Astria Montebello / Superior DRT63ST See-Through Direct Vent Gas Fireplace Brochure

INSTALLATION INSTRUCTIONS
Montebello See-Through
Direct-Vent Gas Fireplaces
MODELS
P/N 506023-12 Rev. B 05/2011
This manual is one of a set of two supporting this product.
Refer to P/N 506025-05 for Care and Operation Instructions.
Ce manuel est disponible en francais, simplement
en faire la demande. Numéro de la pièce 506223-11.
INSTALLER: Leave this manual with the appliance.
CONSUMER: Retain this manual for future reference.
INstallateur : Laissez cette notice avec l’appareil.
Consommateur : Conservez cette notice pour
consultation ultérieure.
Intertek Report No.
100326523PRT-001
LSM40ST-N
LSM40ST-P
Look for the EnerGuide
Gas Fireplace Energy
Efficiency Rating in this manual.
Based on CSA P.4.1-02
This appliance may be installed in an aftermarket permanently located, manufactured home (USA only) or mobile
home, where not prohibited by local codes. This appliance is only for use with the type of gas indicated on the rating
plate. This appliance is not convertible for use with other gases unless a certified kit is used.
WARNING / AVERTISSEMENT/ AVISO
• HOT GLASS WILL CAUSE
BURNS.
• DO NOT TOUCH GLASS
UNTIL COOLED.
• NEVER ALLOW CHILDREN
TO TOUCH GLASS.
• UNE SURFACE VITRÉE CHAUDE
• EL VIDRIO CALIENTE
PEUT CAUSER DES BRÛLURES.
CAUSARÁ QUEMADURAS.
• LAISSER REFROIDIR LA SURFACE
• USTED DEBE NUNCA
VITRÉE AVANT D'Y TOUCHER.
TOCAR EL VIDRIO CALIENTE.
• NE PERMETTEZ JAMAIS À UN ENFANT • LOS NIÑOS DEBEN NUNCA
DE TOUCHER LA SURFACE VITRÉE.
TOCAR EL VIDRIO.
WARNING: If the information in these instructions
is not followed exactly, a fire or explosion may
result, causing property damage, personal injury,
or death.
- Do not store or use gasoline or other flammable
vapors and liquids in the vicinity of this or any other
appliance.
- WHAT TO DO IF YOU SMELL GAS:
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any
phone in your building.
• Immediately call your gas supplier from a
neighbor’s phone. Follow the gas supplier’s
instructions.
• If you cannot reach your gas supplier, call the fire
department.
- Installation and service must be performed by a
qualified installer, service agency or the gas supplier.
AVERTISSEMENT : Assurez-vous de bien suivre les
instructions données dans cette notice pour réduire au
minimum le risque d’incindie ou d’explosion ou pour
éviter tout dommage matériel, toute blessure ou la mort.
- Ne pas entreposer ni utilizer d’essence ni d’autres vapeurs
ou liquides inflammables dans le voisinage de cet appareil
ou de tout autre appareil.
- QUE FAIRE SI VOUS SENTEZ UNE ODEUR DE GAZ :
• Ne pas tenter d’allumer d’appareil.
• Ne touchez à aucan interrupteur. Ne pas vous servir des
téléphones se trouvant dans le bâtiment où vous trouvez.
• Appelez immédiatement votre fournisseur de gaz depuis
un voisin. Suivez les instructions du fournisseur.
• Si vous ne pouvez rejoindre le fournisseur de gaz,
appelez le service des incindies.
- L’installation et l’entretien doivent être assurés par un
installateur ou un service d’entretien qualifié ou par le
fournisseur de gaz.
TM
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
TABLE OF CONTENTS
PACKAGING
Packaging.................................................... 2
Introduction................................................. 2
Approved Vent Components..................... 2
General Information..................................... 2
Misc. Codes/Standards............................ 3
Inputs and Efficiencies............................. 3
Gas Supply Pressure Requirements......... 3
Gas Valve Diagram . ................................ 4
Orifice Sizes............................................. 4
Massachusetts / NYC Requirements........ 4
Cold Climate Insulation................................ 5
Manufactured Home Requirements............. 5
Location....................................................... 5
Vent Termination Clearances . ..................... 6
Hearth Extensions (Optional)....................... 8
Minimum Clearances to Combustibles......... 9
Pre-Installation Steps................................... 10
Typical Installation Sequence ...................... 10
Detailed Installation Steps:
Step 1. Framing........................................... 10
Framing Specifications.............................. 11
Fireplace Dimensions................................ 12
Step 2. Route Gas Line............................... 13
Step 3. Install Vent System......................... 14
General Information.................................. 14
Vent Restrictor Assembly/Installation....... 14
Vent Termination (Vertical/Horizontal)...... 14
Vertical (Roof) Termination....................... 15
Vertical Termination with Straight
Vertical Venting................................ 15
Straight Vent Section Lengths Table.... 15
Vertical Termination with Offset
Vertical Venting................................ 16
Vertical Termination System Figures
and Tables......................................... 18
Horizontal (Wall) Termination................... 19
Horizontal Termination System
Figures and Tables............................ 21
Step 4. Field Wiring..................................... 23
Step 5. Remove Glass Door........................ 23
Step 6. Connecting Gas Line....................... 24
Step 7. Install Firebox Liner Panels............. 25
Step 8. Verify Appliance Operation.............. 25
Step 9. Install Volcanic Stone, Glowing
Embers, and Logs..................................... 26
Step 10. Install Glass Doors, Mesh Pull
Screens, and Modesty Panel . .................. 29
Step 11. Burner Adjustments...................... 30
Finishing Requirements............................... 31
Step 12. Attaching Safety-in-Operation
Warnings...................................... 33
Installation Accessories............................... 34
Gas Conversion Kits........................... 35
The assembled vented gas fireplace is packaged with the following items:
• Fireplace Components:
(1) Literature Kit (in envelope in firebox;
contains Care and Operation Instructions, Installation Instructions, safetyin-operation warning labels, warranty)
(1) Remote Control Kit (in plastic bag in firebox; contains remote control, receiver)
(1) Log Set
(1) Vent Restrictor Assembly
(1) bag Glowing Embers
(4) bags Volcanic Stone
(1) Door Modesty Shield
• Panel Kit (sold separately; REQUIRED for all
fireplace models) - one of the following kits:
– Architectural Stone Ceramic
– Venetian Tile Ceramic
– Buff Herringbone Ceramic
– Buff Rustic Ceramic
– Black Rustic Ceramic
– Black Porcelain
• Outdoor Installation Kit (sold separately;
REQUIRED for indoor/outdoor installations)
Introduction
The Montebello™ See-Through is a direct-vent,
sealed combustion gas fireplace designed
for either indoor/indoor or indoor/outdoor
residential applications (including screened
porches and lanais). See “Minimum Clearances
to Combustibles” on Page 9.
NOTE: INDOOR/OUTDOOR INSTALLATIONS
REQUIRE AN OUTDOOR INSTALLATION KIT
(SOLD SEPARATELY).
These appliances are designed to operate on
natural or propane gas. The system is switchable between standing and intermittent pilot
modes.
External electrical power is required to operate these units. If the system operates on line
voltage, four “AA” batteries (in receiver) can
be used as a backup in case of a power outage.
Approved Vent Components
These fireplaces are designed, tested, and listed
for operation and installation with the following
vent components (8" inner and 11" outer) only:
• Secure Vent™ SV8 direct-vent system components manufactured by Security Chimneys
International.
These approved vent system components are
labeled for identification. Do NOT use any other
manufacturer’s vent components with these
appliances.
2
General Information
WARNING
Young children should be carefully supervised when they are
in the same room as the appliance. Toddlers, young children
and others may be susceptible
to accidental contact burns. A
physical barrier is recommended
if there are at risk individuals in
the house. To restrict access to
a fireplace or stove, install an
adjustable safety gate to keep
toddlers, young children and
other at risk individuals out of
the room and away from hot
surfaces.
AVERTISSEMENT
Les jeunes enfants devraient être
surveillés étroitement lorsqu’ils
se trouvent dans la même pièce
que l’appareil. Les tout petits,
les jeunes enfants ou les adultes
peuvent subir des brûlures s’ils
viennent en contact avec la surface chaude. Il est recommandé
d’installer une barrière physique
si des personnes à risques habitent la maison. Pour empêcher
l’accès à un foyer ou à un poêle,
installez une barrière de sécurité; cette mesure empêchera les
tout petits, les jeunes enfants et
toute autre personne à risque
d’avoir accès à la pièce et aux
surfaces chaudes.
Children and adults should be alerted to the
hazards of high surface temperature and
should stay away to avoid burns or clothing
ignition.
Les enfants et les adultes devraient être
infor-més des dangers que posent les
températures de surface élevées et se
tenir à distance afin d’éviter des brûlures
ou que leurs vêtements ne s’enflamment.
Do not attempt to alter or modify
the construction of the appliance or
its components. Any modification or
alteration may void the warranty,
certification and Listings of this unit.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
WARNING
Improper installation, adjustment,
alteration, service or maintenance
can cause injury or property
damage. Refer to this manual. For
assistance or additional information consult a qualified installer,
service agency or the gas supplier.
WARNING
Failure to comply with these
installation instructions will
result in an improperly installed
and operating appliance, voiding
its warranty. Any change to this
appliance and/or its operating
controls is dangerous.
WARNING
Clothing or other flammable
material should not be placed on
or near the appliance.
AVERTISSEMENT
On ne devrait pas placer de vêtements ni d’autres matières inflammables sur l’appareil ni à proximité.
WARNING
Any safety screen or guard
removed for servicing the appliance must be replaced prior to
operating the appliance.
AVERTISSEMENT
Tout écran ou protecteur retiré pour
permettre l’entretien de l’appareil
doit être remis en place avant de
mettre l’appareil en marche.
WARNING
Improper installation or use of
this appliance can cause serious
injury or death from fire, burns,
explosion or carbon monoxide
poisoning.
Note: Installation and repair should be done
by a qualified service person. The appliance
should be inspected before use and at least
annually by a professional service person.
More frequent cleaning may be required due
to excessive lint from carpeting, bedding
material, etcetera. It is imperative that control
compartments, burners and circulating air
passageways of the appliance be kept clean.
Remarque : L’installation et la réparation devrait être confiées à un technicien
qualifié. L’appareil devrait faire l’objet
d’une inspection par un technicien professionnel avant d’être utilisé et au moins
une fois l’an par la suite. Des nettoyages
plus fréquents peuvent être nécessaires si
les tapis, la literie, et cetera produisent
une quantité importante de pous-sière.
Il est essentiel que les compartiments
abritant les commandes, les brûleurs
et les conduits de circulation d’air de
l’appareil soient tenus propres.
Provide adequate clearances around air openings and adequate accessibility clearance for
service and proper operation. Never obstruct
the front or back openings of the appliance.
Do not use these appliances if any part
has been under water. Immediately call a
qualified, professional service technician to
inspect the appliance and to replace any parts
of the control system and any gas control
which have been under water.
Ne pas utiliser cet appareil s’il a été
plongé, même partiellement, dans
l’eau. Appeler un technicien qualifié pour
inspecter l’appareil et remplacer toute
partie du système de commande et toute
commande qui a été plongée dans l’eau.
Appliance BTU inputs are listed in Table 1A.
Appliance efficiencies are listed in Table 1B.
Only trim kit(s) supplied by the manufacturer
shall be used in the installation of this appliance.
Seules les trousses de garniture fournies
par le fabricant doivent être utilisées pour
l’installation de cet appareil.
These appliances comply with National Safety
Standards and are tested and listed by Intertek
(Report No. 100326523PRT-001) to ANSI
Z21.88 (in Canada, CSA-2.33), and CAN/CGA2.17-M91 (CSA P4.1) in both USA and Canada,
as vented gas fireplace.
These appliances are listed by Intertek for
installation in bedrooms, aftermarket mobile
homes, and manufactured homes.
Misc. Codes/Standards
Installation must conform to local codes or, in
the absence of local codes, with the National
Fuel Gas Code, ANSI Z223.1/NFPA 54 - latest
edition (in Canada, the current CAN/CSA-B149.1
installation code).
The appliance, when installed, must be electrically grounded and wired in accordance with
local codes or, in the absence of local codes,
with the National Electrical Code, ANSI/NFPA
70 - latest edition, or the Canadian Electrical
Code, CSA C22.1 - latest edition.
These appliances are designed to operate on
natural or propane gas only. The use of other
fuels or combination of fuels will degrade the performance of this system and may be dangerous.
The system is switchable between standing
and intermittent pilot modes. External electrical power is required to operate these units.
If the system operates on line voltage, four “AA”
batteries (in receiver) can be used as a backup
in case of a power outage.
These models come standard with a remotely
modulated gas valve. The included transmitter
remotely controls flame appearance and heat
output (manual gas valve adjustment is not
possible).
Inputs and Efficiencies
Inputs
Gas Type (Fireplace Model)
Inputs (BTU/hr)
Natural Gas (LSM40ST-N)
40,000 to 60,000
Liquid Propane (LSM40ST-P) 43,500 to 56,000
Table 1A
EFFICIENCIES
Gas Type (Fireplace Model)
AFUE
EnerGuide
Natural Gas (LSM40ST-N)
68%
67%
Liquid Propane (LSM40ST-P)
70%
67%
Table 1B
Gas Fireplace Energy Efficiency Rating
Based on CSA P.4.1-02
Gas Supply Pressure Requirements
Inlet and manifold gas supply pressure requirements for these appliances are listed in Tables
2 and 3.
Inlet Gas Supply Pressure (all models)
Fuel #
Minimum
Maximum
Natural Gas
5.0" WC
(1.24 kPa)
10.5" WC
(2.61 kPa)
Propane
11.0" WC
(2.74 kPa)
13.0" WC
(3.23 kPa)
Table 2
Manifold Gas Supply Pressure (all models)
Fuel #
Low
High
Natural
Gas
(Lo) 1.6" WC
(0.4 kPa)
(Hi) 3.5" WC
(0.87 kPa)
Propane
(Lo) 6.3" WC
(1.57 kPa)
(Hi) 10.0" WC
(2.49 kPa)
Table 3
(Continued on next page)
3
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Gas Supply Pressure Requirements
Orifice Sizes
(continued)
Sea Level To High Altitude (All Models)
Test gauge connections are provided on the
front of the electronic gas control valve (identified IN for the inlet and OUT for the manifold
side).
These appliances are tested and approved
for installation at elevations of 0–4500 feet
(0– 1372 meters) above sea level using the
standard burner orifice sizes (marked with an
asterisk [*] in Table 4). For elevations above
4500 feet, contact your gas supplier or qualified
service technician.
The control valves have a 3/8" (10 mm) NPT
thread inlet and outlet side of the valve. Refer
to Figure 1.
Propane tanks are at pressures that will cause
damage to valve components. Verify that the
tanks have step-down regulators to reduce the
pressure to safe levels.
These appliances must not be connected to a
chimney or flue serving a separate solid fuel
burning appliance.
These appliances must be isolated from
the gas supply piping system (by closing
their individual manual shut-off valve)
during any pressure testing of the gas
supply piping system at test pressures
equal to or less than 1/2 psig (3.5 kPa).
These appliances and their individual
shut-off valves must be disconnected
from the gas supply piping system
during any pressure testing of that
system at pressures greater than 1/2
psig (3.5 kPa).
Deration
At higher elevations, the amount of BTU fuel
value delivered must be reduced by either:
• using gas that has been derated by the gas
company; or
• changing the burner orifice to a smaller size
as regulated by the local authorities having
jurisdiction and by the (USA) National Fuel
Gas Code NFPA 54/ANSI Z223.1 - latest
edition or, in Canada, the CAN/CSA-B149.1
codes - latest edition.
Install the appliance according to the regulations
of the local authorities having jurisdiction and,
in the USA, the National Fuel Gas Code NFPA
54 / ANSI Z223.1 - latest edition or , in Canada,
the CAN/CSA-B149.1- latest edition.
NOTE: Flame appearance will diminish
4% per thousand feet.
Burner Orifice Sizes
Elevation 0 – 4500 feet (0 – 1372 meters)
Natural Gas
Drill size (inches)
#32 (0.116")*
H8002 •
#52 (0.0635")*
H8003 •
Table 4
Green Wire
(From DFC Wire
Harness)
Manifold (Out)
Test Port
Line (In) Test Port
Propane
Drill size (inches)
* Standard size installed at factory.
• Part/Catalog Number.
Massachusetts Horizontal Vent
Requirements
In the Commonwealth of Massachusetts, horizontal terminations installed less than seven
(7) feet above the finished grade must comply
with the following additional requirements:
• A hard-wired carbon monoxide detector
with an alarm and battery back-up must be
installed on the floor level where the gas
fireplace is installed. The carbon monoxide
detector must comply with NFPA 720, be
ANSI/UL 2034 listed and be ISA certified.
• A metal or plastic identification plate must
be permanently mounted to the exterior of
the building at a minimum height of eight (8)
feet above grade and be directly in line with
the horizontal termination. The sign must
read, in print size no less than one-half (1/2)
inch in size, GAS VENT DIRECTLY BELOW.
KEEP CLEAR OF ALL OBSTRUCTIONS.
New York City, New York (MEA)
See valve diagram in Figure 1.
Installation of these fireplaces is approved for
installation in New York City, NY.
Connect GTMS
Wire Harness
Pressure
Regulator
Tower
Yellow Ground Wire
(From DFC Wire
Harness)
Inlet
3/8" NPT
4
These fireplaces are approved for installation in
the US state of Massachusetts if the following
additional requirements are met:
• Install this appliance in accordance with
Massachusetts Rules and Regulations 248
C.M.R.
• Installation and repair must be done by a
plumber or gas fitter licensed in the Commonwealth of Massachusetts.
• The flexible gas line connector used shall
not exceed 36 inches (92 centimeters) in
length.
• The individual manual shut-off must be a
T-handle type valve.
Gas Valve Diagram
Outlet
3/8" NPT
Orange Wire
(from DFC Wire
Harness)
Requirements for the
Commonwealth of Massachusetts
Figure 1: SIT Proflame Valve
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Cold Climate Insulation
For cold climate installations, seal all cracks
around the appliance with noncombustible
material and wherever cold air could enter the
room. If the floor is above ground level, it is
especially important to insulate outside chase
cavity between studs and under the floor on
which the appliance rests. Gas line holes and
other openings should be caulked or stuffed
with unfaced fiberglass insulation.
If the fireplace is being installed on a cement
slab in cold climates, a sheet of plywood or
other raised platform can be placed underneath to prevent cold transfer to the fireplace
and into the room. It also helps to sheetrock
inside surfaces and tape for maximum air
tightness and caulk firestops.
MANUFACTURED HOME
REQUIREMENTS
This appliance may be installed in an aftermarket, permanently located, manufactured
home and must be installed in accordance
with the manufacturer's instructions and the
Manufactured Home Construction and Safety
Standard, Title 24 CFR, Part 3280, in the
United States, or the Standard for Installation
in Mobile Homes, CAN/CSA Z240 MH Series,
in Canada.
Cet appareil peut être installé cómme
du matéri-el d'origine dans une maison
préfabriquée (É.U. seulement) ou mobile
et doit être installé selon les instructions
du fabricant et conformément à la norme
Manufactured Home Constructions and
Safety, Title 24 CFR, Part 3200 aux Unis
ou à la norme Can/CSA-Z240 Série MM,
Maisons mobiles au Canada.
This appliance is only for use with the type
of gas indicated on the rating plate. This appliance is not convertible for use with other
gases, unless a certified kit is used.
Cet appareil doit être utilisé uniquement
avec le type de gaz indiqué sur la plaque
signalétique. Cet appareil ne peut être converti à d'autres gaz, sauf si une trousse de
conversion est utilisée.
Outdoors
Indoors
(Top View)
Drywall
Top of Fireplace
Opening
When unit is installed with one side flush with a wall, the wall on
other side of unit must not extend beyond front edge of unit.
Figure 2: Typical Installation/Locations
LOCATION
In selecting the location, the aesthetic and
functional use of the appliance are primary
concerns; however, vent system routing to
the exterior and access to the fuel supply are
also important.
CAUTION: Due to high temperatures, the appliance should be located out of traffic and
away from furniture and draperies (Figure 2).
AVERTISSEMENT : En raison des températures élevées, l’appareil devrait
être installé dans un endroit où il y a peu
de circulation et loin du mobilier et des
tentures (Figure 2).
Be aware that this is a heat-producing appliance. Objects placed above the unit are
exposed to elevated temperatures.
Do not insulate the space between the appliance and the area above it.
The appliance should be mounted on a fully
supported base extending the full width and
depth of the unit. The appliance may be located
on or near conventional construction materials.
However, if installed on combustible materials,
(such as carpeting or vinyl tile), a metal or
wood barrier covering the entire bottom surface
must be used.
The location also should be free of electrical,
plumbing, or other heating/air conditioning
ducting.
CAUTION: Ensure that the cross members
are not cut or weakened during installation.
The structural integrity of the manufactured
home floor, wall, and ceiling / roof must be
maintained.
CAUTION: This appliance must be grounded
to the chassis of the manufactured home
in accordance with local codes or in the
absence of local codes, with the National
Electrical Code ANSI / NFPA 70 - latest edition or the Canadian Electrical Code CSA
C22.1 - latest edition.
5
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
VENT TERMINATION
CLEARANCES
These instructions should be used as a guideline and do not supersede local codes in any
way. Install venting according to local codes,
these instructions, the current National Fuel
Gas Code (ANSI-Z223.1) in the USA or the current standards of CAN/CSA-B149.1 in Canada.
Vertical Vent Termination Clearances
Terminate multiple vent terminations according to the installation codes listed above. Also
see Figure 3A.
Terminate single vent caps relative to building
components as shown in Figure 3B.
TERMINATION HEIGHTS FOR VENTS ABOVE
FLAT OR SLOPED ROOFS
Horizontal Overhang
2 FT
MIN.
2 FT MIN.
Lowest
Discharge
Opening
Vent
Termination
Storm Collar
Vertical
Wall
H*
X
12
Flashing
Roof Pitch is X/12
12 in
(305 mm)
minimum
Termination Heights for Vents
Above Flat or Sloped Roofs
(Ref. NFPA 54 / ANSI Z223.1)
Roof Pitch
*Feet
*Meters
Flat to 6/12
1.0
0.3
6/12 to 7/12
1.25
0.38
7/12 to 8/12
1.5
0.46
8/12 to 9/12
2.0
0.61
9/12 to 10/12
2.5
0.76
10/12 to 11/12
3.25
0.99
*H = MINIMUM HEIGHT FROM ROOF TO11/12 to 12/12
LOWEST DISCHARGE OPENING OF VENT
4.0
1.22
12/12 to 14/12
5.0
1.52
14/12 to 16/12
6.0
1.83
16/12 to 18/12
7.0
2.13
18/12 to 20/12
7.5
2.29
20/12 to 21/12
8.0
2.44
1 inch (25.4 mm) Minimum
Clearance to Combustibles
Concentric
Vent Pipe
Vent/air intake termination clearances
above the high side of an angled roof
are listed in the table below.
*H = minimum height from roof to lowest
discharge opening of vent.
Figure 3B: Vertical Vent Termination Clearances
Horizontal Vent Termination Clearances
Figure 3A : Multiple Terminations
The horizontal vent termination must have a minimum of 3 in (76 mm) clearance to any overhead
combustible projection of 2-1/2 in (64 mm) or less (see Figure 4). For projections exceeding
2-1/2 in (64 mm), see Figure 4. For additional vent location restrictions refer to Figure 5 on Page 7.
Combustible
Projection
extending more
than 2.5 inches
Combustible
Projection
extending up
to 2.5 inches
24 in
(610 mm)
3 in
(76 mm)
Horizontal Termination Kit
Horizontal Vent Termination Clearances
Side Elevation View
Ventilated or Unventilated Soffit
For recess allowances of square horizontal termination into exterior walls,
see Figure 30 on Page 20.
Figure 4
6
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
EXTERIOR HORIZONTAL VENT TERMINATION CLEARANCE REQUIREMENTS
NOTE:
•Local codes or regulations may require
different clearances.
• Location of vent termination
VentNOT
terminal
V =must
interfere with access to electrical service.
= Area terminal NOT permitted
V = Vent terminal
V = Vent Xterminal
= Air supply inlet
= Area terminal NOT permitted
= Area
terminal
NOT (12"
permitted
= 9" U.S.
Canada)
X = Air supply inlet
D Exterior Wall
D
36"
G
D
(91.4 cm)
Center Line of
Horizontal
36"
Termination
36" (91.4 cm)
(91.4 cm)
V
G
A
Ventilated
Soffit
V
Inside Corner
A
G
V
[DETAIL]
A
X = Air supply inlet
H = 9" U.S. (12" Canada)
Inside Corner
[DETAIL]
See Item “D” in table below.
V
V
L
B L
B
V
F
B
F
L
V
V
Operable
Window
Fixed Closed
Window
H
H
B
Operable Operable
Window
V
Window
B
Fixed ClosedC
F Fixed Closed
V
V
V
Window Window
B C
C
V
V
C V B
V V
A
C
C
B
B
C
V
B
C
A
A
C
C
CC
B
BB
= 9" U.S. (12" Canada)
X
X
J
B
J
D
X
D
B
I
V
I
V
V
X
K
X
K
V
X
K
Minimum Clearances
Clearance Description
US Installation 
Canadian Installation 
A = Clearance above grade, veranda, porch,
deck, or balcony.
18 in (46 cm) 
18 in (46 cm) 
B = Clearance to window or door that may be
opened.
6 in (15.2 cm) for appliances < 10,000 BTU/hr (3kW);
9 in (23 cm) for appliances > 10,000 BTU/hr (3kW)
and < 50,000 BTU/hr (15kW);
12 in (30 cm) for appliances > 50,000 BTU/hr (15kW).
6 in (15.2 cm) for appliances < 10,000 BTU/hr (3kW);
12 in (30 cm) for appliances > 10,000 BTU/hr (3kW)
and < 100,000 BTU/hr (30kW);
36 in (91.4 cm) for appliances > 100,000 BTU/hr (30kW).
C = Clearance to permanently closed window.
9 in (229 mm) recommended to prevent window
condensation.
12 in (305 mm) recommended to prevent window
condensation.
D =Vertical clearance to ventilated soffit
located above the terminal within a
horizontal distance of 36 in (91.4 cm)
from center line of terminal.
24 in (61 cm)
24 in (61 cm)
E = Clearance to unventilated soffit.
24 in (61 cm)
24 in (61 cm)
F = Clearance to outside corner.
5 in (12.7 cm)
5 in (12.7 cm)
G =Clearance to inside corner.
24 in (61 cm)
36 in (91.4 cm)
H =Clearance to each inside of center line
3 ft (91.4 cm) within a height of 15 ft above the
extended above meter/regulator assembly.
meter/regulator assembly. 
3 ft (91.4 cm) within a height of 15 ft above the
meter/regulator assembly. 
I = Clearance to service regulator vent outlet.
3 ft (91.4 cm) 
3 ft (91.4 cm) 
J = Clearance to non-mechanical air supply
inlet to building or combustion air inlet to
any other appliance.
6 in (15.2 cm) for appliances < 10,000 BTU/hr (3kW);
9 in (23 cm) for appliances > 10,000 BTU/hr (3kW)
and < 50,000 BTU/hr (15kW);
12 in (30 cm) for appliances > 50,000 BTU/hr (15kW).
6 in (15.2 cm) for appliances < 10,000 BTU/hr (3kW);
12 in (30 cm) for appliances > 10,000 BTU/hr (3kW)
and < 100,000 BTU/hr (30kW);
36 in (91.4 cm) for appliances > 100,000 BTU/hr (30kW).
K = Clearance to mechanical air supply inlet.
3 ft (91.4 cm) above, if within 10 ft (3 m) horizontally. 
6 ft (1.83 m) 
L = Clearance above paved sidewalk or paved
driveway located on public property.
7 ft (2.13 m) 
7 ft (2.13 m) 
M =Clearance under veranda, porch, deck, or
balcony.
18 in (46.0 cm)  
18 in (46.0 cm) 




In accordance with the current ANSI Z223.1 / NFPA 54 National Fuel Codes (latest editions).
In accordance with the current CAN/CSA-B149.1 Installation Code (latest editions).
A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single-family dwellings and serves both dwellings.
Only permitted if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor.
Figure 5
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
E
V
V
M
M I
D
E
M
J
E
7
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Hearth Extensions (OPTIONAL)
Optional Outdoor Hearth Extension
Note: Hearth extensions are not required with this appliance.
All outdoor hearth material (combustible and non-combustible) must
be installed a minimum of 6" (152 mm) below the base of the fireplace
(see Figure 7 ).
Optional Indoor Hearth Extension
Combustible indoor hearth material may only be installed at or below
the base of the fireplace (see Figures 6 and 7).
Non-combustible indoor hearth material may be installed above the base
of the fireplace and may butt against the front face of the fireplace (see
Figures 6 and 7).
Also note the following:
Also note the following:
• For vertical installation clearances to combustible outdoor mantels and
overhangs, see Page 32 and the instructions provided in the Outdoor
Installation Kit (required for all outdoor installations; see Page 34).
• Non-combustible outdoor mantels and overhangs may be installed at
any height above the appliance opening.
• Combustible material may project beyond the sides of the fireplace
opening, as long as it is within the shaded area shown in Figure 10
on Page 9.
• Vertical installation clearances to combustible mantels vary according
to the depth of the mantel (see Figure 9 on Page 9).
• Non-combustible mantels may be installed at any height above the
appliance opening.
Indoor
Side
Finish combustible material
must be installed at or below
base of fireplace.
Finish non-combustible material may
butt against front face of fireplace.
Also see Figure 7.
Floor
Panel
Figure 6: Optional Indoor Hearth Extension
Front Face
of Fireplace
Fireplace
(side view)
Outdoor
Side
6" (152 mm)
Indoor hearth extension:
minimum
Finish combustible material must be
installed at or below base of fireplace.
Finish non-combustible material may be
installed above base of fireplace and may
butt against front face of fireplace.
Outdoor hearth extension:
All finish hearth material (combustible
and non-combustible) must be at least
6" (152 mm) below base of fireplace.
Figure 7: Optional Indoor and Outdoor Hearth Extensions
8
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
MINIMUM CLEARANCES TO COMBUSTIBLES
Appliance and Vent Clearances
The appliance is approved with zero clearance to combustible materials
on both sides (as detailed in Table 5), with the following exceptions:
Do NOT insulate space between
appliance and area above it.
Combustible
Enclosure/Shelf
•When the unit is installed with one side flush with a wall, the wall on the
other side of the unit must not extend beyond the front edge of the unit.
•In addition, when the unit is recessed, the side walls surrounding the
unit must not extend beyond the front edge of the unit (see Figure 2
on Page 5).
MINIMUM CLEARANCES TO COMBUSTIBLES 
Back / Sides
0 in (0 mm) Spacers 
Top Spacers
0 in (0 mm)
Floor
0 in (0 mm)
Unit Bottom to Ceiling
72.0 in (1829 mm)
Vertical Vent Pipe
1.0 in (25.4 mm)
Horizontal Vent Pipe
Top: 4.0 in (102 mm) 
Sides: 1.0 in (25.4 mm)
Bottom: 1.0 in (25.4 mm)
~
(102 mm)
IMPORTANT!
91.5" (2324 mm)
minimum
Indoor/Outdoor
90" (2287 mm)
minimum
Indoor/Outdoor
Min. 4"
Min. clearance to
combustibles above any
horizontal vent component
is 4" (102 mm).
Top of
Fireplace
2x4
Figure 8: Min. Height of Combustible Enclosure
SERVICE CLEARANCES
3 ft (0.9 m)
Table 5

4" (102 mm) above any horizontal/inclined vent component.
See Step 1 ("FRAMING") on Page 10 for clearance requirements to
nailing flanges on each side of unit and any adjacent screw heads.
The appliance should be mounted on a fully supported base extending
the full width and depth of the unit. The appliance may be located on
or near conventional construction materials; however, if installed on
combustible materials, such as carpeting, vinyl tile, etc., a metal or wood
barrier covering the entire bottom surface must be used.
Min. Height of Combustible Enclosure
To provide for the lowest possible combustible enclosure (or shelf)
surface, the venting should be routed in a way to minimize obstructions
to the space above the appliance. Do not insulate the space between the
appliance and the area above it (see Figure 8).
Wall Finishes / Surrounds / Mantels
Distance from top of appliance
to bottom of mantel
Front
~
Min. 2 ft vertical
vent section
and one 90-degree
elbow required
Mantel Depth
17 (432)
15 (381)
13 (330)
11 (279)
9 (229)
7 (178)
Side View
12
(305)
8
(203)
10
(254)
Inches
(millimeters)
4
(102)
6
(152)
2
(51)
Top of Appliance
Figure 9: Mantel Clearances
Minimum Distance to Unprotected Side Wall
Note: Combustible wall finish materials and/or surround materials must
not be allowed to encroach the area defined by the appliance front faces
(black sheet metal). Never allow combustible materials to be positioned
in front of or overlapping the appliance face. See Pages 31 and 32.
At 14" minimum
side wall clearance,
a combustible
wall can project
to any length.
Non-combustible materials, such as surrounds and other appliance trim,
may be installed on the appliance front face with these exceptions: they
must not cover any portion of the removable glass panel.
At 8-1/4" side
wall clearance,
a combustible
wall can project
12" maximum.
Top View of Fireplace
0.5"
(13 mm)
Gray area
is “safe
zone”
Vertical installation clearances to combustible mantels vary according
to the depth of the mantel (see Figure 9). Mantels constructed of noncombustible materials may be installed at any height above the appliance
opening.
45°
5 in
(127 mm)
12 in
(305 mm)
Note: Use high-temperature paint (rated 175°F or higher) on the underside of the mantel.
17 in
(432 mm)
14"
(356 mm)
8.25"
(209 mm)
Figure 10: Side Wall Clearances
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Protected wall
shown in white
Combustible materials
are allowed in gray “safe
zone” illustrated here.
Combustible walls are
shown in black.
Protected wall is shown
in white.
Combustible material
may project beyond
the side of the fireplace
opening if it is within
the gray "safe zone"
illustrated here.
9
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
PRE-INSTALLATION STEPS
The appliance is shipped with all gas controls
and components installed and pre-wired.
1. Remove the shipping carton, exposing the
front glass door on the control side.
2. Using a Phillips screwdriver, unfasten two
(2) screws located at the top of the glass
frame (see Figure 50 on Page 29). Tilt the
top of the glass frame away from the unit.
Lift it carefully off the bottom door track
and set the door aside, protecting it from
inadvertent damage.
WARNING
Failure to position the parts in
accordance with these diagrams
or failure to use only parts specifically approved with this appliance
may result in property damage or
personal injury.
AVERTISSEMENT
Risque de dommages ou de
blessures si les pièces ne sont
pas installées conformément à
ces schémas et ou si des pièces
autres que celles spécifiquement
approuvées avec cet appareil sont
utilisées.
TYPICAL INSTALLATION
SEQUENCE
The typical sequence of installation is outlined
below.
Note: Each installation is unique and
may result in variations to the steps
described herein.
See the page numbers referenced in the following steps for detailed procedures.
Step 1. FRAMING (Page 10): Construct
appliance framing. Position
appliance within framing; and
secure with nailing brackets.
Step 2. ROUTE GAS LINE (Page 13):
Route gas supply line to right side
(when viewed from control side of
appliance).
Step 3. INSTALL VENT SYSTEM (Page 14):
install vent system and exterior
termination.
Step 4. FIELD WIRING (Page 23): Connect
120 Vac electrical power to the
appliance receptacle.
Step 5. REMOVE GLASS DOOR ASSEMBLY
(Page 23).
DETAILED INSTALLATION STEPS
Step 1. FRAMING
Frame these appliances as illustrated in Figure
12 on Page 11. All framing details must allow
for a minimum clearance to combustible framing members as shown in Table 5 and Figures
8–10 on Page 9.
If the appliance is to be elevated above floor
level, a solid continuous platform must be
constructed below the appliance.
Headers may be in direct contact with the
appliance top spacers but must not be supported by them or notched to fit around them.
All construction above the appliance must be
self-supporting, DO NOT use the appliance for
structural support.
Secure the fireplace to the side framing members using the unit's nailing flanges — one
top and bottom on each side of the fireplace
front (see Figure 11). Use 8d nails or their
equivalent.
Securing Unit to Framing
by Nailing Flanges
Use Top Flange for
1/2” Thick Drywall
Step 6. CONNECT GAS LINE(Page 24):
Make connection to gas supply.
Front of Fireplace
Step 7. INSTALL FIREBOX LINER PANEL
KIT (Page 25).
Use Center Flange
for Flush Mount
Step 8. VERIFY APPLIANCE OPERATION (Page 25).
Step 9. INSTALL VOLCANIC STONE,
GLOWING EMBERS, AND LOGS
(Page 26).
Step 10.INSTALL GLASS DOORS, MESH
PULL SCREENS, AND MODESTY
PANEL (Page 29).
Step 11.BURNER ADJUSTMENTS (Page
30): Adjust burner air shutter to
ensure proper flame appearance.
FINISHING REQUIREMENTS (Page 31).
Step 12.ATTACHING SAFETY-INOPERATION WARNINGS (Page 33).
Use Bottom Flange for
5/8” Thick Drywall
Left Side Front Corner of Fireplace Shown
(Same requirements for right side)
Note: The nailing flanges, combustible
members and screw heads in areas directly
adjacent to the nailing flanges are EXEMPT
from the 1/2-inch clearance to combustible
requirements for the firebox outer wrapper.
Combustible framing may be in direct
contact with the nailing flanges and may
be located closer than 1/2 inch from screw
heads and the firebox wrapper in areas
adjacent to the nailing flanges. Frame the
opening to the exact dimensions specified
in the framing details in these Installation
Instructions.
Figure 11
10
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Framing SPECIFICATIONS
Framing should be constructions of 2x4 or larger lumber.
LSM40ST
A
B
C
D
E
in
52-1/16
47-5/16
75-1/2
26-5/16
6
(mm)
(1322)
(1202)
(1918)
(668)
(152)
 Dimension B is from fireplace base to top framing member.
 Dimension C is from fireplace base to centerline of horizontal vent pipe.
Minimum vent framing: 2 ft vertical vent and one 90° elbow. For other
venting configurations, see Step 3, INSTALL VENTING SYSTEM.
 1/2-inch board for platform (shown in gray).
 Dimension E is a 6-inch clearance from fireplace base to outdoor
surface (e.g., deck, patio, lanai) that is required as a moisture barrier
(not a combustible clearance) on outdoor side only.
13
(330)
13
(330)
16
(406)
16
(406)
Inches
(millimeters)
6-1/2
(165)
Inches
(millimeters)
6-1/2
(165)
C
C
B
B

D
D
1-1/2
(38)
~
A
A
INDOOR SIDE
t
r
doo
Ou
ce
rfa
Su
,
eck
,d
g.
(e.
io
pat
)
nai
, la
E
OUTDOOR SIDE*
*For indoor/outdoor installations, the control side
of the fireplace must be installed on the indoor side.
Figure 12
11
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
FIREPLACE DIMENSIONS
(shown with Outdoor Kit installed)
FIREPLACE COLLAR AND Vent Size
Fireplace Vent Collar and Vent Pipe (Coaxial DV)
8" Inner / 11" Outer
NOTE: All venting/termination systems (vertical and horizontal)
require installation of the provided Vent Restrictor. See Page 14
for details.
Fireplace Vent Collar
8" Inner / 11" Outer
25-9/32
(642)
inches
(millimeters)
13-3/32
(333)
7-5/16
5-13/32
(186)
(137)
Top View
27-7/16
(697)
26-3/16
inches
(millimeters)
(665)
inches
34-3/4
(millimeters)
(883)
5-3/32
3-15/32
(130)
12-5/16
(88)
(313)
41-1/2
46-19/32
(1184)
(1054)
29-19/32
7 (178)
(752)
33-3/4
(857)
Gas Inlet
19-17/32
Control Switch
Wires Knock-Out
J-Box
(496)
50-1/2
(1283)
Left Side View
Figure 13
Front View (opposite valve access side)
Fireplace Dimensions
(shown with Outdoor Kit installed)
12
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Step 2. RoutE Gas Line
NOTICE: For indoor/outdoor installations,
the CONTROL SIDE of the fireplace must
be installed on the INDOOR side.
Route a 1/2" (13 mm) gas line along the inside
of the right side framing as shown in Figures 14
and 15. Gas lines must be routed, constructed
and made of materials that are in strict accordance with local codes and regulations.
All appliances are factory-equipped with a
flexible gas line connector and 1/2-inch shutoff
valve (see Step 6 on Page 24).
The incoming gas line should be piped into
the valve compartment and connected in one
of the two methods as shown in Figure 36 on
Page 24.
19-1/2"
(495 mm)
7”
(178 mm)
Right Side Front Corner
(Valve Side) Of Fireplace Framing
Figure 14: INDOOR / INDOOR
Proper Sizing of Gas Line
Notes:
Properly size and route the gas supply line
from the supply regulator to the area where the
appliance is to be installed per requirements
outlined in the National Fuel Gas Code, NFPA
54 - latest edition (USA) or CAN/CSA-B149.1
- latest edition (Canada).
• All appliances are factory-equipped with
a flexible gas line connector and 1/2-inch
shutoff valve (see Figure 36 on Page 24).
Never use galvanized or plastic pipe. Refer to
Table 6 for proper sizing of the gas supply line,
if black iron pipe is being used. Gas lines must
be routed, constructed and made of materials
that are in strict accordance with local codes
and regulations.
IMPORTANT: It is critical that a licensed
installer perform this step strictly per
NFPA.
We recommend that a qualified, licensed
plumber or gas fitter be hired to correctly size
and route the gas supply line to the appliance.
Installing a gas supply line from the fuel supply
to the appliance involves numerous considerations of materials, protection, sizing, locations, controls, pressure, sediment, and more.
Certainly no one unfamiliar and unqualified
should attempt sizing or installing gas piping.
Schedule 40, Black Iron Pipe
Inside Diameter (Inches)
Schedule 40 Pipe
Length (feet)
Natural
Gas
Propane
Gas
0-10
1/2
3/8
10-40
1/2
1/2
40-100
1/2
1/2
100-150
3/4
1/2
150-200
3/4
1/2
Table 6
• See Massachusetts Requirements on Page
4 for additional requirements for installations in the state of Massachusetts in the
USA.
• The gas supply line should not be connected
to the appliance until Step 6 (Page 24).
• A pipe joint compound rated for gas should
be used on the threaded joints. Ensure
propane-resistant compounds are used in
propane applications. Be very careful that
the pipe compound does not get inside the
pipe.
• Sediment Trap: It is recommended to install
a sediment trap in the supply line as close as
possible to the appliance (see Figure 36 on
Page 24). Appliances using propane should
have a sediment trap at the base of the tank.
• Check with local building official for local
code requirements (such as whether belowgrade penetrations of the gas line allowed,
etc.).
IMPORTANT NOTE REGARDING
PROPANE INSTALLATIONS
Using a propane tank smaller than
100 lbs may create pressure loss and
insufficient fuel delivery, which can
cause sooting, severe delayed ignition,
or other malfunctions (ref. NPFA 58).
Any damage as a result of insufficient
tank size or other improper installation is
NOT covered under the limited warranty.
1-1/2”
(38 mm)
7”
(178 mm)
19-1/2"
(495 mm)
Right Side Front Corner
(Valve Side) Of Fireplace Framing
Figure 15: INDOOR / OUTDOOR
13
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Step 3. Install Vent System
General Information
The vent system may not service multiple appliances and must never be connected to a flue
serving a solid fuel burning appliance.
These instructions should be used as a
guideline and do not supersede local codes
in any way. Install venting according to local codes, these instructions, the current
National Fuel Gas Code (ANSI-Z223.1) in
the USA or the current standards of CAN/
CSA-B149.1 in Canada.
The vent pipe is tested to be run inside an
enclosed wall (such as a chase). There is no
requirement for inspection openings in the enclosing wall at any of the joints in the vent pipe.
Note: When possible, install the vent
restrictor through the top of the appliance
vent outlet BEFORE installing the vent
system. (It is possible to install the vent
restrictor from inside the firebox after vent
system installation; however, doing so
requires removing the firebox baffle.)
Vent Restrictor Assembly and
Installation
Vent Termination
(Vertical or Horizontal)
All vent systems require installation of a vent
restrictor. A vent restrictor kit is provided with
the fireplace (packaged inside the firebox) and
includes one base, two wings, and four screws
(see Figure 16A).
With the appliance secured in framing,
determine whether to terminate the venting
vertically (through the roof) or horizontally
(through the wall).
Ensure clearances are in accordance with
local installation codes and the requirements
of the gas supplier.
Dégagement conforme aux codes d'in­
stalla­tion locaux et aux exigences du
foumisseunde gaz.
Use only approved venting components. See
“Approved Vent Components” on Page 2.
These fireplaces must be vented
directly to the outside.
Vent Restrictor Kit
1.Assemble the vent restrictor ­components
according to the type of termination and
length of vent run, as shown in Figures 16B
and 16C.
2.Install the vent restrictor in the appliance
top flue outlet, as shown in Figure 16D. The
vent restrictor is held in place by friction
only.
Vent Restrictor Assembly for
Horizontal Termination Systems
For systems with horizontal
termination, use only the vent
restrictor base.
• For Vertical (Roof) Termination Systems,
see Pages 15–18.
• For Horizontal (Wall) Termination Systems,
see Pages 19–22.
See Page 34 for a list of
approved venting components.
Vent Restrictor Assembly for Vertical Termination Systems
For systems with vertical termination, use the four provided
screws to attach the two wings to the base in the applicable
position based on length of vertical run, as shown below.
Assembly for vertical termination with 6 –10 ft vertical runs:
(1) Vent Restrictor Base
(2) Wings
(4) Screws
Figure 16A
Figure 16B
Vent Restrictor Installation
Assembly for vertical termination with 11 – 40 ft vertical runs:
Applicable Vent Restrictor
Assembly (per Figures 16B
and 16C)
Inner Collar
~
Assembly for vertical termination with 41 – 60 ft vertical runs:
~
Appliance Vent Outlet
Install applicable vent restrictor assembly (per Figures 16B and 16C)
into inner collar of appliance vent outlet.
Note: The vent restrictor is held in place by friction only.
14
Figure 16D
Figure 16C
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Vertical (Roof) Termination
Systems
This section includes configurations for vertical
(roof) termination systems with either straight
vertical venting (see below and Page 18) and
offset vertical venting (see Pages 16–18).
Secure Vent™ rigid vent pipe and termination
components are shown in the figures.
The tables on Page 18 summarize each system’s minimum and maximum vertical and
horizontal length values.
For vertical (roof) termination, the minimum
vent height above the roof and/or adjacent
walls is specified in ANSI Z223.1, latest edition (in Canada, the current CAN/CSA-B149.1
installation code) and by major building
codes. Always consult your local codes for
specific requirements. A general guide to
follow is the Gas Vent Rule (see Figure 3B
on Page 6).
Vertical Termination System
with Straight Vertical Venting
Note: If not already done, install the provided vent restrictor before proceeding
(see Page 14).
Determine the number of straight vent sections required. Available straight vent sections (and their effective lengths) are listed in
Table 7, below. See Page 34 for all venting
components.
Plan the vent lengths so a joint does not ­occur
at the intersection of ceiling or roof joists.
Refer to the “VENT SECTION LENGTHS”
charts at right.
Vertical Termination System
with Straight Vertical Venting
Termination
Flashing and
Storm Collar
T
O
T
A
L
Nominal Section
6
12
24
36
48
Length (inches)
Net Section
Length (inches) 4-1/2 10-1/2 22-1/2 34-1/2 46-1/2
inches
Height of Vent
Number of Vent Sections
T
O
T
A
L
inches
ft
4.5
0.375
1
0
0
0
0
Q
T
Y
1
144
12
1
0
0
0
3
Q
T
Y
4
9
0.75
2
0
0
0
0
2
150
12.5
0
1
0
0
3
4
10.5
0.875
0
1
0
0
0
1
154.5
12.875
1
1
0
0
3
5
15
1.25
1
1
0
0
2
160.5
13.375
0
2
0
0
3
5
19.5
1.625
2
1
0
0
0
0
3
172.5
14.375
0
0
0
5
0
5
21
1.75
0
2
0
0
0
2
22.5
1.875
0
0
1
0
0
1
177
14.75
1
0
0
5
0
6
25.5
2.125
1
2
0
0
0
3
31.5
2.625
0
3
0
0
0
3
34.5
2.875
0
0
0
1
0
1
37.5
43.5
3.125
1
1
1
0
0
ft
183
15.25
0
1
0
5
0
6
186
15.5
0
0
0
0
4
4
190.5
15.875
1
0
0
0
4
5
3
196.5
16.375
0
1
0
0
4
5
205.5
17.125
0
1
1
5
0
7
3.625
0
2
1
0
0
3
45
3.75
0
0
2
0
0
2
46.5
3.875
0
0
0
0
1
1
49.5
4.125
1
0
2
0
0
3
51
4.25
1
0
0
0
1
2
55.5
4.625
0
1
2
0
0
3
57
4.75
0
0
1
1
0
2
66
5.25
0
2
2
0
0
4
67.5
5.625
0
0
3
0
0
3
69
5.75
0
0
0
2
0
2
72
6
1
0
3
0
0
4
73.5
6.125
1
0
0
2
0
3
79.5
6.625
0
1
0
2
0
3
81
6.75
0
0
0
1
1
2
90
7.5
0
2
1
0
1
4
91.5
7.625
0
0
2
0
1
93
7.75
0
0
0
0
96
8
1
0
1
2
97.5
8.125
1
0
0
0
102
103.5
108
8.5
8.625
9
2
0
1
0
0
0
0
0
0
0
3
3
207
17.25
0
0
0
6
0
6
211.5
17.625
1
0
0
6
0
7
217.5
18.125
0
1
0
6
0
7
229.5
19.125
0
0
1
6
0
7
232.5
19.375
0
0
0
0
5
5
237
19.75
1
0
0
0
5
6
241.5
20.125
0
0
0
7
0
7
246
20.5
1
0
0
7
0
8
252
21
0
1
0
7
0
8
264
22
0
0
1
7
0
8
276
23
0
0
0
8
0
8
279
23.25
0
0
0
0
6
6
280.5
23.375
1
0
0
8
0
9
283.5
23.625
1
0
0
0
6
7
289.5
24.125
0
1
0
0
6
7
3
301.5
25.125
0
0
1
0
6
7
2
2
310.5
25.875
0
0
0
9
0
9
0
4
315
26.5
1
0
0
9
0
10
2
3
325.5
27.125
0
0
0
0
7
7
2
0
0
4
3
4
330
27.5
1
0
0
0
7
8
336
28
0
1
0
0
7
8
345
28.75
0
0
0
10
0
10
114
9.5
0
2
0
0
2
4
349.5
29.125
1
0
0
10
0
11
117
9.75
1
0
5
0
0
6
372
31
0
0
0
0
8
8
118.5
9.875
1
1
0
3
0
5
376.5
31.375
1
0
0
0
8
9
126
10.5
0
0
1
3
0
4
379.5
31.625
0
0
0
11
0
11
1
0
1
3
0
5
418.5
34.875
0
0
0
0
9
9
135
11.25
0
0
6
0
0
6
423
35.25
1
0
0
0
9
10
138
11.5
465
38.75
0
0
0
0
10
10
130.5 10.875
Min. 1 in (25 mm)
Clearance to
Combustibles
VENT SECTION LENGTHS
VENT SECTION LENGTHS
Nominal
Section Length
6
12
24
36
48
(inches)
Net Section 4-1/2 10-1/2 22-1/2 34-1/2 46-1/2
Length (inches)
Height of Vent
Number of Vent Sections
0
0
0
4
0
4
139.5 11.625
0
0
0
0
3
3
142.5 11.875
1
0
0
4
0
5
Firestop/Spacer
Available Straight Vent Sections
Cat. No. Model No.
Max. 60 ft
(18 m)
Min. 6 ft
(1.8 m)
Secure Vent
Vent Sections
(SV8L6, SV8L12,
SV8L24, SV8L36,
SV8L48)
Description
Effective Length
H2250
SV8L6
6 in (152 mm) Vent Section
4.5 in (114 mm)
H2251
SV8L12
12 in (305 mm) Vent Section
10.5 in (267 mm)
H2252
SV8L24
24 in (610 mm) Vent Section
22.5 in (572 mm)
H2253
SV8L36
36 in (914 mm) Vent Section
34.5 in (876 mm)
H2254
SV8L48
48 in (1219 mm) Vent Section 46.5 in (1181 mm)
Table 7
Metric
Conversion
Inches x 25.4 = mm.
Inches x 2.54 = cm.
Inches x 0.0254 = m.
See Page 34 for a list of all approved venting components.
Figure 17
15
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Vertical Termination System
with Offset Vertical Venting
Note: If not already done, install the provided vent restrictor before proceeding
(see Page 14).
Analyze the vent routing and determine the
quantities of vent sections and number of
elbows required. Refer to Vertical Termination
System Figures and Tables on Page 18 to
select the type of vertical installation desired.
Vent sections are available in net lengths of
4-1/2" (114 mm), 10-1/2" (267 mm), 22-1/2"
(572 mm), 34-1/2" (876 mm) and 46-1/2"
(1181 mm). Refer to the Vent Section Length
Chart on Page 15 for an aid in selecting length
combinations. Elbows are available in 90° and
45° configurations. See Figure 21 on Page 17
for the SV8E45 and SV8E90 elbow dimensional
specifications.
Where required, a telescopic vent section
(SV8LA) may be used to provide the installer
with an option in installing in tight and confined
spaces or where the vent run made up of fixed
length pieces develops a joint in a undesirable
location, or will not build up to the required
length. The SV8LA Telescopic Vent Section has
an effective length of from 1-1/2" (38 mm) to
6-3/4" (171 mm). The SV8LA is fitted with a
dimpled end (identical to a normal vent section
component) and a plain end with 3 pilot holes.
Slip the dimpled end over the locking channel
end of a standard SV8 vent component the
required distance and secure with three screws.
Maintain a minimum 1" (25 mm) clearance
to combustible materials for all vertical elements. Clearances for all horizontal elements
are 4" (102 mm) on top, 1" (25 mm) on sides
and 1" (25 mm) on the bottom.
A. Frame ceiling opening.
Use a plumb line from the ceiling above the
appliance to locate center of the vertical run.
Cut and/or frame an opening, 13" x 13" (330
mm x 330 mm) inside dimensions, about this
center mark (Figure 18).
Roof Framing
Min. 13 in
(330 mm)
Min. 13 in
(330 mm)
Plumb Bob
Ceiling Framing
16
Figure 18
B. Attach vent components to appliance.
D. Install firestop/spacer at ceiling.
Secure Vent™ SV8 direct-vent system components are unitized concentric pipe components
featuring positive twist lock connections (see
Figure 19).
When using Secure Vent, use SV8BF firestop/
spacer at ceiling joists. If there is living space
above the ceiling level, the firestop/spacer
must be installed on the bottom side of the
ceiling. If attic space is above the ceiling, the
firestop/spacer must be installed on the top
side of the joist.
All of the appliances covered in this document
are fitted with collars having locking inclined
channels. The dimpled end of the vent components fit over the appliance collar to create
the positive twist-lock connection.
Arrow
Align four dimples in upper vent
section with inlets of four locking
incline channels on lower vent
section or appliance collar.
Twist upper vent section clockwise
until arrows and dimples align.
Dimple
Locking
Incline
Channel
Connected Vent
Sections
Arrow
Lower Vent Section or Appliance Collar
Figure 19
To attach a vent component to the appliance
collar, align the dimpled end over the collar,
adjusting the radial alignment until the four
locking dimples are aligned with the inlet of
the four inclined channels on the collar (refer
to Figure 19). Push the vent component against
the collar until it fully engages, then twist the
component clockwise, running the dimples
down and along the incline channels until they
seat at the end of the channels.
The unitized design of the Secure Vent components will engage and seal both the inner
and outer pipe without the need for sealant or
screws. If desired, a #6 x 1/2" screw may be
used at the joint, but it is not required, as the
pipe will securely lock when twisted.
Route the vent sections through the framed
opening and secure the firestop/spacer with
8d nails or other appropriate fasteners at
each corner. When running vertical chimney
sections, remember to maintain 1" (25
mm) clearance to combustibles, framing
members, and attic or ceiling insulation.
Attic insulation shield (H3908) may be used
to obtain the required clearances indicated
here. See installation accessories on Page
34. The gap between the vent pipe and a
vertical firestop can be sealed with noncombustible caulking.
E.Support vertical vent run sections.
Note: Proper venting support is very important. The weight of the vent must not be
supported by the fireplace in any degree.
Support the vertical portion of the venting
system every 8 feet (2.4 m) above the fireplace
vent outlet.
One method of support is conventional
plumber’s tape (not provided). Secure the
plumber’s tape to the framing members with
nails or screws.
Loop the plumber’s tape around the vent,
securing the ends of the tape to the framing.
If desired, use #6 x 1/2" sheet metal screws
to secure the support straps to the vent pipe.
See Figure 20.
C. Attach vent components to each other.
Other vent sections may be added to the previously installed section in accordance with
the requirements of the vertical vent figures
and tables.
Blocking
Support Straps
(Plumber’s
Tape)
To add another vent component to a length of
vent run, align the dimpled end over the inclined
channel end of the previously installed section,
adjusting the radial alignment until the four
locking dimples are aligned with the inlets of
the four incline channels of the previous section.
Push the vent component against the previous
section until it fully engages, then twist the
component clockwise, running the dimples
down and along the incline channels until they
seat at the end of the channels. This seating
position is indicated by the alignment of the
arrow and dimple as shown in Figure 19.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Max.
8 ft (2.4 m)
0 in (0 mm)
minimum
clearance
to spacers
Figure 20
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Vertical Termination System
with Offset Vertical Venting (continued)
F. Change vent direction to horizontal/
inclined run.
H. Frame roof opening.
K. Install vertical termination.
Identify location for vent at the roof. Cut and/
or frame opening per Roof Framing Chart (see
Figure 22).
The final step involves installation of the vertical termination. Extend the vent sections to the
height as shown in “Vertical Vent Termination
Clearances” on Page 6.
At any transition to or from a horizontal/
inclined run, install the elbows (SV8E45,
SV8E90; see Figure 21) in the same manner
as the straight vent sections.
The elbows feature a twist section to allow
them to be routed about the center axis of their
initial collar section, to align with the required
direction of the next vent run element. Twist
elbow sections in a clockwise direction only,
to avoid the possibility of unlocking any previously connected vent section (see Figures
19 and 21).
6"
(153 mm)
360° Swivel Joint
(SV8E45)
45° Elbow
10"
(254 mm)
360° Swivel Joint
(SV8E90)
90° Elbow
Figure 21
G. Continue installation of horizontal/
inclined sections.
Continue with installation of the straight vent
sections in horizontal/inclined run as described in Step C. Install support straps every
3 ft (914 mm) along horizontal/inclined vent
runs using conventional plumber’s tape (see
Page 19, Figure 28).
NOTICE: It is important to install
horizontal runs on a steady, (i.e., no
“dips”), slightly positive incline of
approximately 1/4 inch rise-per-foot (20
millimeters rise-per-meter) horizontal,
in a direction away from the fireplace.
(Slightly smaller rise-per-foot run ratios
are acceptable.) Use a carpenter’s level
to measure from a constant surface, and
adjust support straps as necessary.
Note: It is important to maintain the required
clearances to combustibles: 1" (25 mm) at
all sides for all vertical runs; and 4" (102
mm) at the top, 1" (25 mm) at sides, and
1" (25 mm) at the bottom for all horizontal/
inclined runs.
C
D
Framing Dimensions for Roof
Pitch
C
D
0/12
13 in
(330 mm)
13 in
(330 mm)
6/12
13 in
(330 mm)
15-1/2 in
(394 mm)
12/12
13 in
(330 mm)
20-1/2 in
(541 mm)
The vertical termination (Figure 24) installs
in the same manner as other Secure Vent™
sections. Align the termination over the end of
the previously installed section, adjusting the
radial alignment until the four locking dimples
of the termination are aligned with the inlets of
the four incline channels of the last vent section.
Push the termination down until it fully engages,
then twist the termination clockwise, running
the dimples down and along the incline channels until they seat at the end of the channels.
Figure 22: Roof Framing
I. Install roof flashing.
Extend the vent sections through the roof
structure. Install the roof flashing over the
vent section and position such that the vent
column rises vertically (use carpenters level)
(Figure 23 ). Nail along perimeter to secure
flashing or adjust roofing to overlap the flashing edges at top and sides only and trim where
necessary. Seal the top and both sides of the
flashing with waterproof caulking.
J. Install storm collar.
Install the storm collar, supplied with the
flashing, over the vent/flashing joint (see
Figure 23). Loosen the storm collar screw.
Slide collar down until it meets the top of the
flashing. Tighten the adjusting screw. Apply
non-combustible caulking or mastic around
the circumference of the joint to provide a
water tight seal.
Flashing
Figure 24
If the vent system extends more than 5 ft (1.5
m) above the roof flashing, stabilizers may be
necessary.
Additional screws may be used at section joints
for added stability.
Guide wires may be attached to the joint for additional support on multiple joint configurations.
Storm
Storm
Collar
Collar
Figure 23
17
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
VERTICAL TERMINATION SYSTEM
FIGURES AND TABLES
Vertical Termination System with Offset Vertical Venting using Two 90-Degree Elbows
Secure Vent™ rigid vent pipe and termination
components are shown in the figures.
H
Note: Two 45-degree elbows may be used
in place of one 90-degree elbow. If using
45-degree elbows, follow the same rise-torun ratios as shown for 90-degree elbows.
Vertical Firestop/Spacer
(SV8BF)
NOTICE:
Secure Vent Vertical Firestop/Spacer
(SV8BF) must be used anywhere vent
pipe passes through a combustible
floor or ceiling. Secure Vent Horizontal
Firestop/Spacer (SV8HF4) must be used
anywhere vent pipe passes through a
combustible wall.
It is important to install horizontal runs
on a steady, (i.e., no “dips”), slightly
positive incline of approximately 1/4
inch rise-per-foot (20 millimeters
rise-per-meter) horizontal, in a direction away from the fireplace. (Slightly
smaller rise-per-foot run ratios are
acceptable.) Use a carpenter’s level to
measure from a constant surface, and
adjust support straps as necessary.
V1
H max.
V
V + V1 min.
feet
(meters)
feet
(meters)
10
(3.1)
2.5
(0.762)
15
(4.65)
3.5
(1.06)
20
(6.2)
4.5
(1.37)
*
V + V1 + H = 40 ft (12.4 m) max.
V + V1 = 11 ft (3.3 m) min.
Example: A 20-ft horizontal vent run (H + H1 )
would require 4.5 ft min. vertical vent (V + V1 ).
Vertical Termination System
with Straight Vertical Venting
*Install the provided Vent Restrictor (see Page 14).
Figure 26
Vertical Termination System with Offset Vertical Venting using Three 90-Degree Elbows
Vertical
Firestop/Spacer
(SV8BF)
V1
Ceiling
Firestop/Spacer
(SV8BF)
60 ft (18.3 m) max.
6 ft (1.83 m) min.
Horizontal Firestop/Spacer
(SV8HF4)
H
H1
V
*
*Install the provided Vent Restrictor
(see Page 14).
Figure 25
18
H + H1 max.
V + V1 min.
feet
(meters)
feet
(meters)
10
(3.1)
2.5
(0.762)
15
(4.65)
3.5
(1.06)
20
(6.2)
4.5
(1.37)
*
H + H1 = 20 ft (6.2 m) max.
V + V1 = 11 ft (3.3 m) min.
V + V1 + H + H1 = 40 ft (12.4 m) max.
Example: A 20-ft horizontal vent run (H + H1 )
would require 4.5 ft min. vertical vent (V + V1 ).
Figure 27
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
*Install the provided Vent Restrictor (see Page 14).
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Horizontal (Wall) Termination
Systems
This section includes configurations for horizontal venting systems with horizonal termination (terminates through an outside wall) (see
Figures 31–33 on Pages 21–22).
The tables on Pages 21 and 22 summarize each
system’s minimum and maximum vertical and
horizontal length values.
Note: Building codes limit or prohibit
horizontal termination in specific areas. For
location guidelines, see Figure 5 on Page 7.
Secure Vent™ pipe applications are shown in
the illustrations. Secure Vent SV8 direct-vent
system components are unitized concentric
pipe components featuring positive twist-lock
connection (see Figure 19 on Page 16). The
appliances covered in this document are fitted
with collars having locking inclined channels.
The dimpled end of the vent components fit
over the appliance collar to create the positive
twist-lock connection.
A. Plan the vent run.
Analyze the vent routing and determine the
types and quantities of sections required.
See Page 15 for a list of available straight vent
sections and their effective lengths (Table 7),
as well as “VENT SECTION LENGTHS” charts.
See Page 34 for a list of all approved venting
components.
Plan the vent lengths so that a joint does not
occur at the intersection of ceiling or roof
joists. Make allowances for elbows as indicated in Figure 21 on Page 17.
Maintain a minimum 1" (25 mm) clearance
to combustibles on the vertical sections.
Clearances for horizontal runs are 4" (102
mm) on top, 1" (25 mm) on sides, and 1"
(25 mm) at the bottom.
B. Frame exterior wall opening.
Locate the center of the vent ­outlet on the
exterior wall according to the di­m en­sions shown in Figure 12 on Page 11.
Cut and/or frame an opening 16" x 13" (406
mm x 330 mm) inside dimensions, with 10"
above center and 7" below center.
C. Frame ceiling opening.
If the vertical route is to penetrate a ceiling,
use plumb line to locate the center above the
appliance. Cut and/or frame an opening, 13" x
13" (330 mm x 330 mm) inside dimensions,
about this center (see Figure 18 on Page 16).
D. Attach vent components to appliance.
To attach a vent component to the appliance
collar, align the dimpled end over the collar,
adjusting the radial alignment until the four
locking dimples are aligned with the inlets of
the four incline channels on the collar (see
Figure 19 on Page 16).
Horizontal Termination System with Horizontal/Inclined Run
Building Support
Support Brackets
Framing
Horizontal / Inclined Run
Termination
(SV8HTS4)
SV8E90
Elbow
Vertical
Rise
Ceiling
SV8L6/12/24/36/48
Vent Sections
Vertical Firestop/
Spacer (SV8BF)
Support Bracket Spacing
every 3 ft (914 mm)
Min. 2 ft (610 mm) Vertical
Section and One 90° Elbow
Exterior
Wall
Termination
(SV8HTS4)
Support the vertical portion of the
venting system every 8 ft (2.4 m)
above the fireplace vent outlet.
Fireplace
Figure 28
Push the vent component against the collar
until it fully engages, then twist the component
clockwise, running the dimples down and along
the incline channels until they seat at the end of
the channels. The unitized design of the Secure
Vent components will engage and seal both the
inner and outer pipe elements with the same
procedure. Sealant and securing screws are
not required.
G. Support the vertical run sections.
See Step E on Page 16.
On the vertical run, support the venting system
every 8 ft (2.4 m) above the fireplace vent outlet
with field provided support straps (Plumber's
tape). Attach the straps to the vent pipe and
secure to the framing members with nails or
screws (see Figure 20 on Page 16).
E. Attach vent components to each other.
Other vent sections may be added to the previously installed section in accordance with the
requirements of the vent tables. To add another
vent component to a length of vent run, align
the dimpled end of the component over the
inclined channel end of the previously installed
section, adjusting the radial alignment until the
four locking dimples are aligned with the inlets
of the four incline channels of the previous
section. Push the vent component against the
previous section until it fully engages, then
twist the component clockwise running the
dimples down and along the incline channels
until they seat at the end of the channels. This
seating position is indicated by the alignment
of the arrow and dimple as shown in Figure
19 on Page 16.
H. Change vent direction.
At transition from or to a horizontal/inclined
run, install the SV8E45 and SV8E90 elbows in
the same manner as the straight vent sections.
The elbows feature a twist section to allow them
to be routed about the center axis of their initial
collar section to align with the required direction of the next vent run element. Twist elbow
sections in a clockwise direction only so as
to avoid the possibility of unlocking any of
the previously connected vent sections (see
Figure 19 on Page 16).
F. Install firestop/spacer at ceiling.
When using Secure Vent, use SV8BF vertical
firestop/spacer at ceiling joists. If there is ­living
space above the ceiling level, the firestop/ spacer
must be installed on the bottom side of the
ceiling. If attic space is above the ceiling, the
firestop/spacer must be installed on the top side
of the joist. Route the vent sections through the
framed opening and secure the firestop/spacer
with 8d nails or other appropriate fasteners at
each corner.
Remember to maintain 1" (25 mm) clearance
to combustibles, framing members, and attic
or ceiling insulation when running vertical
chimney sections.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
I. Continue installation of horizontal/inclined
sections.
Continue with the installation of the straight vent
sections in horizontal/inclined run as described
in Step E. Install support straps every 3 feet
(1914 mm) along horizontal/inclined vent runs
using conventional plumber’s tape.
See Figure 28.
NOTICE: It is important to install horizontal runs on a steady, (i.e., no “dips”),
slightly positive incline of approximately
1/4 inch rise-per-foot (20 millimeters
rise-per-meter) horizontal, in a direction
away from the fireplace. (Slightly smaller
rise-per-foot run ratios are acceptable.)
Use a carpenter’s level to measure from a
constant surface, and adjust support straps
as necessary.
19
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
It is important to maintain the required clearances to combustibles: 1" (25 mm) at all sides
for all vertical runs; and 4" (102 mm) at the
top, 1" (25 mm) at sides, and 1" (25 mm) at
the bottom for all horizontal/inclined runs.
Use a carpenter’s level to measure from a
constant surface and adjust the support straps
as necessary.
J. Assemble vent run to exterior wall.
If not previously measured, locate the center of
the vent at the exterior wall. Prepare an opening as described in Step B (previous page).
Assemble the vent system to point where the
terminus of the last section is within 5 in. (127
mm) to 8-1/2 in. (216 mm) inboard of the
exterior surface to which the termination is to
be attached, see Figure 30 (below) and Table
8 (Page 21).
If the terminus of the last section is not within
this distance, use the telescopic vent section
(SV8LA) as the last vent section. For wall thicknesses greater than that shown in Figure 30,
refer to Table 8 on Page 21. This table lists
the additional venting components needed (in
addition to the termination and adaptor) for a
particular range of wall thicknesses.
Firestop/Spacer (SV8HF4)
shown on exterior side of wall
4 in
(102 mm)
Adaptor
SV8RCH
1 in
(25mm)
Note: Centerline of vent piping
is NOT the same as centerline
of framed opening.
20
1 in
(25.4 mm)
6- to 48-inch Vent Section
or Telescopic Vent Section
Base of Appliance
Figure 29: Installing Square Horizontal Termination
Min. 5 in (127 mm)
wall thickness
Interior surface of finished wall
Maximum extent of vent run
sections relative to exterior
surface of framing
Siding
L. Install Firestop/Spacer at exterior wall.
When using the square termination, install
Secure Vent™ Firestop/Spacer (SV8HF4) over
the opening at the exterior side of the framing,
long side up, with the 4-inch spacer clearance
at the top as shown in Figure 29, and nail
into place.
IMPORTANT: The vent termination is hot
while in operation and for a period of time
following the use of the fireplace. Young
children should be carefully supervised
when they are in the same area as a hot
termination.
13 in
(330mm)
16 in
(406mm)
6-1/2 in
(165mm)
K. Attach termination adaptor.
Attach the adaptor (adaptor - SV8RCH - provided
with the termination) to the vent section or
telescoping vent section), or elbow as shown in
Figure 29 in the same manner as any SV vent
component (refer to Step E, previous page).
M. Install the Square Termination (SV8HTS4).
For the last step, from outside the exterior
wall, slide the collars of the termination onto
the adaptor (the outer over the outer and the
inner inside the inner) until the termination
seats against the exterior wall surface to which
it will be attached. Orient the housing of the
termination with the arrow pointed upwards.
Secure the termination to the exterior wall. The
horizontal termination must not be recessed
into the exterior wall or siding by more than
the 1-1/4" (32 mm) as shown in Figure 30.
Square
Termination
(SV8HTS4)
Max. 8-1/2 in (216 mm)
wall thickness 
Exterior Surface of Siding
Exterior Surface of Framing
5 to 8-1/2 in (127−216 mm)
Last vent section
(If necessary, use
telescopic vent
section SV8LA.)
~
Square Termination
SV8HTS4
Stucco
_________
 For wall thicknesses greater than
8-1/2 in (216 mm), see Table 8.
~
Adaptor
SV8RCH
Square Termination
SV8HTS4
Max. 1-1/4 in recess of
square termination into
exterior finishing material
Horizontal Square Termination SV8HTS4
Venting Connection and Exterior Wall Recessing
Figure 30
Horizontal terminations have been designed to perform in a wide range of weather conditions. Our terminations meet or exceed industry standards.
When selecting the locations of your horizontal terminations, do not place the termination where water from eaves and adjoining rooflines may create a heavy flow of cascading water onto the termination cap. If the cap must be placed where the possibility of
cascading water exists, it is the responsibility of the builder to direct the water away
from the termination cap by using gutters or other means.
Take care to carefully follow these installation instructions for the termination, including
the use of silicone caulking where required.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
See Table 8 as an aid in venting component selection for a particular
range of exterior wall thicknesses.
Required Venting Components (based on Exterior Wall Thickness)
when using Horizontal Square Termination Kit (SV8HTS4)
Exterior Wall Thickness
Required Components
5 to 8-1/2 in (127 to 216 mm)
• Termination Kit (SV8HTS4)
9-3/4 to 14 in (248 to 356 mm)
• Termination Kit (SV8HTS4)
• 6-in Vent Section (SV8L6)
6-3/4 to 15-1/4 in (171 to 387 mm)
• Termination Kit (SV8HTS4)
• Telescopic Section (SV8LA)
11-1/4 to 19-3/4 in (286 to 502 mm)
• Termination Kit (SV8HTS4)
• Telescopic Section (SV8LA)
• 6-in. Vent Section (SV8L6)
Table 8
HORIZONTAL TERMINATION SYSTEM Figures/Tables
Note:
• Secure Vent™ rigid vent pipe and termination components are shown
in the figures.
• Two 45-degree elbows may be used in place of one 90-degree elbow.
If using 45-degree elbows, follow the same rise-to-run ratios as shown
for 90-degree elbows.
NOTICE:
Secure Vent™ Vertical Firestop/Spacer (SV8BF) must be used
anywhere vent pipe passes through a combustible floor or ceiling.
Secure Vent Horizontal Firestop/Spacer (SV8HF4) must be used
anywhere vent pipe passes through a combustible wall.
It is important to install horizontal runs on a steady, (i.e., no
“dips”), slightly positive incline of approximately 1/4 inch riseper-foot (20 millimeters rise-per-meter) horizontal, in a direction
away from the fireplace. (Slightly smaller rise-per-foot run ratios
are acceptable.) Use a carpenter’s level to measure from a constant
surface, and adjust support straps as necessary.
Horizontal Termination System with Horizontal/Inclined Run using One 90-Degree Elbow
(elbow connection not directly at appliance)
Note: The provided vent restrictor is required in all venting systems.
See Page 14 for settings.
Table C
V Minimum
H Maximum
feet
(meters)
feet
(meters)
3.5
(1.07)
2.5
(0.762)
6.5
(1.98)
3.5
(1.07)
8.5
(2.6)
4.5
(1.37)
10.5
(3.2)
5.5
(1.68)
12.5
(3.8)
6.5
(1.98)
14.5
(4.4)
7.5
(2.3)
16.5
(5.0)
8.5
(2.6)
18.5
(5.6)
9.5
(2.9)
20
(6.0)
10
(3.0)
Example: 20 feet
of horizontal vent
run (H) requires a
minimum 10 feet of
vertical vent (V).
H
Square
Termination
(SV8HTS4)
shown
V
Horizontal Firestop/Spacer (SV8HF4)
Vertical Firestop/Spacer (SV8BF)
V + H = 40 ft (12.4 m) max.
H = 20 ft (6.2 m) max.
See Table 8 as an aid in selecting venting components
for a particular range of exterior wall thicknesses.
Figure 31
21
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
HORIZONTAL VENT FIGURES/TABLES (continued)
Horizontal Termination System with Horizontal/Inclined Run using Two 90-Degree Elbows
(Elbow connection not directly at appliance)
Note: The provided vent restrictor is required in all venting systems.
See Page 14 for settings.
Table D
Horizontal Firestop/Spacer
(SV8HF4)
H
H
1
V
Horizontal Firestop/Spacer
(SV8HF4)
Example: If 20 feet of (H+H1)
horizontal vent run is needed,
then 10 feet minimum of (V)
vertical vent will be required.
V min.
H + H1 max.
Vertical
Firestop/Spacer
(SV8BF)
feet
(meters)
feet
(meters)
3.5
(1.07)
2.5
(0.762)
6.5
(1.98)
3.5
(1.07)
8.5
(2.6)
4.5
(1.37)
10.5
(3.2)
5.5
(1.68)
12.5
(3.8)
6.5
(1.98)
14.5
(4.4)
7.5
(2.3)
16.5
(5.0)
8.5
(2.6)
18.5
(5.6)
9.5
(2.9)
20
(6.0)
10
(3.0)
V + H + H1 = 40 ft (12.4 m) max.
See Table 8 on Page 21 as an aid in selecting venting
components for a particular range of exterior wall thicknesses.
H + H1 = 20 ft (6.2 m) max.
Figure 32: Horizontal Termination with Two 90-Degree Elbows
Horizontal Termination System with Horizontal/Inclined Run using Three 90-Degree Elbows
(Elbow connection not directly at appliance)
Note: The provided vent restrictor is required in all venting systems. See Page 14 for settings.
Table E
H1
H + H1 = 20 ft (6.2 m) max.
V + V1+ H + H1 = 40 ft (12.4 m) max.
Vertical
Firestop/Spacer
(SV8BF)
V = 2.5 ft (0.762 m) min.
V + V1 = 11 ft (3.35 m) min.
Horizontal
Firestop/Spacer
(SV8HF4)
H
V1
V
Horizontal
Firestop/Spacer
(SV8HF4)
Vertical
Firestop/Spacer
(SV8BF)
See Table 8 on Page 21 as an aid in selecting venting
components for a particular range of exterior wall thicknesses.
22
Figure 33: Horizontal Termination with Three 90-Degree Elbows
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Step 4. Field Wiring
Electronic Wiring
power supply wire to the common terminal
of the outlet as shown in Figures 34 and 35.
(See Figures 34 and 35)
CAUTION: Label all wires prior to disconnection when servicing controls. Wiring
errors can cause improper and dangerous
operation.
ATTENTION: Au moment de l'entretien
des commandes, étiquetez tous les fils
avant de les débrancher. Des erreurs
de cáblage peu-vent entraîner un fonctionnement inadéquat et dangereux.
5. Connect the ground supply wire to the pigtail lead attached to outlet's green ground
screw.
Note: The electronic appliance must be
connected to the main power supply.
1. Route a 3-wire, 120 Vac, 60 Hz, 1ph power
supply to the appliance junction box.
6. Appliance-mounted ON/OFF burner control
switch (rocker switch) is factory installed.
7. After wiring is complete, replace the cover
plate.
2. Remove the electrical inlet cover plate from
the side of the unit by removing the plate's
securing screws (see Figure 13, Page 12).
3. Remove the cover plate’s knockout and then
feed the power supply wire through the
knockout opening and into the unit junction
box.
Verify proper operation after servicing.
S'assurer que l'appareil fonctionne adéquatement une fois l'entretien terminé.
Step 5. Remove GLASS DOOR
ASSEMBLY (ON control SIDE)
If not already done, remove the glass door
assembly on the control side of the fireplace
(see Page 29).
4. Connect the black power supply wire to the
power outlet’s red pigtail lead and the white
CAUTION
Green
Ground supply lead must be connected to the wire attached to the green
ground screw located on the outlet
box. See Figures 34 and 35. Failure to
do so will result in a potential safety
hazard. The appliance must be electrically grounded in accordance with
local codes or, in the absence of local
codes, the National Electrical Code,
ANSI/NFPA 70-latest edition.
White
Ground - Green
Neutral - White
120 VAC - Black
Junction Box
J-BOX / RECEPTACLE
WIRING
120V, 60HZ, 1PH
Black
Tab Intact
Tab Intact
Green
Ground
Screw
Hot
Side of
Receptacle
Neutral
Side of
Receptacle
Field Wired
Factory Wired
Figure 35: Junction Box Wiring
(See Figure 35 for detailed drawing
of ELECTRONIC
junction box / receptacle
WIRINGwiring.)
DIAGRAM FOR GRAVITY VENT FIREPLACES
B
AC/DC
Power Adaptor
Junction Box
BR
Electronic Pilot Assembly
Igniter Rod
Flame
Sensor
Hood
Y
O
Hot
Neutral
120V AC
B
Ground
B
W
Pilot
Tube
G
R
Y
Spark Wire Cable
Pilot Sensor Cable
O
G
Pilot
Ground
Wire
Proflame Valve
Electronic Modulation
Y
Wall Receiver
DFC Wire Harness 102662-01
GY
R
B
Y
BR
O
Y
Hi-Temp Sleeve
G
G
BL
Cable Harness 102661-01
Wiring Color Code
B = Black
BL = Blue
BR = Brown
G = Green
G
W
PU
BL
G
W
THIS CONNECTOR NOT
USED ON GRAVITY
VENT UNITS
GY = Gray
O= Orange
PU = Purple
W = White
R = Red
Y = Yellow
Figure 34: Electronic Wiring Diagram for Montebello Gravity Vent Fireplaces
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
PU
O
W
W
Proflame
DFC Board
Unit Mounted Rocker Switch
OFF (o) = Intermittent Pilot Mode
ON (-) = Standing Pilot Mode
23
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Step 6. Connect Gas Line
All codes require a shut-off valve mounted in the
supply line. The orientation of the shut-off valve
should face the front. Figure 36 illustrates two
methods for connecting the gas supply. A Sediment Trap is recommended to prevent moisture
and debris in gas line from damaging the valve.
The flex-line method is acceptable in the U.S.A
where local codes permit; however, Canadian
requirements vary depending on local codes.
See Figure 36 for flex-line description. The
flex-line is rated for both natural and propane
gas. A manual shut off valve is also provided
with the flex-line.
The gas control valve is located on the right
side of the unit.
When using solid gas line connector, access the
valve by removing the glass door assembly on
the control side (see Page 29) and the access
plate (see Figure 37).
The electronic control valve has a 3/8" (10 mm)
NPT thread gas supply inlet.
Bring the shutoff valve on the end of the flex-line
over to the hard pipe and tighten with wrenches
from above through the firebox opening.
Secure all joints tightly using appropriate tools
and sealing compounds (ensure propaneresistant compounds are used in propane
applications). Seal around gas line to prevent
cold air leakage. Use sealants approved by
local codes for the application.
Test All Connections for Gas Leaks
(Factory and Field)
WARNING
Turn on gas supply and test for gas leaks using a
gas leak test solution (also referred to as bubble
leak solution).
Note: Using a soapy water solution is an effective leak test solution but it is not recommended,
because the soap residue that is left on the pipes/
fittings can result in corrosion over time.
A.Light the appliance. See the lighting instructions label in the fireplace control compartment or Care and Operation Instructions.
B. Brush all joints and connections with the gas
leak test solution to check for leaks. If bubbles
are formed, or gas odor is detected, turn the
receiver or remote control to the OFF position.
Either tighten or refasten the leaking connection;
then retest as described above.
C.When the gas lines are tested and leak-free,
be sure to rinse off the leak testing solution.
D. Reinstall the access plate, making certain the
gasket has not been damaged.
3/8" NPT x 1/2" x 3/8" Flare
Flare Fitting Shut-off Valve
3/8" Flex Tubing
3/8" Nipple
1/2" x 3/8"
Reducer
3/8" Union
3/8" Close
Nipple
3/8" Shut-off Valve
Gas Solid Line Connector
Figure 36
Access Panel
Never use an open flame to
check for leaks.
Gas Flex Line Connector
Gas
Valve
Right Side
Modesty Panel
Gas
Stub
GAS CONNECTION
Note: The gas supply line
must be installed in accordance with building codes
by a qualified installer
approved and/or licensed
as required by the locality.
In the Commonwealth of
Massachusetts, installation
must be performed by a
licensed plumber or gas
fitter.
3"
Min
*Sediment
Trap
24
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Main Gas
Shut-Off Valve
Gas Valve
ON/OFF Switch*
Control
Compartment
Access
*ON/OFF Switch - Switches from intermittent
ignition to a standing pilot (a standing pilot
stays lit when fireplace is off).
Figure 37
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Step 7. INSTALL FIREBOX
LINER PANELS
Step 8. Verify Appliance
Operation
Install the ceramic or porcelain firebox liner
panels per the instructions provided in the kit
(ref. document P/N 506019-21).
Turn on the burner, then observe the individual
tongues of flame on the burner.
NOTICE: Liner panels must be
installed before operating fireplace.
Make sure all ports are open and producing
flame evenly across the burner.
If any ports are blocked (or partially blocked),
clean out the ports.
With the gas line installed, run initial system
checkout before closing up the front of the
unit. Follow the pilot lighting instructions provided in the Care and Operation Instructions.
Note: Lighting instructions also can be
found on the lighting label tied to the
bracket above the gas valve. To access
the tag, reach into the right side opening
(see Figure 37 on Page 24).
Appliance Checkout
To light the burner, refer to the lighting instructions in the Care and Operation Instructions or the lighting label tied to the bracket
above the gas valve (behind the right panel).
Make sure the igniter lights the pilot. The
pilot flame should engulf the flame sensor, as
shown in Figure 38.
PILOT ASSEMBLY
Proper Pilot Flame Appearance
Igniter
Rod
Flame
Sensor
When first lighting the appliance, it will take a
few minutes for the line to purge itself of air.
Once purging is complete, the pilot and burner
will light and operate as indicated on Page 30.
Subsequent lighting of the appliance will not
require such purging.
Inspect the pilot flame (remove logs, if necessary, handling carefully).
Pilot Hood
Pilot
Nozzels
Figure 38
25
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Step 9. INSTALL VOLCANIC STONE,
GLOWING EMBERS, AND LOGS
Bag of Glowing Embers
9-1.Remove mesh pull screens, modesty panel, and glass door assembly from one side of fireplace. See Page 29.
9-2.Locate materials (log set, bag of glowing embers, and bags of
volcanic stone).
Note: LOGS ARE FRAGILE! Handle with care to prevent
breakage.
9-3.Install volcanic stone. Place some of the volcanic stone on the
firebox floor around the grate (the entire bag of volcanic stone will
NOT be used).
Note: Do NOT place volcanic stone on burner.
Separate glowing ember material
into THIN, square, dime-sized pieces.
Figure 39: Preparation of Glowing Ember Material
9-4.Prepare and install glowing embers.
Note: This appliance is provided with enough glowing
ember material for several applications. Do NOT use
the entire contents of a new bag at one time.
B
a) Separate some of the glowing ember material into pieces about
the size and thickness of a dime (see Figure 39). Keep the
pieces fluffed up, not matted.
A
IMPORTANT! Ember pieces must be
as SMALL and THIN as a dime.
C
b) Distribute the dime-sized pieces over the surface of the burner,
in the areas shown in Figures 40 and 41.
Note: To prevent flame impingement and soot, do not use
more ember material than necessary.
c) For best glowing effect, replace ember material annually.
Note: Use only catalog number H8312 Glowing Embers
with this fireplace.
Control Side
Figure 40: Placement of Glowing Ember Pieces
WARNING
• DO NOT attempt to install the logs until the appliance installation has been completed, the gas line
connected and tested for leaks, and the initial burner
operation has been checked out.
Place
embers
in circled
areas.
• Logs get very hot and will remain hot up to one hour
after gas supply is turned off. Handle only when
logs are cool. Turn off all electricity to the appliance
before you install volcanic stone, embers and logs.
• The size and position of the log set was engineered
to give the appliance a safe, reliable and attractive
flame pattern. Any attempt to use a different log
set in the fireplace will void the warranty and will
result in incomplete combustion, sooting, and poor
flame quality.
Control Side
(top view of burner shown)
• Place glowing ember material in circled areas ONLY.
• Do NOT place glowing ember material over main flame gas ports.
• To prevent flame impingement and soot, do not use more ember
material than necessary.
Figure 41: Placement of Glowing Ember Pieces
• This appliance is not designed to burn wood. Any
attempt to do so could cause irreparable damage to
the appliance and prove hazardous to your safety.
26
• If logs are not installed according to the log installation instructions, flame impingement and improper
combustion could occur and result in soot and/or
excessive production of carbon monoxide (CO), a
colorless, odorless, toxic gas.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
9-5.Install logs (reference Figure 42 and Table 9).
Note: Logs are FRAGILE! Handle with care to prevent breakage.
Left Rear Log
Center Rear Log
E
D
9-6.Place rectangular notches on underside of Center Log A (Figure
44) over Boss #1 and Boss #4 (Figure 43 ).
Right Rear Log
B
Pin
A
Landing
Center Log
A
Figure 44
Left Front Log C
Right Front Log F
Figure 42: Top View of Logs
9-7.Place notch on underside of Right Rear Log B (Figure 45 ) over
Boss #2 (Figure 43).
Item*
Description
Place opposite end of Right Rear Log B (Figure 45) on Landing for
Log B (see Figure 43 ).
LOG SET
Item*
Description
A
Log, Center
D
Log, Top Right
B
Log, Right Rear
E
Log, Top Left
C
Log, Left Front
F
Log, Top Front
Landing for Log D
(see Step 9-9 and Figure 47 on next page)
B
*Item letters correspond to photos.
FIREBOX ACCESSORIES/PARTS
Cat. No.
Model
H8312
PGE
Bag of Glowing Embers
Description
80L42
FDVS
Bag of Volcanic Stone
Table 9
Boss #1
Landing for Log B
Boss #2
Figure 45
9-8.See Figures 43 and 46. Place notch on underside of Left Front
Log C over Boss #3.
Place opposite end of Left Front Log C on Landing for Log C (see
Figure 43).
C
[CONTROL Side]
Boss #3
Landing for Log C
Boss #4
Figure 43: Burner Bosses and Landings
Figure 46
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
27
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
9-9.Place groove on underside of Top Right Log D over the grate as
shown in Figure 47.
The middle section of Log D will rest on the landing on Log B
(labeled as “Landing for Log D” in Figure 45).
9-11. See Figure 49. Place groove on underside of Top Front Log F over
the grate finger. Rest the other end of the log on the Landing on
Center Log A.
Groove Location
D
B
A
Landing
Groove Location
Figure 49
Figure 47
9-10. See Figure 48. Place hole on underside of Top Left Log E over pin
on Center Log A.
[DETAIL]
A
Pin
E
A
Figure 48
28
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
F
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Step 10. INSTALL GLASS
DOORS, MESH PULL SCREENS,
AND MODESTY PANEL
WARNING
Hot GLASS WILL CAUSE BURNS.
DO NOT TOUCH GLASS UNTIL COOLED.
Installing Glass Doors, Mesh Pull
Screens, and Modesty Panel
(see Figure 50)
Note: These instructions do NOT apply to
the Outer Glass Door provided in the Outdoor Kit (for indoor/outdoor installations).
1) Install one of the glass doors, as follows:
a) Retrieve the glass door. Visually inspect
the gasket on the back of the frame.
Gasket surface must be clean, free of
irregularities, and seated firmly.
• Install only when fireplace is OFF and
COLD.
• Fireplace surfaces get EXTREMELY HOT!
• The glass on the front of the fireplace
reaches EXTREMELY HIGH temperatures
and can cause severe burns if touched.
Even after the gas is turned off, fireplace
surfaces remain extremely hot.
b) Position the door in front of the firebox
opening, with the top of the door held
away from the fireplace (see Figure 50).
c) Lower the bottom of the door assembly
onto the bottom door track, engaging and
centering it in the base channel, and then
gently swing the door up.
d) Using a #3 Phillips screwdriver, fasten the
door frame to the door latches with the
two (2) latch screws. The latches should
pull forward to engage the door frame.
CAUTION
Risk of personal injury
or property damage.
• Do NOT abuse glass doors by striking or
slamming shut
• Never operate fireplace with glass door
assemblies removed.
These direct-vent appliances are designed
to operate only when both glass door
assemblies are installed. Generally, the
glass door assemblies should not be
removed, except when access to components within the firebox is required.
• Securely tighten door latch screws when
reinstalling glass door assemblies to
prevent doors from falling out.
• Handle glass door assemblies with
extreme care. Replace damaged glass
door assemblies with approved replacement assemblies only.
The door assemblies on this fireplace
contain ceramic glass. Handle with care
to prevent damage. If the door frame
or glass on either assembly becomes
­damaged, replace the entire glass door
assembly with a manufacturer-approved
replacement assembly only. Do not
attempt to substitute any materials used
on door assemblies or replace cracked
or broken glass with any other materials.
Note: Securely tighten latch screws when
reinstalling glass door assembly.
2) Install the modesty panel on the top flange
of the glass door, as follows:
a) Grasp the modesty panel with both hands
(with the open hem facing down).
b) Engage it with the top flange of the glass
door frame by pushing it all the way
down. Make sure the installed modesty
panel is firmly in place.
Removing Glass Doors, Mesh Pull
Screens, and Modesty Panel
(see Figure 50)
1) Remove the mesh pull screens, as follows:
a) Lift up the left end of the rod to disengage
it from the slot in the left rod bracket.
b) Slowly remove the right end of the rod
from the hole in the right rod bracket.
c) Set aside the rod and mesh pull screens
for later reinstallation.
2) Remove the modesty panel from the top
flange of the glass door by firmly pulling up
on it with both hands until it is disengaged.
3) Remove one of the glass doors, as follows:
a) See Figure 50. While holding the top of
the glass door frame in place, use a #3
Phillips screwdriver to remove the two
(2) screws securing the door frame to
the two (2) door latches.
b) Carefully tilt the top of the glass door
frame away from the unit (as shown in
Figure 50), and then lift the door assembly up and out of the lower track.
c)Carefully place the glass door assembly
on a padded surface in a safe location to
prevent damage.
Top Flange
on Glass door assembly
Glass Door Latch (2)
3) Install the mesh pull screens, as follows:
a) Retrieve the rod and two mesh pull
screens. If necessary, attach screens to
rod.
b) Slowly insert the right end of the rod into
the hole in the right rod bracket.
Screws
c) Insert the left end of the rod into the slot
in the left rod bracket.
Figure 50
• Only doors certified with the appliance shall
be used.
• Seules des portes certifiées pour cet
appareil doivent être utilisées.
29
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Step 11. Burner Adjustments
Flame Appearance and Sooting
Proper flame appearance is a flame that is blue
at the base and becomes yellowish-orange in
the body of the flame. When the appliance is
first lit, the entire flame may be blue and will
gradually turn yellowish-orange during the first
30 minutes of operation. After 30 minutes of
operation, if the flame is blue, or if the flame is
orange with evidence of sooting (black tip), the
air shutter opening may need to be adjusted.
If the air shutter opening is closed too far,
sooting may develop. Sooting is indicated
by black puffs developing at the tips of very
long orange flames. Sooting results in black
deposits forming on the logs, appliance inside
surfaces and on exterior surfaces adjacent to
the vent termination.
Sooting is caused by incomplete combustion
in the flames and lack of combustion air entering the air shutter opening. To achieve a warm
yellowish-orange flame with an orange body
that does not soot, the shutter opening must be
adjusted between these two extremes.
Air Shutter Adjustment Guidelines
• If there is smoke or soot present, first check
the log set positioning to ensure that the
flames are not impinging on any of the logs.
If the log set is properly positioned and a
sooting condition still exists, then the air
shutter opening should be increased.
• The more offsets in the vent system, the larger
the air shutter opening will need to be.
• An appliance operated with the air shutter
opened too far, may have flames that appear
blue and transparent. These weak, blue and
transparent flames are termed anemic.
• Propane models may exhibit flames which
candle or appear stringy. If this is present
and persists, adjust the air shutter to a more
OPEN position, then operate the appliance
for a few more minutes to ensure that the
flame normalizes and the flames do not
appear sooty.
The following chart is provided to aid you in
achieving the correct air shutter adjustment
for your installation.
Burner Air Shutter Adjustment
Procedure
WARNING
Hot GLASS WILL CAUSE BURNS.
DO NOT TOUCH GLASS UNTIL COOLED.
• Fireplace surfaces get EXTREMELY HOT!
• The glass on the front of the fireplace
reaches EXTREMELY HIGH temperatures
and can cause severe burns if touched.
Even after the gas is turned off, fireplace
surfaces remain extremely hot.
CAUTION
Risk of personal injury
or property damage.
• Air shutter adjustment should only be
performed by a qualified professional
service technician.
• Soot will be produced if the air shutter
is closed too much. Any damage due
to carboning resulting from improperly
setting the air shutter is not covered
under the warranty.
1. Light the appliance (follow lighting procedure in Care and Operation Instructions or
on lighting label in control compartment).
2. Allow the burner to operate for at least 30
minutes while continuously observing the
flame to ensure that the proper flame appearance has been achieved (see Figures
51 and 52).
3. Adjust the air shutter using the lever on the
lower right side of the firebox (Figure 51).
•For more OPEN air shutter, slide lever
to the RIGHT.
•For more CLOSED air shutter, slide
lever to the LEFT.
A minimum shutter setting is designed into
the venturi by four 1/16"‑inch tabs.
• If the flame appears weak or sooty (as
described on the previous page), adjust
the air shutter until proper flame appearance is achieved.
• If flame stays lowered blue, incrementally adjust the air shutter to a more
CLOSED position until proper flame
appearance is achieved.
Note: See Figures 51 and 52 for proper burner
flame appearance.
Volcanic Stone
Air Shutter
Adjustment Lever
Figure 51: Burner Flame Appearance — Control Side
Air Shutter Adjustment Guidelines:
Amount of
Primary Air
Flame
Color
Air Shutter
Adjustment
If air shutter is
closed too far
Flame will
be orange
Air shutter
gap should be
increased
If air shutter is
open too far
Flame will
be blue
Air shutter
gap should be
decreased
Volcanic Stone
30
Figure 52: Burner Flame Appearance — Opposite Control Side
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Finishing Requirements
Wall Details - INDOOR SIDE(S)
Complete the finished interior wall. To install the appliance
facing flush with the finished wall, position framework to
accommodate the thickness of the finished wall (Figure 53).
IMPORTANT!
Min. clearance above any
horizontal vent component
is 4 in (102 mm).
Wall Details - OUTDOOR SIDE
Complete finished exterior wall per the instructions provided
in the Outdoor Installation Kit and the instructions provided
here. To install the appliance facing flush with the finished
exterior wall, position framework to accommodate the
thickness of the exterior finished wall (Figure 54).
INTERIOR WALL FINISHING
EXTERIOR WALL FINISHING
Min. 4 in*
Min. 4 in*
(102 mm)
(102 mm)
Wall Stud
Wall Stud
Header
Combustible
materials are
allowed on face
of appliance
above this point
~
~
Combustible
Finished Wall
Materials
Min. 1 in*
Min. 1 in*
(25 mm)
(25 mm)
2 ft Vertical
Vent and
90° Elbow
2 ft Vertical
Vent and
90° Elbow
Top of
Appliance
Top of
Appliance
Spacers
Spacers
Top of Door Frame
*Insulation is
NOT ALLOWED in
clearance zones
around vent
components.
Keep this area free
from combustible
materials.
Figure 53
Combustible
Sheathing
Top of Door Frame
FIREPLACE
(side view)
FIREPLACE
(side view)
Header
Non-combustible
sheathing required
below this point.
Non-combustible
Extend housewrap
(building paper)
to this point.
Note: Non-combustible
sheathing and
housewrap (building
paper) should extend
to U-channels on
sides and bottom.
*Insulation is
NOT ALLOWED in
clearance zones
around vent
components.
Keep this area free
from combustible
materials.
Figure 54
See Page 4 for Cold Climate Insulation
and Page 9 for Clearances.
31
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Overhang
Combustible Sheathing
A
Non-Combustible Board
B
Non-Combustible Board
A
A
B
Non-Combustible Board
B
Siding
A
Siding
Siding
Trim
C*
C
Combustible Sheathing
Exterior Minimum Clearances
Sheathing Requirements
A
B
C*
12” (305 mm)
7” (178 mm)
6” (152 mm)
*Dimension “C” is clearance required from fireplace base to surface
(e.g., deck, patio, lanai) as a moisture barrier (not a combustible
clearance) on outdoor side only.
Figure 55: Sheathing
Material
A
B
C*
Vinyl
12” (305 mm)
35-1/2” (902 mm)
6” (305 mm)
Non-Vinyl
7” (178 mm)
35-1/2” (902 mm)
6” (305 mm)
*Dimension “C” is clearance required from fireplace base to surface
(e.g., deck, patio, lanai) as a moisture barrier (not a combustible
clearance) on outdoor side only.
Figure 56: Exterior Clearances
32
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Step 12. ATTACHING SAFETY-IN-OPERATION WARNINGS
It is the installer’s responsibility to ensure these warnings are properly affixed during installation. These warning labels are a
critical step in informing consumers of safe operation of this appliance.
Attaching Safety-in-Operation
Warnings
Apposition des mises en garde relatives Colocación de advertencias de
à la sécurité d’utilisation
seguridad en operación
It is required that the set of safety instruction labels
that have been furnished with the fireplace be affixed
to the operation and control points of the fireplace. A
safety instruction label must be affixed to the receiver
wall switch plate where the fireplace is turned on
and off (See Figure A) and on the remote control
handheld transmitter (See Figure B). To properly
complete the installation of this fireplace, locate the
multi-lingual adhesive labels provided with the Care
and Operation Instructions and proceed as follows:
Il est impératif que le jeu d’étiquettes de sécurité qui ont été
fournies avec le foyer soient collées à côté des dispositifs de
contrôle du foyer. Une étiquette de sécurité doit être collée
sur la plaque du récepteur mural contrôlant l’allumage du
foyer (voir Figure A) et sur le boîtier de la télécommande
(Figure B). Pour achever l’installation correcte de ce
foyer, procédez comme suit avec les étiquettes adhésives
en langues étrangères fournies avec les instructions
d’utilisation et d’entretien :
1. Repérez le récepteur mural qui contrôle le foyer
(vérifiez que l’interrupteur contrôle le fonction­nement du foyer en le faisant basculer de Marche
à Arrêt, et vice-versa). Nettoyez soigneusement
la plaque du récepteur mural pour éliminer la poussière
et les traces de graisse ou d’huile. Collez l’étiquette sur
la surface de la plaque du récepteur mural qui contrôle
le foyer (Figure A). Choisissez la langue qui est
principalement parlée dans la résidence du propriétaire.
En cas de doute, collez l’étiquette en anglais.
2. Repérez la télécommande et nettoyez-la soigneuse­
ment pour éliminer la poussière et les traces
de graisse ou d’huile. Collez l’étiquette sur le boîtier
de la télécommande (Figure B). Choisissez la
langue qui est principalement parlée dans la
résidence du propriétaire. En cas de doute, collez
l’étiquette en anglais.
3. Si vous ne trouvez pas les étiquettes, veuillez
appeler Lennox Hearth Products ou votre distribu­
teur Lennox Hearth Products local pour recevoir
gratuitement des étiquettes supplémentaires.
Étiquettes de remplacement, n° cat. H8024
LENNOX HEARTH PRODUCTS
1-800-9-LENNOX
1. Locate the wall receiver that controls the fireplace (verify the switch operates the fireplace
by turning it on and off). Clean the wall receiver
plate thoroughly to remove any dust and oils.
Affix the label to the surface of the plate of the
wall receiver that controls the fireplace (Figure
A). Choose the language primarily spoken in the
home. If unknown, affix the English language
label.
2. Locate the remote control transmitter and
clean it thoroughly to remove any dust and
oils. Affix the label to the surface of handheld
transmitter (Figure B). Choose the language
primarily spoken in the home. If unknown, affix
the English language label.
3. If you are unable to locate the labels, please
call Lennox Hearth Products or your nearest
Lennox Hearth Products dealer to receive additional safety instruction labels free of charge.
Cat. No. H8024 Replacement Label Kit
LENNOX HEARTH PRODUCTS
1-800-9-LENNOX
Note: English is red text on clear label. French
and Spanish are white text on black label.
Remarque : Le texte anglais est rouge sur un support
transparent. Le texte français et espagnol est blanc sur un
support noir.
SAFETY LABEL
DIAGRAMS
DIAGRAMMES DES ÉTIQUETTES
DE SÉCURITÉ
Se requiere que el juego de etiquetas de instrucciones
de seguridad que se incluyeron con la chimenea se
coloque en los puntos de operación y control de la
misma. Se debe colocar una etiqueta de instrucciones
de seguridad en la placa del interruptor de pared
del receptor desde el cual se enciende y se apaga
la chimenea (ver la Figura A) y en el transmisor de
control remoto (ver la Figura B). Para completar
correctamente la instalación de esta chimenea,
encuentre las etiquetas adhesivas multilingües
incluidas con las instrucciones de cuidado y
operación y haga lo siguiente:
1. Identifique el receptor de pared que controla la
chimenea (verifique que el interruptor opera la
chimenea encendiéndola y apagándola). Limpie
bien la placa del receptor de pared para quitar el
polvo y aceite. Pegue la etiqueta en la superficie
de la placa del receptor de pared que controla la
chimenea (Figura A). Seleccione el idioma que
más se habla en la casa. Si no sabe cuál es, use
la etiqueta en inglés.
2. Identifique el transmisor de control remoto y
límpielo bien para quitar el polvo y aceite. Pegue
la etiqueta en la superficie del transmisor (Figura
B). Seleccione el idioma que más se habla en la
casa. Si no sabe cuál es, use la etiqueta en inglés.
3. Si no puede encontrar las etiquetas, sírvase
llamar a Lennox Hearth Products o al distribuidor
de Lennox Hearth Products más cercano para
recibir etiquetas de instrucciones de seguridad
adicionales gratuitas.
Juego de etiquetas de repuesto - Nº de cat. H8024
LENNOX HEARTH PRODUCTS
1-800-9-LENNOX
Nota: La etiqueta en inglés es transparente con
texto rojo. Las etiquetas en francés y español son
negras con texto blanco.
DIAGRAMAS DE ETIQUETAS
DE SEGURIDAD
On
Remote
Off
PRG
Figure A
Figure B
33
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Installation Accessories
Listed Secure Vent™ Components
Cat.
No.
Model
No.
H8323
SV8HTS4
H2265
SV8VTR
H2262
SV8SU
Support Strap
H2263
SV8SP
Support Plate
H3908
SV8ARSA
Description
Horizontal Square
Termination with
Firestop/Spacer
(H8322) and
Adaptor (H2267)
Open Top Shroud CTSO-46
for double terminations
Vertical Termination
Attic Insulation Shield
(adjustable 12” to 22”)
Open Top Shrouds CTSO-33 and CTSO-44
for single terminations
1 typ.
C
1 typ.
2a
2b
C
H2250
SV8L6
6 inch (152 mm)
Vent Section
H2251
SV8L12
12 inch (305 mm)
Vent Section
2 typ.
E D
2a
2b
D
E
2a
2b
B
2a
A
B
A
H2252
SV8L24
24 inch (610 mm)
Vent Section
H2253
SV8L36
36 inch (914 mm)
Vent Section
Cat. No.
Model
A
B
C
D
*E
H2254
SV8L48
48 inch (1219 mm)
Vent Section
H1985
CTSO-33
37-5/8
(955)
37-5/8
(955)
7-1/2
(191)
24-1/2
(622)
3
(76)
H2255
SV8LA
Telescopic Section
H1987
CTSO-44
48-5/8
(1235)
48-5/8
(1235)
7-1/2
(191)
24-1/2
(622)
3
(76)
H2256
SV8E45
45 Degree Elbow
H1986
CTSO-46
48-5/8
(1235)
73 1/4
(1860)
7-1/2
(191)
24-1/2
(622)
3
(76)
Shroud: Open Top, Chase Top - Inches (millimeters)
(Open Top Shroud Termination Kit Instructions P/N 750193M)
H2257
SV8E90
90 Degree Elbow
Arch Top Shroud CTSA-33
A
The following flashings come packaged with
a storm collar
H3236
SV8F
Flat Roof Flashing
H2258
SV8FA
Adjustable Flashing,
1/12 to 7/12
H2259
SV8FB
Adjustable Flashing,
7/12 to 12/12
H3237
SV8SC6
Storm Collar
(pkg of 6)
B
D
C
Shroud: Arch Top, Chase Top - Inches (millimeters)
Cat. No.
Model
A
B
C
D
H1988
CTSA-33
34
(864)
5
(127)
34
(864)
34
(864)
(Arch Top Shroud Kit Instructions P/N 750194M)
H8322
SV8HF4
Firestop/Spacer,
Horizontal
(4-1-1 spacing)
H2261
SV8BF
Firestop/Spacer,
Vertical
(1-1-1 spacing)
Outdoor Kits
H7940
LSM40STODK
Outdoor Kit with
Light-tint Glass
H8061
LSM40ST-ODKT
Outdoor Kit with
Dark-tint Glass
(Outdoor Kit Instructions P/N 506019-20)
34
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Gas Conversion Kits
Gas conversion kits are available to adapt your
appliance from the use of one type of gas to
another. These kits contain all the necessary
components needed to complete the task, including labeling that must be affixed to ensure
safe operation.
Gas Conversion Kits
Kit Model No.
Kit Cat. No.
Description
GCK-NP-LSM40ST
H7951
Natural Gas to Liquid Propane Conversion Kit
GCK-PN-LSM40ST
H7952
Liquid Propane to Natural Gas Conversion Kit
Table 10
(Gas Conversion Kit Instructions P/N 506019-53)
Kit part numbers are listed at right.
Refer to the instructions provided with the
conversion kit when performing any gas
conversion.
35
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MONTEBELLO® SEE-THROUGH DIRECT-VENT GAS FIREPLACES (LSM40ST-N / LSM40ST-P) • INSTALLATION INSTRUCTIONS
Lennox Hearth Products reserves the right to make changes at any time, without notice, in
design, materials, specifications, and prices, and also to discontinue colors, styles, and products.
Consult your local distributor for fireplace code information.
Printed in U.S.A. © 2011 Lennox Hearth Products
36
P/N 506023-12 Rev. B 05/2011
1508 Elm Hill Pike, Suite 108 • Nashville, TN 37210