 Sq. In. for a Single Duct or Opening
59.0 Sq. In. for each of two Horizontal Ducts
→ Table 2—Minimum Space Volumes for 100% Combustion, Ventilation and Dilution Air from Outdoors
ACH
0.60
0.50
0.40
0.30
0.20
0.10
0.00
OTHER THAN FAN-ASSISTED TOTAL
(1,000’S BTUH GAS INPUT RATE)
30
40
50
1,050
1,260
1,575
2,100
3,150
6,300
NP
1,400
1,680
2,100
2,800
4,200
8,400
NP
1,750
2,100
2,625
3,500
5,250
10,500
NP
FAN-ASSISTED TOTAL
(1,000’S BTUH GAS INPUT RATE)
44
66
88
110
132
Space Volume (ft3)
1,100
1,650
2,200
2,750
3,300
1,320
1,980
2,640
3,300
3,960
1,650
2,475
3,300
4,125
4,950
2,200
3,300
4,400
5,500
6,600
3,300
4,950
6,600
8,250
9,900
6,600
9,900
13,200
16,500
19,800
NP
NP
NP
NP
NP
154
3,850
4,620
5,775
7,700
11,550
23,100
NP
The Known Air Infiltration Rate Method shall be used, if the
infiltration rate is known to be:
b. Not less than the sum of the areas of all vent connectors in
the space.
The opening shall commence within 12″ (300 mm) of the
ceiling. Appliances in the space shall have clearances of at
least 1″ (25 mm) from the sides and back and 6″ (150 mm)
from the front. The opening shall directly communicate
with the outdoors or shall communicate through a vertical
or horizontal duct to the outdoors or spaces (crawl or attic)
that freely communicate with the outdoors.
1. Less than 0.40 ACH and
2. Equal to or greater than 0.10 ACH
Infiltration rates greater than 0.60 ACH shall not be used. The
minimum required volume of the space varies with the number of
ACH and shall be determined per Table 2 or Equations 1 and 2.
Determine the minimum required volume for each appliance in the
space and add the volumes together to get the total minimum
required volume for the space.
Indoor Combustion Air© NFPA & AGA
Standard and Known-Air-Infiltration Rate Methods
Table 2-Minimum Space Volumes were determined by using the
following equations from the National Fuel Gas Code ANSI
Z223.1-2002/NFPA 54-2002,8.3.2.2:
Indoor combustion air is permitted for combustion, ventilation,
and dilution, if the Standard or Known-Air-Infiltration Rate
Method is used.
1. For other than fan-assisted appliances, such as a draft
hood-equipped water heater:
CARBON MONOXIDE POISONING HAZARD
Failure to supply outdoor air via grilles or ducts could result
in death and/or personal injury.
Many homes require air to be supplied from outdoors for
furnace combustion, ventilation, and dilution of flue gases.
The furnace combustion air supply must be provided in
accordance with this instruction manual.
Volume
Other
3
I other
= 21ft
ACH 1000 Btu/hr
A04002
2. For fan-assisted appliances such as this furnace:
The Standard Method:
1. The space has no less volume than 50 cubic feet per 1,000
Btuh of the maximum input ratings for all gas appliances
installed in the space and
Volume
Fan
3
I fan
= 15ft
ACH 1000 Btu/hr
A04003
2. The air infiltration rate is not known to be less than 0.40 air
changes per hour (ACH).
17
1 SQ IN.
PER 4000
BTUH*
DUCTS
TO
OUTDOORS
A
CLEARANCE IN FRONT OF COMBUSTION AIR
OPENINGS SHALL BE AT LEAST 3 IN.
1 SQ IN.
PER 2000
BTUH*
12″ MAX
VENT THROUGH ROOF
12″
MAX
F
1 SQ IN.
PER
4000
BTUH*
OUTDOORS
DUCTS
TO
OUTDOORS
CIRCULATING
AIR DUCTS
B
D
VENT
THROUGH
ROOF
CLEARANCE IN FRONT
OF COMBUSTION AIR
OPENINGS SHALL BE
AT LEAST 3 IN.
12″ MAX
1 SQ IN.
PER 2000
BTUH*
CIRCULATING AIR
DUCTS
INTERIOR
HEATED
SPACE
1 SQ IN.
PER
4000
BTUH*
E
G
12″
MAX
C
12″ MAX
12" MAX
1 SQ IN.
PER 1000
BTUH* IN DOOR
OR WALL
UNCONFINED
SPACE
6" MIN
(FRONT)†
1 SQ IN.
PER 1000
BTUH* IN DOOR
OR WALL
12" MAX
CIRCULATING AIR DUCTS
DUCT
TO
OUTDOORS
1 SQ IN.
PER 4000
BTUH*
CIRCULATING AIR DUCTS
*Minimum dimensions of 3 in.
* Minimum opening size is 100 sq in. with
minimum dimensions of 3 in.
† Minimum of 3 in. . when type-B1 vent is used.
NOTE: Use any of the following
combinations of openings:
A&B C&D D&E F&G
A03174
A03175
→ Fig. 18—Air for Combustion, Ventilation, and Dilution → Fig. 19—Air for Combustion, Ventilation, and Difor Outdoors
lution from Indoors
free area of at least 1-in.2/4,000 Btuh of total input rating for
all gas appliances in the space.
3. In spaces that use the Indoor Combustion Air Method,
infiltration should be adequate to provide air for combustion,
permanent ventilation and dilution of flue gases. However, in
buildings with unusually tight construction, additional air
MUST be provided using the methods described in the
Outdoor Combustion Air Method section.
Unusually tight construction is defined as
Construction with:
a. Walls and ceilings exposed to the outdoors have a continuous, sealed vapor barrier. Openings are gasketed or sealed
and
b. Doors and openable windows are weatherstripped and
c. Other openings are caulked or sealed. These include joints
around window and door frames, between sole plates and
floors, between wall-ceiling joints, between wall panels, at
penetrations for plumbing, electrical and gas lines, etc.
NOTE: In determining the free area of an opening, the blocking
effect of the louvers, grilles, and screens must be considered. If the
free area of a louver or grille design is unknown, it may be
assumed that wood louvers have a 20 percent free area, and metal
louvers or grilles have a 60 percent free area. Screens, when used,
must not be smaller than 1/4-in. mesh. Louvers and grilles must be
constructed so they cannot be closed.
When combustion air ducts are used, they must be of the same
cross sectional area as the free area of the openings to which they
connect. The minimum dimension of ducts must not be less than 3
in. (80mm).
If:
Iother = combined input of all other than fan-assisted appliances in Btu/hr
Ifan = combined input of all fan-assisted appliances in Btu/hr
ACH = air changes per hour (ACH shall not exceed 0.60.)
The following requirements apply to the Standard Method and to
the Known Air Infiltration Rate Method.
1. Adjoining rooms can be considered part of a space if:
a. There are no closable doors between rooms.
b. Combining spaces on same floor level. Each opening shall
have free area of at least 1 in.2/1,000 Btuh (2,000 mm2/kW)
of the total input rating of all gas appliances in the space,
but not less than 100 in.2 (0.06 m2). One opening shall
commence within 12″ (300 mm) of the ceiling and the
second opening shall commence within 12″ (300 mm) of
the floor. The minimum dimension of air openings shall be
at least 3 in. (80 mm). (See Fig. 19.)
c. Combining space on different floor levels. The volumes of
spaces on different floor levels shall be considered as
communicating spaces if connected by one or more permanent openings in doors or floors having free area of at least
2 in.2/1,000 Btuh (4,400 mm2/kW) of total input rating of
all gas appliances.
2. An attic or crawlspace may be considered a space that freely
communicates with the outdoors provided there are adequate
permanent ventilation openings directly to outdoors having
18
not required when this furnace is installed on manufacturer’s Coil
Assembly Part No. CD5 or CK5, or Coil Box Part No. KCAKC is
used.
Combination of Indoor and Outdoor Air
1. Indoor openings shall compy with the Indoor Combustion
Air Method below and,
1. Determine application being installed from Table 3.
2. Outdoor openings shall be located as required in the Outdoor
Combustion Air Method mentioned previously and,
2. Construct hole in floor per dimensions specified in Table 3
and Fig. 21.
3. Outdoor openings shall be sized as follows:
3. Construct plenum to dimensions specified in Table 3 and Fig.
21.
a. Calculate the Ratio of all Indoor Space volume divided by
required volume for Indoor Combustion Air Method
below.
4. If downflow subbase (KGASB) is used, install as shown in
Fig. 22. If Coil Assembly Part No. CD5 or CK5 or Coil Box
Part No. KCAKC is used, install as shown in Fig. 23.
b. Outdoor opening size reduction Factor is 1 minus the
Ratio in a. above.
c. Minimum size of Outdoor openings shall be the size
required in Outdoor Combustion Air Method above
multiplied by reduction Factor in b. above. The minimum
dimension of air openings shall be not less than 3 in. (80
mm).
INSTALLATION
Step 1—Leveling Legs (If Desired)
NOTE: Remove furnace perforated, supply-air duct flanges when
they interfere with mating flanges on coil or downflow subbase. To
remove perforated, supply-air duct flanges, use wide duct pliers,
duct flange tool, or hand seamers to bend flange back and forth
until it breaks off. Be careful of sharp edges. (See Fig. 24.)
When furnace is used in upflow position with side inlet(s), leveling
legs may be desired. (See Fig. 20.) Install field-supplied,
corrosion-resistant 5/16-in. machine bolts and nuts.
NOTE: The maximum length of bolt should not exceed 1-1/2 in.
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent unit
operation or performance satisfaction.
Do not bend duct flanges inward as shown in Fig. 21. This
will affect airflow across heat exchangers and may cause limit
cycling or premature heat exchanger failure. Remove duct
flange completely or bend it inward a minimum of 210° as
shown in Fig. 24.
1. Position furnace on its back. Locate and drill a 5/16-in.
diameter hole in each bottom corner of furnace. (See Fig. 20.)
Holes in bottom closure panel may be used as guide locations.
2. For each hole, install nut on bolt and then install bolt and nut
in hole. (Install flat washer if desired.)
Step 3—Installation in Horizontal Applications
3. Install another nut on other side of furnace base. (Install flat
washer if desired.)
These furnaces can be installed horizontally in either horizontal
left or right discharge position. In a crawlspace, the furnace can
either be hung from floor joist or installed on suitable blocks or
pad. Furnace can be suspended from each corner by hanger bolts
and angle iron supports. (See Fig. 25.) Cut hanger bolts (4 each
3/8-in. all-thread rod) to desired length. Use 1 X 3/8-in. flat
washers, 3/8-in. lock washers, and 3/8-in. nuts on hanger rods as
shown in Fig. 25. Dimples are provided for hole locations. (See
Fig. 2.)
4. Adjust outside nut to provide desired height, and tighten inside
nut to secure arrangement.
NOTE: Bottom closure must be used when leveling legs are used.
See Bottom Closure Panel section.
Step 2—Installation in Upflow and Downflow
Applications
NOTE: For downflow applications, this furnace is approved for
use on combustible flooring when special base (available from
manufacturer) Part No. KGASB0201ALL is used. Special base is
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent unit
operation or performance satisfaction.
The entire length of furnace MUST be supported when
furnace is used in a horizontal position to ensure proper
draining. When suspended, bottom brace supports sides and
center blower shelf. When unit is supported from the ground,
blocks or pad should support sides and center blower shelf
area.
5⁄16″
5⁄16″
1 3⁄4″
1 3⁄4″
Step 4—Air Ducts
GENERAL REQUIREMENTS
The duct system should be designed and sized according to
accepted national standards such as those published by: Air
Conditioning Contractors Association (ACCA), Sheet Metal and
Air Conditioning Contractors National Association (SMACNA) or
American Society of Heating, Refrigerating and Air Conditioning
Engineers (ASHRAE), or consult The Air Systems Design Guidelines reference tables available from your local distributor. The
duct system should be sized to handle the required system design
CFM at the design static pressure.
5⁄16″
5⁄16″
1
3⁄4″
1 3⁄4″
A89014
When a furnace is installed so that the supply ducts carry air
circulated by the furnace to areas outside the space containing the
Fig. 20—Leveling Legs
19
A
PLENUM
OPENING
B
D
FLOOR
OPENING
C
A96283
Fig. 21—Floor and Plenum Opening Dimensions
FURNACE
(OR COIL CASING
WHEN USED)
FURNACE
CD5 OR CK5
COIL ASSEMBLY
OR KCAKC
COIL BOX
COMBUSTIBLE
FLOORING
COMBUSTIBLE
FLOORING
DOWNFLOW
SUBBASE
SHEET METAL
PLENUM
SHEET METAL
PLENUM
FLOOR
OPENING
FLOOR
OPENING
A96284
A96285
Fig. 23—Furnace, Plenum, and Coil
Fig. 22—Furnace, Plenum, and Subbase
Assembly or Coil Box Installed
Installed on a Combustible Floor
on a Combustible Floor
Table 3—Opening Dimensions (In.)
FURNACE
CASING
WIDTH
17-1/2
21
24-1/2
PLENUM OPENING
APPLICATION
Upflow Applications
Downflow Applications on Non-Combustible Flooring
Downflow Applications on Combustible Flooring Using KGASB Subbase
Furnace with or without CD5 or CK5 Coil Assembly or KCAKC Coil Box
Downflow Applications on Combustible Flooring NOT Using KGASB Subbase
Furnace with CD5 or CK5 Coil Assembly or KCAKC Coil Box
Upflow Applications
Downflow Applications on Non-Combustible Flooring
Downflow Applications on Combustible Flooring Using KGASB Subbase
Furnace with or without CD5 or CK5 Coil Assembly or KCAKC Coil Box
Downflow Applications on Combustible Flooring NOT Using KGASB Subbase
Furnace with CD5 or CK5 Coil Assembly or KCAKC Coil Box
Upflow Applications
Downflow Applications on Non-Combustible Flooring
Downflow Applications on Combustible Flooring Using KGASB Subbase
Furnace with or without CD5 or CK5 Coil Assembly or KCAKC Coil Box
Downflow Applications on Combustible Flooring NOT Using KGASB Subbase
Furnace with CD5 or CK5 Coil Assembly or KCAKC Coil Box
20
FLOOR OPENING
A
B
C
D
16
15-7/8
24-1/8
19
16-5/8
16-1/2
24-3/4
19-5/8
15-1/8
19
16-3/4
20-3/8
15-1/2
19
16-1/2
20
19-1/2
19-3/8
24-1/8
19
20-1/8
20
24-3/4
19-5/8
18-5/8
19
20-1/4
20-3/8
19
19
20
20
23
22-7/8
24-1/8
19
23-5/8
23-1/2
24-3/4
19-5/8
22-1/8
19
23-3/4
20-3/8
22-1/2
19
23-1/2
20
Downflow Furnaces
PERFORATED
DISCHARGE DUCT
FLANGE
Connect supply-air duct to supply-air opening on furnace. The
supply-air duct attachment must ONLY be connected to furnace
supply/outlet or air conditioning coil casing (when used), when
installed on non-combustible material. When installed on combustible material, supply-air duct attachment must ONLY be connected to an accessory subbase or factory approved air conditioning coil casing. DO NOT cut main furnace casing to attach supply
side air duct, humidifier, or other accessories. All accessories
MUST be connected external to furnace main casing. Supply air
opening duct flanges must be modified per Fig. 24.
NO
YES
Horizontal Furnaces
210°
MIN
Connect supply-air duct to supply air opening on furnace. The
supply-air duct attachment must ONLY be connected to furnace
supply/outlet or air conditioning coil casing (when used). DO NOT
cut main furnace casing to attach supply side air duct, humidifier,
or other accessories. All accessories MUST be connected external
to furnace main casing.
YES
A93029
Fig. 24—Duct Flanges
RETURN AIR CONNECTIONS
furnace, the return air must also be handled by a duct(s) sealed to
the furnace casing and terminating outside the space containing the
furnace.
The furnace and its return air system shall be designed and
installed so that negative pressure created by the air circulating fan
cannot affect another appliance’s combustion air supply or act to
mix products of combustion with circulating air, and that the air
circulating fan of the furnace, if installed in an enclosure communicating with another fuel-burning appliance not of the direct-vent
type, shall be operable only when any door or panel covering an
opening in the furnace fan compartment or in a return air plenum
on ducts in the closed position.
Secure ductwork with proper fasteners for type of ductwork used.
Seal supply- and return-duct connections to furnace with code
approved tape or duct sealer.
Flexible connections should be used between ductwork and
furnace to prevent transmission of vibration. Ductwork passing
through unconditioned space should be insulated to enhance
system performance. When air conditioning is used, a vapor
barrier is recommended.
FIRE HAZARD
Failure to follow this warning could result in fire, personal
injury, or death.
Never connect return-air ducts to the back of the furnace.
Return-air duct connections on furnace side(s) permitted in
upflow applications only.
Maintain a 1-in. clearance from combustible materials to supply air
ductwork for a distance of 36 in. horizontally from the furnace. See
NFPA 90B or local code for further requirements.
For a furnace not equipped with a cooling coil, the outlet duct shall
be provided with a removable access panel. This opening shall be
accessible when the furnace is installed and shall be of such a size
that the heat exchanger can be viewed for possible openings using
light assistance or a probe can be inserted for sampling the air
stream. The cover attachment shall prevent leaks.
Upflow Furnaces
The return-air duct must be connected to bottom, sides (left or
right), or a combination of bottom and side(s) of main furnace
casing. Bypass humidifier may be attached into unused side return
air portion of the furnace casing. DO NOT connect any portion of
return-air duct to back of furnace casing.
DUCTWORK ACOUSTICAL TREATMENT
Metal duct systems that do not have a 90 degree elbow and 10 ft
of main duct to the first branch take-off may require internal
acoustical lining. As an alternative, fibrous ductwork may be used
if constructed and installed in accordance with the latest edition of
SMACNA construction standard on fibrous glass ducts. Both
acoustical lining and fibrous ductwork shall comply with NFPA
90B as tested by UL Standard 181 for Class 1 Rigid air ducts.
Downflow and Horizontal Furnaces
The return-air duct must be connected to return-air opening
provided. DO NOT cut into casing sides or back to attach any
portion of return-air duct. Bypass humidifier connections should
be made at ductwork or coil casing sides exterior to furnace.
SUPPLY AIR CONNECTIONS
Step 5—Filter Arrangement
Upflow Furnaces
Connect supply-air duct to 3/4-in. flange on furnace supply-air
outlet. The supply-air duct attachment must ONLY be connected
to furnace supply-/outlet-air duct flanges or air conditioning coil
casing (when used). DO NOT cut main furnace casing to attach
supply side air duct, humidifier, or other accessories. All accessories MUST be connected external to furnace main casing.
FIRE, CARBON MONOXIDE AND POISONING
HAZARD
Failure to follow this warning could result in fire, personal
injury or death.
Never operate unit without a filter or with filter access door
removed.
21
COMBUSTION-AIR INTAKE
(NON-DIRECT VENT/1-PIPE
APPLICATION,SIZES 040
THROUGH 120 ONLY)
COMBUSTION-AIR PIPE
(DIRECT VENT/2-PIPE
APPLICATION,ALL SIZES)
VENT
3-IN. MINIMUM CLEARANCE TO
COMBUSTION-AIR INTAKE IS REQUIRED
(NON-DIRECT VENT/1-PIPE
APPLICATION,SIZES 040
THROUGH 120 ONLY)
3⁄8-IN. ROD
ANGLE
IRON OR
EQUIVALENT
5 3⁄4″
ALTERNATE SUPPORT
LOCATION 4-IN. MIN
8-IN. MAX
(B)
(A)
DRAIN
(B)
(A)
(A) ROD LOCATION
USING DIMPLE
LOCATORS
(SEE DIMENSIONAL
DWG FOR
LOCATIONS)
(B)
3/8-IN. HEX
NUT
& WASHER (4)
REQD PER ROD
(A) PREFERRED ROD LOCATION
(A)
(B)
13/16-IN. MAX
ALTERNATE SUPPORT
LOCATION FROM BACK
NOTES: 1. A 1 In. clearance minimum between top of
furnace and combustible material.
(B) ALTERNATE ROD LOCATION
2. The entire length of furnace must be
supported when furnace is used in horizontal
position to ensure proper drainage.
3. For non-direct vent/1-pipe application,
bottom side combustion-air entry cannot be
used when furnace is installed with hangers
as shown.
A05054
→
Fig. 25—Crawlspace Horizontal Application for Direct Vent/2-Pipe Installation
and for Non-Direct Vent/1-Pipe Installation
The air filter arrangement will vary due to application, furnace
orientation, and filter type. The filter may be installed in an
external Filter/Media cabinet (if provided) or the furnace blower
compartment. Factory supplied washable filters are shipped in the
blower compartment.
→
Table 4—Filter Information
AIR FILTER LOCATED IN BLOWER COMPARTMENT
FURNACE
FILTER SIZE (IN.)*
FILTER
CASING
TYPE
Side
Return†*
Bottom
Return*
WIDTH (IN.)
17-1/2
(1) 16 X 25 X 1
(1) 16 X 25 X 1 Cleanable
21
(1) 16 X 25 X 1
(1) 20 X 25 X 1 Cleanable
24-1/2
(1 or 2) 16 X 25 X 1 (1) 24 X 25 X 1 Cleanable
If a factory-supplied external Filter/Media cabinet is provided,
instructions for its application, assembly, and installation are
packaged with the cabinet. The Filter/Media cabinet can be used
with the factory-supplied washable filter or a factory-specified
high-efficiency disposable filter (see cabinet instructions).
* Factory-provided with the furnace. Filters may be field modified by cutting
filter material and support rods (3) in filters. Alternate sizes and additional
filters may be ordered from your distributor or dealer.
† Upflow only. Alternate sizes and additional filters may be ordered from your
dealer.
If installing the filter in the furnace blower compartment, determine location for filter and relocate filter retaining wire if
necessary. See Table 4 to determine correct filter size for desired
filter location. Table 4 indicates filter size, location, and quantity
shipped with this furnace. See Fig. 2 for location and size of
bottom and side return-air openings.
22
WASHABLE
FILTER
FILTER
RETAINER
BOTTOM
CLOSURE
PANEL
FRONT FILLER
PANEL
A93045
A93047
Fig. 26—Filter Installed for Side Inlet
171⁄2-IN. WIDE
CASINGS ONLY:
INSTALL FIELD-SUPPLIED
FILTER FILLER STRIP
UNDER FILTER.
Fig. 28—Removing Bottom Closure Panel
21-IN. WIDE
CASINGS ONLY:
SUPPORT RODS (3)
EXTEND 1/4" ON EACH
SIDE OF FILTER AND
REST ON CASING FLANGE
CUT HAZARD
Failure to follow this caution may result in minor personal
injury.
Use care when cutting support rods in filters to protect against
flying pieces and sharp rod ends. Wear safety glasses, gloves,
and appropriate protective clothing.
3″
24 1/2″
1″
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent unit
operation or performance satisfaction.
For airflow requirements above 1800 CFM, see Air Delivery
table in Product Data literature for specific use of single side
inlets. The use of both side inlets, a combination of 1 side and
the bottom, or the bottom only will ensure adequate return air
openings for airflow requirements above 1800 CFM.
NOTE: Side return-air openings can ONLY be used in UPFLOW
configurations. Install filter(s) as shown in Fig. 26. Bottom
return-air opening may be used with all 4 orientations. Filter may
need to be cut to fit some furnace widths. Install filter as shown in
Fig. 27.
NOTE: Remove and discard bottom closure panel when bottom
inlet is used.
WASHABLE
FILTER
Step 6—Bottom Closure Panel
This furnace is shipped with bottom closure panel installed in
bottom return-air opening. This panel MUST be in place when side
return air is used.
To remove bottom closure panel, perform the following:
1. Tilt or raise furnace and remove 2 screws holding front filler
panel. (See Fig. 28.)
2. Rotate front filler panel downward to release holding tabs.
FILTER
SUPPORT
FILTER
RETAINER
3. Remove bottom closure panel.
4. Reinstall front filler panel and screws.
A00290
→
Fig. 27—Bottom Filter Arrangement
23
Table 5—Maximum Capacity of Pipe*
NOMINAL
IRON
PIPE
SIZE
(IN.)
1/2
3/4
1
1-1/4
1-1/2
GAS
SUPPLY
LENGTH OF PIPE (FT)
INTERNAL
DIAMETER
(IN.)
10
20
30
40
50
0.622
0.824
1.049
1.380
1.610
175
360
680
1400
2100
120
250
465
950
1460
97
200
375
770
1180
82
170
320
660
990
73
151
285
580
900
MANUAL
SHUTOFF
VALVE
(REQUIRED)
SEDIMENT
TRAP
UNION
* Cubic ft of gas per hr. for gas pressures of 0.5 psig (14–in. wc) or less and
a pressure drop of 0.5–in wc (based on a 0.60 specific gravity gas).
Ref: Table 9.2 NFGC.
Step 7—Gas Piping
Gas piping must be installed in accordance with national and local
codes. Refer to current edition of NFGC in the United States.
A93324
Fig. 29—Typical Gas Pipe Arrangement
Canadian installations must be made in accordance with NSCNGPIC and all authorities having jurisdiction.
If local codes allow the use of a flexible gas appliance connector,
always use a new listed connector. Do not use a connector which
has previously served another gas appliance.
Gas supply line should be a separate line running directly from
meter to furnace, if possible. Refer to Table 5 for recommended
gas pipe sizing.
An accessible manual shutoff valve MUST be installed external to
furnace casing and within 6 ft of furnace. A 1/8-in. NPT plugged
tapping, accessible for test gauge connection, MUST be installed
immediately upstream of gas supply connection to furnace and
downstream of manual shutoff valve.
Risers must be used to connect to furnace and to meter. Support all
gas piping with appropriate straps, hangers, etc. Use a minimum of
1 hanger every 6 ft. Joint compound (pipe dope) should be applied
sparingly and only to male threads of joints. Pipe dope must be
resistant to propane gas.
→
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in fire, explosion,
personal injury, or death.
- Connect gas pipe to furnace using a backup wrench to avoid
damaging gas controls.
- Gas valve shutoff switch MUST be facing forward or tilted
upward.
- Never purge a gas line into a combustion chamber. Never
test for gas leaks with an open flame. Use a commercially
available soap solution made specifically for the detection
of leaks to check all connections.
- Use proper length of pipe to avoid stress on gas control
manifold.
- If a flexible connector is required or allowed by authority
having jurisdiction, black iron pipe shall be installed at
furnace gas valve and extend a minimum of 2 in. outside
furnace casing.
-Protect gas valve from water and debris. Gas valve inlet
and/or inlet piping must remain capped until gas supply line
is permanently installed to protect the valve from moisture
and debris. Also, install a sediment trap in the gas supply
piping at the inlet to the gas valve.
Piping should be pressure tested in accordance with NFGC, local
and national plumbing and gas codes before the furnace has been
connected. In Canada, refer to current edition of NSCNGPIC. If
the pressure exceeds 0.5 psig (14-in. wc), gas supply pipe must be
disconnected from the furnace and capped before pressure test. If
test pressure is equal to or less than 0.5 psig (14-in. wc), turn off
electric shutoff switch located on furnace gas valve and accessible
manual shutoff valve before test. After all connections have been
made, purge lines and check for leakage.
→
FIRE OR EXPLOSION HAZARD
Failure to follow this warning exactly could result in serious
injury, death, or property damage.
Never test for gas leaks with an open flame. Use a commercially available soap solution made specifically for the
detection of leaks to check all connections. A fire or explosion could result causing property damage, personal injury or
loss of life.
→ Gas
line grommet (factory-supplied loose parts bag) should be
used when installing gas piping. Gas line entry hole filler plug
should be installed in unused gas line entry hole. (See Fig. 30.)
NOTE: The gas valve inlet pressure tap connection is suitable to
use as test gauge connection providing test pressure DOES NOT
exceed maximum 0.5 psig (14-in. wc) stated on gas valve. (See
Fig. 51.)
Install a sediment trap in riser leading to furnace. Trap can be
installed by connecting a tee to riser leading to furnace so
straight-through section of tee is vertical. Then connect a capped
nipple into lower end of tee. Capped nipple should extend below
level of gas controls. Place a ground joint union between gas
control manifold and manual gas shutoff valve. (See Fig. 29.)
The gas supply pressure shall be within the maximum and
minimum inlet supply pressures marked on the rating plate with
the furnace burners ON at HI-HEAT and OFF.
24
Table 6—Electrical Data
UNIT
SIZE
VOLTS—
HERTZ—
PHASE
060–12
080–12
080–16
100–16
100–20
120–20
115-60-1
115-60-1
115-60-1
115-60-1
115-60-1
115-60-1
OPERATING
VOLTAGE RANGE
Max*
Min*
127
104
127
104
127
104
127
104
127
104
127
104
MAX
UNIT
AMPS
UNIT
AMPACITY†
MIN
WIRE
SIZE
MAX WIRE
LENGTH
(FT)‡
MAX FUSE
OR CKT BKR
AMPS**
8.4
8.1
11.6
11.6
13.3
12.9
11.3
10.8
15.3
15.4
17.5
16.8
14
14
12
12
12
12
33
34
37
37
33
34
15
15
20
20
20
20
* Permissible limits of voltage range at which unit will operate satisfactorily.
† Unit ampacity = 125 percent of largest operating component’s full load amps plus 100 percent of all other potential operating components’ (EAC, humidifier, etc.) full
load amps.
‡ Length shown is measured 1 way along wire path between unit and service panel for maximum 2 percent voltage drop.
** Time-delay type is recommended.
COMBUSTION-AIR PIPE GROMMETS
UNUSED 1/2 -IN.
DIAMETER GAS
CONN. HOLE
COMBUSTION
-AIR PIPE
GAS LINE
GAS LINE ENTRY
HOLE FILLER PLUG
VENT PIPE
GAS LINE GROMMET
VENT PIPE GROMMET
NOTE: PIPE GROMMETS AND ENTRY HOLE FILLER
PLUGS ARE INCLUDED IN FACTORY-SUPPLIED
LOOSE PARTS BAG
A05057
→
Fig. 30—Typical Gas Pipe Arrangement
Step 8—Electrical Connections
See Fig. 31, 32, and 50A-H for field wiring diagram showing
typical field 115-v and 24-v wiring. Check all factory and field
electrical connections for tightness.
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent unit
operation.
Furnace control must be grounded for proper operation or
control will lock out. Control is grounded through
green/yellow wire routed to gas valve C-terminal and burner
box screw.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Blower access door switch opens 115-v power to furnace
control. No component operation can occur. Do not bypass or
close switch with panel removed.
115-V WIRING
Before proceeding with electrical connections, make certain that
voltage, frequency, and phase correspond to that specified on the
furnace rating plate. Also, check to be sure that service provided
by power supply is sufficient to handle load imposed by this
equipment. Refer to rating plate or Table 6 for equipment electrical
specifications.
Field-supplied wiring shall conform with the limitations of 63°F
rise.
→ The furnace must be electrically grounded in accordance with local
codes; or in the absence of local codes, with the National Electric
Code ANSI/NFPA 70 and/or the Canadian Electric Code, CSA
C22.1, Part I, if an external electrical source is utilized.
25
FIELD 24-V WIRING
FIELD 115-, 208/230-, 460-V WIRING
FACTORY 24-V WIRING
FACTORY 115-V WIRING
1-STAGE THERMOSTAT TERMINALS
W
FIVE
WIRE
Y
R
G
C
FIELD-SUPPLIED
FUSED DISCONNECT
TWO-WIRE
HEATINGONLY
BLK
W2
BLK
WHT
208/230- OR
460-V
THREE
PHASE
GND
GND
COM
WHT
208/230-V
SINGLE
PHASE
W/W1
GND
115-V FUSED
DISCONNECT
SWITCH
(WHEN REQUIRED)
GND
Y/Y2
JUNCTION
BOX
CONTROL
BOX
GND
R
GND
CONDENSING
UNIT
G
24-V
TERMINAL
BLOCK
FURNACE
NOTES: 1. Connect Y-terminal as shown for proper operation.
2. Some thermostats require a "C" terminal connection as shown.
3. If any of the original wire, as supplied, must be replaced,
use same type or equivalent wire.
A99071
Fig. 31—Typical Heating and Cooling Application Wiring Diagram 1-Stage Thermostat and Condensing Unit
FIELD 24-V WIRING
FIELD 115-, 208/230-, 460-V WIRING
FACTORY 24-V WIRING
FACTORY 115-V WIRING
2-STAGE THERMOSTAT TERMINALS
SEVEN
WIRE
W2
W1
Y2
R
G
Y1
C
FIELD-SUPPLIED
FUSED DISCONNECT
THREE-WIRE
HEATINGONLY
BLK
BLK
WHT
WHT
208/230- OR
460-V
THREE
PHASE
W2
GND
GND
COM
208/230-V
SINGLE
PHASE
W/W1
GND
GND
C
Y/Y2
115-V FUSED
JUNCTION
DISCONNECT
BOX
SWITCH
CONTROL
(WHEN REQUIRED)
BOX
Y1
Y2
R
24-V
TERMINAL
BLOCK
FURNACE
GND
GND
2-SPEED
CONDENSING
UNIT
G
NOTES: 1. Connect Y-terminal as shown for proper operation.
2. Some thermostats require a "C" terminal connection as shown.
3. If any of the original wire, as supplied, must be replaced,
use same type or equivalent wire.
A99072
Fig. 32—Typical Heating and Cooling Application Wiring Diagram 2-Stage Thermostat and Condensing Unit
26
FACTORY
INSTALLED
LOCATION
ELECTRIC
DISCONNECT
SWITCH
COPPER
POWER ENTRY HOLE
FILLER PLUG (FACTORYSUPPLIED LOOSE PARTS BAG)
WIRE ONLY
UNUSED 7/8-IN.
DIAMETER POWER
ENTRY HOLES
ALUMINUM
WIRE
A93033
Fig. 33—Disconnect Switch and Furnace
A05113
→
Use a separate, fused branch electrical circuit containing a properly
sized fuse or circuit breaker for this furnace. See Table 6 for wire
size and fuse specifications. A disconnecting means must be
located within sight from and readily accessible to furnace.
A05113
Fig. 34—Factory Installed J-Box Location
24-V WIRING
Make field 24-v connections at 24-v terminal block on furnace.
(See Fig. 37.) Connect terminal Y/Y2 as shown in Fig. 31 and 32
for proper cooling operation. Use only AWG No. 18, color-coded,
copper thermostat wire for lengths up to 100 ft. For wire lengths
over 100 ft, use AWG No. 16 wire.
NOTE: Proper polarity and proper grounding must be maintained
for 115-v wiring. If polarity is incorrect, control LED status
indicator light will flash rapidly and furnace will NOT operate.
The 24-v circuit contains an automotive-type, 3-amp fuse located
on furnace control. (See Fig. 37.) Any direct shorts of 24-v wiring
during installation, service, or maintenance could cause this fuse to
blow. If fuse replacement is required, use ONLY a 3-amp fuse of
identical size/type. The control will flash code 24 when fuse needs
replacement.
FIRE HAZARD
Failure to follow this warning could result in intermittent
operation or performance satisfaction.
Do not connect aluminum wire between disconnect switch
and furnace. Use only copper wire. (See Fig. 33.)
ACCESSORIES
1. Electronic Air Cleaner (EAC)
Two male quick-connect terminals marked EAC-1 and EAC-2
are provided for EAC connection. (See Fig. 37.) These
terminals are energized with 115-v (1.0-amp maximum)
during blower motor operation.
ELECTRICAL SHOCK AND FIRE HAZARD
Failure to follow this warning coud result in electrical shock,
fire, or death.
The furnace casing MUST have an uninterrupted or unbroken
ground according to NEC ANSI/NFPA 70-2002 and Canadian Electrical Code CSA C22.1 or local codes to minimize
personal injury if an electrical fault should occur. This may
consist of electrical wire or conduit approved for electrical
ground when installed in accordance with existing electrical
codes. Do not use gas piping as an electrical ground.
2. Humidifier (HUM)
Connect an accessory 24 VAC, 0.5 amp maximum humidifier
(if used) to the 1/4-in. male quick-connect HUM terminal and
COM-24V screw terminal on the control board thermostat strip.
The HUM terminal is energized when gas valve is energized.
(See Fig. 36 or 37.)
NOTE: A field-supplied, 115–v controlled relay connected to
EAC terminals may be added if humidifier operation is desired
during blower operation.
→ Factory Installed J-Box Location
Install electrical entry hole filler plugs (factory-supplied in loose
parts bag) in unused power entry holes. (See Fig. 34.)
UNIT DAMAGE HAZARD
Failure to follow this caution may result in unit component
damage.
DO NOT connect furnace control HUM terminal to HUM
(humidifier) terminal on Thermidistat™, Zone Controller or
similar device. See Thermidistat™, Zone Controller, thermostat, or controller manufacturer’s instructions for proper
connection.
J-Box Relocation
1. Remove 2 screws holding auxiliary J-box. (See Fig. 35.)
2. Rotate J-box 180° and attach box to left side, using holes
provided.
→
3. Install electrical entry hole filler plugs (factory-supplied loose
parts Bag) in unused power entry holes. (See Fig. 35.)
ELECTRICAL SHOCK AND FIRE HAZARD
Failure to follow this warning could result in intermittent unit
operation or performance satisfaction.
If manual disconnect switch is to be mounted on furnace,
select a location where a drill or fastener will not contact
electrical or gas components.
27
ALTERNATE
FIELD
LOCATION
FACTORY
INSTALLED
LOCATION
POWER ENTRY HOLE
FILLER PLUG (FACTORYSUPPLIED LOOSE PARTS BAG)
POWER ENTRY HOLE
FILLER PLUG (FACTORYSUPPLIED LOOSE PARTS BAG)
UNUSED 7/8-IN. DIAMETER
POWER ENTRY HOLES
UNUSED 7/8-IN. DIAMETER
POWER ENTRY HOLES
A05058
→ Fig. 35—Relocating J-Box
Step 9—Removal of Existing Furnaces from
Common Vent Systems
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each appliance
connected to the venting system being placed into operation
could result in carbon monoxide poisoning or death.
The following steps shall be followed for each appliance
connected to the venting system being placed into operation,
while all other appliances connected to the venting system are
not in operation:
1. Seal any unused openings in venting system.
2. Inspect the venting system for proper size and horizontal
pitch, as required in the National Fuel Gas Code, ANSI
Z223.1-2002/NFPA 54-2002 or the CSA B149.1, Natural
Gas and Propane Installation Code and these instructions.
Determine that there is no blockage or restriction, leakage,
corrosion and other deficiencies, which could cause an
unsafe condition.
3. As far as practical, close all building doors and windows
and all doors between the space in which the appliance(s)
connected to the venting system are located and other
spaces of the building.
4. Close fireplace dampers.
5. Turn on clothes dryers and any appliance not connected to
the venting system. Turn on any exhaust fans, such as
range hoods and bathroom exhausts, so they are operating
at maximum speed. Do not operate a summer exhaust fan.
6. Follow the lighting instructions. Place the appliance being
inspected into operation. Adjust the thermostat so appliance is operating continuously.
7. Test for spillage from draft hood equipped appliances at the
draft hood relief opening after 5 minutes of main burner
operation. Use the flame of a match or candle.
8. If improper venting is observed during any of the above
tests, the venting system must be corrected in accordance
with the National Fuel Gas Code, ANSI Z223.12002/NFPA 54-2002 and/or CSA B149.1, Natural Gas and
Propane Installation Code.
9. After it has been determined that each appliance connected
to the venting system properly vents when tested as
outlined above, return doors, windows, exhaust fans,
fireplace dampers and any other gas-fired burning appliance to their previous conditions of use.
When an existing Category I furnace is removed or replaced, the
original venting system may no longer be sized to properly vent
the remaining attached appliances. An improperly sized Category
I venting system could cause the formation of condensate in the
furnace and vent, leakage of condensate and combustion products,
spillage of combustion products into the living space, etc.
Step 10—Combustion Air and Vent Pipe Systems
GENERAL
Vent system or vent connectors may need to be resized. For any
other appliances when resizing vent systems or vent connectors,
system or connector must be sized to approach minimum size as
determined using appropriate table found in the NFGC or NSCNGPIC.
→ The 58MTB can be vented as either a direct vent (all sizes) or as
a non-direct vent (except for 140 size) application. A direct vent
system shall be installed in accordance with the direct vent
(2-pipe) procedures in the following Combustion Air and Vent
Pipe Systems section. For non-direct vent (1-pipe) applications,
refer to the non-direct vent (1-pipe) procedures in the same section.
→ Multistory and common venting are prohibited.
DIRECT VENT/2-PIPE SYSTEM
In a direct-vent (2-pipe) system, all air for combustion is taken
directly from outdoor atmosphere, and all flue products are
discharged to outdoor atmosphere. A factory accessory vent
termination kit MUST be used in a direct vent (2-pipe) system.
→ NON-DIRECT VENT/1-PIPE SYSTEM
In a non-direct vent (1-pipe) system, all air for combustion is taken
from the area adjacent to furnace, and all flue products are
discharged to outdoor atmosphere. A factory-supplied perforated
disk assembly (in loose parts bag) MUST be used in combustionair pipe elbow.
→ MATERIALS
Combustion-air and vent pipe, fittings, primers, and solvents must
conform to American National Standards Institute (ANSI) standards and American Society for Testing and Materials (ASTM)
standards. See Table 7 for approved materials for use in the U.S.A.
28
BRN
GRN/YEL
BRN
HI
BLU
1 2 3
PLT
ACRDJ
GRY
HPS
29
GND
GV
GVR 1, 2
HPS
HPSR
HSI
HSIR
HUM
IDM
IDR
IHI/LOR
ILK
JB
LED
LGPS
LPS
LS
OL
PCB
ACR
ACRDJ
BHI/LOR
BHT/CLR
BLWR
BLWM
CAP 1, 2
CPU
DHUM
EAC-1
EAC-2
FRS
FSE
FU1
FU2
LEGEND
RED
PL1
STATUS CODE
LED
1
WHT
YEL
RED
EAC-2 NEUTRAL - L2
LPS
LS
NOTE #8
IDR
HSIR
IHI/LOR
L1
NOTE #11
RED
AIR CONDITIONING RELAY, SPST (N.O.)
AIR CONDITIONING RELAY DISABLE JUMPER
BLOWER MOTOR SPEED CHANGE RELAY, SPDT
BLOWER MOTOR SPEED CHANGE RELAY, SPDT
BLOWER MOTOR RELAY, SPST-(N.O.)
BLOWER MOTOR, PERMANENT-SPLIT-CAPACITOR
CAPACITOR
MICROPROCESSOR AND CIRCUITRY
DHUM CONNECTION
ELECTRONIC AIR CLEANER CONNECTION (115 VAC 1.0 AMP MAX.)
ELECTRONIC AIR CLEANER CONNECTION (COMMON)
FLAME ROLLOUT SW. -MANUAL RESET, SPST-(N.C.)
FLAME-PROVING ELECTRODE
FUSE, 3 AMP, AUTOMOTIVE BLADE TYPE, FACTORY INSTALLED
FUSE OR CIRCUIT BREAKER CURRENT INTERRUPT DEVICE
(FIELD SUPPLIED AND INSTALLED)
EQUIPMENT GROUND
GAS VALVE-REDUNDANT
GAS VALVE RELAY, DPST-(N.O.)
HIGH-HEAT PRESSURE SWITCH, SPST (N.O.)
HIGH-HEAT PRESSURE SWITCH RELAY, SPST (N.C.)
HOT SURFACE IGNITER (115VAC)
HOT SURFACE IGNITER RELAY, SPST (N.O.)
24VAC HUMIDIFIER CONNECTION (0.5 AMP. MAX.)
INDUCED DRAFT MOTOR, 2-SPEED, SHADED POLE
INDUCED DRAFT MOTOR RELAY, SPST-(N.O.)
INDUCER MOTOR SPEED CHANGE RELAY, SPDT
BLOWER ACCESS PANEL INTERLOCK SWITCH, SPST-(N.O.)
JUNCTION BOX
LIGHT-EMITTING DIODE FOR STATUS CODES - AMBER
LOW GAS PRESSURE SWITCH, SPST-(N.O.)
LOW-HEAT PRESSURE SWITCH, SPST (N.O.)
LIMIT SWITCH, AUTO-RESET, SPST (N.C.)
AUTO-RESET INTERNAL MOTOR OVERLOAD TEMPERATURE SWITCH (N.C.)
PRINTED CIRCUIT BOARD CONTROL
Y1 DHUM G Com W/W1 Y/Y2 R
24V
LHT
OFF
DLY
W2
ON
OFF
SELECT CHART
BLOWER
SW LO-HT OFF-DELAY
ONLY
1 *
2 3
90
ON NORM
SEC.
OFF HEAT
1 LO 2 3 *
120
ON
HEAT
SEC.
OFF ONLY
2 3
ON
150
OFF
SEC.
2 3
ON
180
OFF
SEC.
* FACTORY SETTINGS
NOTE #3
C
GRN/YEL
TEST/TWIN
PL1
PL2
PL3
PL4
PL5
PLT
TRAN
TEST/TWIN
PL2
IDM
WHT
BLK
YEL
ORN
BLU
RED
OL
RED
BLU
BLK
BRN
WHT
BRN
START
PL5
HSI
CAP-1
Fig. 36—Wiring Diagram
326797-101 REV. A
PLUG RECEPTACLE
FIELD SPLICE
EQUIPMENT GROUND
FIELD EARTH GROUND
TRAN
L1
IDR
HSIR
IHI/LOR
L2
1
3
2
NOTE #2
PL2
BHI/LOR
LO HEAT
EQUIPMENT
GROUND
L2
1
2
PL5
HSI
PL4
ACR
NOTE #5
PCB
COM 24V
Y1
G
Y/Y2
W2
DHUM
TEST/TWIN
W/W1
R
HUM
CPU
GVR-2
FRS
EAC-1
GVR-1
HPSR
LS
PL1-2
PL1-12
PL1-8
PL1-7
PL1-11
PL1-9
PL1-1
CAP-1
LPS
C
FSE
PL1-5
HI
L2
24VAC SEC 2
SEC 1 TRAN
NOTE #11
GV
L2
L2
PR1 115VAC
START
BLWM
IDM
OL
LGPS
(WHEN USED)
HPS
PL1-10 M
PL1-3
PL1-4
OL
NOTE #6
FU1
NOTE #3
PL1-6
EAC-2
COM
4 LO
COM
3
HI
1
2
SCHEMATIC DIAGRAM
(NATURAL GAS & PROPANE)
LO
SPARE-1 MED LO
NOTE #10
BHT/CLR
MED
HI HEAT
MED HI
SPARE-2
COOLING
BLWR
HI
NOTE #9
ILK
TO 115VAC FIELD-DISCONNECT SWITCH
A02176
If any of the original equipment wire is replaced use wire rated for 105°C.
Use only copper wire between the disconnect switch and the furnace junction box (JB).
This wire must be connected to furnace sheet metal for control to prove flame.
Symbols are electrical representation only.
Solid lines inside PCB are printed circuit board conductors and are not included in the legend.
Replace only with a 3 amp fuse.
Blower motor (BLWM) and inducer motor (IDM) contain internal auto-reset thermal overload switches (OL).
Neutral connections are interchangeable within the NEUTRAL connector block.
Blower motor speed selections are for average conditions, see installation instructions for optimum selection.
MED not available on some models.
Factory connected when LGPS is not used.
Ignition lockout will occur after four consecutive unsuccessful trials-for-ignition. Control will auto-reset after
three hours.
13. Blower-on delay: gas high-heat 60 seconds, gas low-heat 45 seconds, cooling or heat pump 2 seconds.
14. Blower off-delay: gas heating selections are 90, 120, 150, 180 seconds, cooling or heat pump 90 seconds or
5 seconds when dehumidify call is active.
NOTES:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
ILK
JB
GND
PRINTED CIRCIUT BOARD
FIELD WIRING SCREW TERMINAL
CONDUCTOR ON CONTROL PCB
FIELD CONTROL WIRING (24VAC)
FIELD CONTROL WIRING (115VAC)
FACTORY CONTROL WIRING (24VAC)
FACTORY POWER WIRING (115VAC)
CONTROL PCB TERMINAL
TERMINAL
JUNCTION
FU2
L1 NOTE #2
WHT BLK
NEUTRAL
FUSE OR CIRCUIT
BREAKER & DISCONNECT
SWITCH (WHEN REQ’D)
BLWM
OL
2
1
GRN /YEL
2 3
4
BRN
IDM
WHT
12-CIRCUIT PCB CONNECTOR
3-CIRCUIT PCB HSI & IDM CONNECTOR
6-CIRCUIT ICM MOTOR CONNECTOR (NOT SHOWN)
4-CIRCUIT IDM CONNECTOR
2-CIRCUIT HSI CONNECTOR
3-CIRCUIT FACTORY TEST CONNECTOR
TRANSFORMER, 115VAC/24VAC
COMPONENT TEST & TWINNING TERMINAL
WHT
HI
MED HI
MED
MED LO
LO
BLK
WHT
PL3
1
RED
BLK
GRN/YEL
BLK
BLK
RED
WHT
FSE
ORN
LGPS (WHEN USED)
CAP-2
BRN
GRN/YEL
M
WHT
GV
0.5 AMP
@ 24 VAC
WHT
FUSE 3-AMP
FU1
NOTE #6
FRS
CAP-2
CONNECTION DIAGRAM
HUM
SEC-1
SEC-2
BLWR
BHT/CLR
BLW
BHI/LOR
HI-HEAT
COOL
LO-HEAT
PR-1
SPARE-2
HSI HI LO
EAC-1
1 AMP
@ 115 VAC
SPARE - 1
PRINTED CIRCIUT BOARD
ACRDJ
Table 7—Approved Combustion-Air and Vent Pipe, Fitting and Cement Materials
ASTM SPECIFICATION
MATERIAL PIPE FITTINGS SOLVENT CEMENT AND PRIMERS
DESCRIPTION
(MARKED ON MATERIAL)
D1527
ABS
Pipe
—
—
Schedule-40
D1785
PVC
Pipe
—
—
Schedule-40
Solvent
D2235
For ABS
—
—
For ABS
Cement
D2241
PVC
Pipe
—
—
SDR-21 & SDR-26
D2466
PVC
—
Fittings
—
Schedule-40
D2468
ABS
—
Fittings
—
Schedule-40
Solvent
D2564
For PVC
—
—
For PVC
Cement
D2661
ABS
Pipe
Fittings
—
DWV at Schedule-40 IPS sizes
D2665
PVC
Pipe
Fittings
—
DWV
F438
CPVC
—
Fittings
—
Schedule-40
F441
CPVC
Pipe
—
—
Schedule-40
F442
CPVC
Pipe
—
—
SDR
Solvent
F493
For CPVC
—
—
For CPVC
Cement
F628
ABS
Pipe
—
—
Cellular Core DWV at Schedule-40 IPS sizes
F656
For PVC
—
—
Primer
For PVC
F891
PVC
Pipe
—
—
Cellular Core Schedule-40 & DWV
Other gas appliances with their own venting system may also use
the abandoned chimney as a raceway providing it is permitted by
local code, the current edition of the National Fuel Gas Code and
the vent or liner manufacturer’s installation instructions. Care must
be taken to prevent the exhaust gases from one appliance from
contaminating the combustion air of other gas appliances.
FIRE AND EXPLOSION HAZARD
Failure to follow this warning could result in fire, property
damage, personal injury, or death.
Solvent cements are combustible. Keep away from heat,
sparks, and open flame. Use only in well-ventilated areas.
Avoid breathing in vapor or allowing contact with skin or
eyes.
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent unit
operation.
When vent pipe is exposed to temperatures below freezing,
such as when it passes through an unheated space or when a
chimney is used as a raceway, pipe must be insulated as
shown in Table 10 with Armaflex-type insulation.
In Canada, construct all combustion-air and vent pipes for this unit
of CSA or ULC listed schedule-40 PVC, PVC-DWV or ABSDWV pipe and pipe cement. SDR pipe is NOT approved in
Canada.
In direct vent (2-pipe) systems, combustion air and vent pipes must
terminate together in same atmospheric pressure zone, either
through roof or sidewall (roof termination preferred), using accessory termination kit. See Table 8 for required clearances.
→ Furnace
combustion air and vent pipe connections are sized for
2-in. pipe. Any pipe size change should be made outside furnace
casing in vertical pipe. The transition has to be made as close to the
furnace as reasonably possible.
→ In non-direct vent (1-pipe) system, vent pipe termination must be
installed with adequate clearances to building openings and
equipment to comply with national and local codes. See Table 9
for required clearances.
→ COMBUSTION AIR PIPE
General
Furnace combustion-air connection must be attached as shown in
Fig. 38. Combustion-air intake housing plug may need to be
relocated in some applications.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in property
damage, personal injury, or death.
All combustion-air and vent pipes must be airtight and
watertight. Pipes must also terminate exactly as shown in Fig.
44 for direct vent (2-pipe) system and Fig. 45 for non-direct
vent (1-pipe) system.
For Non-Direct Vent (1-Pipe) system, combustion-air must terminate outside of furnace casing with 1 elbow. Orient elbow so that
its opening faces down for upflow or downflow applications.
Orient elbow so that its opening faces sideways (left or right) for
horizontal left or horizontal right applicationS. Maintain a 3-in
minimum clearance between the opening of the combustion-air
inlet pipe and any object.
→ An abandoned masonry chimney may be used as a raceway for
properly insulated and supported combustion-air (when applicable) and vent pipes. Each furnace must have its own set of
combustion-air and vent pipes and be terminated individually, as
shown in Fig. 44 for Direct Vent (2-Pipe) system and Fig. 45 for
Non-Direct Vent (1-Pipe) system.
→A
furnace shall not be connected to a chimney flue serving a
separate appliance designed to burn solid fuel.
30
SETUP SWITCHES
LOW-HEAT ONLY AND
BLOWER OFF-DELAY
TWINNING AND/OR
COMPONENT TEST
TERMINAL
ACRDJ - AIR CONDITIONING
RELAY DISABLE JUMPER
ACRDJ
PLT
HUM
TRANSFORMER 24-VAC
CONNECTIONS
0.5-AMP024 VAC
PL1 - LOW VOLTAGE MAIN
HARNESS CONNECTOR
LED
FUSE 3-AMP
STAT
SEC-2
NEUTRAL-L2
PL3
OD E
EAC-2
PL1
LED OPERATION &
DIAGNOSTIC LIGHT
SEC-1
US C
3-AMP FUSE
TEST/TWIN
R
HUMIDIFIER TERMINAL
(24-VAC 0.5 AMP MAX.)
1 2 3
Y1 DHUM G COM WW1 Y/Y2
24V
24-V-THERMOSTAT
TERMINALS
ON
OFF
W2
LHT
OFF
DLY
1
PL3 -ICM CONTROL
HARNESS CONNECTOR
1
BLW
115-VAC (L2) NEUTRAL
CONNECTIONS
BHI/LOR
BHT/CLR
BLWR
HI HEAT
IDM
IHI/LOR
COOL
PR-1
PL2
EAC-1
1
SPARE-2
SPARE-2
L1
1-AMP@115 VAC
COOL
SPARE-1
SPARE-1
BLOWER SPEED
SELECTION TERMINALS
HSIR
IDR
LO HEAT
HI HEAT
LO HEAT
HSI
HI LO
115-VAC (L1) LINE
VOLTAGE CONNECTION
PL2 - HOT SURFACE
IGNITER & INDUCER
MOTOR CONNECTOR
EAC-1 TERMINAL
(115-VAC 1.0 AMP MAX.)
A02017
Fig. 37—Control Center
4. Permanently attach elbow/perforated disk assembly to straight
portion of pipe using RTV or by cementing as shown in Fig.
39.
UNIT CORROSION HAZARD
Excessive exposure to contaminated combustion air may
result in safety and performance related problems.
Combustion air must not be taken from inside structure
because inside air is frequently contaminated by halogens,
which include fluorides, chlorides, bromides, and iodides.
These elements are found in aerosols, detergents, bleaches,
cleaning solvents, salts, air fresheners, adhesives, paint, and
other household products. Locate combustion-air inlet as far
as possible from swimming pool and swimming pool pump
house.
Assembly of Combustion Air Pipe (Direct Vent-2-Pipe
System ONLY)
1. Using Table 12, determine the smallest combustion air diameter permitted. Pick the larger diameter and use it for both
combustion and vent pipe.
NOTE: Do not count elbows or pipe sections in terminations or
within furnace (All elblows shown in Fig. 44 and Fig. 45 are not
to be counted).
NOTE: All pipe joints must have cemented attachment of
combustion-air inlet pipe to inlet housing connection, since it may
be necessary to remove pipe for servicing.
UNIT MAY NOT OPERATE
Failure to follow this caution may result in incomplete
combusiton, flame disturbance, or flame sense lockout.
When installing combusiton air and vent system of short pipe
length, the smallest allowable pipe diameter must be used.
Assembly of Combustion Air Pipe (Non-Direct Vent/1-Pipe
System ONLY)
1. Permanently install perforated disk assembly (factorysupplied in loose parts bag) in combustion-air elbow using
RTV or by cementing, as shown in Fig. 39. For 120,000 Btuh
size units only: separate the 2 halves of perforated disk
assembly and use only the shouldered disk half.
NOTE: A 2-in. diameter pipe must be used within furnace casing.
Make all pipe diameter transitions outside furnacec casing per Fig.
41.
2. If required per Table 12, insert perforated disk assembly
(factory-supplied in loose parts bag) in intake housing where
combustion air pipe will be connected. If half disk set is
required, install only shouldered disk half.
2. Determine the length of straight portion of combustion-air
inlet pipe from Fig. 39.
3. Cut field-supplied 2-in. diameter PVC pipe to length as
determined per Fig. 39.
31
Table 8—Direct Vent Termination Clearance
32
A05009
→ Table 9—Other than Direct Vent Termination Clearance
33
A05013
Table 10—Maximum Allowabl Exposed Vent Pipe Length (ft) With and Without Insulation in
Winter Design Temperature Ambient*
UNIT
SIZE
060
080
100
120
WINTER DESIGN
TEMPERATURE
(°F)
20
0
-20
20
0
-20
20
0
-20
20
0
-20
20
0
-20
20
0
-20
20
0
-20
MAX PIPE
DIAMETER
(IN.)
2
2
2
2
2
2
2.5
2.5
2.5
2.5
2.5
2.5
3
3
3
3
3
3
4
4
4
WITHOUT
INSULATION
WITH 3/8–IN. OR
THICKER INSULATION†
44
21
20
55
30
16
58
29
14
40
38
21
63
30
12
70
38
19
65
26
5
70
70
57
55
55
55
70
70
67
40
40
40
70
70
70
70
70
70
70
70
65
* Pipe length (ft) specified for maximum pipe lengths located in unconditioned spaces. Pipes located in unconditioned space cannot exceed total allowable pipe length
as specified in Table 11.
† Insulation thickness based on R value of 3.5 per in.
fitting’s tap plug with 3/16-in. drill and connect a field-supplied
3/8-in. tube. This tube should be routed to open condensate drain
for furnace and A/C (if used), and should be trapped, as shown in
Fig. 42.
Attachment of Combustion Air Pipe
1. Determine location of combustion air intake pipe connection
to combustion air intake housing as shown in Fig. 38 for
application.
NOTE: (Direct Vent/2-Pipe System ONLY). Moisture in combustion air intake may be a result of improper termination. Ensure
combustion air pipe termination is similar to those as shown in Fig.
44 so that it will not be susceptible to area where light snow or
others sources of moisture could be pulled in.
2. Reposition combustion air intake housing plug fitting in
appropriate unused intake housing connection.
3. Install combustion-air pipe grommet (factory-supplied in
loose parts bag) into selected furnace casing combustion-air
pipe hole. (See Fig. 40.)
4. Insert assembled combustion air inlet pipe into intake housing
as shown in Fig. 38.
→ VENT PIPE
General
5. Drill a 1/8-in. hole in 2-in, combustion air pipe using the hole
in intake housing as a guide.
Furnace vent connection must be attached as shown in Fig. 38.
6. Install a field-supplied No. 6 or No. 8 sheet metal screw into
combustion air pipe.
CARBON MONOXIDE POISONING AND PROPERTY
DAMAGE HAZARD
Failure to follow this warning could result in property
damage, personal injury, or death.
Vent pipes must be airtight.
7. Install casing hole filler cap (factory-supplied in loose parts
bag) in unused combustion air pipe casing hole.
NOTE: Do not attach combustion air intake pipe permanently to
combustion air intake housing since it may be necessary to remove
pipe for service of burner box components or flame sensor.
NOTE: A 2-in. diameter pipe must be used within the furnace
casing. Make all pipe diameter transitions outside furnace casing
per Fig. 41.
Attachment of Combustion Air Intake Housing Plug Fitting
The combustion-air intake plug fitting must be installed in unused
combustion air intake housing. This fitting must be attached by
using RTV sealant, or by drilling a 1/8-in. hole in fitting, using
hole in intake housing as a guide. Install a field-supplied No. 6 or
No. 8 sheet metal screw.
The minimum vent pipe length for these furnaces is 5 ft. Short pipe
lengths (5-8 ft) may discharge condensate droplets. These condensate droplets may be undesirable. A 12-in. minimum offset pipe
section is recommended to reduce excessive condensate droplets
from exiting vent pipe outlet. (See Fig. 43.)
NOTE: DO NOT OVERTIGHTEN SCREW. Breakage of intake
housing or fitting may cause air leakage to occur.
Attachment of Vent Pipe
A plugged drain connection has been provided on this fitting for
use when moisture is found in combustion air intake pipe and
combustion box. If use of this drain connection is desired, drill out
1. Determine vent pipe diameter and maximum pipe lengths
using Table 12.
34
FIELD-SUPPLIED
2-IN. DIAMETER
PVC 90° ELBOW
NOTE: Select 1 vent pipe connection and NOTE: Select 1 vent pipe connection and
1 combustion-air pipe connection.
1 combustion-air pipe connection.
COMBUSTIONAIR
AIR
FLOW
COMBUSTIONAIR
FIELD-SUPPLIED
2-IN. DIAMETER
PVC PIPE
VENT
VENT
VENT
*
VENT
*
COMBUSTIONAIR
UPFLOW
COMBUSTIONAIR
AIR
FLOW
A
COMBUSTIONAIR
DOWNFLOW
COMBUSTION-AIR DISC
(FACTORY-SUPPLIED IN
LOOSE PARTS BAG)
COMBUSTIONAIR
A96211
Length of Straight Pipe Portion of
Combustion-Air Inlet Pipe Assembly (In.)
VENT
VENT
**
**
AIR
FLOW
AIR
FLOW
CASING WIDTH
17-1/2
21
24-1/2
A
8-1/2 ± 1/2
10-1/2 ± 1/2
12 ± 1/2
Fig. 39—Combustion-Air Inlet Pipe Assembly
†
†
HORIZONTAL-LEFT DISCHARGE
HORIZONTAL-RIGHT DISCHARGE
tioned in section ″Assembly of Combustion Air Pipe (Direct
Vent/2-Pipe system ONLY).″
* For Non-Direct Vent (1-Pipe) system, orient elbow so that its
opening faces down.
NOTE: Do not count elbows or pipe sections in terminations or
within furnace (all elbows shown in Fig. 44 and Fig. 45 are not be
counted).
** For Non-Direct Vent (1-Pipe) system, orient elbow so that its
opening faces sideways.
† An external trap kit (see furnace product data sheet) must be used.
A05092
→
2. Determine location of vent pipe connection to inducer housing
as shown in Fig. 38 for application.
Fig. 38—Combustion-Air and Vent Pipe
Connections
3. Install vent pipe grommet (factory-supplied in loose parts bag)
into selected furnace casing vent pipe hole. (See Fig. 44.)
Table 11A—Furnace Setup Switch Description
SETUP
SWITCH
NO.
SWITCH
NAME
NORMAL
POSITION
DESCRIPTION
OF
USE
SW-1
Adaptive
Heat
Mode
OFF
When off, allows 2-stage operation with a
single-stage thermostat.
Turn on when using 2-stage
thermostat to allow Low Heat
operation when R to W/W1 closes
and High Heat operation when
R to W/W1 and W2 close.
SW-2
Blower
OFF
delay
ON or OFF
Control blower OFF
delay time. Used in
conjunction with SW-3.
See Table 9B.
SW-3
Blower
OFF
delay
ON or OFF
Control blower OFF
delay time. Used in
conjunction with SW-2.
See Table 9B.
4. Reposition elastomeric (rubber) inducer housing outlet cap
and clamp to appropriate unused inducer housing connection.
Tighten clamp.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in unit component
damage.
Inducer housing outlet cap must be installed and fully seated
against inducer housing. Clamp must be tightened to prevent
any condensate leakage.
5. Be certain that mating surfaces of inducer housing connection
elastomeric (rubber) coupling, and 2-in. diameter vent pipe are
clean and dry. Assemble the elastomeric (rubber) vent coupling (with 2 loose clamps) onto inducer housing connection.
Insert the 2-in. diameter vent pipe through the elastomeric
(rubber) coupling and fully into inducer housing connection
until it touches a stop inside the inducer housing outlet.
Tighten the screws on both clamps to 15-in-lb. of torque. pipe
to inducer housing. Tighten the clamp screws to 15 in.-lb. of
torque.
Table 11B—Blower Off Delay Setup Switch (SW)
2–Stage Units with PSC Blower Motors
DESIRED HEATING MODE
BLOWER-OFF DELAY (SEC)
90
120
150
180
SETUP SWITCH
SW-2
SW-3
OFF
OFF
OFF
ON
ON
OFF
ON
ON
NOTE: Starting at furnace, slope vent pipe a minimum of 1/4-in.
per linear ft with no sags between hangers.
NOTE: (Direct Vent/2-Pipe ONLY) vent pipe system has the
same diameter and same length as combustion air pipe as men-
35
TABLE 12—MAXIMUM ALLOWABLE PIPE LENGTH (FT)
ALTITUDE (FT)
UNIT MAX
INPUT RATE
(BTUH)
DIRECT VENT (2-PIPE) ONLY
TERMINATION
TYPE
PIPE DIA
(IN.)*
60,000
2 Pipe or 2-in
Concentric
80,000
2 Pipe or 2-in
Concentric
100,000
2 Pipe or 3-in
Concentric
120,000
2 Pipe or 3-in.
Concentric
1-1/2
2
1-1/2
2
2-1/2
2
2-1/2
3
2-1/2 one disk
3†
3† no disk
0 to 2000
ALTITUDE (FT)
UNIT MAX
INPUT RATE
(BTUH)
PIPE DIA
(IN.)*
3
4
5
6
1-1/2
2
1-1/2
2
2-1/2
2
2-1/2
3
2-1/2
NA
3†
NON-DIRECT VENT
(1-PIPE) ONLY
PIPE DIA
(IN.)*
20
70
10
55
70
5
40
70
10
45
70
15
70
NA
50
70
NA
30
70
NA
40
70
10
70
NA
35
70
NA
20
70
NA
35
70
5
70
NA
30
70
NA
20
70
NA
30
70
NA
70
NA
30
70
NA
10
70
NA
25
70
NA
70
NA
20
70
NA
NA
70
NA
20
70
1
2
3
4
5
6
17
70
49
70
35
70
14
63
70
70
12
67
44
70
26
70
9
62
70
70
7
66
30
70
16
70
NA
62
63
70
NA
61
25
70
16
70
NA
61
56
70
NA
61
25
70
6
66
NA
61
50
70
NA
61
15
70
NA
61
NA
61
43
70
1
2
3
4
5
6
16
68
46
70
33
70
65
59
70
11
63
41
70
24
70
58
59
70
6
62
28
70
15
70
51
58
70
NA
57
23
70
14
66
44
57
70
NA
57
22
70
5
61
38
57
70
NA
56
13
70
NA
56
31
56
70
PIPE DIA
(IN)*
60,000
2 Pipe or 2-in
Concentric
80,000
2 Pipe or 2-in
Concentric
100,000
2 Pipe or 3-in
Concentric
1-1/2
2
2
2-1/2
2-1/2
3
3† no disk
NA
4† no disk
1-1/2
2
2
2-1/2
2-1/2
3
NA
3†
4† no disk
100,000
120,000
UNIT MAX
INPUT RATE
(BTUH)
3001 to 4000
120,000
1-1/2
2
2
2 Pipe or 2-in
Concentric
2-1/2
2-1/2
2 Pipe or 3-in
Concentric
3
3
NA
2 Pipe or 3-in.
Concentric
3† no disk
4† no disk
DIRECT VENT (2-PIPE) ONLY
2
TERMINATION
TYPE
80,000
ALTITUDE (FT)
TERMINATION
TYPE
2 Pipe or 2-in
Concentric
2 Pipe or 3-in.
Concentric
4† no disk
NUMBER OF 90° ELBOWS
1
1-1/2
2
2
2-1/2
2-1/2
3
NA
3†
NA
4† no disk
NON-DIRECT VENT
(1-PIPE) ONLY
PIPE DIA
(IN.)*
60,000
2001 to 3000
DIRECT VENT (2-PIPE) ONLY
NON-DIRECT VENT
(1-PIPE) ONLY
PIPE DIA
(IN.)*
NUMBER OF 90° ELBOWS
NUMBER OF 90° ELBOWS
See notes at end of table
NOTE: See label on vent extension pipe for proper installation.
This pipe may be shortened if an elbow is used to connect vent
extension tube to field-installed vent pipe.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in unit component
damage.
Vent pipe must be installed and fully seated against inducer
housing internal stop. Clamp must be tightened to prevent any
condensate leakage.
Installation Guidelines for Combustion Air Pipe and Vent Pipe
It is recommended that all pipes be cut, prepared, and preassembled before permanently cementing any joint.
1. Attach combustion air pipe and vent pipe per instructions in
sections ″Combustion Air Pipe″ and ″Vent Pipe.″
6. Install casing hole filler cap (factory-supplied in loose parts
bag) in unused vent pipe casing hole.
2. Working from furnace to outside, cut pipe to required
length(s).
Attachment of Vent Extension Pipe
3. Deburr inside and outside of pipe.
Furnaces with 100,000 Btuh and larger input are supplied with a
PVC vent extension pipe (2-in. diameter by 12-in. long). This pipe
has a built-in channel to assist vent condensate disposal. When this
vent extension pipe is supplied, it MUST be used to connect the
field vent pipe to furnace inducer housing on ALL upflow and
downflow applications.
4. Chamfer outside edge of pipe for better distribution of primer
and cement.
36
TABLE 12—MAXIMUM ALLOWABLE PIPE LENGTH (FT) (Continued)
ALTITUDE (FT)
UNIT MAX
INPUT RATE
(BTUH)
TERMINATION
TYPE
PIPE DIA
(IN.)*
60,000
2 Pipe or 2-in
Concentric
80,000
2 Pipe or 2-in
Concentric
100,000
2 Pipe or 3-in
Concentric
120,000
2 Pipe or 3-in.
Concentric
1-1/2
2
2
2-1/2
2-1/2
3
3† no disk
NA
4† no disk
4001 to 5000‡
ALTITUDE (FT)
UNIT MAX
INPUT RATE
(BTUH)
PIPE DIA
(IN.)*
60,000
2 Pipe or 2-in
Concentric
80,000
2 Pipe or 2-in
Concentric
100,000
2 Pipe or 3-in
Concentric
120,000
2 Pipe or 3-in.
Concentric
1-1/2
2
2
2-1/2
2-1/2
3
3† no disk
NA
4† no disk
NON-DIRECT VENT
(1-PIPE) ONLY
PIPE DIA
(IN.)*
2
3
4
5
6
1-1/2
2
2
2-1/2
2-1/2
3
NA
3†
4† no disk
NON-DIRECT VENT
(1-PIPE) ONLY
PIPE DIA
(IN.)*
15
64
44
70
31
70
53
56
70
10
59
39
70
22
70
46
55
70
5
58
26
70
13
67
40
54
70
NA
53
21
70
12
62
33
53
70
NA
52
20
70
NA
57
26
52
70
NA
52
11
70
NA
52
20
52
70
1
2
3
4
5
6
14
60
41
70
29
70
42
53
70
9
55
36
70
21
67
35
52
70
NA
54
23
70
12
62
29
50
70
NA
49
18
70
11
57
22
49
70
NA
48
17
70
NA
52
15
48
70
NA
47
8
70
NA
47
9
47
70
1
2
3
4
5
6
13
57
38
70
27
68
31
49
70
8
52
33
70
19
63
24
48
70
NA
50
21
68
10
58
18
47
70
NA
45
16
67
9
53
11
45
70
NA
44
15
66
NA
48
NA
44
67
NA
43
6
64
NA
43
NA
43
62
TERMINATION
TYPE
PIPE DIA
(IN)*
60,000
2 Pipe or 2-in
Concentric
80,000
2 Pipe or 2-in
Concentric
100,000
2 Pipe or 3-in
Concentric
120,000
2 Pipe or 3-in.
Concentric
1-1/2
2
2
2-1/2
2-1/2
3
3† no disk
NA
4† no disk
1-1/2
2
2
2-1/2
2-1/2
3
NA
3†
4† no disk
DIRECT VENT (2-PIPE) ONLY
NUMBER OF 90° ELBOWS
1
1-1/2
2
2
2-1/2
2-1/2
3
NA
3†
4† no disk
NON-DIRECT VENT
(1-PIPE) ONLY
PIPE DIA
(IN)*
UNIT MAX
INPUT RATE
(BTUH)
6001 to 7000‡
DIRECT VENT (2-PIPE) ONLY
TERMINATION
TYPE
5001 to 6000‡
ALTITUDE (FT)
DIRECT VENT (2-PIPE) ONLY
NUMBER OF 90° ELBOWS
NUMBER OF 90° ELBOWS
See notes at end of table
5. Clean and dry all surfaces to be joined.
11. Horizontal portions of the venting system shall be supportive
to prevent sagging support. Support combustion air piping (if
applicable) and vent piping a minimum of every 5 ft (3 ft for
SDR-21 or -26 PVC) using perforated metal hanging strap.
6. Check dry fit of pipe and mark insertion depth on pipe.
7. After pipes have been cut and preassembled, apply generous
layer of cement primer to pipe fitting socket and end of pipe
to insertion mark. Quickly apply approved cement to end of
pipe and fitting socket (over primer). Apply cement in a light,
uniform coat on inside of socket to prevent buildup of excess
cement. Apply second coat.
12. Slope combustion air piping (if applicable) and vent piping
downward towards furnace a minimum of 1/4 in. per linear ft
with no sags between hangers.
13. Horizontal portions of the venting system shall be installed so
as to prevent the accumulation of condensate.
8. While cement is still wet, twist pipe into socket with 1/4 turn.
Be sure pipe is fully inserted into fitting socket.
14. Use appropriate methods to seal openings where combustion
air pipe (if applicable) and vent pipe pass through roof or
sidewall.
9. Wipe excess cement from joint. A continuous bead of cement
will be visible around perimeter of a properly made joint.
10. Handle pipe joints carefully until cement sets.
37
TABLE 12—MAXIMUM ALLOWABLE PIPE LENGTH (FT) (Continued)
NON-DIRECT VENT
(1-PIPE) ONLY
PIPE DIA
(IN.)*
DIRECT VENT (2-PIPE) ONLY
ALTITUDE (FT)
UNIT SIZE
(BTUH)
TERMINATION
TYPE
PIPE DIA
(IN.)*
60,000
2 Pipe or 2-in
Concentric
80,000
2 Pipe or 2-in
Concentric
100,000
2 Pipe or 3-in
Concentric
120,000
2 Pipe or 3-in.
Concentric
1-1/2
2
2
2-1/2
2-1/2
3
3† no disk
NA
4† no disk
7001 to 8000‡
DIRECT VENT (2-PIPE) ONLY
ALTITUDE (FT)
UNIT SIZE
(BTUH)
TERMINATION
TYPE
PIPE DIA
(IN.)*
60,000
2 Pipe or 2-in
Concentric
80,000
2 Pipe or 2-in
Concentric
100,000
2 Pipe or 3-in
Concentric
120,000
2 Pipe or 3-in.
Concentric
1-1/2
2
2
2-1/2
2-1/2
3
3† no disk
NA
4† no disk
1
2
3
4
5
6
1-1/2
2
2
2-1/2
2-1/2
3
NA
3†
4† no disk
NON-DIRECT VENT
(1-PIPE) ONLY
PIPE DIA
(IN.)*
12
53
36
66
25
63
20
46
61
7
48
31
65
17
58
13
44
56
NA
46
19
63
8
53
7
43
51
NA
41
14
62
7
48
NA
41
46
NA
40
12
60
NA
43
NA
40
41
NA
38
NA
59
NA
38
NA
38
36
1
2
3
4
5
6
11
49
33
62
23
59
10
43
35
6
44
28
60
15
54
NA
41
30
NA
42
17
58
7
49
NA
39
25
NA
37
12
56
5
44
NA
37
20
NA
35
10
55
NA
39
NA
35
15
NA
34
NA
53
NA
34
NA
34
10
1
2
3
4
5
6
NUMBER OF 90° ELBOWS
TERMINATION
TYPE
PIPE DIA
(IN.)*
1-1/2
2
2
2-1/2
2-1/2
3
NA
3†
4† no disk
NON-DIRECT VENT
(1-PIPE) ONLY
PIPE DIA
(IN.)*
60,000
2 Pipe or 2-in
Concentric
2
2
45
40
38
33
31
29
80,000
2 Pipe or 2-in
Concentric
100,000
2 Pipe or 3-in
Concentric
120,000
2 Pipe or 3-in.
Concentric
2
2-1/2
2-1/2
3
NA
4† no disk
2
2-1/2
2-1/2
3
3†
4† no disk
30
57
21
54
39
10
25
55
13
49
37
5
14
53
5
44
35
NA
9
51
NA
39
33
NA
7
49
NA
34
31
NA
NA
47
NA
29
29
NA
8001 to 9000‡
DIRECT VENT (2-PIPE) ONLY
ALTITUDE (FT)
NUMBER OF 90° ELBOWS
UNIT SIZE
(BTUH)
9001 to 10,000‡
NUMBER OF 90° ELBOWS
*Disk usage-Unless otherwise specified, use perforated disk assembly (factory-supplied in loose parts bag). If one disk is stated, separate 2 halves of perforated disk
assembly and use shouldered disk half. When using shouldered disk half, install screen side toward inlet box.
†Wide radius elbow.
‡Vent sizing for Canadian installations over 4500 ft (1370 m) above sea level are subject to acceptance by the local authorities having jurisdiction.
NA-Not Allowed; pressure switch will not make.
NOTES:
1. Do not use pipe size greater than those specified in table or incomplete combustion, flame disturbance, or flame sense lockout may occur.
2. Size both the combustion-air and vent pipe independently, then use the larger diameter for both pipes.
3. Assume two 45° elbows equal one 90° elbow. Wide radius elbows are desirable and may be required in some cases.
4. Elbows and pipe sections within the furnace casing and at the vent termination should not be included in vent length or elbow count.
5. The minimum pipe length is 5 ft for all applications.
6. Use 3-in. diameter vent termination kit for installations requiring 4-in diameter pipe.
38
COMBUSTION-AIR PIPE GROMMETS
UNUSED 1/2 -IN.
DIAMETER GAS
CONN. HOLE
COMBUSTION
-AIR PIPE
GAS LINE
GAS LINE ENTRY
HOLE FILLER PLUG
VENT PIPE
GAS LINE GROMMET
VENT PIPE GROMMET
NOTE: PIPE GROMMETS AND ENTRY HOLE FILLER
PLUGS ARE INCLUDED IN FACTORY-SUPPLIED
LOOSE PARTS BAG
A05057
→
Fig. 40—Pipe Grommets and Entry Hole Filler Plug Installation
→
FURNACE
NOT IN
HORIZONTAL
SECTION
PIPE DIAMETER
TRANSITION IN
VERTICAL SECTION
A93034
Fig. 41—Combustion-Air and Vent Pipe Diameter
Transition Location and Elbow Configuration
3/8 ID TUBE
3/16
DRILL
COMBUSTION – AIR
INTAKE HOUSING
BURNER
BOX
COMBUSTION-AIR
PIPE (DIRECT
VENT/2 PIPE)
COMBUSTION-AIR
PIPE (NON-DIRECT
VENT/1-PIPE)
4″MIN
TRAP
TO OPEN
DRAIN
A05093
→ Fig. 42—Air Intake Housing Plug Fitting Drain
EXAMPLE:
An 080-12 size furnace located in Indianapolis, elevation
650 ft above sea level, could be installed as either a direct
vent/2-pipe system that requires 3 elbows and 32 ft of vent
pipe, along with 5 elbows and 34 ft of combustion-air pipe
OR a non-direct vent/1-pipe system that requires 3 elbows
and 32 ft vent pipe.
For a direct vent/2-pipe system, Table 12 indicates this
application would allow a 2-in. diameter vent pipe, but
require a 2-1/2 in. diameter combustion air pipe. According
to Table 12, 2-in. diameter pipe is good for 35 ft with 3
elbows, but only 30 ft with 5 elbows. Therefore, 2-1/2 in.
diameter pipe must be used for both vent and combustionair pipes since larger required diameter must always be
used for both pipes.
For a non-direct vent/1-pipe system, Table 12 indicates that
this application would allow a 2-in. diameter vent pipe.
If same installations were in Albuquerque, elevation 5250 ft
above sea level:
For a direct vent/2-pipe system, Table 12 indicates that
2-1/2 in. diameter vent pipe and combustion-air pipe are
required.
For a non-direct vent/1-pipe system, Table 12 indicates that
2-1/2-in. diameter vent pipe is required.
If same applications are to be installed at 5001- to 6000 ft
elevation:
For a direct vent/2-pipe system, 2-in. pipe is only good for
23 ft (with 3 elbows) and 17 ft (with 5 elbows). Therefore,
2-1/2 in. diameter combustion air and vent pipe must be
used.
For a non-direct vent/1-pipe system, a 2-in. diameter pipe is
only good for 23 ft with 3 elbows. A 2-1/2-in. diameter vent
pipe must be used.
→ VENT TERMINATION
General
Combustion-air (direct vent/2-pipe system only) and vent pipe
must terminate outside structure, either through sidewall or roof.
For vent termination clearance, refer to Table 8 for Direct
39
COMBUSTION AIR
PIPE (DIRECT VENT
/2-PIPE)
COMBUSTION AIR
PIPE (NON-DIRECT
VENT/1-PIPE)
12″ MIN
COMBUSTION AIR
PIPE (NON-DIRECT
VENT/1-PIPE)
12″ MIN
VENT PIPE
VENT PIPE
COMBUSTION AIR
PIPE (DIRECT
VENT/2-PIPE)
HORIZONTAL TO ROOF
HORIZONTAL TO SIDEWALL
COMBUSTION AIR
PIPE (DIRECT VENT
/2-PIPE)
COMBUSTION AIR
PIPE (NON-DIRECT
VENT/1-PIPE)
VENT PIPE
COMBUSTION AIR
PIPE (NON-DIRECT
VENT/1-PIPE)
12″ MIN
COMBUSTION AIR
PIPE (DIRECT VENT
/2-PIPE)
12″ MIN
VENT PIPE
VERTICAL TO ROOF
VERTICAL TO SIDEWALL
NOTE: A 12-In. minimum offset pipe section is recommended with
short (5-ft. to 8-ft) vent systems. This recommendation is to
reduce excessive condensate droplets from exiting the vent pipe.
A96230
→
Fig. 43—Short Vent (5 to 8 ft) System
4. Termination or termination kit should be positioned where it
will not be damaged by or subjected to foreign objects such as
stones, balls, etc.
5. Termination or termination kit should be positioned where
vent vapors are not objectionable.
Extended Exposed Sidewall Pipes
Sidewall combustion air pipe termination (direct vent/2-pipe
system only) and vent pipe termination may be extended beyond
area shown in Fig. 44 or in Fig. 45 per application in outside
ambient by insulating pipe as indicated in Table 10.
1. Determine combustion air pipe diameter (direct vent/2-pipe
system only) and vent pipe diameter, as stated above, using
total pipe length and number of elbows.
2. Using winter design temperature (used in load calculations),
find appropriate temperature for your application and furnace
model.
3. Determine required insulation thickness for exposed pipe
length(s).
NOTE: Pipe length(ft) specified for maximum pipe lengths located in unconditioned spaces cannot exceed total allowable pipe
length as specified in Table 12.
Vent Termination Kit (Direct Vent/2-Pipe System Only)
NOTE: Always refer to the instructions in termination kit for the
latest version.
Vent/2-Pipe system and Table 9 for Non-direct Vent/1-Pipe
system. For exterior piping arrangements, refer to Fig. 44 for
Direct Vent/2-Pipe system and Fig. 45 for Non-Direct/1-Pipe
system.
Roof termination is preferred since it is less susceptible to damage
or contamination, and it has less visible vent vapors. Sidewall
termination require sealing or shielding of building surfaces with a
corrosive resistance material due to corrosive combustion products
of vent system.
NOTE: (Direct Vent/2-Pipe system ONLY). A factory accessory
termination kit MUST be used. See section ″Vent Termination Kit
(Direct Vent/2-Pipe System Only)″ in this instruction.
When determining appropriate location for termination, consider
the following guidelines:
1. Comply with all clearance requirements stated in Table 8 or
Table 9 per application.
2. Termination or termination kit should be positioned where
vent vapors will not damage plants/shrubs or air conditioning
equipment.
3. Termination or termination kit should be positioned so that it
will not be affected by wind eddy, such as inside building
corners, nor by recirculation of flue gases, airborne leaves, or
light snow.
40
Roof Termination (Preferred)
At least 36 in.
Concentric Vent and Combustion Air
Roof Termination (preferred)
Vertical separation
between combustion
air and vent
8 3/4 in. for 3 in. kit
6 3/4 in. for 2 in. kit
A
A
At least
36 in.
Maintain 12 in.
min. clearance above
highest anticipated
snow level, maximum of
24 in. above roof
18 in. maximum
Maintain 12 in. min.
clearance above
highest anticipated
snow level
Maximum of 24 in.
above roof
1 in. maximum (type)
Abandoned masonry
used as raceway
(per code)
12 in. minimum from
overhang or roof
Note: "A" denotes 0 to < 2 in.
At
le
36 ast
i
n.
12 in. min from
overhang or roof
A
Maintain 12 in.
min. clearance above
highest anticipated
snow level or grade
whichever is greater
Concentric Vent
and Combustion - Air
Side Termination
A
12 in. separation
between bottom of
combustion air and
bottom of vent
90°
A
→
Side wall termination
of less than 12 in.
Maintain 12 in.
min. clearance above
highest anticipated
snow level or grade
whichever is greater
6 in.
ast 3
At le
At least 36 in.
A05090
Fig. 44—Combustion Air and Vent Pipe Termination
for Direct Vent (2-pipe) System (All Sizes)
Roof Termination (Preferred)
Vent
Maintain 12 in.
minimum clearance
above highest anticipated
snow level maximum of
24 in. above roof.
Abandoned masonry
used as raceway
(per code)
12 in. min. from
overhang or roof
6 in. minimum clearance
between wall and end of vent pipe.
10 in. maximum pipe length
Maintain 12 in.
minimum clearance
above highest anticipated
snow level or grade
whichever is greater
12 in. min. from
overhang or roof
Sidewall Termination
with Straight Pipe (preferred)
90°
Maintain 12 in.
minimum clearance
above highest anticipated
snow level or grade
whichever is greater.
Side wall termination
with 2 elbows (preferred)
→
A05091
Fig. 45—Vent Pipe Termination for Non-Direct
Vent (1-pipe) System (Sizes 040 Through 120 Only)
41
→
Table 13—Vent Termination Kit for Direct Vent/2-Pipe System
DIRECT VENT (2-PIPE) TERMINATION KIT
TERMINATION SYSTEM
2-in.
3-in.
2-in.
3-in.
Single Penetration of Wall or Roof
Single Penetration of Wall or Roof
2-Pipe Termination System
2-Pipe Termination System
Concentric Vent Kit
Concentric Vent Kit
Termination Bracket Kit
Termination Bracket Kit
DIAM. OF COMBUSTION AIR AND VENT
PIPES (IN INCHES)
1, 1-1/2, 2, or 2-1/2
2-1/2, 3 or 4
1, 1-1/2 or 2
2-1/2, 3 or 4
(Direct Vent/2-Pipe System ONLY)-When 2 or more 58MTB
furnaces are vented near each other, 2 vent terminations may be
installed as shown in Fig. 44, but next vent termination must be at
least 36 in. away from first 2 terminations. It is important that vent
terminations be made as shown in Fig. 44 to avoid recirculation of
flue gases.
Step 11—Condensate Drain
Combustion air and vent pipes MUST terminate outside structure.
A factory accessory termination kit must be installed as shown in
Table 13. There are four options of vent/combustion air termination kits available as shown in Table 13.
NOTE: Combustion air pipe must have the same diameter as vent
pipe.
Concentric Vent/Combustion Air Termination Kit (Direct Vent/
2-Pipe System Only)
Determine an appropriate location for termination kit using the
guidelines provided in section ″Vent Termination: General″ in this
instruction.
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent unit
operation.
Unit must not be installed, operated, and then turned off and
left in an unoccupied structure during cold weather when
temperature drops to 32°F and below unless drain trap and
drain line have adequate freeze protection. See Service and
Maintenance Instructions for winterizing procedure.
1. Cut one 4-in. diameter hole for 2-in. kit, or one 5-in. diameter
hole for 3-in. kit.
2. Loosely assemble concentric vent/combustion air termination
components together using instructions in kit.
3. Slide assembled kit with rain shield REMOVED through hole.
NOTE: Do not allow insulation or other materials to accumulate
inside of pipe assembly when installing it through hole.
GENERAL
Condensate trap is shipped installed in the blower shelf and factory
connected for UPFLOW applications. Condensate trap must be
RELOCATED for use in DOWNFLOW and HORIZONTAL
applications.
Roof terminations—Locate assembly through roof to appropriate height as shown in Fig. 44.
Sidewall terminations—Locate assembly through sidewall
with rain shield positioned no more than 1-in. from wall as
shown in Fig. 44.
4. Disassemble loose pipe fittings. Clean and cement using same
procedures as used for system piping.
Condensate trap MUST be used for all applications.
An external trap is not required when connecting the field drain to
this condensate trap.
The field drain connection (condensate trap or drain tube coupling)
is sized for l/2-in. CPVC, 1/2-in. PVC, or 5/8-in. ID tube
connection.
5. Check required dimensions as shown in Fig. 44.
Two-Pipe Termination Kit (Direct Vent/2-Pipe System Only)
Drain pipe and fittings must conform to ANSI standards and
ASTM D1785, D2466 or D2846. CPVC or PVC cement must
conform to ASTM D2564 or F493. Primer must conform to ASTM
F656. In Canada, use CSA or ULC listed schedule 40 CPVC or
PVC drain pipe, fittings, and cement.
Determine an appropriate location for termination kit using the
guidelines provided in section ″Vent Termination: General″ in this
instruction.
1. Cut 2 holes, 1 for each pipe, of appropriate size for pipe size
being used.
When a condensate pump is required, select a pump which is
approved for condensing furnace applications. To avoid condensate spillage, select a pump with an overflow switch.
2. Loosely install elbow in bracket and place assembly on
combustion-air pipe.
Roof terminations—Loosely install pipe coupling on properly cut vent pipe. Coupling must be positioned so bracket will
mount as shown in Fig. 44.
For applications using combustion-air pipe option, indicated
by dashed lines in Fig. 44, install 90° street elbow into 90°
elbow, making a U-fitting. A 180° U-fitting may be used.
Sidewall terminations—Install bracket as shown in Fig. 44.
For applications using vent pipe option indicated by dashed
lines in Fig. 44, rotate vent elbow 90° from position shown in
Fig. 44.
3. Disassemble loose pipe fittings. Clean and cement using same
procedures as used for system piping.
Furnace condensate is mildly acidic, typically in the pH range of
3.2 to 4.5. Due to corrosive nature of this condensate, a condensate
pH neutralizing filter may be desired. Check with local authorities
to determine if a pH neutralizer is required.
APPLICATION
The furnace, A/C, and humidifier drains may be combined and
drained together. The A/C drain must have an external, fieldsupplied trap prior to the furnace drain connection. All drain
connections (furnace, A/C, or humidifier) must be terminated into
an open or vented drain as close to the respective equipment as
possible to prevent siphoning of the equipment’s drain.
Multiventing and Vent Terminations
See Fig. 46 for example of possible field drain attachment using
1/2-in. CPVC or PVC tee for vent and A/C or humidifier drain
connection.
When 2 or more 58MTB Furnaces are vented near each other, each
furnace must be individually vented. NEVER common vent or
breach vent 58MTB furnaces.
Outdoor draining of the furnace is permissible if allowed by local
codes. Caution should be taken when freezing. Ambient may
freeze drain pipe and prohibit draining.
4. Check required dimensions as shown in Fig. 44.
42
CONDENSATE TRAP
OPEN STAND
PIPE FOR
A/C OR
HUMIDIFIER
DRAIN
WIRE TIE(S)
TEE
HEAT TAPE
(3 WRAPS MINIMUM)
TO OPEN
DRAIN
A93036
Fig. 47—Condensate Trap Heat Tape
A94054
Fig. 46—Example of Field Drain Attachment
Step 1—General
The furnace must have a 115-v power supply properly connected
and grounded.
PERSONAL INJURY HAZARD
Caution should be taken to prevent draining where slippery
conditions may cause personal injuries.
Excessive condensate draining may cause saturated soil
conditions which could result in damage to plants.
NOTE: Proper polarity and proper grounding must be maintained
for 115-v wiring. If polarity is incorrect, control status indicator
light will flash rapidly and the furnace will not operate.
Natural gas service pressure must not exceed 0.5 psig (14-in. wc),
and be no less than 0.16 psig (4.5-in. wc).
CONDENSATE DRAIN PROTECTION
Thermostat wire connections at R and W/W1 are the minimum
required for gas heating operation. W2 must be connected for
2-stage heating thermostats. COM, Y/Y2, and G are required for
cooling, heat pumps, and some clock thermostats. These must be
made at the 24-v terminal block on the control. (See Fig. 37.)
Freezing condensate left in condensate trap and drain line may
cause cracks, and possible water damage may occur. If freeze
protection is required, use condensate freeze protection accessory
or equivalent 3 to 6 watt per ft at 120-v and 40°F self-regulating,
shielded, and waterproof heat tape. See Installation Instructions
supplied with accessory or heat tape manufacturer’s recommendations.
This furnace can be installed with either a single-stage heating or
a 2-stage heating thermostat.
1. Fold heat tape in half and wrap on itself 3 times.
For single-stage thermostats, connect thermostat W to W/W1 at
furnace control terminal block. (See Fig. 31 and 50H.) For
single-stage thermostats, the control will determine, based on
length of previous heating on and off cycles, when to operate in
low- and high- gas heat for optimum comfort. Setup switch-1
(SW-1) must be in the factory-shipped OFF position. See Fig. 36
and Table 11A and B for setup switch information.
2. Locate heat tape between sides of condensate trap back. (See
Fig. 47.)
3. Use wire ties to secure heat tape in place. Wire ties can be
positioned in notches of condensate trap sides. (See Fig. 47.)
4. Wrap field drain pipe with remaining heat tape, approximately
1 wrap per ft.
If a 2-stage heating thermostat is to be used, move SW-1 to ON
position at end of furnace installation. This overrides built-in
control process for selecting high and low fire and allows the
2-stage thermostat to select gas heating modes. The W2 from
thermostat must be connected to W2 on control terminal block.
(See Fig. 32 and 50A-G.)
5. When using field-supplied heat tape, follow heat tape manufacturer’s instructions for all other installation guidelines.
START-UP ADJUSTMENT AND SAFETY CHECK
→
FURNACE MAY NOT OPERATE
Failure to follow this caution may result in furnace operation
stopping and water pipes freezing during cold weather.
Furnace control must be grounded for proper operation, or
control will lock out. Control is grounded through
green/yellow wire connected to gas valve C-terminal and
burner box screw.
Before operating furnace, check each flame rollout manual reset
switch for continuity. If necessary, press and release button to reset
switch. The blower compartment door must be in place to
complete the 115-v circuit to the furnace.
43
A99118
Fig. 48—Inducer Housing Drain Cap
FIRE HAZARD
Failure to follow this caution may result in intermittent unit
operation or performance satisfaction.
This furnace is equipped with a manual reset limit switch in
the burner box area. The switch will open and shut off power
to the gas valve if a flame rollout or overheating condition
occurs in the burner enclosure area. DO NOT bypass the
switch. Correct inadequate combustion-air supply, component failure, or restricted flue gas passageway before resetting
the switch.
A99119
Fig. 49—Filling Condensate Trap
FIRE AND EXPLOSION HAZARD
Failure to follow this warning could result in a fire, explosion,
personal injury, or death.
Never purge a gas line into a combustion chamber. Never test
for gas leaks with an open flame. Use a commercially
available soap solution made specifically for the detection of
leaks to check all connections, as specified in ″Gas Piping″
and ″Start-up Adjustment, and Safety Check″ sections of
these instructions.
Step 2—Prime Condensate Trap With Water
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent unit
operation or performance satisfaction.
Condensate trap must be PRIMED or proper draining may not
occur. The condensate trap has internal chambers which can
ONLY be primed by pouring water into the inducer drain side
of condensate trap.
Step 4—Sequence of Operation
Using schematic diagram in Fig. 36, follow the sequence of
operation through the different modes. Read and follow diagram
very carefully.
NOTE: If power interruption occurs during ″call for heat″ (W/W1
or W/W1 and W2), the control will run the blower for the selected
blower off delay period after power is restored, if the thermostat is
still calling for gas heating. The amber LED will flash code 12
during this period, after which the LED will be ON continuous as
long as no faults are detected. After this period, the furnace will
respond to the thermostat normally.
1. Remove upper inducer housing drain connection cap. (See
Fig. 48.)
2. Connect field-supplied 1/2-in. ID tube to upper inducer
housing drain connection.
3. Insert field-supplied funnel into tube.
The blower door must be installed for power to be conducted
through blower door interlock switch ILK to furnace control CPU,
transformer TRAN, inducer motor IDM, blower motor BLWM,
hot surface igniter HSI, and gas valve GV.
4. Pour 1 quart of water into funnel/tube. Water should run
through inducer housing, overfill condensate trap, and flow
into open field drain. (See Fig. 49.)
5. Remove funnel and tube from inducer housing and replace
drain connection cap and clamp.
Step 3—Purge Gas Lines
After all connections have been made, purge the gas lines and
check for leaks.
44
before going to Ignition-Lockout. Lockout will be reset
automatically after three hours, by momentarily interrupting
115 vac power to the furnace, or by interrupting 24 vac power
at SEC1 or SEC2 to the furnace control CPU (not at W/W1, G,
R, etc.).
If flame is proved when flame should not be present, the
furnace control CPU will lock out of Gas-Heating mode and
operate the inducer motor IDM on high speed until flame is no
longer proved.
TWO-STAGE HEATING WITH SINGLE-STAGE
THERMOSTAT (ADAPTIVE MODE)
(See Fig. 31 for thermostat connections.)
NOTE: Low-heat-only switch, SW-1, selects either the low-heatonly operation mode when ON, or adaptive heating mode when
OFF, in response to a call for heat. (See Fig. 37.)
This furnace can operate as a 2-stage furnace with a single-stage
thermostat because furnace control CPU includes a programmed
adaptive sequence of controlled operation, which selects low-gasheat or high-gas-heat operation. This selection is based upon the
stored history of the length of previous gas heating on/off periods
of the single-stage thermostat.
5. Blower-On Delay-If burner flame is proven the blower motor
BLWM is energized 66 sec after gas valve GV-M is opened.
Low-heat-The blower motor BLWM is energized at LO
HEAT speed.
Hi-heat-The BLWM is energized at HI HEAT speed.
Simultaneously, the electronic air cleaner terminal EAC-1 is
energized and remains energized as long as the blower motor
BLWM is energized.
The furnace will start up in either low- or high-gas heat. If the
furnace starts up in low-gas heat, the control CPU determines the
low-gas heat on time (from 0 to 16 minutes) which is permitted
before switching to high-heat.
If power is interrupted, the stored history is erased. When this
happens, the control CPU will initially select low-heat for up to 16
minutes and then switch to high-heat, as long as the thermostat
continues to ″call for heat.″ Subsequent selection is based on
stored history of thermostat cycle times.
6. Switching From Low- To High- Heat- If the furnace control
CPU switches from low-heat to high-heat, the furnace control
CPU will switch the inducer motor IDM speed from low to
high. The high-heat pressure switch relay HPSR is deenergized to close the NC contact. When sufficient pressure is
available the high-heat pressure switch HPS closes, and the
high-heat gas valve solenoid GV-HI is energized. The blower
motor BLWM will switch to HI HEAT speed five seconds
after the furnace control CPU switches from low-heat to
high-heat.
When wall thermostat ″calls for heat″, R-W/W1 circuit closes. The
furnace control performs a self check, verifies the low-heat and
high-heat pressure switch contacts LPS and HPS are open, and
starts inducer motor IDM in high speed.
1. Inducer Prepurge Period- If the furnace control CPU selects
low-heat operation the inducer motor IDM comes up to speed,
the low-heat pressure switch LPS closes, and the furnace
control CPU begins a 15-second prepurge period. After the
low-heat pressure switch re-closes the furnace control CPU
will begin a 15-second prepurge period, and continue to run
the inducer motor IDM at high-speed.
If the furnace control CPU selects high-heat operation, the
inducer motor IDM remains running at high-speed, and the
high-heat pressure switch relay HPSR is de-energized to close
the NC contact. When sufficient pressure is available the
high-heat pressure switch HPS closes, and the high-heat gas
valve solenoid GV-HI is energized. The furnace control CPU
begins a 15-second prepurge period after the low-heat pressure
switch LPS closes. If the high-heat pressure switch HPS fails
to close and the low-heat pressure switch LPS closes, the
furnace will operate at low-heat gas flow rate until the
high-heat pressure switch closes for a maximum of 2 minutes
after ignition.
7. Switching From High- To Low- Heat-The control CPU will
not switch from high-heat to low-heat while the thermostat
R-to-W circuit is closed when a single-stage thermostat is
used.
8. Blower-Off delay- When the thermostat is satisfied, the R to
W circuit is opened, de-energizing the gas valve GV-M,
stopping gas flow to the burners, and de-energizing the
humidifier terminal HUM. The inducer motor IDM will
remain energized for a 15-second post-purge period. The
blower motor BLWM and air cleaner terminal EAC-1 will
remain energized for 90, 120, 150, or 180 seconds (depending
on selection at blower-OFF delay switches). The furnace
control CPU is factory-set for a 120-second blower-OFF
delay.
TWO-STAGE HEATING WITH TWO-STAGE THERMOSTAT
(NON-ADAPTIVE HEATING MODE)
(See Fig. 32 and 50A-G for thermostat connections).
NOTE: In this mode, the low-heat only switch must be ON to
select the low-heat only operation mode in response to closing the
thermostat R-to-W1 circuit. Closing the thermostat R-to-W1and-W2 circuits always causes high-heat operation, regardless of
the setting of the low-heat-only switch.
The wall thermostat ″calls for heat″, closing the R to W1 circuit for
low-heat or closing the R to W1 and-W2 circuits for high-heat. The
furnace control performs a self-check, verifies the low-heat and
high-heat pressure switch contacts LPS and HPS are open, and
starts the inducer motor IDM in high-speed.
2. Igniter Warm-Up-At end of the inducer prepurge period, the
Hot Surface Igniter HSI is energized for a 17-sec igniter
warm-up period.
3. Trial-For-Ignition Sequence-When the igniter warm-up period is completed the main gas valve relay contacts GVR close
to energize the gas valve GV, the gas valve opens. The gas
valve GV permits gas flow to the burners where it is ignited by
the Hot Surface Igniter HSI. Five seconds after the GVR
closes, a 2-second flame period begins. The HSI igniter will
remain energized until the flame is sensed or until the
2-second flame proving period begins.
The start-up and shutdown functions and delays described in item
1 above apply to 2-stage heating mode as well, except for
switching from low- to high-heat and vice versa.
4. Flame-Proving-When burner flame is proved at the flameproving sensor electrode FSE, the inducer motor IDM
switches to low-speed unless running at high-speed, and the
furnace control CPU begins the blower-ON delay period and
continues to hold the gas valve GV-M open. If the burner
flame is not proved within two seconds, the control CPU will
close the gas valve GV-M, and the control CPU will repeat the
ignition sequence for up to three more Trials-For-Ignition
1. Switching From Low- To High- Heat-If the thermostat R to
W1 circuit is closed and the R to W2 circuit closes, the furnace
control CPU will switch the inducer motor IDM speed from
low to high. The high-heat pressure switch relay HPSR is
de-energized to close the NC contact. When sufficient pressure is available the high-heat pressure switch HPS closes, and
45
conditioning relay ACR. When the air conditioning relay
ACR is energized the R to Y1-and-Y2 circuits switch the
outdoor unit to high-cooling speed, and the R to G-andY1-and-Y/Y2 circuits switch the furnace blower motor
BLWM to COOL speed.
the high-heat gas valve solenoid GV-HI is energized. The
blower motor BLWM will switch to HI HEAT speed five
seconds after the R to W2 circuit closes.
2. Switching From High- To Low- Heat- If the thermostat R to
W2 circuit opens, and the R to W1 circuit remains closed, the
furnace control CPU will switch the inducer motor IDM speed
from high to low. The high-heat pressure switch relay HPSR
is energized to open the NC contact and de-energize the
high-heat gas valve solenoid GV-HI. When the inducer motor
IDM reduces pressure sufficiently, the high-heat pressure
switch HPS will open. The gas valve solenoid GV-M will
remain energized as long as the low-heat pressure switch LPS
remains closed. The blower motor BLWM will switch to LO
HEAT speed five seconds after the R to W2 circuit opens.
NOTE: When transitioning from low-cooling to high-cooling the
outdoor unit compressor will shut down for 1 minute while the
BLWM continues to run at low-cool speed (same speed as
LO-HEAT) until the outdoor unit compressor comes back on at
high speed.
The electronic air cleaner terminal EAC-1 is energized with
115 vac whenever the blower motor BLWM is operating.
When the thermostat is satisfied, the R to G-and-Y circuit
are opened. The outdoor unit stops, and the furnace blower
BLWM and electronic air cleaner terminal EAC-1 will
remain energized for an additional 90 seconds. Jumper Y1
to DHUM to reduce the cooling off-delay to 5 seconds.
(See Fig. 37.)
COOLING MODE
The thermostat “calls for cooling”
1. Single-Speed Cooling
(See Fig. 31 or 32 and 50A, C, or E for thermostat connections.)
3. Two-Speed Cooling and Two-Stage Thermostat
(See Fig. 32 and Fig. 50A-G for thermostat connections)
The thermostat closes R-to-G-and-Y circuits. The R-to-Y
circuit starts the outdoor unit, and R-to-G-and-Y/Y2 circuits
start the furnace blower motor BLWM on COOL speed.
The electronic air cleaner terminal EAC-1 is energized with
115-v when blower motor BLWM is operating.
When the thermostat is satisfied, the R-to-G-and-Y circuits are
opened. The outdoor unit will stop, and furnace blower motor
BLWM will continue operating on COOL speed for an
additional 90 sec. Jumper Y/Y2 to DHUM to reduce the
cooling off-delay to 5 seconds. (See Fig. 37.)
NOTE: The ACRDJ must be disconnected to allow thermostat
control of the outdoor unit staging. (See Fig. 37.)
The thermostat closes the R to G-and-Y1 circuits for
low-cooling or closes the R to G-and-Y1-and-Y2 circuits
for high-cooling. The R to Y1 circuit starts the outdoor unit
on low-cooling speed, and the R to G-and-Y1 circuit starts
the furnace blower motor BLWM on low-cool speed (same
speed as LO HEAT).
The R to Y1-and-Y2 circuits start the outdoor unit on high-cooling
speed, and the R to G-and-Y/Y2 circuits start the furnace blower
motor BLWM on COOL speed.
The electronic air cleaner terminal EAC-1 is energized with 115
vac whenever the blower motor BLWM is operating.
When the thermostat is satisfied, the R to G-and-Y1 or R to
G-and-Y1-and-Y2 circuits are opened. The outdoor unit stops, and
the furnace blower BLWM and electronic air cleaner terminal
EAC-1 will remain energized for an additional 90 seconds. Jumper
Y1 to DHUM to reduce the cooling off-delay to 5 seconds. (See
Fig. 37.)
2. Two-Speed Cooling and Single-Stage Thermostat
(Adaptive Mode)
(See Fig. 31 and 50A-H for thermostat connections.)
This furnace can operate a two-speed cooling unit with a
single-stage thermostat because the furnace control CPU
includes a programmed adaptive sequence of controlled
operation, which selects low-cooling or high-cooling operation. This selection is based upon the stored history of
the length of previous cooling period of the single-stage
thermostat.
THERMIDISTAT MODE
NOTE: The air conditioning relay disable jumper ACRDJ must
be connected to enable the adaptive cooling mode in response to a
call for cooling. (See Fig. 32.) When in place the furnace control
CPU can turn on the air conditioning relay ACR to energize the
Y/Y2 terminal and switch the outdoor unit to high-cooling.
(See Fig. 50A-D for Thermidistat connections.)
The dehumidification output, DHUM on the Thermidistat should
be connected to the furnace control thermostat terminal DHUM.
When there is a dehumidify demand, the DHUM input is activated,
which means 24 vac signal is removed from the DHUM input
terminal. In other words, the DHUM input logic is reversed. The
DHUM input is turned ON when no dehumidify demand exists.
Once 24 vac is detected by the furnace control on the DHUM
input, the furnace control operates in Thermidistat mode. If the
DHUM input is low or OFF for more than 48 hours, the furnace
control reverts back to non-Thermidistat mode.
The cooling operation described above also applies to operation
with a Thermidistat. The exceptions are listed below:
The furnace control CPU can start up the cooling unit in
either low- or high-cooling. If starting up in low-cooling,
the furnace control CPU determines the low-cooling ontime (from 0 to 20 minutes) which is permitted before
switching to high-cooling.
If the power is interrupted, the stored history is erased and
the furnace control CPU will select low-cooling for up to
20 minutes and then energize the air conditioning relay
ACR to energize the Y/Y2 terminal and switch the outdoor
unit to high-cooling, as long as the thermostat continues to
call for cooling. Subsequent selection is based on stored
history of the thermostat cycle times.
The wall thermostat ″calls for cooling″, closing the R to
G-and-Y circuits. The R to Y1 circuit starts the outdoor unit
on low-cooling speed, and the R to G-and-Y1 circuits starts
the furnace blower motor BLWM at low-cool speed (same
speed as LO HEAT).
If the furnace control CPU switches from low-cooling to
high-cooling, the furnace control CPU will energize the air
a. When the R to G-and-Y1 circuit is closed and there is a
demand for dehumidification, the furnace blower motor
BLWM will continue running at low-cool speed (same
speed as LO HEAT).
46
A00275
A00277
Fig. 50A—Two-Stage Furnace with Single-Speed Air
Conditioner
Fig. 50C—Two-Stage Furnace with Single-Speed Heat
Pump (Dual Fuel)
A00276
A00278
Fig. 50D—Two-Stage Furnace with Two-Speed Heat
Pump (Dual Fuel)
Fig. 50B—Two-Stage Furnace with Two-Speed Air
Conditioner
47
A00281
Fig. 50G—Two-Stage Thermostat With Two-Stage
Furnace and Two-Speed Air Conditioner
A00279
Fig. 50E—Dual Fuel Thermostat with Two-Stage
Furnace and Single-Speed Heat Pump
A00282
Fig. 50H—Single-Stage Thermostat With Two-Stage
Furnace and Two-Speed Air Conditioner
A00280
Fig. 50F—Dual Fuel Thermostat With Two-Stage
Furnace and Two-Speed Heat Pump
48
Notes for Fig. 50A-H:
1. Heat pump MUST have a high pressure switch for dual fuel applications.
2. Refer to outdoor equipment Installation Instructions for additional information and setup procedure.
3. Select the ″ZONE″ position on the two-speed heat pump control.
4. Outdoor Air Temperature Sensor must be attached in all dual fuel applications.
5. Dip switch No.1 on Thermidistat should be set in OFF position for air conditioner installations. This is factory default.
6. Dip switch No. 1 on Thermidistat should be set in ON position for heat pump installations.
7. Dip switch No. 2 on Thermidistat should be set in OFF position for single-speed compressor operation.
This is factory default.
8. Dip switch No. 2 on Thermidistat should be set in ON position for two-speed compressor operation.
9. Configuration Option No. 10 ″Dual Fuel Selection″ must be turned ON in all dual fuel applications.
10. NO connection should be made to the furnace HUM terminal when using a Thermidistat.
11. Optional connection. If wire is connected, dip switch No. 1 on furnace control should be set in ON position
to allow Thermidistat/Thermostat to control furnace staging.
12. Optional connection. If wire is connected, ACRDJ jumper on furnace control should be removed to allow
Thermidistat/Thermostat to control outdoor unit staging.
13. Furnace must control its own high-stage heating operation via furnace control algorithm. This is factory default.
14. The RVS Sensing terminal ″L″ should not be connected. This is internally used to sense defrost operation.
15. DO NOT SELECT the ″FURNACE INTERFACE″ or ″BALANCE POINT″ option on the two-speed heat pump
control board. This is controlled internally by the Thermidistat/Dual Fuel Thermostat.
16. Dip switch D on Dual Fuel Thermostat should be set in OFF position for single-speed compressor operation.
This is factory default.
17. Dip switch D on Dual Fuel Thermostat should be set in ON position for two-speed compressor operation.
49
and-G signals disappear at the same time, the blower motor
BLWM will remain on for the selected blower-OFF delay period.
If the R to W/W1-and-Y1 signals disappear, leaving the G signal,
the blower motor BLWM will remain on for the selected blowerOFF delay period then switch to continuous-blower speed.
When the R to W/W1-and-Y/Y2, R to W/W1-and-Y/Y2-and-G, R
to W/W1-and-Y1-and-Y/Y2, or R to W/W1-and-Y1-and-Y/Y2and-G circuits are energized the furnace control CPU will switch
to or turn on the blower motor BLWM at COOL speed, and begin
a high-heat cycle. The blower motor BLWM will remain on until
the end of the prepurge period, then shut off for 24 seconds then
come back on at HI HEAT speed. When the W/W1 input signal
disappears, the furnace control begins a normal inducer post-purge
period and the blower switches to COOL speed after a 3 second
delay. If the R to W/W1-and-Y/Y2-and-G or R to W/W1-and-Y1and-Y/Y2-and-G signals disappear at the same time, the blower
motor BLWM will remain on for the selected blower-OFF delay
period. If the R to W/W1-and-Y/Y2 or R to W/W1-and-Y1-andY/Y2 signals disappear, leaving the G signal, the blower motor
BLWM will remain on for the selected blower-OFF delay period
then switch to continuous-blower speed.
b. When the R to G-and Y/Y2 circuit is closed and there is a
demand for dehumidification, the furnace blower motor
BLWM will drop the blower speed from COOL to HI
HEAT for a maximum of 10 minutes before reverting back
to COOL speed. If there is still a demand for dehumidification after 20 minutes, the furnace control CPU will drop
the blower speed back to HI HEAT speed. This alternating
10-minute cycle will continue as long as there is a call for
cooling.
c. When the ″call for cooling″ is satisfied and there is a
demand for dehumidification, the cooling blower-off delay
is decreased from 90 seconds to 5 seconds.
CONTINUOUS BLOWER MODE
When the R to G circuit is closed by the thermostat, the blower
motor BLWM will operate on continuous-blower speed (can be set
to LO HEAT, HI HEAT, or COOL speed). Factory default is LO
HEAT speed. Terminal EAC-1 is energized as long as the blower
motor BLWM is energized.
During a call for heat, the blower BLWM will stop during igniter
warm-up (17 seconds), ignition (7 seconds), and blower-ON delay
(66 seconds), allowing the furnace heat exchangers to heat up more
quickly, then restarts at the end of the blower-ON delay period at
LO HEAT or HI HEAT speed respectively.
In high-heat, the furnace control CPU will hold the blower motor
BLWM at HI HEAT speed during the selected blower-OFF delay
period before reverting to continuous-blower speed.
When the thermostat ″calls for low-cooling″, the blower motor
BLWM will switch to operate at low-cool speed (same speed as
LO HEAT). When the thermostat is satisfied, the blower motor
BLWM will operate an additional 90 seconds on low-cool speed
before reverting back to continuous-blower speed.
When the thermostat ″calls for high-cooling″, the blower motor
BLWM will operate at COOL speed. When the thermostat is
satisfied, the blower motor BLWM will operate an additional 90
seconds on COOL speed before reverting back to continuousblower speed.
COMPONENT SELF-TEST
NOTE: The furnace control component test allows all components to run for a short time; except the gas valve and humidifier
terminal HUM are not energized for safety reasons. The EAC-1
terminal is energized when blower is energized. This feature helps
diagnose a system problem in case of a component failure. The
component test feature will not operate if any thermostat signal is
present at control and not until all time delays are completed.
To Begin Component Self-Test:
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in electrical shock,
personal injury, or death.
Blower access panel door switch opens 115-v power to
control board. No component operation can occur. Caution
must be taken when manually closing this switch for service
purposes.
When the R to G circuit is opened, the blower motor BLWM will
continue operating for an additional 5 seconds, if no other function
requires blower motor BLWM operation.
Continuous Blower Speed Selection from Thermostat -To
select different continuous-blower speeds from the room thermostat, momentarily turn off the FAN switch or push-button on the
room thermostat for 1-3 seconds after the blower motor BLWM is
operating. The furnace control CPU will shift the continuousblower speed from the factory setting of LO HEAT to HI HEAT
speed. Momentarily turning off the FAN switch again at the
thermostat will shift the continuous-blower speed from HI HEAT
to COOL. Repeating the procedure will shift the continuousblower speed from COOL to LO HEAT speed. The selection can
be changed as many times as desired and is stored in the memory
to be automatically used following a power interruption.
NOTE: If TEST/TWIN and COM-24v terminals are jumpered
longer than 2 sec, LED will flash rapidly and ignore component
test request.
HEAT PUMP
Component test sequence for 2-stage furnace is as follows:
1. Remove blower access door.
2. Disconnect thermostat R lead from furnace control.
3. Manually close blower door switch.
4. For approximately 2 sec, short (jumper) the COM-24v terminal
on control to the TEST/TWIN 3/16-in. quick-connect terminal
on control until LED turns off. Remove jumper from terminals. (See Fig. 37.)
(See Fig. 50C-F for thermostat connections)
a. LED will display previous status code 4 times.
When installed with a heat pump, the furnace control automatically
changes the timing sequence to avoid long blower off times during
demand defrost cycles. When the R to W/W1-and-Y1 or R to
W/W1-and-Y1-and-G circuits are energized, the furnace control
CPU will switch to or turn on the blower motor BLWM at low cool
speed (same speed as LO HEAT), and begin a low-heat cycle. The
blower motor BLWM will remain on until the end of the prepurge
period, then shut off for 24 seconds then come back on at LO
HEAT speed. When the W/W1 input signal disappears, the furnace
control begins a normal inducer post-purge period and the blower
remains running at LO HEAT speed. If the R to W/W1-and-Y1-
b. Inducer motor starts on high-speed and continues to run
until Step g of component test sequence.
c. Hot surface igniter is energized for 15 sec, then off.
d. Blower motor operates on LO-HEAT speed for 10 sec.
e. Blower motor operates on HI-HEAT speed for 10 sec.
f. Blower motor operates on COOL speed for 10 sec.
g. Inducer motor goes to low-speed for 10 sec, then stops.
5. Reconnect R lead to furnace control, remove tape from blower
door switch, and re-install blower door.
50
NOTE: Manifold pressure MUST always be measured with
burner enclosure front REMOVED.
6. Operate furnace per instruction on outer door.
7. Verify furnace shut down by lowering thermostat setting
below room temperature.
b. Remove regulator seal caps that conceal adjustment screws
for low-and high-heat gas valve pressure regulators. (See
Fig. 51.)
8. Verify that furnace restarts by raising thermostat setting above
room temperature.
c. Move setup switch SW-1 on control center to ON position.
This keeps furnace locked in low-heat operation.
OPERATE FURNACE
Follow procedures on operating instructions label attached to
furnace.
d. Jumper R and W/W1 thermostat connections on control to
start furnace.
FURNACE RESTART
e. Turn low-heat adjusting screw (3/32 hex Allen wrench)
counterclockwise (out) to decrease input rate or clock-wise
(in) to increase input rate.
With furnace operating, set thermostat below room temperature
and observe that furnace goes off. Set thermostat above room
temperature and observe that furnace restarts.
NOTE: DO NOT set low-heat manifold pressure less than 1.3-in.
wc or more than 1.7-in. wc for natural gas. If manifold pressure is
outside this range, change main burner orifices to obtain pressure
in this range.
Step 5—Adjustments
SET GAS INPUT RATE
Furnace gas input rate on rating plate is for installations at altitudes
up to 2000 ft.
In the U.S.A., the input ratings for altitudes above 2000 ft must be
reduced by 2 percent for each 1000 ft above sea level.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in reduced furnace
life.
DO NOT bottom out gas valve regulator adjusting screw.
This can result in unregulated manifold pressure and result in
excess overfire and heat exchanger failures.
In Canada, the input ratings must be derated by 5 percent for
altitudes of 2001 ft to 4500 ft above sea level.
Adjust manifold pressure to obtain input rate.
Furnace input rate must be within ± 2 percent of input on furnace
rating plate adjusted for altitude.
NOTE: If orifice hole appears damaged or it is suspected to have
been redrilled, check orifice hole with a numbered drill bit of
correct size. Never redrill an orifice. A burr-free and squarely
aligned orifice hole is essential for proper flame characteristics.
1. Determine Natural Gas Orifice Size And Manifold Pressure
For Correct Input.
a. Obtain average gas heat value (at installed altitude) from
local gas supplier.
b. Obtain average gas specific gravity from local gas supplier.
f. Move setup switch SW-1 to OFF position after completing
low-heat adjustment.
c. Verify furnace model and size. Table 14 can only be used
for model 58MTB furnaces with heating inputs of
20,000/13,000 (High/Low) Btuh per burner.
g. Jumper R and W1 and W2 thermostat connections on
control. (See Fig. 37.) This keeps furnace locked in
high-heat operation.
d. Find installation altitude in Table 14.
h. Turn high-heat adjusting screw (3/32 hex Allen wrench)
counterclockwise (out) to decrease input rate or clockwise
(in) to increase rate.
NOTE: For Canada altitudes of 2001 to 4500 ft, use U.S.A.
altitudes of 2001 to 3000 ft in Table 14.
e. Find closest natural gas heat value and specific gravity on
Table 14.
NOTE: DO NOT set high-heat manifold pressure less than 3.2-in.
wc or more than 3.8-in. wc for natural gas. If manifold pressure is
outside this range, change main burner orifices to obtain pressure
in this range.
f. Follow heat value and specific gravity lines to point of
intersection to find orifice size and manifold pressure
settings for proper operation.
i. When correct input is obtained, replace caps that conceal
gas valve regulator adjustment screws. Main burner flame
should be clear blue, almost transparent. (See Fig. 52.)
EXAMPLE: (0-2000 ft altitude using Table 14)
Heating value = 1050 Btu/cu ft
Specific gravity = 0.62
Therefore: Orifice No. 45
Manifold pressure 3.6-in. wc for high heat
1.5-in. wc for low heat
* Furnace is shipped with No. 45 orifices.
In this example all main burner orifices are the correct size
and do not need to be changed to obtain the proper
input rate.
j. Remove jumper R-to-W1 and W2.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in component
damage due to flame impingement of burners and heat
exchangers.
DO NOT redrill orifices. Improper drilling (burrs, out-ofround holes, etc.) can cause excessive burner noise and
misdirection of burner flames. (See Fig. 53.)
g. Check and verify burner orifice size in furnace. NEVER
ASSUME ORIFICE SIZE; ALWAYS CHECK AND
VERIFY.
2. Adjust Manifold Pressure To Obtain Input Rate.
a. Remove burner enclosure front.
51
Table 14—Model 58MTB Orifice Size and High/Low-Heat Manifold Pressures for Correct Inputs
for Use with 060 Through 120 Size Furnaces Only
(Tabulated Data Based on 20,000/13,000 Btuh per Burner,
Derated 2 Percent for Each 1000 ft Above Sea Level)*
U.S.A. and Canada
ALTITUDE
RANGE
(FT)
0
to
2000
0%
derate
U.S.A. and Canada
ALTITUDE
RANGE
(FT)
U.S.
Altitudes
2001
to
3000
or
Canada
Altitudes
2001
to
4500
5%
derate
U.S.A. Only
ALTITUDE
RANGE
(FT)
3001
to
4000
7%
derate
AVG GAS
HEAT VALUE
(BTU/CU FT)
850
875
900
925
950
975
1000
1025
1050
1075
1100
AVG GAS
HEAT VALUE
(BTU/CU FT)
775
800
825
850
875
900
925
950
975
1000
1025
AVG GAS
HEAT VALUE
(BTU/CU FT)
750
775
800
825
850
875
900
925
950
975
1000
0.58
Orifice
Manifold
no.
Pressure
43
3.7/1.5
43
3.5/1.5
44
3.7/1.6
44
3.5/1.5
44
3.4/1.4
44
3.2/1.3
45
3.7/1.6
45
3.5/1.5
45
3.3/1.4
45
3.2/1.3
47
3.6/1.5
Orifice
no.
43
43
44
44
44
44
45
45
45
47
47
0.58
Manifold
Pressure
3.8/1.6
3.5/1.5
3.8/1.6
3.6/1.5
3.4/1.4
3.2/1.4
3.7/1.5
3.5/1.5
3.3/1.4
3.7/1.6
3.6/1.5
Orifice
no.
43
43
44
44
44
45
45
45
45
47
47
0.58
Manifold
Pressure
3.7/1.6
3.5/1.5
3.7/1.6
3.5/1.5
3.3/1.4
3.8/1.6
3.6/1.5
3.4/1.4
3.2/1.4
3.6/1.5
3.5/1.5
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
no.
Pressure
43
3.8/1.6
42
3.2/1.4
42
3.3/1.4
43
3.6/1.5
43
3.7/1.6
43
3.8/12.6
43
3.4/1.4
43
3.5/1.5
43
3.6/1.5
44
3.7/1.6
44
3.8/1.6
43
3.4/1.4
44
3.5/1.5
44
3.6/1.5
44
3.7/1.6
44
3.3/1.4
44
3.4/1.4
44
3.5/1.5
45
3.8/1.6
44
3.2/1.4
44
3.4/1.4
45
3.6/1.5
45
3.7/1.6
44
3.2/1.3
45
3.4/1.5
45
3.6/1.5
45
3.7/1.6
45
3.3/1.4
45
3.4/1.4
45
3.5/1.5
47
3.7/1.6
45
3.2/1.4
45
3.4/1.4
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
no.
Pressure
42
3.2/1.4
42
3.3/1.4
42
3.4/1.4
43
3.7/1.5
43
3.8/1.6
42
3.2/1.4
43
3.4/1.5
43
3.6/1.5
43
3.7/1.5
44
3.7/1.6
44
3.8/1.6
43
3.5/1.5
44
3.5/1.5
44
3.6/1.5
44
3.7/1.6
44
3.3/1.4
44
3.4/1.4
44
3.5/1.5
45
3.8/1.6
44
3.2/1.4
44
3.3/1.4
45
3.6/1.5
45
3.7/1.6
45
3.8/1.6
45
3.4/1.4
45
3.5/1.5
45
3.6/1.5
45
3.2/1.4
45
3.4/1.4
45
3.5/1.5
47
3.7/1.6
45
3.2/1.3
45
3.3/1.4
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
no.
Pressure
43
3.8/1.6
42
3.3/1.4
42
3.4/1.4
43
3.6/1.5
43
3.7/1.6
43
3.8/1.6
43
3.4/1.4
43
3.5/1.5
43
3.6/1.5
44
3.6/1.5
44
3.8/1.6
43
3.4/1.4
44
3.4/1.4
44
3.5/1.5
44
3.7/1.5
44
3.2/1.4
44
3.3/1.4
44
3.5/1.5
45
3.7/1.6
45
3.8/1.6
44
3.3/1.4
45
3.5/1.5
45
3.6/1.5
45
3.7/1.6
45
3.3/1.4
45
3.4/1.5
45
3.5/1.5
45
3.2/1.3
45
3.3/1.4
45
3.4/1.4
47
3.6/1.5
45
3.7/1.6
45
3.2/1.4
* Orifice numbers shown in shading are factory installed.
NOTE: Percents of derate are based on midpoints of U.S. altitude ranges.
52
Orifice
no.
42
42
43
43
44
44
44
44
45
45
45
0.66
Manifold
Pressure
3.4/1.4
3.2/1.4
3.7/1.6
3.5/1.5
3.8/1.6
3.6/1.5
3.5/1.5
3.3/1.4
3.8/1.6
3.6/1.5
3.5/1.5
Orifice
no.
42
42
43
43
43
44
44
44
45
45
45
0.66
Manifold
Pressure
3.5/1.5
3.3/1.4
3.8/1.6
3.6/1.5
3.4/1.4
3.6/1.5
3.4/1.5
3.3/1.4
3.8/1.6
3.6/1.5
3.4/1.4
Orifice
no.
42
42
43
43
44
44
44
44
45
45
45
0.66
Manifold
Pressure
3.5/1.5
3.2/1.4
3.7/1.6
3.5/1.5
3.8/1.6
3.6/1.5
3.4/1.4
3.2/1.3
3.7/1.5
3.5/1.5
3.3/1.4
Table 14—Model 58MTB Orifice Size and High/Low-Heat Manifold Pressures for Correct Inputs (Continued)
for Use With 060 Through 120 Size Furnaces Only
(Tabulated Data Based on 20,000/13,000 Btuh per Burner,
Derated 2 Percent for Each 1000 ft Above Sea Level)*
U.S.A. Only
ALTITUDE
RANGE
(FT)
4001
to
5000
9%
derate
U.S.A. Only
ALTITUDE
RANGE
(FT)
5001
to
6000
11%
derate
U.S.A. Only
ALTITUDE
RANGE
(FT)
6001
to
7000
13%
derate
AVG GAS
HEAT VALUE
(BTU/CU FT)
725
750
775
800
825
850
875
900
925
950
AVG GAS
HEAT VALUE
(BTU/CU FT)
700
725
750
775
800
825
850
875
900
925
950
975
1000
AVG GAS
HEAT VALUE
(BTU/CU FT)
650
675
700
725
750
775
800
825
850
875
0.58
Orifice
Manifold
no.
Pressure
43
3.7/1.5
44
3.4/1.4
44
3.7/1.6
44
3.51.5
44
3.2/1.4
45
3.5/1.5
45
3.3/1.4
45
3.3/1.4
47
3.7/1.6
47
3.5/1.5
Orifice
no.
43
43
44
44
44
45
45
45
47
47
48
48
48
0.58
Manifold
Pressure
3.6/1.5
3.4/1.4
3.6/1.5
3.4/1.4
3.2/1.3
3.6/1.5
3.4/1.4
3.2/1.4
3.6/1.5
3.4/1.4
3.7/1.6
3.5/1.5
3.3/1.4
Orifice
no.
42
43
44
44
44
45
45
45
47
47
0.58
Manifold
Pressure
3.2/1.3
3.6/1.5
3.8/1.6
3.6/1.5
3.3/1.4
3.8/1.6
3.5/1.5
3.3/1.4
3.7/1.6
3.5/1.5
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
no.
Pressure
43
3.8/1.6
42
3.2/1.4
42
3.3/1.4
43
3.5/1.5
43
3.7/1.5
43
3.8/1.6
44
3.8/1.6
43
3.4/1.4
43
3.5/1.5
44
3.6/1.5
44
3.7/1.6
44
3.8/1.6
44
3.4/1.4
44
3.5/1.5
44
3.6/1.5
45
3.8/1.6
44
3.3/1.4
44
3.4/1.4
45
3.6/1.5
45
3.7/1.6
44
3.2/1.3
45
3.4/1.4
45
3.5/1.5
45
3.6/1.5
45
3.2/1.4
45
3.3/1.4
45
3.4/1.5
47
3.6/1.5
45
3.2/1.3
45
3.3/1.4
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
no.
Pressure
43
3.7/1.6
42
3.2/1.3
42
3.3/1.4
43
3.5/1.5
43
3.6/1.5
43
3.7/1.6
44
3.7/1.6
43
3.4/1.4
43
3.5/1.5
44
3.5/1.5
44
3.6/1.5
44
3.7/1.6
44
3.3/1.5
44
3.4/1.4
44
3.5/1.5
45
3.7/1.6
44
3.2/1.4
44
3.3/1.4
45
3.5/1.5
45
3.6/1.5
45
3.8/1.6
45
3.3/1.4
45
3.4/1.5
45
3.6/1.5
47
3.7/1.6
45
3.3/1.4
45
3.4/1.4
47
3.5/1.5
47
3.7/1.5
45
3.2/1.3
48
3.8/1.6
47
3.5/1.5
47
3.6/1.5
48
3.6/1.5
48
3.8/1.6
47
3.4/1.4
48
3.5/1.5
48
3.6/1.5
48
3.7/1.6
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
no.
Pressure
42
3.3/1.4
42
3.4/1.4
42
3.5/1.5
43
3.7/1.6
43
3.8/1.6
42
3.2/1.4
43
3.4/1.5
43
3.6/1.5
43
3.7/1.6
44
3.7/1.6
44
3.8/1.6
43
3.4/1.4
44
3.4/1.5
44
3.6/1.5
44
3.7/1.6
44
3.2/1.4
44
3.3/1.4
44
3.4/1.5
45
3.7/1.5
45
3.8/1.6
44
3.2/1.4
45
3.4/1.5
45
3.6/1.5
45
3.7/1.6
45
3.2/1.4
45
3.4/1.4
45
3.5/1.5
47
3.6/1.5
45
3.2/1.3
45
3.3/1.4
* Orifice numbers shown in shading are factory installed.
NOTE: Percents of derate are based on midpoints of U.S. altitude ranges.
53
Orifice
no.
42
42
43
43
44
44
44
45
45
45
0.66
Manifold
Pressure
3.4/1.4
3.2/1.4
3.7/1.5
3.4/1.4
3.7/1.6
3.5/1.5
3.3/1.4
3.8/1.6
3.6/1.5
3.4/1.4
Orifice
no.
42
43
43
43
44
44
44
45
45
45
47
47
48
0.66
Manifold
Pressure
3.4/1.4
3.8/1.6
3.6/1.5
3.4/1.4
3.6/1.5
3.4/1.4
3.2/1.4
3.7/1.5
3.5/1.5
3.3/1.4
3.7/1.6
3.5/1.5
3.8/1.6
Orifice
no.
42
42
43
43
44
44
44
45
45
45
0.66
Manifold
Pressure
3.6/1.6
3.3/1.4
3.8/1.6
3.5/1.5
3.8/1.6
3.5/1.5
3.3/1.4
3.8/1.6
3.6/1.5
3.4/1.4
Table 14—Model 58MTB Orifice Size and High/Low-Heat Manifold Pressures for Correct Inputs (Continued)
for Use With 060 Through 120 Size Furnaces Only
(Tabulated Data Based on 20,000/13,000 Btuh per Burner,
Derated 2 Percent for Each 1000 ft Above Sea Level)*
U.S.A. Only
ALTITUDE
RANGE
(FT)
7001
to
8000
15%
derate
U.S.A. Only
ALTITUDE
RANGE
(FT)
Altitudes
8001
to
9000
17%
derate
U.S.A. Only
ALTITUDE
RANGE
(FT)
9001
to
10,000
19%
derate
AVG GAS
HEAT VALUE
(BTU/CU FT)
625
650
675
700
725
750
775
800
825
850
AVG GAS
HEAT VALUE
(BTU/CU FT)
600
625
650
675
700
725
750
775
800
AVG GAS
HEAT VALUE
(BTU/CU FT)
575
600
625
650
675
700
725
750
775
0.58
Orifice
Manifold
no.
Pressure
43
3.8/1.6
43
3.5/1.5
44
3.8/1.6
44
3.5/1.5
44
3.3/1.4
45
3.7/1.6
45
3.5/1.5
45
3.3/1.4
47
3.6/1.5
47
3.4/1.4
Orifice
no.
43
43
44
44
44
45
45
45
47
0.58
Manifold
Pressure
3.8/1.6
3.5/1.5
3.7/1.6
3.5/1.5
3.2/1.4
3.6/1.5
3.4/1.4
3.2/1.3
3.6/1.5
Orifice
no.
43
43
44
44
44
45
45
47
47
0.58
Manifold
Pressure
3.8/1.6
3.5/1.5
3.7/1.6
3.4/1.4
3.8/1.6
3.6/1.5
3.3/1.4
3.7/1.6
3.5/1.5
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
no.
Pressure
42
3.3/1.4
42
3.4/1.4
42
3.5/1.5
43
3.7/1.6
43
3.8/1.6
42
3.2/1.4
43
3.4/1.4
43
3.5/1.5
43
3.6/1.5
44
3.6/1.5
44
3.8/1.6
43
3.4/1.4
44
3.4/1.4
44
3.5/1.5
44
3.6/1.5
45
3.8/1.6
44
3.3/1.4
44
3.4/1.4
45
3.6/1.5
45
3.7/1.6
45
3.8/1.6
45
3.4/1.4
45
3.5/1.5
45
3.6/1.5
45
3.2/1.3
45
3.3/1.4
45
3.4/1.4
47
3.5/1.5
47
3.7/1.5
45
3.2/1.3
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
no.
Pressure
42
3.3/1.4
42
3.4/1.4
42
3.5/1.5
43
3.6/1.5
43
3.8/1.6
42
3.2/1.4
43
3.4/1.4
43
3.5/1.5
43
3.6/1.5
44
3.6/1.5
44
3.7/1.6
44
3.8/1.6
44
3.3/1.4
44
3.4/1.5
44
3.6/1.5
45
3.8/1.6
44
3.2/1.4
44
3.3/1.4
45
3.5/1.5
45
3.6/1.5
45
3.8/1.6
45
3.3/1.4
45
3.4/1.4
45
3.5/1.5
47
3.7/1.6
45
3.2/1.3
45
3.3/1.4
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
0.64
Orifice
Manifold
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
no.
Pressure
42
3.2/1.4
42
3.3/1.4
42
3.3/1.5
43
3.6/1.5
43
3.7/1.6
42
3.2/1.3
44
3.8/1.6
43
3.5/1.5
43
3.6/1.5
44
3.5/1.5
44
3.7/1.5
44
3.8/1.6
44
3.3/1.4
44
3.4/1.4
44
3.5/1.5
45
3.7/1.6
45
3.8/1.6
44
3.3/1.4
45
3.4/1.5
45
3.6/1.5
45
3.7/1.6
45
3.2/1.4
45
3.3/1.4
45
3.4/1.5
47
3.6/1.5
47
3.7/1.6
45
3.2/1.4
*Orifice numbers shown in shading are factory installed.
NOTE: Percents of derate are based on midpoints of U.S. altitude ranges.
54
Orifice
no.
42
42
43
43
44
44
44
45
45
45
0.66
Manifold
Pressure
3.6/1.5
3.3/1.4
3.7/1.6
3.5/1.5
3.7/1.6
3.5/1.5
3.3/1.4
3.7/1.6
3.5/1.5
3.3/1.4
Orifice
no.
42
42
43
43
44
44
44
45
45
0.66
Manifold
Pressure
3.6/1.5
3.3/1.4
3.7/1.6
3.4/1.5
3.7/1.6
3.4/1.4
3.2/1.4
3.6/1.5
3.4/1.4
Orifice
no.
42
42
43
43
44
44
45
45
45
0.66
Manifold
Pressure
3.6/1.5
3.3/1.4
3.7/1.6
3.4/1.4
3.6/1.5
3.4/1.4
3.8/1.6
3.5/1.5
3.3/1.4
ON/OFF
SWITCH
INLET
PRESSURE
TAP
FF
O
for 2 percent derate for each 1000 ft above sea level. See
Example and Table 15 for derate multiplier factor.
LOW-FIRE
ADJUSTMENT
ALLEN SCREW
(UNDER CAP)
HIGH-FIRE
ADJUSTMENT
ALLEN SCREW
(UNDER CAP)
EXAMPLE:
100,000 Btuh input furnace installed at 4300 ft.
Derate
Furnace Input Rate
Furnace Input Rate X Multiplier =
at Installation
at Sea Level
Factor
Altitude
100,000
X
0.91
=
91,000
ON
CANADA
At installation altitudes from 2001 to 4500 ft, this furnace
must be derated 5 percent by an authorized Gas Conversion
Station or Dealer. To determine correct input rate for
altitude, see example above and use 0.95 as derate multiplier factor.
;;;;
MANIFOLD
PRESSURE
TAP
A97358
b. Reinstall burner box cover.
Fig. 51—Redundant Automatic Gas Control Valve
NOTE: Clocking gas input rate MUST always be performed with
the burner box cover INSTALLED.
BURNER FLAME
c. Check that gas valve adjustment caps are in place for
proper input to be clocked.
BURNER
d. Obtain yearly heat value average for local gas supply.
NOTE: Be sure heating value of gas used for calculations is
correct for your altitude. Consult local gas utility for altitude
adjustment of gas heating value.
e. Check and verify orifice size in furnace. NEVER ASSUME
THE ORIFICE SIZE. ALWAYS CHECK AND VERIFY.
f. Turn off all other gas appliances and pilots.
g. Move setup switch SW-1 to ON position. This keeps
furnace locked in low-heat operation.
h. Jumper R-to-W/W1.
MANIFOLD
i. Let furnace run for 3 minutes in low-heat operation.
A89020
j. Measure time (in sec) for gas meter to complete 1 revolution. Note reading.
Fig. 52—Burner Flame
k. Refer to Table 16 for cubic ft of gas per hr.
l. Multiply gas rate cu ft/hr by heating value (Btu/cu ft).
m. Move setup switch SW-1 to OFF position and jumper R
and W1 and W2 thermostat connections. This keeps
furnace locked in high-heat operation. Repeat items ’i’
through ’l’ for high-heat operation.
EXAMPLE: (0-2000 ft altitude)
Furnace input from rating plate is 100,000 Btuh.
Btu heating input = Btu/cu ft X cu ft/hr
Heating value of gas = 975 Btu/cu ft
Time for 1 revolution of 2-cu ft dial = 70 sec
Gas rate = 103 cu ft/hr (from Table 16)
Btu heating input = 103 X 975 = 100,425 Btuh. In this
example, the orifice size and manifold pressure adjustment
is within ±2 percent of the furnace input rate.
BURNER
ORIFICE
A93059
Fig. 53—Burner Orifice
3. Verify Natural Gas Input Rate By Clocking Gas Meter.
NOTE: Be sure all pressure tubing, combustion-air and vent
pipes, and burner enclosure front are in place when checking input
by clocking gas meter.
a. Calculate high-altitude adjustment (if required).
UNITED STATES
At altitudes above 2000 ft, this furnace has been approved
NOTE: Measured gas inputs (high-heat and low-heat) must be
within ±2 percent of that stated on furnace rating plate when
installed at sea level or derated per that stated above when installed
at higher altitudes.
n. Remove jumper across R, W/W1, and W2 thermostat
connections to terminate call for heat.
55
SET TEMPERATURE RISE
Table 15—Altitude Derate Multiplier for U.S.A.
ALTITUDE
(FT)
0–2000
2001–3000
3001–4000
4001–5000
5001–6000
6001–7000
7001–8000
8001–9000
9001–10,000
PERCENT
OF DERATE
0
4–6
6–8
8–10
10–12
12–14
14–16
16–18
18–20
DERATE MULTIPLIER
FACTOR FOR U.S.A.*
1.00
0.95
0.93
0.91
0.89
0.87
0.85
0.83
0.81
UNIT DAMAGE HAZARD
Failure to follow this caution may result in overheating the
heat exchangers or condensing flue gases in heat exchanger
areas not designed for condensate.
Temperature rise must be within limits specified on furnace
rating plate. Recommended operation is at midpoint of rise
range or slightly above.
Place SW-1 in ON position. Jumper R to W/W1 and W2 to check
high-gas-heat temperature rise. To check low-gas-heat temperature
rise, remove jumper to W2. Determine air temperature rise for both
high and low gas heat. Do not exceed temperature rise ranges
specified on unit rating plate for high and low gas heat.
* Derate multiplier factor is based on midpoint altitude for altitude range.
Table 16—Gas Rate (CU FT/HR)
This furnace must operate within the temperature rise ranges
specified on the furnace rating plate. Determine the air temperature
as follows:
SIZE OF TEST DIAL
SIZE OF TEST DIAL
SECONDS
SECONDS
FOR 1
FOR 1
1
2
5
1
2
5
REVOLUTION Cu Ft Cu Ft Cu Ft REVOLUTION Cu Ft Cu Ft Cu Ft
a. Place duct thermometers in return and supply ducts as close
to furnace as possible. Be sure thermometers do not ’see’
heat exchangers so that radiant heat does not affect thermometer readings. This is particularly important with
straight run ducts.
10
360
720
1800
50
72
144
360
11
327
655
1636
51
71
141
355
12
300
600
1500
52
69
138
346
13
277
555
1385
53
68
136
340
14
257
514
1286
54
67
133
333
15
240
480
1200
55
65
131
327
16
225
450
1125
56
64
129
321
17
212
424
1059
57
63
126
316
18
200
400
1000
58
62
124
310
19
189
379
947
59
61
122
305
20
180
360
900
60
60
120
300
21
171
343
857
62
58
116
290
b. Derate for altitude if applicable.
22
164
327
818
64
56
112
281
23
157
313
783
66
54
109
273
c. Return and supply ducts for excessive restrictions causing
static pressures greater than 0.50-in. wc.
24
150
300
750
68
53
106
265
25
144
288
720
70
51
103
257
26
138
277
692
72
50
100
250
27
133
267
667
74
48
97
243
28
129
257
643
76
47
95
237
29
124
248
621
78
46
92
231
30
120
240
600
80
45
90
225
31
116
232
581
82
44
88
220
32
113
225
563
84
43
86
214
33
109
218
545
86
42
84
209
34
106
212
529
88
41
82
205
35
103
206
514
90
40
80
200
36
100
200
500
92
39
78
196
37
97
195
486
94
38
76
192
38
95
189
474
96
38
75
188
39
92
185
462
98
37
74
184
40
90
180
450
100
36
72
180
41
88
176
439
102
35
71
178
42
86
172
429
104
35
69
173
43
84
167
419
106
34
68
170
44
82
164
409
108
33
67
167
45
80
160
400
110
33
65
164
46
78
157
391
112
32
64
161
47
76
153
383
116
31
62
155
48
75
150
375
120
30
60
150
49
73
147
367
124
29
58
145
b. When thermometer readings stabilize, subtract return-air
temperature from supply-air temperature to determine temperature rise.
If the temperature rise is outside this range, check the following:
a. Gas input for low- and high gas heat operation.
d. Adjust temperature rise by adjusting blower speed. Increase blower speed to reduce temperature rise. Decrease
blower speed to increase temperature rise.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Disconnect 115-v electrical power before changing speed tap.
For high-heat, the following connections can be made at HI HEAT
on control:
a. Med-high (Yellow)
b. Med (Orange) -Available only on 5-speed motors. Factory
setting for these motors.
c. Med-Low (Blue) - Do NOT use for HI GAS-HEAT on
80K & 120K Btuh input models. Factory setting for
4-speed motors.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in damage to the heat
exchangers due to over temperature or condensate corrosion.
1. NEVER connect Low Speed (Red) wire to ″HI HEAT″.
2. Do NOT connect Medium Low Speed (Blue) wire to ″HI
-HEAT″ on 80,000 Btuh and 120,000 Btuh input model
sizes.
56
THERMOSTAT SUBBASE
TERMINALS WITH
THERMOSTAT REMOVED
Table 17–Speed Selection
LEAD COLOR
White
Black
Yellow
Orange†
Blue
Red
SPEED
Common
High
Med-High
Med
Med-Low
Low*
AS SHIPPED
COM
Cool
SPARE
High-Gas Heat
Spare/High-Gas Heat
Low-Gas Heat
HOOK-AROUND
VOLT/AMMETER
R Y W G
* Continuous blower speed
† Available on 5-speed blowers only
For low-heat, the following connections can be made at LO
-HEAT on control:
10 TURNS
a. Med (Orange) -Available only on 5-speed motors
b. Med-Low (Blue)
FROM UNIT 24-VOLT
TERMINAL BLOCK
c. Low (RED) - Factory setting.
To change blower motor speed selections for heating mode,
remove blower motor lead from control HI-HEAT terminal. (See
Fig. 37.) Select desired blower motor speed lead from one of the
other motor leads and relocate it to HI-HEAT terminal. See Table
17 for lead color identification. Reconnect original lead on SPARE
terminal. Follow this same procedure for proper selection of
LO-HEAT and COOL speed selection.
EXAMPLE: 5.0 AMPS ON AMMETER
10 TURNS AROUND JAWS
= 0.5 AMPS FOR THERMOSTAT SETTING
A80201
Fig. 54—Amp Draw Check with Ammeter
gradually block off return air after furnace has been operating
for a period of at least 5 minutes. As soon as limit control has
shut off burners, return-air opening should be unblocked to
permit normal air circulation. By using this method to check
limit control, it can be established that limit is functioning
properly and operates if there is a restricted return-air supply
or motor failure. If limit control does not function during this
test, cause must be determined and corrected.
Set Blower Off Delay
a. Remove Blower Access Door if installed.
b. Turn Dip switch 2 and 3 ON or OFF for desired blower off
delay. See Table 11A and B or Fig. 36 and 37.
ADJUST BLOWER OFF DELAY (HEAT MODE)
If desired, the main blower off time delay period may be
lengthened or shortened when operating in the heating mode to
provide greater comfort. See Table 11 for position of switches and
Fig. 36 or 37 for location of switches on control center.
2. Check Pressure Switch
This control proves operation of draft inducer. Check switch
operation as follows:
SET THERMOSTAT HEAT ANTICIPATOR
a. Turn off 115-v power to furnace.
When using a nonelectronic thermostat, the thermostat heatanticipator must be set to match the amp draw of the electrical
components in R-W/W1 circuit. Accurate amp draw readings can
be obtained at thermostat subbase terminals R and W.
b. Remove outer furnace door and disconnect inducer motor
lead wires from wire harness.
c. Turn on 115-v power to furnace.
d. Set thermostat to ″call for heat″ and wait 1 minute. When
pressure switch is functioning properly, hot surface igniter
should not glow, and status code LED flashes a Status
Code 32. If hot surface ignitor glows when inducer motor
is disconnected, shut furnace down immediately. Determine reason pressure switch did not function properly and
correct condition.
Fig. 54 illustrates an easy method of obtaining actual amp draw.
The amp reading should be taken after blower motor has started
and furnace is operating in low heat. To operate furnace in
low-heat, first move SW-1 to ON position, then connect ammeter
wires as shown in Fig. 54. The thermostat anticipator should NOT
be in the circuit while measuring current. If thermostat has no
subbase, the thermostat must be disconnected from R and W/W1
wires during current measurement Return SW-1 to final desired
location after completing the reading.
e. Turn off 115-v power to furnace.
f. Reconnect inducer motor leads, reinstall main furnace door,
and turn on 115-v power supply.
See thermostat manufacturer’s instructions for adjusting heat
anticipator and for varying heating cycle length.
When using an electronic thermostat, set cycle rate for 3 cycles per
hour.
Step 6—Check Safety Controls
This section covers the safety controls that must be checked before
the installation is complete. The flame sensor, gas valve, and
pressure switch were all checked in the Start-up procedure section
as part of normal operation.
1. Check Primary Limit Control
This control shuts off gas control system and energizes
air-circulating blower motor if furnace overheats.
Recommended method of checking this limit control is to
57
CHECKLIST
1. Put away tools and instruments. Clean up debris.
2. Check SW-1 through SW-3 after completing installation to
ensure desired settings for thermostat type (SW-1) and
blower-OFF delay (SW-2 and SW-3).
3. Verify flame rollout manual reset switch has continuity.
4. Verify that blower and outer doors are properly installed.
5. Cycle test furnace with room thermostat.
6. Check operation of accessories per manufacturer’s instructions.
7. Review User’s Guide with owner.
8. Leave literature packet near furnace.
58
CHECKLIST—DIRECT VENT (2-PIPE) INSTALLATION
LOAD CALCULATION
Condensate Drain
____________
Heating Load (Btuh)
________
Unit Level or Pitched Forward
____________
Cooling Load (Btuh)
________
Internal Tubing Connections Free of Kinks
and Traps
____________
Furnace Model Selection
________
External Drain Connection Leak Tight and
Sloped
________
Condensate Trap Primed before Start-Up
________
Heat Tape Installed if Required
COMBUSTION AIR AND VENT PIPING
Termination Location
________
Roof or Sidewall
________
Termination Kit — 2 Pipe or Concentric
________
Combustion-Air Pipe Length
________
Combustion-Air Pipe Elbow Quantity
________
Vent Pipe Length
________
Vent Pipe Elbow Quantity
________
Pipe Diameter Determined from Sizing Table
________
Pipe Sloped To Furnace
CHECKLIST—START-UP
Over Ceilings
________
Low-Ambient Exposed Pipes
Gas Input Rate
(Set Within 2 percent of Rating Plate)
________
Temperature Rise Adjusted
Thermostat Anticipator
________
Anticipator Setting Adjusted or
________
Cycle Rate (3 Cycles per Hr) Selected
Safety Controls Check Operation
Pipe Insulation
________
________
59
________
Primary Limit
________
Pressure Switch
CHECKLIST—NON DIRECT VENT (1-PIPE) INSTALLATION
LOAD CALCULATION
____________
Heating Load (Btuh)
____________
Cooling Load (Btuh)
____________
Furnace Model Selection
Condensate Drain
________
Unit Level or Pitched Forward
________
Internal Tubing Connections Free of Kinks
and Traps
________
External Drain Connection Leak Tight and
Sloped
________
Condensate Trap Primed before Start-Up
________
Heat Tape Installed if Required
VENT PIPING
Termination Location
________
Roof or Sidewall
________
Vent Pipe Length
________
Vent Pipe Elbow Quantity
________
Pipe Diameter Determined from Sizing Table
________
Pipe Sloped To Furnace
Pipe Insulation
________
Over Ceilings
________
Low-Ambient Exposed Pipes
Copyright 2005 CARRIER Corp. • 7310 W. Morris St. • Indianapolis, IN 46231
CHECKLIST—START-UP
________
Gas Input Rate (Set Within 2 percent of
Rating Plate)
________
Temperature Rise Adjusted
Thermostat Anticipator
________
Anticipator Setting Adjusted or
________
Cycle Rate (3 Cycles per Hr) Selected
Safety Controls Check Operation
________
Primary Limit
________
Pressure Switch
58mtb1si
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
PC 101
Printed in U.S.A.
Catalog No. 58MTB-1SI
Pg 60
8-05
Replaces: 58MTA-8SI
Tab 6a 8a