A.O. Smith | FPS40 | User manual | Page 1 POWER VENT WATER HEATERS Service Workbook w

POWER VENT WATER HEATERS
Service Workbook
Models
FPS 40 and 50
ay ta FPSE 40 and 50
echnica
Information Dept. /A\. (0). SAO] Series 222-233
Irving, Texas WareR PRODUCTS FPD 40 and 50
COMPANY Series 222-233
A DIVISION OF A. O. SMITH CORPORATION
Printed in the U.S.A. 693 4514 Part No. TC-010
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
TABLE OF CONTENTS
PAGE PAGE
Evaluating the Installation 3 FPS Troubleshooting
FPS 3 Blower Description 22-24
FPSE 4 Blower Runs Constantly 25-27
FPD 5 Gas Valves 28-29
Interior Clearances 6 FPS Wiring Schematic 30
Exterior Clearances 7 FPSE/FPD Sequence of Operation 31-32
Condensation 8 Removing the FPD Main Burner 33
Sealing the Vent 9 FPSE/FPD Troubleshooting 34-48
Venting Calculations
FPS/FPSE Horizontal 10 FPSE/FPD IID Operational 42
FPS/FPSE Vertical 11 Profile
FPD Horizontal 12
FPSE/FPD Wiring Schematic 49
FPS Sequence of Operation 13
General Questions & Answers 50-51
FPS Service
Checking the Draft 14 Additional Information 51
Service Charts (FPS) 15,16
Negative Pressure 17 Competitive Analysis 52-53
Backdraft 18
Makeup Air Ducts 19
Inlet Air Clip 20
FPS Pilot Kits 21
The information contained in this workbook is designed to answer commonly faced situations encountered in the operation of the POWER SHOT®
and SEALED SHOT" Product and is not meant to be all inclusive. If you are experiencing a problem not covered in this workbook, please
contact the A.Q. smith Technical Information Department at 1-800-527-1953 or your local A.O. Smith Water Products Company representative
for further assistance.
This workbook is intended for use by licensed plumbing professionals and reference should be made to the installation manual accompanying
the product.
©1993
A.O. Smith
Water Products Co.
Technical Information
Irving, Texas
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
No duplication or reproduction of this book may be made without the express written authorization of the A.O. Smith Water Products Company
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
EVALUATING THE INSTALLATION
The A.O. Smith power vent family of residential water heaters are designed to meet different
installation conditions. Therefore we must evaluate the job site in which these heaters are to be
installed.
me, я FPS
Alcove or Closet
Dedicated Fresh Make-up
Air Supply
EVALUATING THE FPS
The FPS Power Shot can be installed in an alcove, closet, or anywhere a source of fresh make-
up air is available. Makeup air provides air for combustion, dilution air for venting, and relieves
negative pressure conditions in the building when the heater is in the standby mode.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
inside building.
Where backdraft
conditions occur
during heater standb
EVALUATING THE FPSE
Here the FPSE Power Shot” is illustrated in a large open basement. Air for combustion is drawn
from inside the building. The FPSE, featuring electronic spark ignition, was chosen for this
Installation because a negative pressure condition could develop from other appliance exhaust
fans installed in the house.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
, Vapor Barrier
Safad
WITTUOWE
A Closed combustion required
Back draft unacceptable
Super-insulated homes
— Vapor Barrier
EVALUATING THE FPD
The FPD Sealed Shot” with its own dedicated air vent and exhaust vent, is the heater of choice
in installations where closed combustion is required - for example in living quarters. The FPD
Is recommended when installing a water heater in a super insulated energy efficient house, with
sealed gaskets around windows and doors, and vapor barriers in the walls and ceilings.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
0" From
Side 8 Rear
4" In Front *
21" From
The Top
0" PVC Vent
To Combustibles
INTERIOR CLEARANCES
All interior clearance requirements indicate distances between the heater and combustible
materials. Zero inch clearances are allowed from the sides and rear of the heater. Allow a
minimum of 4" in front and 21" on top.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
EXTERIOR CLEARANCES
Exterior installation clearance requirements are crucial and must be met to ensure compliance
with all safety and code requirements. If all clearances cannot be met, do not unpack the
heater.
All exterior clearance requirements for the FPS, the FPSE, and FPD are measured from the vent
termination. The minimum clearances for side wall venting are 3 feet from an inside corner, 4
feet from windows and doors, 1 foot above any window or door, 1 foot above ground level, at
least 7 feet above a public walkway, and 3 feet above any forced air intake within 10 feet. The
FPS and FPSE can be vertically vented with minimum exterior clearances of 4 feet from or 1
foot above any gable, dormer, or roof structure with building interior access. Again, check for
these clearances prior to installation.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
u
he
3/8 " FLEXIBLE
Se
CONDENSATION
In certain installations, you may experience condensation in the venting. This will be most
prevalent in the colder climates and especially with relatively long runs of venting in unheated
rooms. To prevent the damaging condensation from draining into the blower and/or water
heater, install the condensate tee provided with the heater in the exhaust vent after the blower
elbow, and attach a 3/8" plastic tube for the drain as shown. The loop in the tube prevents
exhaust gases from escaping through the drain line. A second method for handling vent pipe
condensate is to install the venting with a slight downward slope toward the termination end.
This slope should be no more than 1/8" per 5 feet of horizontal run.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
SEAL BLOWER MOTOR TEE
SEAL VENT JOINTS
PIPE HANGERS
HIGH TEMPERATURE
SEALANT ILLUSTRATED
IN PINK
STANDARD CAULKING
ILLUSTRATED IN
SEALING THE VENT
Proper sealing of the vent system is essential tor correct operation of the heater. On the initial
firing of the heater, check all joints in the system for a proper seal, especially where the blower
motor tee joins the heater and the PVC blower connection. If a blower joint leaks air, it should
be caulked with the high temperature silicone sealant provided. Other joints may be sealed with
standard caulking. The vent system should be supported every three (3) feet of vertical run and
every five (5) feet of horizontal run.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
12" minimum
above roof
VERTICAL
MAXIMUM OF 35 EQUIVALENT FEET
90: ELBOW = 5 FEET
45 ELBOW = 2.5 FEET
MAXIMUM OF 3 ELBOWS
A DO NOT INCLUDE BLOWER ELBOW
OR TERMINATION TEE IN
CALCULATIONS
FPS/FPSE VERTICAL VENTING CALCULATIONS
The FPS or FPSE can be vented vertically up to 35 equivalent feet from the heater. A minimum
of 1 foot must be maintained between the roof and the termination tee. The calculation method
of equivalent feet for vertical venting is the same as for side wall venting.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
11
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
HORIZONTAL
te | INTAKE VENT - MAXIMUM 20 EQUIVALENT FEET
ay 90° ELBOW = 5 FEET
VENT E 45° ELBOW = 2.5 FEET
, MAXIMUM OF 3 ADDITIONAL ELBOWS
IN EACH VENT.
EXHAUS DO NOT INCLUDE IN THE CALCULATIONS
VENT THE FIRST ELBOW OR TERMINATION
ELBOW IN EITHER THE EXHAUST OR
INTAKE VENTS.
FPD HORIZONTAL VENTING CALCULATIONS
The FPD Sealed Shot features a two pipe system with a fresh air intake vent and an exhaust
vent. It is designed for side wall venting. A maximum of 20 equivalent feet may be added to the
intake vent system and a maximum of 20 equivalent feet may also be added to the exhaust vent.
However, excluding the termination elbow, you can have no more than four elbows in each vent.
The calculation method of equivalent feet for venting is the same for the FPD as for the FPS,
and FPSE.
Since improper venting is a chief cause of heater malfunction, careful planning and adherence
to these venting requirements will minimize service calls and ensure proper operation.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
12
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
MAIN BURNER GAS FLOWS
GAS VALVE
… GAS PRESSURE
SWITCH
AN LO Ja Ия.
FPS SEQUENCE OF OPERATION
To trouble shoot the Power Shot”, you must first understand its sequence of operation. When
the thermostat calls for heat and the main gas valve opens, gas flows into the gas solenoid valve
closing the gas pressure switch contacts. Closing the gas pressure switch activates the blower
assembly.
When the blower reaches full speed, the air pressure switch contacts close activating the gas
solenoid valve, allowing gas to flow to the main burner.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
13
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
CHECKING THE DRAFT
On initial start up, check for the correct draft on the Power Shot”. To check the draft, place a
smoke stick directly in front of the inlet air damper while the heater is firing. A properly operating
system will draw the smoke into the inlet air damper.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
14
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
CONDITION
CAUSE
SOLUTION
Burnt gas odor
Leaking vent
joints
Seal vent joints
Blocked vent
Clear vent
blockage
The majority of the complaints associated with the operation of the FPS® will likely be a direct
result of improper venting. If the customer complains of smelling burnt gas around the water
heater, first check for vent gases that may be leaking from the PVC joints or around the area
between the blower assembly and water heater. Seal all leaks with the high temperature
silicone sealant provided.
Check for restrictions in the venting that may cause some spillage of burnt gas into the room and
check your draft, visually inspecting the vent termination for blockage, clearing blockage as
necessary.
air or back-
air ducts
FPS
CONDITION CAUSE SOLUTION
Sooting Inlet air damper Correct operation
not operational of inlet air
damper
Water Dripping Condensation Install condensate
from blower tee
Pilot Outage Insufficient make-up Install make-up
drafts in vent
Improper venting is also a major cause of sooting in water heaters. If you experience sooting
with the POWER SHOT“, check that the inlet air damper swings freely and opens 1 1/4" when
the blower is running.
If water is dripping from the blower, condensate is the culprit. To correct the problem, install a
condensate tee, and pipe to drain.
If the customer complains of nuisance pilot outage, this may be due to a lack of combustion air,
or other appliance (exhaust fans, clothes dryers, etc.) creating a backdraft in the FPS venting.
In either case, install additional make-up air ducts.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
15
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
CONDITION CAUSE SOLUTION
Excessive heat Inlet air damper not Free up air damper
build-up in pvc opening completely
venting
Blower does not Replace entire
run when main blower assembly
burner fires
Wrong main burner Install correct
orifice size orifice
Intermittent Build up of Replace thermo-
fan cycling pressure in the stat gas valve
without burner main burner tube if cycling occurs
operation between thermostat more than twice
(Propane Only) gas valve and per hour.
solenoid gas valve
A malfunctioning vent damper may also cause excessive heat buildup in the PVC vent piping.
If unable to free up the damper, replace the entire combustion control tee.
If blower does not run when the main burner fires, replace the control box. Also check burner
orifice for correct size.
Intermittent cycling of the fan, without main burner operation, indicates a build-up of pressure
in the main burner tube between the thermostatic gas valve and solenoid gas valve.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
16
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
Nata
AO > VINE
AFL Ч - PRODUMN
= = “ED
NEGATIVE PRESSURE
Diagnosing pilot outage complaints requires an examination of the environment in which the
heater is installed. Mechanical vent fans are the chief cause of negative pressure. If the house
is too tight, more air will be exhausted from the structure than is being brought in from the
outside, resulting in a negative pressure condition. Fireplaces, furnaces, wind, and thermal
stacking within the house can also play a role in creating negative pressure conditions.
Negative pressure can result in air being backdrafted through the water heater vent down into
the combustion chamber, blowing out the pilot. This may happen randomly because it may be
a particular combination of appliances which cause the condition.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
17
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
BACKDRAFT
To check for a negative condition close all windows, outside doors, and fireplace dampers. Turn
on all exhausting appliances, including kitchen draft hoods, clothes dryers, furnaces, bathroom
vents, etc. Open all inner doors between these appliances and the Power Shot".
Once all appliances are on and inner doors open, open the inlet air damper on the Power Shot”
when the heater is not firing. Using your hand, check for air movement. If air is being blown
back into the room, a negative pressure condition exists.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
18
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
AN LO Jas ESAS Un.
ja.
WATER PRODU!
COMPANY
MAKEUP AIR DUCTS
To alleviate a negative pressure condition, install makeup air ducts (per makeup air
specifications listed in the national fuel gas code) of sufficient capacity to allow all appliances
requiring makeup air to operate properly.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
19
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
ren
PET
INLET AIR CLIP
An inlet air damper clip has been provided on the FPS 216 and 217 series. When this clip is
installed, backdrafts are blown out into the room and not directed down into the combustion
chamber, preventing pilot outage.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
20
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
AAA aio
PA Tad Tor” San Ta? oe he To Sa Ae EE ЕН
Series 216 & 217 Series 220
FPS PILOT KITS
For FPS 216 & 217 series installations where nuisance pilot outage cannot be eliminated бу
adding makeup air or installing the inlet air damper clip, А.О. Smith has developed a new piiot
burner assembly. This new pilot burner, available from A.O. Smith through your local distributor,
minimizes the effects of backdrafts caused by negative pressure. To install the new burner Kit,
remove the main burner assembly from the combustion chamber and replace the main burner
tube with the new one. As shown, the new pilot burner assembly is mounted on the new main
burner tube.
All FPS 220 series heaters come factory equipped with the new pilot burner, easily recognizable
by its dual pilot.
KIT - FPS BURNER KIT NO.
FPS 40 (Nat) 216 Series 181877-0
FPS 40 (LP ) 217 Series 181877-1
FPS 50 (Nat) 216 Series 181877-2
FPS 50 (LP ) 217 Series 181877-2
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
21
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
TROUBLESHOOTING
Most problems will first appear as blower malfunctions - either a blower that does not run or a
blower that runs constantly. In these instances, further trouble shooting is required to determine
the exact cause.
IF THE BLOWER DOES NOT RUN, make sure that:
the pilot burner and thermocouple are operating correctly, and
120 volts AC is supplied to the heater, and
the thermostat is calling for heat.
Repair or replace these items, if necessary, as you would in any standard residential gas water
heater.
IF THE BLOWER DOES NOT RUN, test the blower by disconnecting the 4 wire cable from the
blower control box, and, using an insulated jumper wire, jumping sharp corner to sharp corner
on the plug receptacle as shown.
If the jumped blower does not run, replace the blower.
- If the jumped blower does run, the blower is ok, and you will need to investigate
further. Continue your investigation by testing the cable, the wiring harness, ana
the gas pressure switch.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
22
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
TO TEST THE CONTROL CABLE, reinstall the cable into the control box. Disconnect the cable
from the wiring harness near the bottom of the heater, and using your insulated jumper wire,
jump sharp corner to sharp corner on the plug as shown.
- If the blower does not run, replace the cable.
- If the blower runs, the cable is ok and you will need to continue troubleshooting.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
23
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
“SWITCH
AOS VE
EA TT
WATER += =>”; ори
COMPAN
TO TEST THE WIRING HARNESS AND GAS PRESSURE SWITCH, disconnect the two wires
from the gas pressure switch, and using your insulated jumper wire, connect the wires together
- If the blower does not run, replace the wiring harness.
- If the blower runs, replace the gas pressure switch.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
24
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
IF THE BLOWER RUNS CONSTANTLY, make sure that:
: the pilot burner and thermocouple are operating correctly, and
- the thermostat is NOT calling for heat.
Repair or replace these items as necessary.
IF THE BLOWER STILL CONTINUES TO RUN, test the blower by unplugging the 4 wire cable
from the control box.
If the disconnected blower still runs, replace the control box.
If the blower stops running, the blower is ok and you will need to investigate
further. Continue your investigation by testing the control cable, and the wiring
harness and gas pressure switch.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
25
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
TO TEST THE CONTROL CABLE, reinstall cable into the control box, and, disconnect the cable
from the wiring harness near the bottom of the heater.
- If the blower continues to run, replace the cable.
- If the disconnected blower stops, jump sharp corner to sharp corner on the plug
as shown. If the jumped blower does not run, replace the cable. If the blower
runs, the cable is ok and you will need to continue troubleshooting.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
26
2
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
al
FA r
РЕ al Г Li их
“ PREBSURE
SWITCH
TO TEST THE WIRING HARNESS AND GAS PRESSURE SWITCH, disconnect one wire from
the gas pressure switch.
- If the blower continues to run, replace the wiring harness.
- If the blower stops, replace the gas pressure switch.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
27
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
TO TEST THE GAS VALVES If the main burner will not fire, make sure that:
- 120 volts AC is supplied to the blower,
the pilot burner and thermocouple are operating correctly, and
- the thermostat is calling for heat.
E
ser
vs
= TE
E a. =i
ag
a a.“ a
ma
TO TEST THE THERMOSTAT, place the top knob in the "PILOT" position, connect a gas
pressure gauge to the pressure tap on the thermostat, then place the top knob in the "ON"
position,
If the gas pressure gauge does not pressurize, replace the thermostat.
If the gas pressure gauge pressurizes (3.5" w.c. for natural and 10" w.c. for
propane), the thermostat is ok and you will need to troubleshoot the solenoid gas
valve. Continue on and test the solenoid gas valve. Continue by observing blower
operation.
©1993
A.O. Smith
Technical Information
Water Products Co.
Irving, Texas
28
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
OBSERVE BLOWER OPERATION:
If the blower does not start, follow the blower trouble shooting steps previously
discussed.
If the blower does run, but the main burner still does not fire, test the solenoid gas
valve.
GAS
PRESSURE
SWITCH
es" cas
SOLENOID
VALVE
MULTIMETER
PINS
-
TO TEST THE SOLENOID GAS VALVE, disconnect the two wire leads from the solenoid gas
valve, and, with a meter, check for twenty four volts AC between the leads.
- If twenty four volts AC is present, replace the gas solenoid valve.
If twenty four volts AC is not present, check for vent blockages or excessive
equivalent feet of venting. If the venting checks out ok, the blower air pressure
switch is defective, and the blower control box must be replaced.
©1993
A.O. Smith
Water Products Co.
Technical Information
Irving, Texas
29
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
WARNING:
DISCONNECT FROM ELECTRICAL SUPPLY
BEFORE SERVICING UNIT. REPLACE
ALL DOORS AND PANELS BEFORE
OPERATING HEATER.
FPS
WIRING SCHEMATIC
JUNCTION
BLOWER
BOX
GRN , r
В } 110 VOLT
t— 120 V., 60 CYCLE — BOWER
SOURCE
RELAY N.O. BLOWER TRANSFORMER $y ~= =
MOTOR CONNECTOR
BLK WHT.
GND. 110 V. в _
T GAN TI
AD) 4-WIRE CABLE
YEL W “TT > SUPPLIED
N WITH UNIT
| ET
| LEGEND
1 B - BLACK
| SINGLE Y W - WHITE
COIL y Y - YELLOW
: SOLENOID R - RED
G - GREEN
Lo GY - GREEN/YELLOW
| = A U - BLUE
SINGLE COIL NO. € CONNECTOR
SOL
©1993
A.O. Smith
Water Products Co.
Technical Information
Irving, Texas
30
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
GAS AND ELECTRIC
POWER ON
3 AIR SWITCH CLOSES “OFF/ON” SWITCH
pre bi
E e
6. IGNITOR LIGHTS PILOT
AND PROVES PILOT
8. MAIN BURNER |
4. IGNITION CONTROL FIRES — Y Panda
STARTS SEQUENCE Bs a
E.C.O. м
/ | |
г, ae
[A -— 1. THERMOSTAT
Ре
> MAIN VALVE OPENS
ED A.M
WATER PRODUCTS
5. PILOT VALVE OPENS WATER
(24 VOLTS)
FPSE/FPD SEQUENCE OF OPERATION
To troubleshoot FPSE and FPD water heaters, you must understand how they operate -both
mechanically and electrically.
To test the mechanical operation, make sure that:
- both the gas and electricity are "ON", and
- the ON/OFF switch on the electrical control box is in the "ON" position.
When the thermostat calls for heat, the blower is activated. Once the blower reaches full
speed, the negative air pressure switch is closed. This activates the ПО module to open
the pilot valve and begin sparking at the pilot burner assembly. Once the pilot flame is
established and confirmed back to the IID, the sparking is stopped and the main gas
valve is opened, allowing gas flow to the main burner.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
31
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
CONDITION CAUSE SOLUTION
Vent pipe too hot Wrong burner Install correct
(above 170°F). orifice. orifice.
Not enough dilution Check for
air. restriction in
inlet air path.
Dilution air too Intake air
hot. temperature too
high.
SERVICE CHART FPSE/FPD
Excessive temperatures in the exhaust vents can be caused by an incorrect main burner orifice,
or blockages in the inlet air path resulting in insufficient dilution air. Excessive temperatures can
also result if the dilution air is too hot. In this situation, change the location of the inlet air vent
or reduce the ambient temperature.
CONDITION CAUSE SOLUTION
Yellow flame Combustion air Clear intake air
(sooting). path restricted. path.
Water dripping Condensation. Install condensate
from blower. tee.
Slope vent
downward.
SERVICE CHART FPSE/FPD
If you experience a yellow flame and sooting, check for and remove any restriction in the
combustion air path.
If water is dripping from the blower, install a condensate tee or slope the vent downward.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
32
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
REMOVING THE FPD MAIN BURNER ASSEMBLY
To service the main burner on the FPD remove the right side and bottom panels of the control
box. To access the FPD main burner:
remove all the screws that secure the door assembly to the skirt ring,
loosen the nuts that secure the burner assembly to the gas valve,
disconnect the ground and spark ignition wires from the IID, and
lift out the burner assembly.
To install the burner assembly, reverse the above procedures.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
33
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
EN
||
TROUBLESHOOTING
Most problems will first appear as blower malfunctions - either a blower that does not run or a
blower that runs constantly. In these instances, further trouble shooting is required to determine
the exact cause.
IF THE BLOWER DOES NOT RUN, make sure that:
120 volts AC is supplied to the heater,
the ON/OFF switch is in the "ON" position,
the high limit is closed,
the thermostat is calling for heat, and
there is gas supplied to the unit.
è
И... Then...
Does not read Replace electrical
control box
Plug cable back in
and go to step 2
Reads 120 VAC
STEP 1. TO TEST THE SUPPLY VOLTAGE, unplug the 4 wire cable from the electrical control
box, and, using a multimeter, test for 120 volts AC between terminals 1 and 3 on the plug
receptacle.
- If the meter does not read 120 volts AC, replace the entire blower assembly
including the electrical control box, and retest.
- If the meter reads 120 volts AC plug the cable back in, and go to Step 2.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
34
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
Does not read Repl 4 wi
120 VAC eplace 4 wire cable
Plug cable in and
Reads 120 VAC go to step 3
STEP 2. TO TEST THE 120 VOLT PORTION OF THE CABLE, unplug the cable from the outer
door, and, using a multimeter, test for 120 volts AC between terminal 1 and 3 on the plug end.
- If the meter does not read 120 volts AC, replace the 4 wire cable and retest.
- If the meter reads 120 volts AC, plug cable back in and go to Step 3.
©1993
A.O. Smith
Water Products Co.
Technical Information
Irving, Texas
35
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
В 8 # y ES | : Ww A 3 3 pa Te :
et Es
po
Pari tweeen terminal 2 and ground
If Meter... Then...
Does not read Press reset button, still no
120 VAC voltage - replace high limt
Reads 120 VAC Go to step 4
STEP 3. TO TEST THE HIGH LIMIT, remove outer door cover, and using as multimeter, test
for 120 volts AC between terminal 2 on the high limit and ground.
- If the meter does not read 120 volts AC, press the high limit reset button. If still no
voltage, replace the high limit.
- If meter reads 120 volts AC, go to Step 4.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
36
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
If Meter... Then...
Does not read
120 VAC Replace Thermostat
Reads 120 VAC Go to step 5
STEP 4. TO TEST THE THERMOSTAT, adjust the thermostat to call for heat. Using a
multimeter, test for 120 volts AC, between terminal 2 on the thermostat and ground.
- If the meter does not read 120 volts AC, replace the thermostat, and retest.
If meter reads 120 volts AC, go to Step >.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
37
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
If Meter... Then...
Does not read Replace electrical
120 VAC control box
Reads 120 VAC Gotostep 6
STEP 5. TO TEST BLOWER VOLTAGE, unplug the blower motor from the electrical control box.
Using a multimeter, test for 120 volts AC, between the black and white connection on the control
DOX.
- If the meter does not read 120 volts AC, replace the electrical control box.
If the meter does read 120 volts AC go to step 6.
©1993
А.О. Smith Technical Information
Water Products Co. Irving, Texas
38
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
E Then...
Blower does
not run
Blower runs Go to step 7
Replace blower
STEP 6. TO TEST THE BLOWER MOTOR, plug the blower back in.
- If the blower does not run, replace the blower
- If the blower does run, continue on to step 7.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
39
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
IF THE BLOWER RUNS BUT THERE IS NO SPARK AT THE PILOT ASSEMBLY:
turn off the gas, and
turn the ON/OFF switch on the electrical control box to "OFF", then back to "ON",
and check for sparking at the pilot assembly.
IF THERE IS STILL NO SPARK, CONTINUE TROUBLE-SHOOTING WITH STEP 7.
If Meter... Then...
Does not read Check air switch tube for
24 VAC blockage - no blockage
replace control box
Reads 24 VAC Go to step 8
STEP 7. TO TEST THE AIR SWITCH, unplug the 4 wire cable from the electrical control box,
and jump terminals 1 and 3 together on the receptacle. Using a multimeter, test for 24 volts AC
between terminals 2 and 4 on the cable receptacle.
- If the meter does not read 24 volts AC, check the air switch suction tube for
blockage. If no blockage, replace the electrical control box.
If the meter reads 24 volts AC, go to Step 8.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
40
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
| = = ©! ras e |
fl tha Ea AL LS a. maca |
pre ro a Aa | NOT FIEL D REPAIRABLE |
| On De
X PART NO "03 Jaz E
MODEL No. ЭР | т
МРТ = 24 VAC 8050 +
TH CURRENT = 150 AMP. BY. MV AT MVAC
OUTPUT Py an LS AMP AT spi
SPARE GAP TG 1H
Then...
If Meter...
Does not read
24 VAC
Reads 24 VAC
Replace cable &
wiring harness
Go to step 9
STEP 8. TO TEST THE 24 VOLT PORTION OF THE CABLE, remove the jumper and plug the
4 wire cable back in. Test for 24 volts AC between the TH and GND terminals on the IID.
- If meter reads 24 volts AC, go to Step 9.
- If the meter does not read 24 volts AC, replace the 4 wire cable and wiring
harness.
©1993
A.O. Smith
Water Products Co.
Technical Information
41
Irving, Texas
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
I.1.D. OPERATIONAL
TRIAL FOR TRIAL FOR TRIAL FOR
dei IGNITION IGNITION
60 60 60
SEC, SEC 1] SEC >
IID OPERATIONAL PROFILE
To trouble shoot electronic spark ignition systems, you must understand the operational profile
of the IID.
When 24 volts AC is supplied to the IID, a trial for ignition begins. The pilot valve is
opened and a 10,000 volt spark is sent to the pilot assembly for up to 60 seconds.
Once a pilot flame is detected by a signal on the ground wire, the IID will turn off the
spark and open the main valve. If a flame is not proven, the pilot gas and spark will
continue for 60 seconds, followed by a 30 second purge which allows any unburned gas
to be evacuated by the blower.
This trial for ignition will repeat 3 times. If a pilot has not been established or recognized
by the end of the 3rd trial for ignition, the IID will go into lockout. The blower will keep
running but the IID will not try for ignition until the ON/OFF switch is reset.
Remember that the IID, can lockout and must be reset when conducting tests.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
42
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
If Meter...
Does not read
24 VAC Replace |.I.D. module
Reads 24 VAC Go to step 10
STEP 9. TO TEST THE IID PILOT CIRCUIT, reset the ON/OFF switch, and using a multimeter,
test for 24 volts AC between PV and MV/PV on the IID.
- If the meter does not read 24 volts AC, replace the IID module, and retest.
If the meter reads 24 volts AC, go to Step 10.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
43
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
If Pilot... Then...
Check for 7/64" spark gap, and
Is not sparking spark & GND cable continuity
Is sparking Go to step 11
STEP 10. TO TEST THE SPARK, reset the ON/OFF switch, and visually check for a spark a
the pilot assembly.
- If the pilot assembly is not sparking check for:
7/04 spark gap between the pilot hood and spark rod,
spark cable continuity, and
for ground cable continuity between the lID and pilot assembly.
- If pilot assembly is sparking go to Step 11.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
44
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
|
I
за
| ав эПОЧЯ! уа\уе |
+ TN 5 = E = a = à ë
| Lo Ns a | Meer dor 24 TAC
Y \ r E ;
\ |
| lot ti bing
ie and you have confirmed: Then...
| . Gas supply is on,
No pilot . pilot tube not leaking, and Replace gas
flame . 24V on pilot valve solenoid valve
Pilot is established Go to step 12
STEP 11. TO TEST THE PILOT FLAME CIRCUIT, visually check for the pilot flame.
- If there is no pilot flame established and you have checked that the gas supply is
on, that there is no leak in the pilot tubing, and you have 24 VAC between the pilot
valve solenoid terminals, replace the gas valve.
- If the pilot flame is established go to step 12.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
45
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
Г
=
p
| 2 МНН
== =
Reset ON/OFF switch
Check for main burner flame
И as Then...
Main burner ignites Sequence is complete
Main burner
does not ignite Go to step 13
STEP 12. TO TEST THE MAIN BURNER CIRCUIT, reset the ON/OFF switch, and visually
check for the main burner flame.
- If the main burner ignites the sequence is complete.
- If the main burner does not ignite go to step 13.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
46
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
MODEL Mo. 5
НР за Мас. м
p 745
160 He SPARE GG
LR +
My
Ё PV a MY AT ë С
BRENT: 16
RUT PY OR
TS E
does notant
If Meter... Then...
Does not read Replace |.1.D.
24 VAC module
Reads 24 VAC Go to step 14
STEP 13. TO TEST THE MV OUTPUT CIRCUIT, if the burner does not light, check for 24 volts
AC between MV and MV/PV on the IID.
- If meter does not read 24 volts AC, replace the IID module.
- If the meter reads 24 volts AC, go to step 14.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
47
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
If Meter...
Does not read Replace wiring
24 VAC harness
Replace gas
Reads 24 VAC valve
STEP 14. TO TEST THE MAIN VALVE, reset the ON/OFF switch, and test for 24 volts AC at
the main gas valve solenoid.
- If the meter does not read 24 volts AC, replace wiring harness and retest.
- If the meter reads 24 volts AC, replace the gas valve.
©1993
A.O. Smith Technical Information
Water Products Co. Irving, Texas
48
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
FPSE & FPD
WIRING SCHEMATIC
ELECTRONIC IGNITION
O © CONNECTION
| TO MOTOR
CORDSET
6 FL.
115 V.A.C.
BLACK
x (ON
= 3
à | OFF / =
« Ñ MIL
>
al | © > AIR
el o = : PRESSURE
ole o TRANSFORMER SWITCH
= |
olelala I
| E.C.O. o |
| | Ч | О THERMOSTAT | À al
G/Y A WHITE O— — © _ |
=
BLUE Le as ‘ |
ROBERTSHAW PROOUCTS
CONTROL MOOULE
< o q _ + =
S$ 2 234528 2 E
| otr rlalal |
MN A GREY o G
TT YT TA
AREA pan
- +
BROWN Y Y
| IGNITOR WIRE
GND ORANGE NFILOT
©1993
A.O. Smith
Technical Information
Water Products Co.
Irving, Texas
49
Q.
Q.
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
QUESTIONS AND ANSWERS
FPS MODELS
What is the CFM of the blower?
Maximum of 60 CFM.
Will the blower move more air through
the unit than conventional venting and
thereby cause less heat to be
transferred into the water?
No. The unit has been tested to
the DOE test methods for
recovery efficiency using the
minimum and maximum amount
of vent piping with the resulting
Q. Will a snow/riser kit be available?
A snow/riser kit can be constructed in the field in
parts of the country where applicable. The
venting should be terminated a minimum of 12
inches above normal annual maximum snowfall
accumulations.
Avoid installations where snow drifting or
prevailing wind conditions will interfere with the
venting of the heater. Installation of a
condensate tee is necessary to prevent
condensation from reaching the blower housing.
Do not use oil
GPH rates as shown on the Q. Is there a maximum distance that the vent cap
spec sheet. The baffle and air can terminate from the exterior wall?
intakes of the heater still
regulate chamber air flow. A, No, as long as the overall equivalent
length is not exceeded. (The colder the
Can this unit be vented to a chimney? vent piping, the more condensation will
be experienced.)
No. The unit may have Q. May | paint the vent piping?
condensing flue gases which
would attack mortar or standard A. Yes. Use a latex paint if it will adhere to
vent piping. the smooth surface.
based paint. They contain solvents
Can | vent the FPS unit vertically? which may attack the PVC.
The Series 216 & 217 are
sidewall venting only. Q. May | use an FPS to replace a Sidewinder?
The Series 220 and higher can
be vented either vertically or A. Yes, but the entire FPS unit must be
horizontally. used. Note that the FPV/KPV units use
a larger joint penetration hole than is
necessary for the FPS. Close the gap
by using insulation and a centering plate
to center the vent pipe and prevent air
drafts into the house.
©1993
A.O. Smith Technical Information
Water Products Co.
50
Irving, Texas
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
If the vent is blocked, will the blower
motor continue to run?
Yes, but the air pressure switch
will open and interrupt power to
the gas solenoid valve, shutting
off the main burner.
FPSE MODELS
Q.
6.
Will increasing the vent pipe size
allow a longer equivalent feet run?
No. The 3 inch vent is the only
size venting approved.
What is the pressure that the air
switch will close to prove draft?
0.3 PSI.
Can an extension be added to the air
intake on the blower?
A. No.
FPD MODELS
a. Can the air intakes and exhaust vents
be combined in multiple heater
installations?
A. No. Each one must be installed
separately.
Q. Can this unit terminate in a window
well?
A. No. Clearances to an air inlet
opening must be observed.
ADDITIONAL INFORMATION
Blower motor specification:
Manufactured by FASCO industries,
Draws .75 AMP.
Turns at 3325 RPM.
Pilot burner specification:
Standing pilot
Rated 500 BTU per hr.
Vent material specification:
3" PVC Schedule 40 or Class 160
3" CPVC Schedule 40 or Class 160
IID module specification:
Robertshaw Controls, Model SP745, Draws 1.63
AMPS at 24 VAC, pilot spark gap 7/64".
Note 1: Propane units do not have a bypass in
the gas solenoid valve. This may result
in occasional cycling on stand by
between calls for heat. If you experience
more than two stand by cycles per hour,
consider replacing the main gas control
valve.
Note 2: If hard wiring is required by local codes,
use the knockout provided on the blower
control box.
©1993
A.O. Smith
Water Products Co.
Technical Information
Irving, Texas
21
FPS/FPSE/FPD
TECHNICAL TRAINING AND SERVICE WORKBOOK
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Irving, Texas
Technical Information
©1993
A.O. Smith
Water Products Co.
52
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TECHNICAL TRAINING AND SERVICE WORKBOOK
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Irving, Texas
Technical Information
53
©1993
A.O. Smith
Water Products Co.