Lennox LSM40EN-2, LSM45MN-2, LSM45EN-2, LSM45MP-2, LSM40MP-2 User Manual

INSTALLATION INSTRUCTIONS

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.

WARNING: If the information in these instructions
is not followed exactly, a fire or explosion may
result, causing property damage, personal injury,
or death.

WARNING /AVERTISSEMENT/AVISO

• HOT GLASS WILL CAUSE
BURNS.

• DO NOT TOUCH GLASS
UNTIL COOLED.

• NEVER ALLOW CHILDREN
TO TOUCH GLASS.

• UNE SURFACE VITRÉE CHAUDE
PEUT CAUSER DES BRÛLURES.

• LAISSER REFROIDIR LA SURFACE
VITRÉE AVANT D'Y TOUCHER.

• NE PERMETTEZ JAMAIS À UN ENFANT
DE TOUCHER LA SURFACE VITRÉE.

• EL VIDRIO CALIENTE
CAUSARÁ QUEMADURAS.

• USTED DEBE NUNCA
TOCAR EL VIDRIO CALIENTE.

• LOS NIÑOS DEBEN NUNCA
TOCAR EL VIDRIO.

- 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.

- 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.

Montebello®
Direct Vent Gas Fireplaces

MODELS

P/N 850026M Rev. G 06/2011

This manual is one of a set of two supporting this product.
Refer to P/N 875027M for Care and Operation Instructions.

Ce manuel est disponible en francais, simplement
en faire la demande. Numéro de la pièce 850026CF.

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.

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.

LSM40MN-2
LSM40MP-2

OTL Report No. 116-F-22-5

MILLIVOLT:

LSM45MN-2
LSM45MP-2

Portland

US

ELECTRONIC:

LSM40EN-2
LSM45EN-2

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

TABLE OF CONTENTS

Packaging .........................................Page 2

Introduction ......................................Page 2

General Information ..........................Page 2

Massachusetts and New York

Requirements ................................Page 4

Cold Climate Insulation .....................Page 5

Manufactured Home Requirements ..Page 5

Location ............................................Page 5

Vent Termination Clearances ............Page 6

Minimum Clearances to Combustibles Page 8

Detailed Installation Steps .................Page 9

Typical Installation Sequence ...........Page 9

Step 1. Framing ...............................Page 9

Fireplace and Framing Specifications ..Page 10

Step 2. Routing Gas Line ................Page 11

Proper Sizing of Gas Line ..................Page 11

Step 3. Install the Vent System .......Page 12

Vertical Termination Systems ............Page 13

Vent Section Length Chart ................Page 13

Vertical Vent Tables and Figures ........Page 16

Horizontal Termination System .........Page 17

Horizontal Vent Tables and Figures ...Page 19

Step 4. Field Wiring .........................Page 21

Step 5. Removing Glass Door

Frame Assembly ...........................Page 22

Step 6. Connecting Gas Line ...........Page 22

Step 7. Checking Appliance

Operation ......................................Page 23

Step 8. Installing Logs and Panels ..Page 24

Step 9. Installing Glass Door ..........Page 26

Step 10. Burner Adjustments ............Page 26

Finishing Requirements ....................Page 28

Step 11. Attaching Safety-in-

Operation Warnings .....................Page 29

Installation Accessories ....................Page 30

Gas Conversion Kits .........................Page 31

Please read and understand these
instructions before beginning your

installation.

PACKAGING

The assembled vented gas fireplace is pack­aged with:

1 - one envelope located in the firebox contain-

ing the literature package, which consists of
the care and operation manual, installation
instructions, safety in operation warning
labels and warranty

2- one bag of glowing embers and volcanic

stone

3 - one of the following brick liner kits:

a. Brick Liner Kit, Rustic
b. Brick Liner Kit, Herringbone
c. Brick Liner Kit, Old Cottage
d. Brick Liner Kit, Black.
e. Brick Liner Kit, Red Rustic
f. Brick Liner Kit, Red Herringbone

4 - one of the following log sets:

a. Birch Log set

b. Oak Log set
5 - pull screen
6 - door modesty shield

INTRODUCTION

The Millivolt appliances are designed to operate
on natural or propane gas and have a millivolt
gas control valve with piezo ignition system.

The Electronic appliances are designed to
operate on natural or propane gas and have a
electronic intermittent pilot ignition system. No
external electrical power is required to operate
these units.

These vented gas fireplaces are sealed com­bustion gas fireplaces designed for residential
applications.

Use Only These Approved Vent Components

- These fireplaces are designed, tested and
listed for operation and installation with,
the following (8" inner and 11" outer) vent
components only:

• Secure Vent™ Direct Vent System Compo-

nents 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.

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 infor­més 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.

2

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • 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.

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 se servir de cet appareil s'il a été
plongé dans l'eau, complètement ou en
partie. Appeler un technicien qualifié pour
inspecter l'appareil et remplacer toute partie
du système de contrôle et toute commande
qui ont été plongés dans l'eau.

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 OMNI­Test Laboratories, Inc. (Report No. 116-F-22-5)
to ANSI Z21.50 (in Canada, CSA-2.22), and
CAN/CGA-2.17-M91 in both USA and Canada,
as vented gas fireplaces.

Both millivolt and electronic versions of
these appliances are listed by OMNI-Test
Laboratories for installation in bedrooms and
mobile homes.

Misc. Codes / Standards -

The Installation must conform to local codes.
In the absence of local codes, installation must
comply with the current National Fuel Gas Code,

ANSI Z223.1. (In Canada, the current CAN/
CSA-B149.1 installation code).

The appliance, when installed, must be electri­cally grounded 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.

Provide adequate clearances around air open­ings and adequate accessibility clearance for
service and proper operation. Never obstruct
the front openings of the appliance.

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.

These fireplaces are designed as supplemental
heaters. Therefore, it is advisable to have an
alternate primary heat source when installed
in a dwelling.

Millivolt Models - The millivolt appliances are
manually controlled and feature a spark igniter
(piezo) that allows the appliance's pilot gas to be
lit without the use of matches or batteries. This
system provides continued service in the event
of a power outage.

The Millivolt models come standard with the
manually-modulated gas valve; flame appear­ance and heat output can be controlled at the

gas valve. The BTU Input for these appliances

is shown in Table 1.

Electronic Models - The electronic appliances
are manually controlled and feature an electronic
intermittent pilot ignition system. External elec­trical power is required to operate these units.

Electronic models come standard with a
manually-modulated gas valve; flame appear­ance and heat output can be controlled at the

gas valve. The BTU Input for these appliances

is shown in Table 1.

Input (BTU/HR) - All Models

Model No. Input (BTU/Hr)

Natural Gas

LSM40-2 40,000 to 50,000
LSM45-2 47,000 to 60,000

Propane Gas

LSM40-2 40,000 to 50,000
LSM45-2 48,000 to 60,000

Table 1

3

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

H
I

L

O

W

TPTH TP TH

P

I

L

O

T

P

I

L

O

T

O

N

it

O

F

F

Hi / Lo
Variable Flame
Height Adjustment

Manifold
Pressure
Gauge Port

Inlet Pressure
Gauge

Port

Main Gas

Control Knob
Off / Pilot / On

Pilot
Adjustment
Screw

IN

OUT

Gas Supply Inlet

Gas Outlet to Burner

HI

LO

Gas Pressure - All Models

Tables 2 and 3 show the appliances' inlet and
manifold gas pressure requirements:

4

Inlet Gas Supply Pressure

(all models)

Fuel # Minimum Maximum

Natural Gas

Propane

5.5" WC

(1.37 kPa)

11.0" WC

(2.74 kPa)

10.5" WC

(2.61 kPa)

13.0" WC

(3.23 kPa)

Table 2

Manifold Gas Supply Pressure

(all models)

Fuel # Low High

Natural

Gas

Propane

(Lo) 2.2" WC

(.55 kPa)

(Lo) 6.3" WC

(1.57 kPa)

(Hi) 3.5" WC

(.87 kPa)

(Hi) 10.0" WC

(2.49 kPa)

Table 3

Test gauge connections are provided on the
front of the millivolt and electronic gas control
valve (identified IN for the inlet and OUT for the
manifold side).

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 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).

These appliances must not be connected to a
chimney or flue serving a separate solid fuel
burning appliance.

Orifice Sizes - Sea Level To High Altitude
(All Models)

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 "*" in Table

4). For elevations above 4500 feet, contact your
gas supplier or qualified service technician.

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.

• Changing the burner orice 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)

Model Nat.Gas

drill size (inches)

LSM40-2 .1405" (#28)*

• H2286

LSM45-2 .161" (#20)*

• H2288

Table 4

* Standard size installed at factory

• Part /Cat. Number

Propane

drill size (inches)

.086" (#44)*

• H2287

.093" (#42)*

• H4816

Gas Valve Diagrams

See Figure 1 for Millivolt models and Figure 2
For Electronic Models.

Figure 1 - SIT Millivolt Gas Valve

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

Gas Supply Inlet

Inlet Pressure
Gauge Port

Manifold
Pressure
Gauge Port

Gas Outlet to Burner

Hi / Lo
Variable Flame
Height
Adjustment

Pilot
Adjustment
Screw

Figure 2 - SIT Electronic Gas Valve

REQUIREMENTS FOR THE COMMON­WEALTH OF MASSACHUSETTS

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 exible 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.

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 identication 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)

Installation of these fireplaces are approved for
installation in New York City in the US state
of New York.

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

Drywall

Top Of Fireplace
Opening

Non-Combustible

HORIZONTAL VENT

VERTICAL VENT

HORIZONTAL VENT

VERTICAL VENT

COLD CLIMATE INSULATION

For cold climate installations, seal all cracks
around your appliance with noncombustible
material and wherever cold air could enter
the room. It is especially important to insulate

Cross Corner

Application

outside chase cavity between studs and under
floor on which appliance rests, if floor is above
ground level. Gas line holes and other open­ings should be caulked or stuffed with unfaced
fiberglass insulation.

If the fireplace is being installed on a cement

Room Divider

Application

Recessed

Application

Island

Application

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

Flat

Application

Application

Flat on Wall

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 matéri­el 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.

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.

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.

Figure 3 - Typical Installation

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.

Due to high temperatures, the appliance
should be located out of traffic and away from
furniture and draperies (Figure 3).

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 3).

The location should also be free of electrical,
plumbing or other heating/air conditioning
ducting.

These direct-vent appliances are uniquely
suited for installations requiring a utility shelf
positioned directly above the fireplace. Util­ity shelves like these are commonly used for
locat-ing television sets and decorative plants.

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 (see Figure 8

on Page 8).

The minimum height from the base of the appli­ance to the underside of combustible materials
used to construct a utility shelf in this fashion
is shown in Figure 8 on Page 8.

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.

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

5

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

3"

(76 mm)

Termination Kit

Combustible Projection

greater than 2-1/2 inches in length

Horizontal Vent Termination Clearances

Combustible Projection

2-1/2 inches or less in length

24"

(610 mm)

Ventilated Or

Unventilated Soffit

12

X

Roof Pitch is X/12

2 FT
MIN.

2 FT MIN.

Lowest

Discharge

Opening

H*

*H = MINIMUM HEIGHT FROM ROOF TO
LOWEST DISCHARGE OPENING OF VENT

TERMINATION HEIGHTS FOR VENTS ABOVE

FLAT OR SLOPED ROOFS

Horizontal Overhang

Vertical
Wall

Vent

Termination

Storm Collar

Concentric

Vent Pipe

Flashing

1 inch (25.4 mm) Minimum
Clearance to Combustibles

VENT TERMINATION CLEARANCES

These instructions should be used as a guide­line and do not supersede local codes in any
way. Install vent 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 4.

Terminate single vent caps relative to building
components according to Figure 5.

Vertical Vent Termination Clearances

The vent / air intake termination clearances
above the high side of an angled roof is as
shown in the following chart:

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
11/12 to 12/12 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

Figure 5

12”

(305mm)

Minimum

Horizontal Vent Termination Clearances

Figure 4 - Multiple Terminations

6

The horizontal vent termination must have a minimum of 3" (76 mm) clearance to any overhead

combustible projection of 2-1/2" (64 mm) or less (see Figure 6). For projections exceeding

2-1/2" (64 mm), see Figure 7. For additional vent location restrictions refer to Figure 7 on Page 7.

See Figure 30 on Page 18 for the recess allowances,
into exterior walls, of the square horizontal terminations.

Figure 6 - Side Elevation View

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

EXTERIOR HORIZONTAL VENT TERMINATION CLEARANCE REQUIREMENTS

NOTE: Local Codes Or Regulations May Require
Different Clearances.

NOTE: Location Of The Vent Termination Must Not
Interfere With Access To The Electrical Service.

3 ft.

X

A



3 ft.

Exterior Wall

Horizontal

Termination

B

V

L

X

= Air Supply Inlet

* See Item D in the Text Below.

*18”

24"

Inside Corner

Center Line

of Termination

18”

36"

DETAIL D

F

V

Ventilated Soffit

V

Fixed

Closed

Window

V

C

A

= Vent Terminal

V

Inside

Corner Detail

G

V

A

= 9" in U.S.



A

= 12" in Canada

B

C

C

C

Operable

V

Window

B

B

= Area where Terminal is NOT permitted

B



A

J

Minimum Clearances Canadian Installation * US Installation **

A = Clearance above grade, veranda, porch, deck
or balcony.

B = Clearance to window or door that may be opened. 6 in. (15.2 cm) for appliances < 10,000 BTU/hr (3kW),

C = Clearance to permanently closed window 12 inches (305 mm) recommended to prevent window

12 inches (30 cm) * 12 inches (30 cm) **

12 in. (30 cm) for appliances > 10,000 BTU/hr (3kW) and <
100,000 BTU/hr (30kW), 36 inches (91 cm) for appliances
> 100,000 BTU/hr (30kW)*

condensation

H

E

D

M

I

X

V

K

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 inches (30 cm) for appliances
> 50,000 BTU/hr (15kW)*

9 inches (229 mm) recommended to prevent window
condensation

V

D = Vertical clearance to ventilated soffit located

24 inches (61.0 cm) 24 inches (61.0 cm)
above the terminal within a horizontal distance of
36 in. (91.4cm) from the center line of the terminal

E = Clearance to unventilated soffit 24 inches (61.0 cm) 24 inches (61.0 cm)
F = Clearance to outside corner 5 inches (12.7 cm) 5 inches (12.7 cm)
G = Clearance to inside corner 36" (91.4 cm) 24 inches (61.0 cm)
H = Clearance to each inside of center line extended

above meter / regulator assembly

3 feet (91 cm) within a height of 15 feet above the meter /

regulator assembly *

3 feet (91 cm) within a height of 15 feet above the meter
/ regulator assembly **

I = Clearance to service regulator vent outlet 3 feet (91 cm) * 3 feet (91 cm) **

J = Clearance to non-mechanical air supply inlet
to building or the combustion air inlet to any other
appliance

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 inches (91 cm) for appliances

> 100,000 BTU/hr (30kW)*

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 inches (30 cm) for appliances
> 50,000 BTU/hr (15kW)*

K = Clearance to mechanical air supply inlet 6 feet (1.83 meters) * 3 feet (91 cm) above, if within 10 feet (3 m) horizontally**

L = Clearance above paved sidewalk or paved

7 feet (2.13 m) ‡ 7 feet (2.13 m) ‡
driveway located on public property

M = Clearance under veranda, porch, deck or

18 in. (46.0 cm) * ‡ 18 in. (46.0 cm) ** ‡
balcony

* In accordance with the current CSA-B149.1 National Gas and B149.2 Propane Installation Code - Latest Editions.

** In accordance with the current ANSI Z223.1 / NFPA 54 National Fuel Codes - Latest Edition.
‡ A vent shall not terminate directly above a sidewalk or paved driveway which 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 2 sides beneath the floor.

Figure 7

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

7

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

17"

14"

8-1/4”

45°

12"

5"

12 (305)

10 (254)

8 (203)

6 (152)

4 (102)

7

(178)

17

(432)

15

(381)

13

(330)

2 (51)

9

(229)

11

(279)

MINIMUM CLEARANCES TO COMBUSTIBLES

The appliance is approved with zero clearance to combustible materials
on all sides (as detailed in Table 5), with the following exception: 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 3).

Combustible Shelf Height -

Top Vent - with 2 Feet Vertical Vent and One 90 Degree Elbow

Model Secure Vent
LSM40-2 *84-1/16 (2135)
LSM45-2 89-1/16 (2252)

* Includes 3” clearance to combustibles (required above vent components)

Inches (millimeters)

APPLIANCE MINIMUM CLEARANCES*

Inches (millimeters)

Sides 1/2 (13), 0 (0) Spacers **

Top Spacers 0 (0)

Floor 0 (0)

Back 1/2 (13), 0 (0) Spacers

Bottom of Appliance To Ceiling 69 (1743)

Vent 3 (76)

Top* / 1 (25.4) Sides & Bottom

SERVICE CLEARANCES Feet (meters)

Front 3 feet (0.9 meters)

Table 5

*Note: 3 in. (75 mm) above any horizontal/inclined vent component.

**Note: See Page 9, Step 1 for clearance requirements to the nailing
flange located at each side of the unit and any screw heads adjacent to 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, vinyl tile, etc., a metal or wood
barrier covering the entire bottom surface must be used.

Shelf Height

To provide for the lowest possible shelf surface, the venting attached to
the top vent 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). The minimum height from
the base of the appliance to the underside of combustible materials used
to construct a utility shelf in this fashion is shown in Figure 8.

Wall Finishes / Surrounds / Mantels

Do not insulate the
space between the
appliance and the
area above it.

Figure 8

Figure 9

Combustible Materials
Allowed In Shaded Area
"Safe Zone"

Shelf Height

(see table)

Shelf Above Fireplace With Top Venting

MANTEL

MANTEL

MANTEL

MANTEL

MANTEL

MANTEL

Top of Appliance

Top View of

Fireplace

2 Foot Vertical
Vent (Min.)

MANTEL

CLEARANCES

Inches (mm)

Fireplace

(side view)

Note: Combustible wall finish materials and/or surround materials must
not be allowed to encroach the area defined by the appliance front face
(black sheet metal). Never allow combustible materials to be positioned
in front of or overlapping the appliance face. See Figure 10 and Figure
53 on Page 28.

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.

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.

NOTE: We recommend the use of high temperature paint (rated 175° F
or higher) on the underside of the mantel.

8

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

Figure 10

Side
Wall

Minimum Distance to
Protected Side Wall

Side
Wall

Minimum Distance to
Unprotected Side Wall

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

Step 3. (Page 12) Install the vent system and

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.

DETAILED 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 valve access side.

2. Using a Phillips screwdriver, unfasten two (2)
screws located at the top of the glass frame
(see Figure 49). 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.

Step 4. (Page 21) Field Wiring
a. Millivolt and Electronic Appliances –

b. Electronic Appliances – Connect 120

Step 5. (Page 22) Remove glass door assem-

Step 6. (Page 22) Make connection to gas

Step 7. (Page 23) Verifying appliance opera-

Step 8. (Page 24) Install ceramic panels, logs

Step 9. (Page 26) Install glass door assembly.
Step 10. (Page 26) Adjust burner to ensure

Step 11. (Page 29) Attach Safety in Operation

Step 1. FRAMING

Frame these appliances as illustrated in Figure
12 on Page 10, unless the appliance is to be
installed in a corner. See Figure 13 on Page
11 for corner framing installations. All framing

details must allow for a minimum clearance to
combustible framing members as shown in
Table 5 on Page 8.

If the appliance is to be elevated above floor
level, a solid continuous platform must be
constructed below the appliance.

exterior termination.

The operating control switch is factory
installed.

Vac electrical power to the appliance
receptacle.

bly.

supply.

tion.

and glowing embers.

proper flame appearance.

Warnings.

Use Bottom Flange For
5/8” Thick Drywall

Left Side Front Corner of Fireplace Shown

(Right Side Requirements the Same)

Unit Being Secured By Its Nailing Flanges

To The Framing

Note: The nailing flanges, combustible members
and screw heads located in areas directly adjacent
to the nailing flanges, are EXEMPT from the 1/2”
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” 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 of this manual.

Unit Being Secured by Its Nailing

Flanges to the Framing

Figure 11

TYPICAL INSTALLATION SEQUENCE

The typical sequence of installation is outlined
below. However, each installation is unique and
may result in variations to the steps described.

See the Page numbers references in the follow­ing steps for detailed procedures.

Step 1. (Page 9) Construct the appliance

framing. Position the appliance within
the framing and secure with nailing
brackets.

Step 2. (Page 11) Route gas supply line to

the right side.

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.

The fireplace should be secured 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.

Use Top Flange For
1/2” Thick Drywall

Front Of
Fireplace

Use Center Flange
For Flush Mount

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

9

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

E

A

B

D

Top View

Front View

5-3/32 (129)

Right Side View

14-1/8
8-1/2”
(216)

5-1/4”
(133)

(359)

26-15/32

(672)

C

25-29/32

(658)

25-1/2

(648)

7

2-1/2 (64)

(178)

19-5/8

(498)

Gas Inlet

(This

Side

Only)

Electrical

Inlet

8-3/8

(213)

F

G

H

J

A

B

C

8-1/2
(216)

13

(

330

)

VENT FRAMING

-

TOP VENT WITH 2 FEET
VERTICAL VENT AND
ONE 90° ELBOW

Framing should be constructed

of 2x4 or larger lumber.

Inches (mm)

(641)

25-1/4

15

(

381

)

6-1/2
(165)

1/2 A

FIREPLACE AND FRAMING SPECIFICATIONS

Framing Dimensions

Models A B C

LSM40-2

LSM45-2

Models P4 P4

LSM40M 35% 38.1

LSM40E 35.8

LSM45M 50.8 42.3

LSM45E 51.2

in. 50-3/4 43 75-1/8

mm 1289 1092 1908

in. 56-7/8 48 80-1/16

mm 1445 1219 2034

Efficiencies %

Natural Gas Propane

Figure 12

Model

No.

LSM40-2

LSM45-2

Notes

Diagrams, illustrations and photo­graphs are not to scale – consult
installation in structions. Product
design s, materials, dimensions,
specifications, colors and prices are
subject to change or discontinuance
without notice.

Vent Size

Co-axial DV

Vent Size

A B C D E F G H J

in. 50-5/8 37-1/4 42-7/8 25-5/16 34 37-5/8 33-3/32 29-9/32 34-3/4

mm 1286 946 1089 643 864 956 840 744 883

in. 56-11/16 42-1/4 47-7/8 28-3/8 40-1/8 43-5/8 38-3/32 34-1/2 40-59/64

mm 1440 1073 1216 721 1019 1108 968 876 1039

Fireplace Dimensions

8" Inner

11" Outer

10

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

C

Back wall of chase/enclosure

(including any finishing materials)

D

A

B

Right Side
Front Corner
Of Fireplace
Framing

6-1/4”

(159 mm)

19-5/8”

(498 mm)

Model

No.

LSM40-2

LSM45-2

Figure 13 - Corner Framing with Square Termination (SV8HTS)

Step 2. ROUTING GAS LINE

Route a 1/2" (13 mm) gas line along the inside
of the right side framing as shown in Figure

14. 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 22).

The incoming gas line should be piped into the
valve compartment and connected in one of the
two methods as shown in Figure 37 on Page 22.

Figure 14

Proper Sizing of Gas Line

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).

A B C D

in. 50-5/8 83-5/8 59-1/8 41-7/8

mm 1286 2124 1502 1064

in. 56-3/4 89-7/8 63-1/2 44-7/8

mm 1441 2283 1613 1140

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. We recommend
that a qualified individual such as a 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.

Inside Diameter (Inches)

Schedule 40 Pipe

Length (feet)

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

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

Schedule 40

Black Iron Pipe

Natural

Gas

Propane

Gas

Notes:

• All appliances are factory-equipped with

a flexible gas line connector and 1/2 inch
shutoff valve (see Figure 37 on Page 22).

• 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 22).

• 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.

• It is recommended to install a sediment trap

in the supply line as close as possible to the
appliance (see Figure 37). Appliances using
propane should have a sediment trap at the
base of the tank.

• Check with local building ofcial for local

code requirements (i.e. are below grade
penetrations of the gas line allowed?, etc.).

IMPORTANT: If propane is used, be aware that
if tank size is too small (i.e. under 100-lbs, if
this is the only gas appliance in the dwelling.
Ref. NPFA 58), there may be loss of pressure,
resulting in insufficient fuel delivery (which
can result in sooting, severe delayed ignition
or other malfunctions). Any damage resulting
from an improper installation, such as this,
is not covered under the limited warranty.

11

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

VENT RESTRICTOR INSTALLATION

RESTRICTOR

APPLIANCE VENT OUTLET

Install the restrictor as shown from

inside the unit, in the inner fireplace collar.

When vertically terminating the vent system above

the roof, install a vent restrictor in the top vent of

the fireplace outlet.

Step 3. INSTALL THE VENT SYSTEM

General Information

These instructions should be used as a guide­line and do not supersede local codes in any
way. Install vent according to local codes,
these instructions, the current National Fuel
Gas Code (ANSI-Z223.1) in the USA or the
current standards of CAN/CGA-B149.1 and

-B149.2 in Canada.

Ensure clearances are in accordance with
local installation codes and the requirements
of the gas supplier.

Dégagement conforme aux codes d'installation
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.

The vent system may not service multiple
appliances, and must never be connected to a
flue serving a solid fuel burning appliance. The
vent pipe is tested to be run inside an enclosing
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.

Installation of Vent Restrictor

A vent restrictor may be needed with this appli­ance. The restrictor is installed in the appliance
top flue outlet as shown in Figure 15,

For vertical venting from 6 feet to 12 feet or
more, from the top of the fireplace to the top
of the termination, the installation of a vent
restrictor is required.

If necessary, install a vent restrictor in the ap­pliance flue outlet as shown in Figure 15. It is
held in place by friction, only.

Note: The restrictor is included within the
firebox.

AIR INLET BAFFLE

GRATE

Figure 16

Select Venting System - Horizontal or Vertical

With the appliance secured in framing, de­termine vent routing and identify the exterior
termination location. The following sections
describe vertical (roof) and horizontal (exterior
wall) vent applications. Refer to the section
relating to your installation. A list of approved

venting components is shown on Page 30.

Figure 15

12

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

Termination

Flashing And
Storm Collar

Firestop/Spacer

SV8 6/12/24/36/48
Vent Sections

40' Max

(12.2 M)

6' Min

(1.8 M)

1" (25 mm)
Minimum
Clearance to
Combustibles

TRAHCHTGNELNOITCESTNEV

lanimoN

htgneLnoitceS

)sehcni(

6 21 42 63 84

T
O
T
A
L

Q
T
Y

noitceSteN

)sehcni(htgneL

2/1-4 2/1-01 2/1-22 2/1-43 2/1-64

tneVfothgieH snoitceStneVforebmuN

sehcni tf

5.4 573.0 1 0 0 0 0 1

9 57.0 2 0 0 0 0 2

5.01 578.0 0 1 0 0 0 1

51 52.1 1 1 0 0 0 2

5.91 526.1 2 1 0 0

0

3

12 57.1 0 2 0 0 0 2

5.22 578.1 0 0 1 0 0 1

5.52 521.2 1 2 0 0 0 3

5.13 526.2 0 3 0 0 0 3

5.43 578.2 0 0 0 1 0 1

5.73 521.3 1 1 1 0 0 3

5.34 526.3 0 2 1 0 0 3

54 57.3 0 0 2 0 0 2

5.64 578.3 0 0 0 0 1 1

5.94 521.4 1 0 2 0 0 3

15 52.4 1 0 0 0 1 2

5.55 526.4 0 1 2 0 0 3
75 57.4 0 0 1 1 0 2
66 52.5 0 2 2 0 0 4

5.76 526.5 0 0 3 0 0 3
96 57.5 0 0 0 2 0 2
27 6 1 0 3 0 0 4

5.37 521.6 1 0 0 2 0 3

5.97 526.6 0 1 0 2 0 3
18 57.6 0 0 0 1 1 2
09 5.7 0 2 1 0 1 4

5.

19 526.7 0 0 2 0 1 3

39 57.7 0 0 0 0 2 2
69 8 1 0 1 2 0 4

5.79 521.8 1 0 0 0 2 3

201 5.8 2 0 0 0 2 4

5.301 526.8 0 0 0 3 0 3

801 9 1 0 0 3 0 4
411 5.9 0 2 0 0 2 4
711 57.9 1 0 5 0 0 6

5.811 578.9 1 1 0 3 0 5

621 5.01 0 0 1 3 0 4

5.031 578.01 1 0 1 3 0 5
531 52.11 0 0 6 0 0 6
831 5.11 0 0 0 4 0 4

5.931 526.11 0 0 0 0 3 3

5.241 578.11 1 0 0 4 0 5

TRAHCHTGNELNOITCESTNEV

noitceSlanimoN
)sehcni(htgneL

6 21 42 63 84

T
O
T
A
L

Q
T
Y

noitceSteN

)sehcni(htgneL

2/1-4 2/1-01 2/1-22 2/1-43 2/1-64

tneVfothgieH snoitceStneVforebmuN

sehcni tf

441 21 1 0 0 0 3 4
051 5.21 0 1 0 0 3 4

5.451 578.21 1 1 0 0 3 5

5.061 573.31 0 2 0 0 3 5

5.271 573.41 0 0 0 5 0 5
771 57.41 1 0 0 5 0 6
381 52.51 0 1 0 5 0 6
681 5.51 0 0 0 0 4 4

5.091 578.51 1 0 0 0 4 5

5.691 573.61 0 1 0 0 4 5

5.502 521.71 0 1 1 5 0 7
702 52.71 0 0 0 6 0 6

5.112 526.71 1 0 0 6 0 7

5.712 521.81 0 1 0 6 0 7

5.922 521.91 0 0 1 6 0 7

5.232 573.91 0 0 0 0 5 5
732 57.91 1 0 0 0 5 6

5.142 521.02 0 0 0 7 0 7
642 5.02 1 0 0 7 0 8
252 12 0 1 0 7 0 8
462 22 0 0 1 7 0 8
672 32 0 0 0 8 0 8
972 52.32 0 0 0 0 6 6

5.

082 573.32 1 0 0 8 0 9

5.382 526.32 1 0 0 0 6 7

5.982 521.42 0 1 0 0 6 7

5.103 521.52 0 0 1 0 6 7

5.013 578.52 0 0 0 9 0 9
513 5.62 1 0 0 9 0 01

5.523 521.72 0 0 0 0 7 7
033 5.72 1 0 0 0 7 8
633 82 0 1 0 0 7 8
543 57.82 0 0 0 01 0 01

5.943 521.92 1 0 0 01 0 11
273 13 0 0 0 0 8 8

5.673 573.13 1 0 0 0 8 9

5.973 526.13 0 0 0 11 0 11

5.814 578.43 0 0 0 0 9 9
324 52.53 1 0 0 0 9 01
564 57.83 0 0 0 0 01 01

VERTICAL TERMINATION SYSTEMS (ROOF)

See Figure 17 and Figures 25 through 27 on
Page 16 and their associated Vertical Vent Tables

which illustrate the various vertical venting con­figurations that are possible for use with these
appliances. Secure Vent™ pipe applications
are shown in these Figures. A Vertical Vent
Table summarizes each system’s minimum and
maximum vertical and horizontal length values
that can be used to design and install the vent
components in a variety of applications.

The vertical vent system terminates through
the roof. The minimum vent height above the

roof and/or adjacent walls is specied in ANSI

Z223.1-(latest edition) (In Canada, the current

CAN/CSA-B149.1 installation code) by major

building codes. Always consult your local
codes for specific requirements. A general
guide to follow is the Gas Vent Rule (refer to

Figure 5 on Page 6).

Vertical (Straight) Installation

(Figure 17)

Determine the number of straight vent sections
required. 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) net section lengths are
available (see Tables on this page and Page
30 - Vent Sections). Plan the vent lengths so

that a joint does not occur at the intersection of
ceiling or roof joists. Refer to the Vent Section

Length Chart.

Figure 17

Effective Vent Length

Note: Convert inches into metric equivalent
measurement, as follows:

Millimeters (mm) = Inches x 25.4
Centimeters (cm) = Inches x 2.54
Meters (M) = Inches x .0254

Model Effective Length

SV4.5L6 4-1/2"
SV4.5L12 10-1/2"
SV4.5L24 22-1/2"
SV4.5L36 34-1/2"
SV4.5L48 46-1/2"

Table 7

13

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

13” Min.
(330 mm)

13” Min.
(330 mm)

Vertical (Offset) Installation

Analyze the vent routing and determine the
quantities of vent sections and number of elbows
required. Refer to Vertical Vent Figures and
Tables on Page 16 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 13 for an aid in select-
ing length combinations. Elbows are available
in 90° and 45° configurations. Refer to Figure
21 on Page 15 for the SV8 E45 and SV8 E90
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 3" (76 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

Ceiling
Framing

Plumb
Bob

Figure 18

B. Attach vent components to appliance - Se­cure Vent SV8 direct-vent system components

are unitized concentric pipe components
featuring positive twist lock connections (see
Figure 19).

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.

Align the dimple (four places) of the
upper vent section with the opening
of the locking incline channel on
the lower vent section or appliance
collar. Twist vent component clock­wise to engage and seal until arrow

Arrow

Appliance Collar or
Vent Section

and dimple align.

Dimple

Locking Incline
Channel

Connected Vent
Sections

Arrow

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.

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.
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.

D. Install firestop/spacer at ceiling - When

using Secure Vent, use SV8BF restop/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. Attic insulation
shield (H3908) may be used to obtain the
required clearances indicated here. See
installation accessories on Page 30. The gap

between the vent pipe and a vertical firestop
can be sealed with non-combustible caulking.

E. Support the 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.

Blocking

Support Straps
(Plumber's tape)

8 feet (2.4 m)

Maximum

1 inch (25.4
mm) minimum
clearance to
combustibles

Figure 20

14

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

C

D

Storm
Collar

One method of support is by utilizing field pro­vided support straps (conventional plumber's
tape). Secure the plumber's tape to the framing
members with nails or screws. Strap the tape
around the vent, securing the ends of the tape
to the framing. If desired, sheet metal screws
#6 x 1/2" length may be used to secure the
support straps to the vent pipe. See Figure 20.

F. Change vent direction to horizontal/inclined
run - At transition from or to a horizontal/inclined

run, install the SV8 E45 and SV8 E90 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 14 and Figure 21.

10"

(254mm)

Swivel Joint

(360° swivel)

SV8E45

(45° Elbow)

6"

(153mm)

Swivel Joint

(360° swivel)

SV8E90

(90° Elbow)

Figure 21

Framing Dimensions for Roof

Inches (millimeters)

Pitch C D

0/12

6/12

12/12

13 in.

(330 mm)

13 in.

(330 mm)

13 in.

(330 mm)

13 in.

(330 mm)
15-1/2 in.

(394 mm)
20-1/2 in.

(541 mm)

Figure 22 - Roof Framing

I. Install the 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 ashing or adjust roong 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.

K. Install the vertical termination - The
final step involves installation of the Vertical
Termination. Extend the vent sections to the
height as shown in the "Vertical vent termina­tion section" on Page 6. The SV8VTR Vertical
Termination (Figure 24) can be installed in the
exact same fashion as any other Secure Vent™
section. 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.

G. Continue installation of horizontal/inclined
sections - Continue with the installation of the

straight vent sections in horizontal/inclined run
as described in Step C. Install support straps
every 3' (914 mm) along horizontal/inclined
vent runs using conventional plumber’s tape.

See Page 17, Figure 28. It is very important
that the horizontal/inclined run be maintained
in a straight (no dips) and recommend to be in
a slightly elevated plane, in a direction away
from the fireplace 1/4" per foot (20 mm per
meter) which is ideal, through rise per foot run

ratios that are smaller are acceptable all the way
down to at or near level. Use a carpenter’s level

to measure from a constant surface and adjust

the support straps as necessary.

It is important to maintain the required clear­ances to combustibles: 1" (25 mm) at all sides
for all vertical runs; and 3" (76 mm) at the
top, 1" (25 mm) at sides, and 1" (25 mm) at
the bottom for all horizontal/inclined runs.

H. Frame roof opening - Identify location for
vent at the roof. Cut and/or frame opening per
Roof Framing Chart (Figure 22).

J. Install the storm collar - Install the storm
collar, supplied with the flashing, over the vent/
ashing joint (see Figure 23). Loosen the storm
collar screw. Slide collar down until it meets

the top of the ashing. Tighten the adjusting

screw. Apply non-combustible caulking or

mastic around the circumference of the joint

to provide a water tight seal.

Storm

Flashing

Collar

Figure 23

Figure 24

If the vent system extends more than 5 feet (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 congurations.

15

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

V

H

1

H

V

1

Ceiling
Firestop/Spacer
(SV8BF)

Wall
Firestop/Spacer
(SV8HF)

H

V

V1

Ceiling

Firestop/Spacer

(SV8BF)

40 feet (12.2 meters)

Maximum

6 feet (1.8 meters)

Minimum

Ceiling

Firestop/Spacer

(SV8BF)

VERTICAL VENT FIGURES/TABLES

Notes:

• SecureVent™(rigidventpipe)isshown

in the Figures.

• It is very important that thehorizontal/

inclined run be maintained in a straight (no
dips) and recommended to be in a slightly

elevated plane, in a direction away from the
fireplace of 1/4" rise per foot (20 mm per
meter) which is ideal, though rise per foot
run ratios that are smaller are acceptable all
the way down to at or near level.

• SV8BF (Secure Vent) firestop/spacer must

be used anytime vent pipe passes through a
combustible floor or ceiling. SV8HF (Secure
Vent) firestop/spacer must be used anytime
vent pipe passes through a combustible wall.

• Two 45 degree elbows may be used in place

of one 90 degree elbow. The same rise to
run ratios, as shown in the venting figures
for 90 elbows, must be followed if 45 degree
elbows are used.

H Maximum

feet (meter) feet (meter)

10 (3.1) 2.5 (0.762)
15 (4.65) 3.5 (1.07)
20 (6.2) 4.5 (1.37)

V + V

V + V1 = 11 feet (3.3 meters) Minimum for LSM40-2

V + V1 = 10.5 feet (3.2 meters) Minimum for LSM45-2

1

Table A

+ H = 40 feet (12.4 meters) Max.

Example: If 20 feet of (H)
horizontal vent run is needed,
then 4-1/2 feet minimum of (V)
vertical vent will be required.

V Minimum

A Vent Restrictor, as shown in Figure 15 on
Page 12, may need to be used in this application

Figure 25 - Top Vent - STRAIGHT

Figure 26 - Top Vent - Corner Framing with Square Termination (SV8HTS)

TWO 90 DEGREE ELBOWS

Table B

H + H

Maximum

1

feet (meter) feet (meter)

10 (3.1) 2.5 (0.762)
15 (4.65) 3.5 (1.06)
20 (6.2) 4.5 (1.37)

H + H1 = 20 feet (6.2 m) Max.

V + V1 + H + H1 = 40 ft. (12.4 m) Max.

V + V1 = 11 feet (3.3 meters) Min. for LSM40-2

V + V1 = 10.5 feet (3.2 meters) Min. for LSM45-2

V Minimum

Example: If 20 feet of (H+ H
tal vent run is needed, then 4-1/2 feet
minimum of (V) vertical vent will be
required.

Figure 27 - Top Vent - THREE ELBOWS

) horizon-

1

16

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

TYPICAL HORIZONTAL VENT INSTALLATION

HORIZONTAL (OUTSIDE WALL)
TERMINATION SYSTEM

See Figures 28, 31, 32 and 33 on Pages 17,
19 and 20 and their associated Horizontal Vent

Table which illustrate the various horizontal
venting configurations that are possible for

Building

Support

Framing

SV8E90

Elbow

Support

Brackets

Horizontal / Inclined Run

use with these appliances. Secure Vent™
pipe applications are shown in these Figures.
A Horizontal Vent Table summarizes each
system’s minimum and maximum vertical and
horizontal length values that can be used to
design and install the vent components in a
variety of applications.

The horizontal vent system terminates through

Vertical

Rise

Ceiling

Firestop/Spacer

Support Bracket Spacing
Every 3 ft (914 mm)

SV8 L6/12/24/36/48

Vent Sections

2-1/2 Foot Vertical

Vent (min.)

an outside wall. Building Codes limit or prohibit

terminating in specific areas. Refer to Figure 7
on Page 7 for location guidelines.

Fireplace

SV8HTS
Termination
Shown

Exterior
Wall

SV8HTS
Termination
Shown

Exterior
Wall

Secure Vent SV8 direct-vent system compo­nents are unitized concentric pipe components
featuring positive twist lock connection, (refer
to Figure 19 on Page 14). 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.

A. Plan the vent run -
Analyze the vent routing and determine the
types and quantities of sections required
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) net section lengths are available. It is
recommended that you 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 15.

Maintain a minimum 1" (25 mm) clearance
to combustibles on the vertical sections.
Clearances for the horizontal runs are; 3"
(76 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 dimen­sions shown in Figure 12 on Page 10.
Cut and/or frame an opening, 15" x 13"
(381 mm x 330 mm) inside dimensions, with
9" 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
(refer to Figure 18 on Page 14).

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 (refer to Figure

19 on Page 14).

Figure 28

Support the vertical portion of the venting system
every 8 feet (2.4m) above the fireplace vent outlet.

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.

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 14.

F. Install firestop/spacer at ceiling -

When using Secure Vent, use SV8BF restop/
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.

G. Support the vertical run sections -
See Section E on Page 14.

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 14).

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, it is very important that the

horizontal/inclined run be maintained in a
straight (no dips) and recommended to be in
a slightly elevated plane, in a direction away
from the fireplace of 1/4" rise per foot (20 mm
per meter) which is ideal, though rise per foot

run ratios that are smaller are acceptable all the
way down to at or near level.

It is important to maintain the required clear­ances to combustibles: 1" (25 mm) at all sides
for all vertical runs; and 3" (76 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.

17

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

Firestop/Spacer (SV8HF) shown

on the exterior side of the wall. It

may also be installed on the

interior side.

SV8HTS

Termination

Shown.

13"

(330mm)

8 ¹⁄₂"

(216)

6 ¹⁄₂"

(165 mm)

15"

(381 mm)

Note: Centerline of Vent Piping is

NOT the Same as the Centerline of

the Framed Opening.

6 to 48 inch Vent Section,

Telescopic vent section.

See Figure 9 on page 7

for Min. Distance to Base

of Appliance.

Base of Appliance

3"

(76 mm)

Adapter

SV8RCH

1"

(25 mm)

1"

(25 mm)

Siding

Stucco

1- 1/4 ” M a xim um Rec ess of
Sq uare Te r minat ion in t o
Exterior Fin is hi ng Material

Exterior Surface of

Framing

5 in. to 8-1/2 in.

(127 to 216 mm)

Exterior Surface of Siding

Minimum wall thickness

5 in. (127 mm)

Interior Surface of

Finished Wall

Maximum wall thickness

8-1/2 in. (216 mm)

SV8HTS

Square Termination

shown

Ma xim um Ext ent of
Ve nt Run Sect ion s
Rela tiv e to E xteri or
Su rfa ce of Fr ami ng

Last Vent Section. Use
T e le s co p ic V en t
Section ( SV8LA), If
Necessary

Adapter

SV8RCH

SV8HTS

Square Termination

Shown

Venting Connection and Exterior Wall Recessing

of the Horizontal Square Termination (SV8HTS).

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. 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 SV8HTS termination is to be attached, see
Figure 30 and Table 8.

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 19. This table lists
the additional venting components needed (in
addition to the termination and adaptor) for a
particular range of wall thicknesses.

K. Attach termination adaptor - Attach the

See Figure 12 on Page 10 for Minimum
Distance to Base of Appliance

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

Figure 29

Installing the Square Horizontal Termination (SV8HTS)

(refer to Step E).

L. Install Firestop/Spacer at exterior wall

- When using the square termination, install

SV8HF Firestop/Spacer over the opening at the
exterior side of the framing, long side up, with
the 3 inch spacer clearance at the top as shown
in Figure 29, and nail into place.

(The Firestop/Spacer may also be installed over
the opening at the interior side of the framing).

M. Install the square termination (SV8HTS)-
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.

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.

18

u

For wall thicknesses greater than

Figure 30 - Wall Thickness and Horizontal Termination Requirements

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 the installation instructions for the termination, including
the use of silicone caulking where required.

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

u

8-1/2 inches, see Table 8

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

H

V

Wall Firestop/Spacer

(SV8HF)

Ceiling

Firestop/Spacer

(SV8BF)

See Table 8 as an aid in venting component selection for a particular
range of exterior wall thicknesses.

Venting Components Required for Various Exterior Wall Thick-

nesses, when using Square Termination Kit (SV8HTS)

Vent Components Required Exterior Wall Thickness - inches (mm)

Termination Kit Only 5 to 8-1/2 (127 to 216)

Termination Kit and 6 In. Vent

Section (SV8L6)
Termination Kit and Tele-

scopic Section (SV8LA)
Termination Kit and Tele-

scopic Section (SV8LA) and

9-3/4 to 14 (248 to 356)

6-3/4 to 15-1/4 (171 to 387)

11-1/4 to 19-3/4 (286 to 502)

6 in. vent section (SV8L6)

Table 8

Table C

H Maximum

V Minimum

feet (meter) feet (meter)

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 = 40 feet (12.4 m) Max.

H = 20 ft. (6.2 m) Max.

Example: If 20 feet of (H) hori­zontal vent run is needed, then
10 feet minimum of (V) vertical
vent will be required.

HORIZONTAL VENT FIGURES/TABLES

Notes:

• SecureVent™ components (rigid vent pipe and terminal) are shown

in the Figures.

• Two 45 degree elbows may be used in place of one 90 degree elbow.

The same rise to run ratios, as shown in the venting figures for 90
elbows, must be followed if 45 degree elbows are used.

• SV8BF (Secure Vent) firestop/spacer must be used anytime vent pipe

passes through a combustible floor or ceiling. SV8HF (Secure Vent)
firestop/spacer must be used anytime vent pipe passes through a

combustible wall.

• Itisveryimportantthatthehorizontal/inclinedrunbemaintained

in a straight (no dips) and recommended to be in a slightly elevated
plane, in a direction away from the fireplace of 1/4" rise per foot (20
mm per meter) which is ideal, though rise per foot run ratios that are
smaller are acceptable all the way down to at or near level.

Square termination (SV8HTS) shown.

See Table 8 as an aid in venting component selection for
a particular range of exterior wall thicknesses.

Figure 31 - Top Vent - ONE 90 DEGREE ELBOW - ELBOW CONNECTION NOT DIRECTLY AT APPLIANCE

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

19

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

V

H

H

1

Wall Firestop/Spacer

(SV8HF)

Wall Firestop/Spacer

(SV8HF)

Ceiling

Firestop/Spacer

(SV8BF)

V

H

H

1

V

1

Wall Firestop/Spacer

(SV8HF)

Ceiling

Firestop/Spacer

(SV8BF)

Wall

Firestop/Spacer

(SV8HF)

Ceiling

Firestop/Spacer

(SV8BF)

HORIZONTAL VENT FIGURES/TABLES

(continued)

Table D

V Minimum

See Table 8 on Page 19 as an aid in venting component selection for a particular range of
exterior wall thicknesses.

H

+ H

Maximum

1

feet (meter) feet (meter)

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 feet (12.4 m) Max.

H + H

= 20 ft. (6.2 m) Max.

1

Figure 32 - Top Vent - TWO 90 DEGREE ELBOWS

Table E

H

+ H1 = 20 feet (6.2 m) Max.

V + V

+ H + H1 = 40 ft. (12.4 m) Max.

1

V = 2.5 feet Min. (0.762 m)

V + V

= 11 feet (3.35 m) Min. for LSM40-2

1

V + V

= 10.5 feet (3.2 m) Min. for LSM45-2

1

20

See Table 8 on Page 19 as an aid in venting component selection for a particular range of exterior wall thicknesses.

Figure 33 - Top Vent - THREE 90 DEGREE ELBOWS

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

Thermopile

TH

TP

TH

TP

Millivolt Wiring Diagram

If any of the original wire as supplied must be replaced,
it must be replaced with Type AWM 105° C – 18 GA. wire

*OR OPTIONAL WALL-MOUNTED ON/OFF SWITCH OR
OPTIONAL REMOTE CONTROL RECEIVER

*Turn the appliance-mounted ON/OFF burner control switch

to the OFF position if an optional

control switch is installed.

Factory Wired

Field Wired

Schematic Representation Only

APPLIANCE-MOUNTED ON/OFF SWITCH

ELECTRONIC

WIRING DIAGRAM

BLK

W

120 V.

24 V.

TRANSF

ELECTRONIC IGNITION

CONTROL BOARD

*WALL MOUNTED ON/OFF SWITCH (OPTIONAL)

OR REMOTE CONTROL RECEIVER

APPLIANCE MOUNTED

ON/OFF SWITCH

PILOT BURNER
IGNITER-SENSOR
ASSEMBLY

GAS VALVE

EV2

EV1

GROUND

CONNECTOR

GREEN LED

WHITE (6)

WHITE (20)

ORANGE (20)

BLACK (20)

PURPLE (9)

GREEN (12)

BLUE (20)

BLACK (16)

WHITE

FIELD WIRED

FACTORY WIRED

*Turn The Appliance-Mounted ON/OFF Burner Control Switch
To The OFF Position If An Optional Control Switch Is Installed

Black
White
Ground

Junction Box

120 VAC

Step 4. FIELD WIRING

CAUTION

Ground supply lead must be con­nected to the wire attached to the
green ground screw located on
the outlet box. See

36. Failure to do so will result in a

Figures 35 and

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. (In Canada,

the current CSA C22-1 Canadian
Electrical Code).

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 peu­vent entraîner un fonctionnement inadéquat
et dangereux.

Verify proper operation after servicing.

S'assurer que l'appareil fonctionne adé­quatement une fois l'entretien terminé.

Refer to Section A for millivolt appliances and

Section B for electronic appliances. The gas

valve is set in place and pre-wired at the factory
on both models.

A. Millivolt Wiring (See Figure 34) –

1. Appliance-mounted ON/OFF burner control

switch (rocker switch) is factory installed.
Optional wall-mounted switch, or one of
the optional remote control kits may also
be used.

2. If wall-mounted ON/OFF control is selected

mount it in a convenient location on a wall
near the fireplace.

3. Wire the control switch within the millivolt

control circuit using the 15 feet of 2 conduc­tor wire supplied with the unit.

Note: The supplied 15 feet of 2 conductor wire

has one end of each conductor connected
to the gas valve circuit and the other end of
each conductor placed on top of the unit.

CAUTION: Do Not connect the optional wall

switch to a 120V power supply.

4. If an optional control switch is installed,

turn the appliance-mounted ON/OFF burner
control switch to the OFF position.

B. Electronic Wiring
(See Figures 35 and 36)

Note: The electronic appliance must be con­nected to the main power supply.

1. Route a 3-wire 120Vac 60Hz 1ph power

supply to the appliance junction box.

2. Remove the electrical inlet cover plate from

the side of the unit by removing the plate's
securing screws (see Figure 12 on Page 10).

3. Remove the cover plate's knockout and then

feed the power supply wire through the knock-

out opening and into the unit junction box.

4. Connect the black power supply wire to the

power outlet's red pigtail lead and the white

power supply wire to the common terminal of
the outlet as shown in Figures 35 and 36.

5. Connect the ground supply wire to the

pigtail lead attached to outlet's green
ground screw.

6. Appliance-mounted ON/OFF burner control

switch (rocker switch) is factory installed.
Optional wall-mounted switch, or one of
the optional remote control kits may also
be used.

7. If wall-mounted ON/OFF control is to be

used, mount it in a convenient location on
a wall near the fireplace.

8. If an optional control is to be used, wire it in

the low voltage circuit (see Figure 35).

Note: The supplied 15 feet of 2 conductor wire
has one end of each conductor connected in
parallel with the appliance mounted ON/OFF
burner control switch and the other end of each
conductor placed on top of the unit.

CAUTION: Do Not connect the optional wall
switch to a 120V power supply.

9. If an optional control switch is installed,

turn the appliance-mounted ON/OFF burner
control switch to the OFF position.

10.After the wiring is complete, replace the

cover plate.

Figure 34

Figure 35

See Figure 36 for detailed
drawing of junction box /
receptacle wiring

21

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

Piezo
Igniter

Gas Valve

ON/OFF Switch

Access Plate

Right Side

Modesty Panel

Hi-Lo

Extension Knob

Gas
Valve

3/8" NPT x

Flare Fitting

3/8" Flex Tubing

3/8" Nipple

3/8" Union

3/8" Close
Nipple

3/8" Shut-off Valve

1/2" x 3/8"

Reducer

Gas

Stub

1/2" x 3/8" Flare

Shut-off Valve

Gas Solid Line Connector

Gas Flex Line Connector

*Sediment
Trap

3"

Min

J-BOX/RECEPTIACLE

WIRING

120V, 60HZ, 1PH

Factory Wired

Field Wired

Junction Box

Tab Intact

Tab
Intact

n e e r G - d n u o r G

e t i h W - l a r

t
u e N

120 VAC - Black

Green
Ground
Screw

White

Green

Neutral
Side of
Receptacle

Hot
Side of
Receptacle

Black

Figure 36- J-BOX WIRING

Step 6. CONNECTING 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 37 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 locality. Instal­lation must be in compliance with local codes.
These appliances are equipped with a gas flex­line for use in connecting the unit to the gas line.
See Figure 37 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 front door assembly
on the valve access side and the access plate
(refer to Figure 38).

The millivolt and electronic control valve has
a 3/8" (10 mm) NPT thread gas supply inlet.

Bring the shutoff valve on the end of the ex-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 propane
resistant compounds are used in propane ap­plications). It is recommended to seal around
the gas line to prevent cold air leakage.

22

Step 5. REMOVE GLASS DOOR FRAME

Remove glass door assembly. See Removing
Glass Enclosure Panels on Page 26.

Figure 37 - GAS CONNECTION

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

Figure 38

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.

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

ELECTRONIC

Flame

Sensor

Hood

Ignitor Rod

Pilot
Nozzels

MILLIVOLT

Thermocouple

Hood

Igniter Rod

3/8" Min

(9 mm)

Thermopile

Pilot
Nozzels

TEST ALL CONNECTIONS FOR GAS LEAKS
(FACTORY AND FIELD):

WARNING

Never use an open flame to
check for leaks.

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 (refer to the lighting

instructions label in the control compartment
or in the Care and Operation Instructions
manual).

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
gas control knob (off/pilot/on) 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. Re-install the access plate, making certain the

gasket has not been damaged.

Step 7. CHECKING APPLIANCE
OPERATION

Turn on burner then observe the individual
tongues of flame on the burner. 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 gas line installed run initial system check­out before closing up the front of the unit.
Follow the pilot lighting instructions provided.
For piezo igniter location refer to Figure 38
(millivolt appliances only).

Note: Lighting Instructions are also found on
the literature tag tied to the bracket above the
gas valve. To access the tag, reach into the
right side opening.

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 in the instruction
manual. Subsequent lighting of the appliance will
not require such purging. Inspect the pilot flame
(remove logs, if necessary, handling carefully).

Millivolt Appliance Checkout

The pilot flame should be steady, not lifting
or floating. Flame should be blue in color with
traces of orange at the outer edge.

The top 3/8" (10 mm) at the pilot generator
(thermopile) and the top 1/8" minimum (tip)
of the quick drop out thermocouple should be
engulfed in the pilot flame.

Figure 39

Electronic Appliance Checkout

To light the burner, turn ‘ON’ the optional remote
wall switch or turn the appliance mounted ON/
OFF switch to the “ON” position. Ensure the
igniter lights the pilot. The pilot flame should
engulf the flame sensor as shown in Figure 40.

The ame should project 1" (25 mm) beyond

the hood at all three ports (see Figure 39).
Replace logs if removed for pilot inspection.

To light the burner; rotate the gas valve control
knob counterclockwise to the “ON” position
(“ON” will be at the bottom side of the valve)
and turn “ON” the appliance mounted ON/
OFF switch.

Figure 40

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

23

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

Step 8. LOG, VERMICULITE, VOLCANIC STONE AND GLOWING
EMBER PLACEMENT

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.
The size and position of the log set was engi-

•

neered 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.
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 grate, volcanic
stone, vermiculite, embers and logs.
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.
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.

REFERENCE - Firebox Accessories / Parts

Cat. No. Model Description

88L53 FGE Bag of Glowing Embers
80L42 FDVS Bag of Volcanic Stone
H6319 Bag of Vermiculite

Figure 41

For Propane Gas Only, Do Not Place Embers On Main Ports

Step 1. Install the ceramic panels per the instructions provided in kit

(reference form #750182M).

Step 2. Place a mixture of volcanic stone and vermiculite around the

burner as shown in Figure 43.

Step 3. Separate the glowing embers (rockwool) into pieces about the

size of a quarter (see Figure 41). Keep the pieces uffed, not
matted. Distribute these pieces over the burner as shown in
Figure 42. Do not use more than necessary. When properly
positioned, the Glowing Embers will cover approximately 75%
of the burner on natural gas. For propane gas, do not place
embers on main ports.

Note: Excessive use of embers may result in sooting or poor flame.
This appliance is provided with enough Glowing Embers for several
applications, do not feel compelled to use all that is in a new bag. For
best glowing effect, replace the ember material annually. Replacement
Glowing Embers are available (Catalog Number 88L53).

Step 4. Position the individual logs as shown in Figures 44 through 48.

Logs should be placed in the order shown. Place logs 2 and 3
against the pins on the grate, NOT over them.

Proper log and twig placement is critical to encourage outstand-

ing flame appearance and prevent sooting. When positioned
properly as shown, twigs will be positioned between flame
peaks and will not impinge any flames. Positioning is the same
for all colors of log sets.

Glowing Embers (Rockwool)

Figure 42

Mixture Of Volcanic Stone And Vermiculite

Figure 43 - (LSM45-2 Shown)

24

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

LSM40-2 & LSM45-2 Log Placement

2

6

Figure 44

3

7

5

1

Log Number Description

1 Log, Center
2 Log, Rear
3 Log, Center/Left
4 Log, Center/Right
5 Log, Rear/Top
6 Log, Front/Left
7 Log, Front/Center

2

4

Figure 46

Align Groove At The Bottom Of Log (2) Over
The Grate And Push It Towards The Rear.

3

4

Figure 45

1

Align Two Holes At Bottom Of Log (1)
Over The Pins On The Gas Burner.

Engage Logs (3 & 4) With The Grate Pins And Align Groves At
The Bottom Of The Logs Over The Grate.

Figure 47

6 5

Engage Log (6) With The Grate Pin
And Align Groove At The Bottom Of
The Log Over The Grate.

Align Hole At Bottom Of Log (5)
Over The Pin On Log (2).

Engage Log (7)
With The Pin On
Log (4).

Figure 48

7

2

4

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

25

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

Step 9. INSTALLATION AND REMOVAL
OF GLASS DOOR

WARNING

• When reinstalling the glass

door, the door latch screws
must be securely tightened
to prevent the glass door
from falling out, which could
potentially cause damage and
possible injury.

• Do not attempt to substitute the

materials used on this door,
or replace cracked or broken
glass.

• Handle this glass with extreme

care! Glass is susceptible to
damage – Do not scratch or
handle roughly while reinstall­ing the glass door frame.

• The glass door of this appli-

ance must only be replaced
as a complete unit as provided
by the manufacturer. Do not
attempt to replace broken,
cracked or chipped glass sepa­rately.

• Do not attempt to touch the

front enclosure glass with your
hands while the fireplace is in
use.

WARNING

Do not operate appliance with
the glass front removed, cracked
or broken.

AVERTISSEMENT

Ne pas utiliser l'appareil si le
panneau frontal en verre n'est
pas en place, est craqué ou
brisé.

Only doors certified with the appliance
shall be used.

Seules des portes certifiées pour cet
appareil doivent être utilisées.

CAUTION: DO NOT abuse glass door by
striking or slamming shut.

Installing Glass Enclosure Panel
(see Figure 49)

Retrieve the glass door. Visually inspect the
gasket on the backside of the frame. Gasket
surface must be clean, free of irregularities
and seated firmly.

Position the door in front of the firebox opening
with the top of the door held away from the
fireplace (Figure 49). Lower the bottom of the
door assembly on the bottom door track and
set on padded surface. Pivot the door up after
engaging and centering in the base channel.

Using a Phillips screwdriver, fasten the door
frame to the door latch with the two (2) screws.
The latch should pull forward to engage the
door frame.

Install the door modesty shield on top flange
glass door as follows: grab the door modesty
shield with both hands, with the open hem
going down and engage it with the upper lip
of the glass door frame by pushing it all the
way down. Make sure the installed shield is
firmly in place.

With the firescreen hanging on the screen rod,
insert the right side of the rod into the existing

hole on the right modesty panel. Bend down

the rod at the center and drop the left end into
the slot on the left modesty panel, being careful
not to scratch the paint.

Top Flange Glass door
assembly

Screws

Firebox Floor

Glass Door Assembly

Glass Door Latch (2)

INSTALLING THE GLASS DOOR

Figure 49

Step 10. BURNER ADJUSTMENTS

Flame Appearance and sooting

Proper flame appearance is a flame which 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
15 minutes of operation. After 15 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, rst 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 ames which

candle or appear stringy. If this is present

and persists, adjust the air shutter to a more

closed 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.

Air Shutter Adjustment Guidelines:

Amount of

Primary Air

If air shutter is
closed too far

If air shutter is
open too far

Flame

Color

Flame will
be orange

Flame will
be blue

Air Shutter

Adjustment

Air shutter
gap should be
increased

Air shutter
gap should be
decreased

26

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

Air Shutter

Opening

Burner

Orifice

Gas

Valve

Venturi

Venturi

Burner Air Shutter Adjustment Procedure

WARNING

• Air shutter adjustment should
only be performed by a quali­fied professional service
technician.

• Ensure that the front glass

door assembly is in place and
sealed After adjustment.

Main Burner Factory Air Shutter

Opening Setting - Inches (millimeter)

Model Nat.Gas Propane Gas

LSM40-2

LSM45-2

1/16 (1.59) 9/32 (7.14)
1/16 (1.59) 9/32 (7.14)

CAUTION

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.

To adjust the ame, rotate the air shutter toward

the back or toward the front of the fireplace.
Position the air shutter to the factory setting as
shown in the table in Figure 50. Allow the burner
to operate for at least 15 minutes. Observe the
flame continuously. If it appears weak or sooty

as previously described, adjust the air shutter

until the flame appearance is as desired.

Use the extension knob (refer to Figure 38), to
adjust the flame height as desired, by sliding
the knob over the variable flame adjustment
knob located on the front of the valve. Replace
the extension knob back to the hanger after
the adjustment.

Propane models may exhibit a flame pattern
that may candle or appear stringy. If this is
problematic or persists as the appliance is

continually operated, adjust the air shutter

closed as described in the previous paragraphs.
Operate the appliance for a period of time as the
effect diminishes, ensuring that the appliance
does not develop sooty flames. When satisfied
that the appliance operates properly, proceed
to finish the installation.

Figure 50

(Birch Logs Shown) LSM40-2

Figure 51 - Burner Flame Appearance

(Rustic Oak Logs Shown) LSM45-2

Leave the control knob in the ON position and
the remote switch OFF.

Figure 52 - Burner Flame Appearance

27

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

Glass Door

Assembly

Fireplace

Finish Combustible
Or Non-Combustible
Material

Bottom Of
Fireplace

1/8 Inch
Minimum

Door Track

Finish Combustible
Or Non-Combustible
Material

Front Face
Of Fireplace

Floor Panel

* Insulation is NOT ALLOWED in the clearance zones around vent

Installations with horizontal terminations which have minimum

FINISHING REQUIREMENTS
Wall Details

Complete 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).

Combustible
Finished Wall
Materials

Header
(2x4’s)

Combustible
materials are
allowed above
this point on
the face of the
appliance.

8-3/8" Min.

(213 mm)

The gray shaded
area must be
non-combustible
or Dura Rock

Vent & 90° Elbow

Appliance

3" Min.

(76 mm)*

2 Foot Vertical

1

*

Top of

Spacers

Non-combustible materials, such as surrounds and other appliance trim,
may be installed on the appliance front face with the exceptions.

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.

Combustible materials may project beyond the side of the replace open­ing as long as it is kept within the shaded area illustrated in Figure 10.

Top of Door Frame

Fireplace (right side)

1

vertical vent height only will require 4”(102mm) minimum
side clearance as shown in shaded zone above. All other
installations require 1" (25mm) minimum side clearance as
specified in Table 4 on Page 5.

components. Keep this area free from combustible materials.

28

Figure 53

A hearth extension is not required with this appliance. If a hearth extension
is used, there are two methods of installation. One, the finish combustible
or non-combustible material could be ended by butting up against the
front face of the fireplace and the floor panel (refer to Figure 54).

Two, the finish combustible or non-combustible material could be ended
below the fireplace (refer to Figure 55). Remove the floor panel as shown
in Figure 54 by removing the screws on the right side of the panel and
sliding the left side away from the tab. Discard the screws and floor panel.

It is critical that there is at least a 1/8" gap between the bottom of the
door track and the surface of the finish material.

Figure 54

Figure 55

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

Step 11. ATTACHING SAFETY-IN-OPERATION WARNINGS
It is the installers 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

Your fireplace has been furnished with safety instruc­tion labels that are to be affixed to the operation and
control point of the fireplace. A safety instruction
label should be affixed to the wall switch plate where
the fireplace is turned on and off (See Figure A) or
wall thermostat (See Figure B) and if used on the
remote control handheld transmitter (Figure C).
The warnings should already have been put in place
when the fireplace initial set-up was completed.
If they are not affixed at these spots, locate the
multi-lingual adhesive labels provided with these
instructions and proceed as follows:

1. Locate the wall switch or wall thermostat that
controls the fireplace (verify the switch operates
the fireplace by turning it on and off). Clean the
wall switch plate or wall thermostat thoroughly
to remove any dust and oils. Affix the label to
the surface of the plate of the wall switch that
controls the fireplace (Figure A) or the wall
thermostat (Figure B). Choose the language
primarily spoken in the home.

2. If a remote control is used to control the fireplace,
locate the transmitter and clean it thoroughly
to remove any dust and oils. Affix the label to
the surface of handheld transmitter (Figure C).
Choose the language primarily spoken in the
home.

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.

APPOSITION DES MISES EN GARDE RELATIVES
À LA SÉCURITÉ D’UTILISATION

Votre foyer a été livré avec des étiquettes de sécurité qui
doivent être collées à côté des dispositifs de contrôle
du foyer. Une étiquette de sécurité doit être collée sur
la plaque de l’interrupteur contrôlant l’allumage du
foyer (voir Figure A) ou sur le thermostat mural (voir
Figure B) et, le cas échéant, sur le boîtier de la télé-
commande (Figure C). Les mises en garde auraient dû
être collées au moment de l’installation initiale du foyer.
Si ce n’est pas le cas, prenez les étiquettes adhésives
multilingues fournies avec ces instructions et procédez
comme suit:

1. Repérez l’interrupteur ou le thermostat 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 murale de l’interrupteur
ou le thermostat mural pour éliminer la poussière
et les traces de graisse ou d’huile. Collez l’étiquette
sur la surface de la plaque de l’interrupteur mural
qui contrôle le foyer (Figure A) ou du thermostat
mural (Figure B). Choisissez la langue qui est
principalement parlée dans la résidence du
propriétaire.

2. Si une télécommande est utilisée pour contrôler
le foyer, nettoyez la soigneusement pour éliminer
la poussière et les traces de graisse ou d’huile.
Collez l’étiquette sur le boîtier de la télécommande
(Figure C). Choisissez la langue qui est principale-
ment parlée dans la résidence du propriétaire.

3. Si vous ne trouvez pas les étiquettes, veuillez
appeler Lennox Hearth Products ou votre distribu­teur Lennox Hearth Products local pour recevoir
gratuitement des étiquettes supplémentaires.

Étiquettes de remplacement, n° cat. H8024

LENNOX HEARTH PRODUCTS
1-800-9-LENNOX

Remarque : Le texte anglais est rouge sur un support
transparent. Le texte français et espagnol est blanc
sur un support noir.

COLOCACIÓN DE ADVERTENCIAS DE
SEGURIDAD EN OPERACIÓN

Su chimenea incluye etiquetas de instrucciones de
seguridad que deben colocarse en el punto de operación
y control de la chimenea. Se debe colocar una etiqueta de
instrucciones de seguridad en la placa del interruptor de
pared desde el cual se enciende y se apaga la chimenea

(ver la Figura A) o en el termostato de pared (ver la Figura
B) y en el transmisor de control remoto (Figura C) si

se usa. Las advertencias ya deben haberse colocado
cuando se completó la instalación inicial de la chimenea.
Si no están colocadas en estos lugares, encuentre las
etiquetas adhesivas multilingües proporcionadas con
estas instrucciones y prosiga de la siguiente manera:

1. Identifique el interruptor o el termostato de pared
que controla la chimenea (verifique que el interruptor
opera la chimenea encendiéndola y apagándola).
Limpie bien la placa del interruptor o el termostato de
pared para quitar el polvo y aceite. Pegue la etiqueta
en la superficie de la placa del interruptor que controla
la chimenea (Figura A) o en el termostato de pared
(Figura B). Seleccione el idioma que más se habla
en la casa.

2. Si se usa un control remoto para controlar la
chimenea, encuentre el transmisor y límpielo bien
para quitar el polvo y aceite. Pegue la etiqueta en la
superficie del transmisor (Figura C). Seleccione el
idioma que más se habla en la casa.

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.

Figure A

SAFETY LABEL

DIAGRAMS

DIAGRAMMES DES ÉTIQUETTES

DE SÉCURITÉ

Figure B

DIAGRAMAS DE ETIQUETAS

DE SEGURIDAD

Figure C

29

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

INSTALLATION ACCESSORIES

Listed Secure Vent™ Components

Cat.

No.

H2266 SV8HTS Horizontal Square

H2265 SV8VTR Vertical Termination

H2250 SV8L6 6 inch (152mm)

H2251 SV8L12 12 inch (305mm)

H2252 SV8L24 24 inch (610mm)

H2253 SV8L36 36 inch (914mm)

H2254 SV8L48 48 inch (1219mm)

H2255 SV8LA Telescopic Section
H2256 SV8E45 45 Degree Elbow

H2257 SV8E90 90 Degree Elbow

Model

No.

Termination with
Firestop/Spacer
(H2260) and
Adaptor (H2267)

Vent Section

Vent Section

Vent Section

Vent Section

Vent Section

Description

H2262 SV8SU Support Strap

H2263 SV8SP Support Plate

H3908 SV8ARSA Attic Insulation

Shield (adjustable
12” to 22”)

2a

B

CTSO-33/44 Shrouds
for Single terminations

C

D

E

(ref. Instruction P/N

750193M)

A

CTSO-46 Shroud
for double
terminations

C

D

1 typ.

2a

2b

2a

2b

2b

A

2a

Open Top Shroud Kits

Inches (millimeters)

Cat. No. Model A B C D *E

H1985 CTSO-33

H1987

CTSO-44

H1986 CTSO-46

37-5/8

(955)

48-5/8
(1235)

48-5/8
(1235)

37-5/8

(955)

48-5/8

(1235)

73 1/4

(1860)

7-1/2
(191)

7-1/2
(191)

7-1/2
(191)

24-1/2

24-1/2

24-1/2

typ.

B

(622)3 (76)

(622)3(76)

(622)3(76)

12typ.

E

30

The following flashings come packaged
with a storm collar

H3236 SV8F Flat Roof Flashing
H2258 SV8FA 1/12 to 7/12 Adjust-

able Flashing

H2259 SV8FB 7/12 to 12/12

Adjustable Flashing

H3237 SV8SC6 Storm Collars,

6 pack

H2260 SV8HF Firestop/Spacer -

Horizontal
(3 - 1 - 1 spacing)

H2261 SV8BF Firestop/Spacer -

Vertical
(1 - 1 - 1 spacing)

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

A

B

C

(ref. Instruction P/N 750194M)

D

Closed Top Shroud Termination Kits

Inches (millimeters)

Cat. No. Model A B C D

H1988 CTSA-33

34"

(864)

5"

(127)

34"

(864)

34"

(864)

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

GAS CONVERSION KITS

WARNING

This conversion kit shall be installed by a qualified service agency in
accordance with the manufacturer’s instructions and all applicable codes
and requirements of the authority having jurisdiction. If the information in
these instruction is not followed exactly, a fire, explosion or production of
carbon monoxide may result causing property damage, personal injury
or loss of life. The qualified service agency is responsible for the proper
installation of this kit. The installation is not proper and complete until the
operation of the converted appliance is checked as specified in the manu­facturer’s instructions supplied with the kit.The qualified service agency
performing this installation assumes responsibility for this conversion.

AVERTISSEMENT

Cette trousse de conversion doit être installée par un technicien agréé,
selon les instructions du fabricant et selon toutes les exigences et tous les
codes pertinents de l’autorité compétente. Assurez-vous de bien suivre
les instructions dans cette notice pour réduire au minimum le risque
d’incendie, d’explosion ou la production de monoxyde de carbone pouvant
causer des dommages matériels, des blessures ou la mort. Le tecnicien
agréé est responsable de l’installation de cette trousse. L’installation n’est
pas adéquate ni complète tant que le bon fonctionnement de l’appareil
converti n’a pas été vérifié selon les instructions du fabricant fournies avec
la trousse. Le fournisseur de service qualifié ayant réalisé l'installation
assume les responsabilités liées à la conversion.

Step 1. TURN OFF THE GAS SUPPLY TO THE
APPLIANCE and disconnect power supply at
the circuit breaker. Ensure appliance is cold.

CAUTION: THE GAS SUPPLY SHALL BE
SHUT OFF PRIOR TO DISCONNECTING THE
ELECTRICAL POWER, BEFORE PROCEEDING
WITH THE CONVERSION.

ATTENTION. AVANT D’EFFECTUER
LA CONVERSION, COUPEZ D’ABORD
L’ALIMENTATION EN GAZ, ENSUITE,
COUPEZ L’ALIMENTATION ÉLECTRIQUE.

Step 2. Remove the front glass door/frame

and the access plate from the appliance. See
Figures 38 and 49.

Step 3. Carefully remove the logs and the grate
assembly. Exercise care so as not to break

the logs.

Step 4. Refer to Figure 56. Remove the burner

assembly with attached venturi tube.

Burner Assembly

In Canada:
THE CONVERSION SHALL BE CAR­RIED OUT IN ACCORDANCE WITH THE
REQUIREMENTS OF THE PROVINCIAL
AUTHORITIES HAVING JURISDICTION
AND IN ACCORDANCE WITH THE RE­QUIREMENTS OF THE CAN/CSA-B149.1
INSTALLATION CODE.

LA CONVERSION DEVRA ÊTRE EF­FECTUÉE CONFORMÉMENT AUX RE­COMMANDATIONS DES AUTORITÉS
PROVINCIALES AYANT JURIDICTION
ET CONFORMÉMENT AUX EXIGENCES
DU CODE D'INSTALLATION CAN/CSA­B149.1.

Gas conversion kits are available to adapt your
appliance from the use of one type of gas to
the use of another. These kits contain all the
necessary components needed to complete the
task including labeling that must be affixed to
ensure safe operation.

Kit part numbers are listed here and the fol­lowing steps detail the conversion procedure.

Natural Gas To Propane Gas

Conversion Kit

Model No. Unit Type Cat. No.
LSM40MP-2 Millivolt H2268
LSM45MP-2 Millivolt H4811

LSM40EN-2 Electronic H3238
LSM45EN-2 Electronic H4813

Propane to Natural Gas

Conversion Kit

Model No. Unit Type Cat. No.

LSM40EN-2 Millivolt H2269
LSM45EN-2 Millivolt H2271

Gas Valve Assembly

Burner Orifice

Figure 56

Step 5. Refer to Figure 57 on Page 32 and
the instructions provided with the kit. Using
a Torx T20 (with 1/4” shank and center hole),
remove and discard the three pressure regula­tor mounting screws. Remove the pressure
regulator, spring, poppet, diaphragm and
bushing. Discard all removed components.
Ensure the rubber gasket installed on the back
of the replacement pressure regulator is properly
positioned and install the new pressure regula­tor using the new screws supplied with the kit.
Tighten screws to 25 In. lb. torque.

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

31

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

SIT Millivolt Gas
Valve Shown

Pressure

Regulator

Remove
These
Components

SIT Electronic Gas Valve

LO

HI

Pressure

Regulator

Millivolt & Electronic Gas Valves

Figure 57

Step 6. Refer to Figure 58 and remove the
pilot hood assembly to access the hexed pilot
orifice. Remove and replace the orifice with
the one provided with the kit.

SIT Millivolt Pilot Assembly Shown

Thermopile
(on millivolt
pilot assem-

Pilot
Orifice

blies only)

SIT Electronic Pilot

Pilot
Orifice

Millivolt & Electronic Pilot Assemblies

Figure 58

Step 7. (Refer to Figure 56 on Page 31 and
Figure 59)

VERIFY THE PROPER ORIFICE SIZE
BEFORE INSTALLING IT.

A. Remove the orifice from the manifold and

replace it with the one provided in the kit. See
the following table for orifice sizes for natural
and propane models. Figure 59 illustrates

the orice. Use pipe joint compound or

Teflon tape on all pipe fittings before install­ing (ensure propane resistant compounds
are used in propane applications, do not

use pipe joint compounds on are ttings).

B. Retrieve the burner and slide the venturi tube

over the orifice. Set the burner assembly
into its position and secure it.

C. Reinstall the grate assembly.

Burner Orifice Sizes

Elevation 0-4500 feet ( 0-1372 meters)

Model Nat.Gas

drill size (inches)

LSM40-2 .1405" (#28)*

• H2286

LSM45-2 .161" (#20)*

• H2288

Table 9

* Standard size installed at factory

• Part /Cat. Number

Propane

drill size (inches)

.086" (#44)*

• H2287

.093" (#42)*

• H4816

Figure 59

Step 8. Reassemble the remaining components
by reversing the procedures outlined in the
preceding steps.

Step 9. Attach the conversion label provided
in the conversion kit to the rating plate on the
appliance.

Step 10. Turn on gas supply and test for gas
leaks.

Step 11. Attach manometer to the manifold
side pressure test fitting and verify manifold
pressure reads 3.5 inches water column (0.87
kPa) for natural gas, and 10.0 inches water
column (2.49 kPa) for propane gas.

ALWAYS TEST PRESSURES WITH THE VALVE
REGULATOR CONTROL AT THE HIGHEST
SETTING.

32

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • INSTALLATION INSTRUCTIONS

NOTES

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

33

LENNOX HEARTH PRODUCTS • MONTEBELLO® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • 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. © 2005/2011 Lennox Hearth Products

P/N 850026M Rev. G 06/2011

34

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

1508 Elm Hill Pike, Suite 108 • Nashville, TN 37210