Lennox Merit Series User manual

™
CARE AND OPERATION INSTRUCTIONS
P/N 506017-02 Rev. F 06/2011
This manual is one of a set of three supporting this product. Refer to P/N
506015-03 for Installation Instructions and 506019-40 for additional instructions.
Ce manuel est disponible en francais, simplement en faire la demande.
Numéro de la pièce 506223-06.
MODELS
MLDVTCD-35NM
MILLIVOLT:
MLDVTCD-35NE
ELECTRONIC:
Report No. 100353019PRT-002
MLDVTCD Direct-Vent
Contemporary Design
Gas Fireplaces
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.
DON’T
THROW
IT AWAY!
This manual contains
important operating
and safety
information.
Wait...
▪
F
▪
R
▪
E
▪
E
▪
▪
See Page 2 For Details
▪
SAFETY
GUARD
PROTECTS AGAINST BURNS
TableofContents ........................................... 2
Safety and Your Fireplace ....................................2
FREE Safety Guard Offer (Protects Against Burns) . . . . . . . . . . . . . . . . . 2
Important Safety Information .................................4
Attaching the Safety-in-Operation Warnings ..................... 5
[EN FRANÇAIS] L’information de sûreté importante ...............3–4
Apposition des mises en garde relatives à la sécurité d’utilisation . . . . 5
[EN ESPAÑOL] Información importante de seguridad ..............3–4
Colocación de advertencias de seguridad en operación ............5
WHAT'S INSIDE
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.

2
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
Safety and
Your Fireplace
To prevent severe burns and injuries, install
a screen or physical barrier to prevent direct
contact with the glass.
To order a FREE Lennox
®
SAFETY GUARD
for your fireplace, see details at left.
Follow the safety instructions below
and be sure everyone in your household
understands this burn hazard:
•The surfaces on your fireplace get
EXTREMELY HOT!
•The glass on the front
of the fireplace reaches
EXTREMELY HIGH
temperatures and can
cause severe burns if touched.
•Keep children away from an operating
fireplace. Closely supervise children in
any room where a fireplace is operating
to prevent contact with glass.
•Keep clothing, furniture,
gasoline, and other
flammable liquids away
from the fireplace.
•Even after the gas is turned off, fireplace
surfaces remain extremely hot.
Be sure to attach the enclosed Safety-in-
Operation Warnings where you turn on your
fireplace, to help remind everyone of the
dangers associated with high temperatures
(see page 5).
Read Important Safety Information on
page 4.
All parts of your Lennox
Hearth Products fireplace
get EXTREMELY HOT!
TABLE OF CONTENTS
Safety and Your Fireplace ................................. 2
Important Safety Information .............................. 4
Attaching the Safety-in-Operation Warnings .................. 5
Appliance Installation, Service, and Maintenance Notices ..........6
ApplianceOperationNotices ................................6
WarrantyInformation......................................6
GeneralInformation ...................................... 7
Operation/Care of Your Appliance ............................8
VariableFlameAdjustment..................................9
Maintenance............................................10
Front Glass Enclosure Panel, Removal and Installation . . . . . . . . . . . 11
Install Contemporary Media................................12
Burner Flame Appearance/Sooting. . . . . . . . . . . . . . . . . . . . . . . . . . . 14
BurnerAirShutterAdjustments.............................15
Millivolt Appliance Checkout ...............................15
Electronic Appliance Checkout..............................15
ReplacementParts.......................................16
ProductReferenceInformation.............................16
WiringDiagrams........................................16
AccessoryComponents...................................17
Lighting Instructions – Millivolt .............................20
Lighting Instructions – Electronic . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Maintenance Schedule....................................24
Troubleshooting Guide – Millivolt. . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Troubleshooting Guide – Electronic . . . . . . . . . . . . . . . . . . . . . . . . . . 26
ReplacementPartsList...................................27
•FREE
SAFETY GUARD OFFER•
The Lennox®SAFETY GUARD protects against
severe burns and injuries by preventing direct contact
with the front glass surface of your fireplace.
To receive your FREE SAFETY GUARD, call 1-800-786-7976
or visit www.lennox.com (Lennox Hearth Products / Owner Resources)
Thank you for your purchase. We appreciate your business!
Please carefully read and follow all instructions in this manual.
Pay special attention to all warnings and safety information.
Following these safety, care, and operation instructions will help
ensure many years of dependable and enjoyable service from
your fireplace.

3
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
Afin d'éviter de vous brûler gravement ou de
vous blesser, installez une grille ou une barrière
physique pour empêcher tout contact direct
avec la vitre.
Pour commander un PANNEAU DE PROTECTION
Lennox®GRATUIT pour votre foyer, consultez
les détails dans la partie gauche.
Suivez les instructions de sécurité ci-dessous
et veillez à ce que tous les membres de votre
famille soient conscients du danger de brûlure
encouru :
•Les surfaces de votre foyer deviennent
EXTRÊMEMENT CHAUDES !
•La vitre située à l'avant du foyer
atteint des températures
EXTRÊMEMENT ÉLEVÉES et peut causer
de graves blessures en cas de contact.
•Tenez les enfants à l'écart du foyer lorsqu'il
fonctionne. Surveillez attentivement
les enfants dans les pièces où un foyer
est utilisé afin d'éviter qu'ils ne soient
en contact avec la vitre.
•Tenez tous les vêtements, les
meubles, l'essence et tout autre
liquide inflammable à l'écart du foyer.
•Même après fermeture du gaz, les surfaces
du foyer restent extrêmement chaudes.
Veillez à coller les Étiquettes de mise en garde
relatives à la sécurité d'utilisation à l'endroit
où vous utilisez le foyer, pour rappeler à tous les
utilisateurs les dangers liés aux températures
élevées (voir page 5).
Lisez la section Informations importantes
relatives à la sécurité, page 4.
Toutes les parties de votre foyer
Lennox Hearth Products deviennent
EXTRÊMEMENT CHAUDES !
Instale una malla o barrera física para evitar
el contacto directo con el vidrio y prevenir
las quemaduras y lesiones graves.
Ver los detalles a la izquierda para ordenar
un Lennox®SAFETY GUARD GRATIS
para su chimenea.
Siga las instrucciones de seguridad a
continuación y asegúrese de que todos
en su hogar sepan acerca de este peligro
de quemadura:
•¡Las superficies de la chimenea se ponen
MUY CALIENTES!
•El vidrio delante de la chimenea alcanza
temperaturas EXTREMADAMENTE ALTAS y
puede causar quemaduras graves si se toca.
•Mantenga a los niños alejados de la
chimenea en funcionamiento. Supervise
en forma cercana a los niños en cualquier
cuarto donde haya una chimenea
funcionando para impedir el contacto
con el vidrio.
•Mantenga la ropa, mobiliario, gasolina
y otros líquidos inflamables alejados
de la chimenea.
•Aún después de haber apagado el gas,
las superficies de la chimenea permanecen
extremadamente calientes.
Asegúrese de colocar las Etiquetas de
advertencia de seguridad de operación en
el lugar donde enciende la chimenea, para
que todos recuerden los peligros asociados
con las altas temperaturas (ver la página 5).
Lea la Información importante de seguridad
en la página 4.
¡Todas las partes de la chimenea
Lennox Hearth Products se ponen
MUY CALIENTES!
Seguridad y
su chimenea
La sécurité et
votre foyer
[FRENCH] [SPANISH]

4
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
Important Safety Information
1. WARNING: Do not operate appliance with the glass front
removed, cracked or broken. Replacement of the glass
should be done by a licensed or qualified service person .
2. Do not use this appliance if any part has been under water.
Immediately call a qualified service technician to inspect
the appliance and to replace any part of the control system
and any gas control which has been under water.
3. Due to high temperatures, the appliance should be located
out of traffic and away from furniture and draperies.
4. Children and adults should be alerted to the hazards of
high surface temperature and should stay away to avoid
burns or clothing ignition.
5. Clothing or other flammable material should not be placed
on or near the appliance.
6. 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.
7. Any safety screen or guard removed for servicing an
appliance must be replaced prior to operating the
appliance.
8. 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, et cetera.
It is imperative that control compartments, burners, and
circulating air passageways of the appliance be kept
clean. See maintenance instructions on page 10.
L'information de sûreté importante
1. AVERTISSEMENT. Ne pas utiliser l’appareil si le panneau frontal
en verre n’est pas en place, est craqué ou brisé. Confiez le
remplacement du panneau à un technicien agréé
2. Ne pas utiliser cet appareil s’il a été plongé, même partiellement,
dans l’eau. Appeler un technicien qualifié pour inspecter
l’appareil et remplacer toute partie du système de commande
et toute commande qui a été plongée dans l’eau.
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.
4. 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.
5. On ne devrait pas placer de vêtements ni d’autres matières
inflammables sur l’appareil ni à proximité.
6. 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.
7. Tout écran ou protecteur retiré pour permettre l’entretien de
l’appareil doit être remis en place avant de mettre l’appareil en
marche.
8. 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 poussière. Il est essentiel que les
compartiments abritant les commandes, les brûleurs et les
conduits de circulation d’air de l’appareil soient tenus propres.
Voyez les instructions d’entretien à la page 10.
[SPANISH]
Información importante de seguridad
1. ADVERTENCIA: No opere el artefacto con el frente de vidrio quitado,
agrietado o roto. Un técnico de servicio licenciado o capacitado
debe reemplazar el vidrio.
2. No use este artefacto si alguna de sus partes ha estado bajo agua.
Llame de inmediato a un técnico de servicio calificado para que
inspeccione el artefacto y reemplace cualquier parte del sistema
de control y cualquier control de gas que haya estado bajo agua.
3. Debido a las altas temperaturas, el artefacto debe situarse fuera
de las áreas de tráfico y lejos del mobiliario y cortinas.
4. Se debe alertar a los niños y adultos sobre los peligros de
las altas temperaturas en la superficie y que se mantengan
alejados para evitar quemaduras o ignición de la ropa.
5. No debe colocarse ropa u otros materiales inflamables
sobre y cerca del artefacto.
6. Se debe supervisar de cerca a los niños cuando estén en el mismo
cuarto que el artefacto. Los niños pequeños, los jóvenes y otras
personas pueden ser susceptibles a quemaduras por contacto
accidental. Se recomienda instalar una barrera física si hay
personas en riesgo en la casa. Para restringir el acceso a una
chimenea o estufa, instale una puerta de seguridad ajustable
para mantener a los niños pequeños, jóvenes y otras personas
en riesgo fuera del cuarto y lejos de las superficies calientes.
7. Cualquier malla o resguardo de seguridad quitado para dar servicio
a un artefacto, debe reinstalarse antes de operar el artefacto.
8. Una persona de servicio competente debe realizar la instalación y
reparación. Una persona de servicio profesional debe inspeccionar
el artefacto antes de usar al menos una vez por año. Se puede
requerir limpieza más frecuente debido a la pelusa excesiva
del alfombrado, del material de cobijas, etc. Es imprescindible
mantener limpios los compartimientos de control, los quemadores
y los pasajes de circulación del aire del artefacto. Ver las
instrucciones de mantenimiento en la página 10.

5
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
APPOSITION DES MISES EN GARDE RELATIVES
À LA SÉCURITÉ D’UTILISATION
Votrefoyeraétélivréavecdesétiquettesdesécuritéqui
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). Lesmisesengardeauraientdû
être colléesaumomentdel’installationinitialedufoyer.
Si ce n’est pas le cas, prenez les étiquettes adhésives
multilinguesfourniesaveccesinstructionsetprocédez
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 distribu-
teur Lennox Hearth Products local pour recevoir
gratuitement des étiquettes supplémentaires.
Étiquettes de remplacement, n° cat. H8024
LENNOX HEARTH PRODUCTS
1-800-9-LENNOX
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
seguridadquedebencolocarseenelpuntodeoperación
ycontroldelachimenea.Sedebecolocarunaetiquetade
instruccionesdeseguridadenlaplacadelinterruptorde
pareddesdeelcualseenciendeyse apagalachimenea
(verlaFiguraA)oeneltermostatodepared(verlaFigura
B)y en el transmisor de control remoto (Figura C)si
se usa. Las advertencias ya deben haberse colocado
cuandosecompletólainstalacióninicialdelachimenea.
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
quecontrolalachimenea(verifiquequeelinterruptor
opera la chimenea encendiéndola y apagándola).
Limpiebienlaplacadelinterruptoroeltermostatode
paredpara quitarelpolvoyaceite.Peguelaetiqueta
enlasuperficiedelaplacadelinterruptorquecontrola
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. Sinopuedeencontrarlasetiquetas,sírvasellamara
LennoxHearthProductsoaldistribuidordeLennox
HearthProductsmáscercanopararecibiretiquetas
deinstruccionesdeseguridadadicionalesgratuitas.
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.
ATTACHING SAFETY-IN-OPERATION
WARNINGS
Your replace has been furnished with safety instruc-
tion labels that are to be affixed to the operation and
control point of the fireplace. A safety instruction
labelshouldbeaffixedtothewallswitchplatewhere
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
controlsthe fireplace(verifythe switchoperates
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. Ifaremotecontrolisusedtocontrolthefireplace,
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
LennoxHearth Productsoryour nearestLennox
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.
HOMEOWNER’S INSTRUCTIONS - ATTACHING SAFETY-IN-OPERATION WARNINGS
Figure A Figure B Figure C
SAFETY LABEL
DIAGRAMS
DIAGRAMAS DE ETIQUETAS
DE SEGURIDAD
DIAGRAMMES DES ÉTIQUETTES
DE SÉCURITÉ

6
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
Appliance Installation, Service,
and Maintenance Notices
IMPORTANT: Improper installation,
adjustment, alteration, service, or main-
tenance can cause injury or property
damage. Refer to this manual. For assist-
ance or additional information, consult a
qualified installer, service agency or the
gas supplier.
Only trim kit(s) supplied by the manufac-
turer shall be used in the installation of
this appliance.
Draft relief openings must not be covered
or blocked.
These appliances must not be connected
to a chimney or flue serving a separate
solid fuel burning appliance.
Any change to this appliance and/or its
operating controls is dangerous. Improper
installation or use of this appliance can
cause serious injury or death from fire,
burns, explosion or carbon monoxide
poisoning.
Carbon Monoxide Poisoning: Early signs
of carbon monoxide poisoning are simi-
lar to the flu with headaches, dizziness
and/or nausea. If you have these signs,
obtain fresh air immediately. Turn off the
gas supply to the appliance and have it
serviced by a qualified professional, as
it may not be operating correctly. Some
people are more affected by carbon
monoxide than others, including pregnant
women, people with heart or lung disease
or anemia, those under the influence of
alcohol, and those at high altitudes.
Turn off gas and electrical power to the
fireplace and allow it to cool before clean-
ing or servicing the appliance.
Warranty Information
Your gas appliance is covered by a limited
twenty-year warranty. You will nd a copy
of the warranty accompanying this manual.
Please read the warranty to be familiar with
its coverage.
Retain this manual. File it with your other docu-
ments for future reference.
Failure to comply with the installation and
operating instructions provided will result
in an improperly installed and operating
appliance, voiding its warranty.
Do not attempt to alter or modify the
construction of the appliance or its com-
ponents. Any modification or alteration
may void the warranty, certification, and
listings of this unit.
Appliance Operation Notices
Do not operate appliance with the glass
front removed, cracked, or broken.
These fireplaces are vented gas appli-
ances. Do not burn wood or other material
in these appliances.
These fireplaces are decorative and
are designed to provide supplemental
heat. Therefore, it is advisable to have
an alternate primary heat source when
installed in a dwelling.
This appliance is only for use with the
type of gas indicated on rating plate. This
appliance is not convertible for use with
other gases, unless a certified kit is used.
These appliances are designed to oper-
ate on natural gas or propane gas only.
The use of other fuels or combinations of
fuels will degrade the performance of this
system and may be dangerous.
Provide adequate clearances around
air openings and adequate accessibility
clearance for service and proper opera-
tion. Never obstruct the front openings of
the appliance.
Do not use this appliance if any part has
been under water. Immediately call a
qualified service technician to inspect the
appliance and to replace any part of the
control system and any gas control that
has been under water.
Theventterminationishotwhileinopera-
tion and for a period of time following the
use of the fireplace. To prevent contact
withhotsurfaces,werecommendtheuse
of a termination guard. See Page 19 for
ordering information.

7
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
GENERAL INFORMATION
The fireplace models covered in this manual
are direct-vent sealed combustion gas fire-
places designed for residential application.
These direct-vent appliances operate with the
combustionchambercompletelyisolatedfrom
the indoor environment.
All air for combustion is brought in from the
outside and exhaust gases are vented through
the same direct-vent, co-axial (intake/exhaust)
vent system.
The Millivolt appliances have a millivolt gas
control valve with piezo ignition system. If any
optional accessories which require electrical
power are being installed, the electrical power
must be provided at the time of appliance
installation.
The Electronic appliances have a battery
backed-up electronic intermittent pilot sys-
tem. The battery back-up will allow you to
continue operation of the appliance during a
power outage.
These appliances comply with National Safety
Standards and are tested and listed by ETL/
Intertek (Report No. 100353019PRT-002) to
ANSI ZZ21.50 (in Canada, CSA-2.22), and
CAN/CGA-2.17-M91 in both USA and Canada,
as vented gas fireplaces.
The Installation must conform to local codes
or, in the absence of local codes, with the
National Fuel Gas Code, ANSI Z223.1/NFPA
54-latest edition, or the Natural Gas and Pro-
paneInstallationCode,CAN/CSAB149.1-latest
edition. Theappliance,wheninstalled,mustbe
electrically grounded in accordance with local
codes or, in the absence of local codes, the
latest edition of the National Electrical Code,
ANSI/NFPA70,ortheCanadianElectricalCode,
CSA C22.1 - latest editions.
Inlet Gas Supply Pressure (all models)
Fuel # Minimum Maximum
Natural Gas 4.5" WC
(1.12 kPa)
10.5" WC
(2.61 kPa)
Propane 11.0" WC
(2.74 kPa)
13.0" WC
(3.23 kPa)
Table 2
Manifold Gas Supply Pressure (all models)
Fuel # Low High
Natural
Gas
(Lo) 2.2" WC
(0.55 kPa)
(Hi) 3.5" WC
(0.87 kPa)
Propane (Lo) 6.3" WC
(1.57 kPa)
(Hi) 10.0" WC
(2.49 kPa)
Table 3
Gas Pressure Requirements
(All Models)
Gas pressure requirements are listed in
Tables 2 and 3.
Test gauge connections are provided on the
front of the millivolt gas control valve, identi-
fied IN for the inlet and OUT for the manifold
side (see Figure 3 on Page 9). A 1/8" NPT
Test gauge connection is provided at the inlet
and outlet (manifold) ports on the electronic
gas control valve (see Figure 4 on Page 9).
Input (BTU/HR) Manually Modulated
Gas Valves (all models)
Model Input Rate (BTU / HR)
Nat. Gas Prop. Gas
MLDVTCD-35
14,500 high
11,500 low 13,500 high 10,500 low
Table 1
BTU Input
Millivolt and electronic models come standard
with a manually-modulated gas valve; flame
appearance and heat output can be controlled
at the gas valve. The BTU inputs for these ap-
pliances are shown in Table 1.
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)abovesealevelusingthestandardburner
orice 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.
Installtheapplianceaccordingtotheregulations
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
Series Nat.Gas drill size (inches) Propane drill size (inches)
MLDVTCD-35
#49 (0.073") *
21L82•
0.045" **
75L10 •
Table 4
* Standard size installed at factory.
** Standard size in LP conversion kit.
•Part/Cat.Number.
Burn-in Period
During the first few fires in this appliance,
there will be some odor due to the curing of
the paint and burning off of lubricants used in
themanufacturingprocess. Dependingonyour
use, the burn-in period may take a few hours
or a few days.
KEEP YOUR HOUSE WELL VENTILATED
DURING THE BURN-IN PROCESS. THE ODOR
AND HAZE EMITTED DURING THE BURN-IN
PROCESS CAN BE QUITE NOTICEABLE AND
MAY SET OFF A SMOKE DETECTOR.
If an optional blower is installed, do NOT turn
it on during the burn-in period.
IMPORTANT NOTE!
A white film may develop on the glass
enclosure panel during the first few
fires as part of the burn-in process.
The first few times you use the
fireplace, clean the glass after
each use (AFTER THE GLASS HAS
COMPLETELY COOLED); otherwise,
the white film will bake onto the
glass and become difficult to
remove.
See “Cleaning Glass” on Page 10.
These appliances must be isolated from
thegassupplypipingsystem(byclosing
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 dur-
ing any pressure testing of that system
at pressures greater than 1/2 psig (3.5
kPa).

LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
8
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Gas Controls/Control Compartment
Access
Thegascontrolscanbefoundbehindthecontrol
compartment access door.
Removing Control Compartment Door:
Open the panel by gently lifting it upward and
forwards. Slide the door, first to one side and
then the other, so the tabs clear both of the
locating holes.
Figure 2
Control Compartment Door Tab
On millivolt systems, the piezo igniter, HI/LO
ame adjustment knob, and pilot and main
gas OFF/ON control knob are located below
the glass panel enclosure. The gas valve for
electronic systems is also located below the
glass enclosure panel. See Figure 1.
Reinstalling Control Compartment Door:
To reinstall, insert the tabs on each side of the
doorintothe correspondingholesin thecontrol
compartment opening, one side first then the
other. To close, pull the door gently up and
close by pushing forward and pushing the top
edge down into the groves at the brackets until
it locks in place.
The standard controls for appliance operation
are located behind the panel below the appli-
ance front glass enclosure panel (Figure 1).
Optional control switches are also available
(see Page 17 - Remote Wall Switch, Remote
Control, Unit Mounted Rocker Switch or Wall
Thermostat).
Operation of millivolt and electronic gas con-
trol systems are different. Before lighting and
operatingyourappliancedetermineifyouhave
a millivolt or electronic appliance. Familiarize
yourself with the gas control valve that your
appliance uses. Refer to Figure 1 for access
to the gas control valve.
Millivolt Appliances - Appliances with
Millivolt systems will be tted with the gas
control valve shown in Figure 3.
Electronic Appliances - Appliances with
electronic systems will be fitted with the
electronic valve shown in Figure 4.
Millivolt Appliances - To light millivolt ap-
pliances refer to Figure 1. Detailed lighting
instructions are found on Pages 20 and 21.
Millivolt appliance lighting instructions may
also be found on the pull out lighting instruc-
tion labels attached to the gas control valve.
Once the pilot is lit, the main burner may be
turnedON andOFFusing awallswitch,remote
control, on unit rocker switch (FRS), or wall
thermostat. To operate: Toggle the switch
between its ON and OFF positions.
If your millivolt appliance is equipped with an
optional remote switch kit (wall switch, remote
control, rocker switch, or wall thermostat) and
the pilot is lit, the appliance main burner may
be turned on and off using the optional switch.
Note: To prevent excessive resistance in burner
circuit (which can cause burner operation
problems), only one burner control switch
should be wired to valve.
OPERATION AND CARE OF YOUR APPLIANCE
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
Lesjeunesenfantsdevraientêtresurveillésétroitementlorsqu’ilssetrou-
ventdanslamêmepiècequel’appareil.Lestoutpetits,lesjeunesenfants
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.
Figure 1
Gas Flex Line
Gas Shut-Off
Valve Valve Piezo Spring Door
Latch
Lower Control
Compartment

9
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
Electronic Appliances
Tolightelectronicappliancesrefertothedetailed
lighting instructions found on Pages 22 and
23 of these instructions. Electronic appliance
lighting instructions may also be found on the
pull out lighting instruction labels attached to
the gas control valve.
If your electronic appliance is equipped with an
optional remote wall switch or remote control
kit the appliance main burner may be turned on
and off with the wall switch or remote control.
Ifyourelectronic applianceisnot equippedwith
awallswitchorremotecontrol, themainburner
must be turned off and on with a gas control
switch located in some other location by the
installer. Contact the installer for directions.
Check batteries, if installed, routinely (every
three months).
Note: It is recommended that batteries not
be installed in the battery holder until a power
outage, or if the appliance is to be operated
solely with two (2) "D" batteries.
Referto theLightingInstructionsonPage 22 to
lighttheapplianceintheeventofapowerfailure.
TO LIGHT YOUR APPLIANCE IN A POWER
OUTAGE DO THE FOLLOWING:
•Installbatteriesinbatterypack.
•Turnunitmountedswitchorwallswitchto
the ON Position.
•Unitshouldsparkatpilotandlight.
•OperateNormally.
•Replacebatteriesifneeded.
•Afterpowerisrestored,removebatteries.
Figure 3 - SIT Millivolt Gas Valve
Variable Flame
Height Adjustment
Manifold Pressure
Port
Inlet
Pressure
Port
Main Gas Control Knob
H
I
L
O
W
TPTH TP TH
P
I
L
O
T
P
I
L
O
T
O
N
it
O
F
F
IN OUT
Gas Inlet
Terminals TPTH, TP and TH
Gas
Outlet
Figure 4 - Dexen Electronic Gas Valve
Variable Flame
Height Adjustment
Manifold Pressure
Port
Inlet
Pressure
Port
Main Gas Control Knob
H
I
L
O
W
TPTH TP TH
P
I
L
O
T
P
I
L
O
T
O
N
it
O
F
F
IN OUT
Gas Inlet
Terminals TPTH, TP and TH
Gas
Outlet
Supply Gas
Inlet
Pressure-Tap
(Manifold)
Regulator
Mounting
Screw
Burner Stage
Terminal Gas
Outlet
To Burner
Ground (TP)
Pilot Stage
Terminal
Pilot Gas Outlet
Pressure-Tap
(Inlet)
PILOT
OUT
VENT
LO
TH TP
TH
TP
HI
IN
IN
Variable Flame Height Adjustment
All millivolt and electronic appliances are
equipped with a variable gas control valve.
Flame height for these models may be adjusted
through a range between fixed low and high
settings while the appliance is in operation.
Adjust the flame height as desired after lighting
theappliancebyrotatingthevariableadjustment
control knob (HI/LO) located on the front of the
valve (refer to Figures 3 and 4).

10
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
MAINTENANCE
(See Maintenance Schedule, Page 24)
Refer to the maintenance schedule for mainte-
nance tasks, procedures, frequency and by whom
they should be performed. Always verify proper
operation of the appliance after servicing.
Replacing Contemporary Media
Replace the contemporary media previously
removed. See Pages 12 and 13. Use only
the proper replacement materials from the
manufacturer (see Pages 19 and 27 for order-
ing information).
Note: Improper positioning of media can create
carbon build-up and will alter the performance
of the appliance.
Inspect Wiring
Refer to wiring diagrams on Page 16.
CAUTION:Whenservicingcontrols,label
all wires prior to disconnection. Wiring
errors can cause improper and danger-
ous operation. Verify proper operation
after servicing.
ATTENTION: Au momentdel'entretien
descommandes,étiqueteztouslesfils
avant de les débrancher. Des erreurs
de cáblage peuvent entraîner un fonc-
tionnement inadéquat et dangereux.
Inspect and clean all wire connections. Ensure
that there is no melting or damage. Inspection
should include:
• Terminals at the Valve
• OFF/ON Switch
• (Optional Control Switch) Wall Thermostat,
Remote Control or Remote Wall Switch Kit
Inspect Burner Flame Appearance
Ensure that the burner flame appearance
resembles the flame shown in Figures 6 and
7 on Pages 13 and 14 and as described in
FlameAppearanceandSootingonPage14.The
Homeowner must contact a qualified service
technician at once if any abnormal condition
is observed.
Small Area Paint Touch-up
Only use a factory supplied paint kit for touch-
ups. Paint is available at your local authorized
LennoxHearthProductsdealer. Neverattempt
to paint a hot fireplace.
Ifthesurfacelater becomesstainedor marred,
it may be lightly sanded and touched up with
spray paint.
CAUTION: Wear gloves and safety
glasses for protection while doing
required maintenance.
Verify proper operation after servicing.
S'assurer que l'appareil fonctionne adé-
quatement une fois l'entretien terminé.
Always turn off gas to the pilot (millivolt
appliances) before cleaning. Before re-
lighting, refer to the lighting instructions
inthismanual.Instructionsarealsofound
on a pull-out panel located in the control
compartment.
Inspect Venting System
The appliance and venting system should be
thoroughly inspected before initial use and
at least annually by a qualified service techni-
cian (inspection should include ensuring that
exhaust or intake passages are unobstructed
and vent components are properly assembled
and not damaged). Homeowner must contact
a qualified service technician at once if any
abnormal condition is observed.
If the venting system is disassembled for any
reason, a qualified service technician should
follow vent installation instructions for proper
reassembly and proper sealing of the venting
system components. However, more frequent
periodic inspections and cleanings should be
performed by the homeowner.
Cleaning Glass
(AlsoseeFrontGlassEnclosure Panel, Removal
and Installation on Page 11.)
Note: Cleanglassafterfirsttwoweeksof opera-
tion (after Burn-In period is over) and then only
when necessary and when the fireplace is cool.
Wipe surface with clean, dampened, soft cloth.
Follow with a dry, soft towel as desired. Take
care not to scratch the glass surface.
IMPORTANT: Do not use abrasive clean-
ers on glass. Never clean the glass when
it is hot.
The viewing glass should be cleaned periodi-
cally to remove any build-up caused from the
following:
• During start-up, it is normal for condensa-
tion to form on the inside of the glass (this
condensation and fog will usually disappear
in a few minutes). The moisture can cause
lint,dustandotherairborneparticlestocling
to the glass surface.
• Initial curing of the high temperature paint
and burning off of lubricants used in the
manufacturing process may result in a film
on the glass.
• A white coating may form on the glass as a
result of impurities and minerals in the fuel.
It is recommended that the glass be cleaned
two or three times during each heating season,
depending on the circumstances present. The
following cleaning solutions are approved for
use to clean glass:
• Non-ammonia based household cleaner
• 50%-50% mix of white vinegar and water
• Gas replace/stove glass cleaner
Inspect Glass Gasket
Visually inspect the gasket on the backside
of the glass enclosure panels. The gasket
surface must be clean, free of irregularities
and seated firmly.
Clean Control Compartment
Keepcontrolcompartmentcleanby vacuuming
or brushing at least twice a year. More frequent
cleaning may be required due to excessive lint
from carpeting, bedding materials, etc. It is
important that control compartments, burners
andcirculatingairpassagewaysoftheappliance
be kept clean.
Clean Sub-Floor And Burner
Carefully remove the contemporary media
covering the firebox sub-floor. Place it in a
container for future use. Vacuum out any
foreignmatter(lint,carbon,etc.)ontheburner.
Ensure the burner ports are “open.” Remove
any carbon deposits from the burner outlet
using a vacuum cleaner, or a soft bristled
brush (i.e. paint brush).
WARNING
Turnoffgasandelectricalpower
to the fireplace and allow it to
coolbeforecleaningorservicing
the appliance.

11
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
Front Glass Enclosure Panel, Removal
and Installation
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.
These are direct-vent appliances. They are
designed to operate only when the front glass
enclosure panels are installed. Generally the
front glass enclosure panel should not be re-
moved except to gain access to the components
within the firebox.
Removing Glass Enclosure Panels
(see Figure 5)
1. To accesstheglassdoorsecuringlatches,
first open the lower control compartment
door (Figure 5)by sliding and pulling the
bottom panel forward.
2. Pullthelatchesforwardanddowntorelease
them from the door channel.
3. Pull the bottom of the door out a few inches
and grasp it on the right and left. Gently lift
to release the door from its channel above
the door. Pull the door forward.
4. Retrievethe glassdoor. Visuallyinspect the
gasket on the backside of the frame. Gasket
surface must be clean, free of irregularities
and seated firmly.
5. Inspect the gasket for defects. Ensure it
is properly located. Make sure the bead is
not rolled up into the channel at the top of
the door, but remains flat against the top
of the glass (see Figure 5).
6. Position the door in front of the firebox
opening with the bottom of the door held
away from the fireplace (Figure 5). Hook
the top flange of the door frame over the
top of the firebox frame.
7. Let the bottom of the door frame swing
gentlyintowardsthefireplaceensuringthat
the gasket seats evenly as the door frame
draws shut. Fasten the two latches located
underneath the firebox floor to the door's
vee-flange.Closeboth thelatchessecurely.
8. If desired, install the optional hood. Note
the location of the three clips inside the top
air channel above the door. The clips are
equally spaced on the top surface of the
air channel opening. Use a screwdriver to
open the clips slightly if needed. Engage
the back edge of the eyebrow into the clips
to secure.
Control
Compartment
Panel Hood
Glass
Door
Header
Spacing
Top
Standoffs
Flush
Nailing
Flange
1/2”
Nailing
Flange
5/8”
Nailing
Flange
Glass Door
Spring Latch
Ensure Gasket Is Not Rolled
Up Into Door Frame Channel
WARNING
•Donotattempttosubstitutethe
materials used on this door,
or replace cracked or broken
glass.
•Handlethisglasswithextreme
care! Glass is susceptible to
damage – Do not scratch or
handleroughlywhilereinstall-
ing the glass door frame.
•The glass door(s) of this appli-
ance must only be replaced as
a complete unit as provided
by the manufacturer. Do not
attempt to replace broken,
crackedorchippedglasssepa-
rately.
•Do not attempt to touch the
frontenclosureglasswith your
hands while the fireplace is in
use.
WARNING
Do not operate appliance with
theglassfrontremoved,cracked
or broken.
AVERTISSEMENT
Ne pas utiliser l'appareil si le
panneau frontal en verre n'est
pas en place, est craqué ou
brisé.
WARNING
Any safety screen or guard
removed for servicing the appli-
ance 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.
Note: When installing the glass door, ensure the
spacing on both sides are equal.
Figure 5 -
INSTALLING OR REMOVING GLASS DOOR

12
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
Table Of Contemporary Media
Cat.
No.
Model Contemporary Media
Name
H7536 MTRS Tumbled River Stone
H7537 MCCG-OB Contemporary Glass
Obsidian Black
H7538 MBSK Contemporary Beach
Sand
H7578 MCCG-DW Contemporary Glass
Diamond White
H7579 MCCG-SB Contemporary Glass
Deep Sea Blue
H7581 MBLPK-35ZG Merit Liner Kit, Zen
Garden
Remove the front glass enclosure panel (see
Removing Glass Enclosure Panels onPage11).
This fireplace is designed to accept a number
of alternate contemporary media options,
allowing the homeowner to customize this
product to fit any decor.
Install Zen Garden Refractory Panels
(MBLPK-35ZG)
1. Porcelain panels come installed in the ap-
pliance. Remove them by bending the tab,
sliding the left and right side panels out
first, then removing the rear panel.
2. Install Zen Garden panels:
• Remove the lintel by removing two screws.
• Insert the rear panel into rebox and po-
sition against the rear wall of the firebox
(see Figure 6 - Detail A on Page 13).
• Carefully insert the left side panel into
firebox, at a slight angle away from the
sidewall. Position the side panel as far
back along the wall as it will go (until it
is against the rear panel) and lower it into
place, while standing it upright and press-
ing it down over the knife edge at the rear
of the sub-oor. The sub-oor knife edge
will cut into the refractory panel. Repeat
the same procedure for the right side pan-
el (see Figure 6 - Detail B on Page 13).
• Re-install the lintel.
Install Tumbled River Stone (MTRS)
IMPORTANT: Refractorypanelsshould be
installed before any of the contemporary
media are installed.
1. Place stones on the firebox sub-floor, in
any atheistically pleasing manner to suite
individual taste. See Figure 6 - Detail C
on Page 13 for an example.
IMPORTANT: Be sure stones do not im-
pinge on the burner outlet.
Install Crushed Glass And Sand
(MCCG and MBSK)
IMPORTANT: Refractorypanelsshould be
installed before any of the contemporary
media are installed.
1. Pour out glass or sand on firebox sub-
floor, completely covering the sub-floor.
See Figure 6 - Detail D on Page 13 for an
example.
IMPORTANT: Avoid letting glass or sand
fall into the burner outlet. Make sure no
glass or sand falls into the burner ports.
Install Contemporary Facade
1. Refer to the Facade Installation Instruc-
tions (P/N 506019-40) to install the Con-
temporary Facade.
WARNING
•DONOTattempttoinstallthe
contemporary media until the
appliance installation has been
completed, the gas line con-
nected and tested for leaks and
the initial burner operation has
been checked out.
•The size and position of the
contemporary media was engi-
neered to give the appliance
a safe, reliable and attractive
flame pattern. Any attempt to
use a different media in the
fireplace will void the warranty
and will result in incomplete
combustion, sooting, and poor
flame quality.
•Contemporarymediagetvery
hot and will remain hot up to
one hour after gas supply is
turned off. Handle only when
contemporary media are cool.
•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 contemporary media are
not installed according to the
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.
•Onlyusematerialslistedhere.
Only contemporary media
authorized have been tested
for use within the firebox and
itsenvironment. Donotattempt
to use any different materials
in the fireplace. Doing so may
be dangerous and will void
the warranty and will result in
incomplete combustion, soot-
ing, and poor flame quality.
INSTALLING CONTEMPORARY MEDIA
NOTE: Turn off all electricity to the appliance
before you install contemporary floor media.

13
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
Figure 6
MLDVTCD-35 REFRACTORY PANELS AND CONTEMPORARY MEDIA PLACEMENT
Detail A
Rear Zen Garden Panel
Burner Outlet
Detail B
Burner Outlet
Left Zen Garden Panel Right Zen Garden Panel
Black Obsidian Contemporary Glass
Detail C
Detail D
Diamond White Contemporary Glass
Burner Outlet
Tumbled River Stone
Burner Outlet
Contemporary Beach Sand
(Note: River Stone And Beach Sand May Be Used Together)
(Note: Beach Sand And River Stone May Be Used Together)

14
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
Figure 7 - Burner Flame Appearance Model MLDVTCD-35
(River Stone And Beach Sand With Porcelain Panels Shown)
Air Shutter Adjustment Guidelines:
Amount of
Primary Air
Flame
Color
Air Shutter
Adjustment
If air shutter is
closed too far Flame will be orange Air shutter gap should be
increased
If air shutter is
open too far Flame will be blue Air shutter gap should be
decreased
BURNER ADJUSTMENTS
(QUALIFIED TECHNICIANS ONLY)
Flame Appearance and sooting
Proper flame appearance is a flame which is
blueat thebaseandbecomesyellowish-orange
in the body of the flame.
When the appliance is first lit, the entire flame
may be blue and will gradually turn yellowish-
orangeduringthe first 15minutesof 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 openings is closed too far,
sooting may develop. Sooting is indicated
by black puffs developing at the tips of very
long orange ames. Sooting results in black
deposits forming on the appliance inside sur-
faces and on exterior surfaces adjacent to the
vent termination.
Sooting is caused by incomplete combustion
in the ames and lack of combustion air enter-
ing 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, 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.

15
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
Figure 8 - Burner Air Shutter Adjustment
Ref. Air shutter Patent:
U.S. Pat. 5,553,603
Air Shutter
Burner Tube
Adjustment Set-Screw
Main Burner Factory Air Shutter
Opening Setting - Inches (millimeter)
Model Natural Gas Propane Gas
MLDVTCD-35 (Closed) Expose Half
Of The Hole
Adjustment Rod Up
(closed min. position)
Electronic Appliance Checkout
To light the burner, refer to the lighting instruc-
tions on Page 22. Ensure the igniter lights the
pilot. The pilot flame should engulf the flame
sensor as shown in Figure 10.
Figure 10
ELECTRONIC PILOT ASSEMBLY
Thermocouple
Thermopile
Pilot
Nozzels
SIT MILLIVOLT PILOT ASSEMBLY
3/8" Min.
(9 mm)
Igniter Rod
Hood
Proper Pilot Flame Appearance
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. The flame should
project 1" (25 mm) beyond the hood at all three
ports. See Figure 9.
To light the burner, refer to the lighting instruc-
tions on Page 20.
Figure 9
Note: If the igniter is damaged, a
replacement kit is available, order
Catalog Number 87L54.
ELECTRONIC
Pilot
Hood
Sensor
Igniter
WARNINGS
•Air shutter adjustment should
only be performed by a quali-
fiedprofessionalservicetech-
nician.
•Ensure front glass panel are
in place and sealed during
adjustment.
CAUTIONS
•Soot will be produced if the
airshutteris closed toomuch.
Any damage due to carboning
resulting from improperly
setting the air shutter is not
covered under the warranty.
• Theairshutterdoorandnearby
appliance surfaces are hot.
Exercise caution to avoid
injury while adjusting flame
appearance.
• Ensuretheairshuttersettingis
atleastequivalentto1/2ofthe
airholeexposedwhenoperat-
ing the unit with propane gas.
Burner Air Shutter Adjustment Procedure
1. Locate and adjust the air shutter to the
standard setting, as shown in Figure 8.
2. Lightappliance(follow lightingprocedureon
lighting label in control compartment or see
the lighting instructions, Pages 20 and 22
in this manual).
3. Allowtheburnertooperateforatleast15min-
uteswhileobservingtheflamecontinuouslyto
ensure that the proper flame appearance has
been achieved (see Figure 7 on Page 14). If
the following conditions are present, adjust
accordingly.
• If ame appears weak or sooty, adjust
theairshutter,incrementally,toamore
open position until the proper flame
appearance is achieved.
• If ame stays lowered blue, adjust the
air shutter, incrementally, to a more
closed position until the proper flame
appearance is achieved.
4. Leave the control knob (off/pilot/on) in the
ON position and the burner OFF/ON switch
OFF (and remote switches, if applicable).
5. When satisfied that the burner flame ap-
pearance is normal, close the lower control
compartment door.

16
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
Figure 11 Figure 12
ORDERING REPLACEMENT
PARTS
A complete parts list is found at the end of
this manual. Use only parts supplied from the
manufacturer.
Withproper careandmaintenance,yourappli-
ance will provide many years of enjoyment. If
you should experience any problem, first refer
to the troubleshooting guide in this manual.
If the problem persists, contact your Lennox
Hearth Products dealer or distributor.
Order parts through your Lennox Hearth Prod-
ucts distributor or dealer. Parts will be shipped
at prevailing prices at time of order.
When ordering parts, provide the following
information:
1. Appliance model number.
2. Appliance serial number.
3. Part number.
4. Part description.
5. Quantity required.
6. Appliance installation date.
PRODUCT REFERENCE INFORMATION
Model Number________________________________________________________
Serial Number ________________________________________________________
Date Installed_________________________________________________________
Gas Type Used ________________________________________________________
Dealer Name _________________________________________________________
Please call Lennox Hearth Products for the
phone number of your nearest LHP dealer,
who will answer your questions or address
your concerns.
LENNOX HEARTH PRODUCTS
1508 Elm Hill Pike, Suite 108
Nashville, TN 37210
Visit us at www.Lennox.com
1-800-9-LENNOX
If you encounter any problems or have any
questions concerning the installation or ap-
plication of this system, please contact your
dealer or distributor.
PRODUCT REFERENCE
INFORMATION
We recommend that you record the important
reference information about your fireplace in
the space provided below.
JUNCTION BOX
W
GR
BK
120 VAC
BK
R
TRANSFORMER 3V
INTERMITTENT ELECTRONIC WIRING DIAGRAM
BROWN
BROWN
BLACK
BATTERY BACK-UP
TO WALL
SWITCH, FRS
OR THERMOSTAT
BLACK (SENSOR)
BLACK (IGNITER)
SPARK TO PILOT IGNITER
IGNITER MODULE
3V
RED
BK WGR
OPTIONAL BLOWER
SWITCH
FAN
(OPTIONAL)
PILOT
IN
OUT
VENT
LO
HI
TH
TP
TH
TP
IN
ORANGE (THTP)
BLACK (TP)
GREEN (TH)
TP-TH
TP
TH
OPTIONAL APPLIANCE-
MOUNTED ON/OFF
SWITCH
BK/W(1)
BK/W(1)
WALL-MOUNTED ON/OFF SWITCH (OPTIONAL)
THERMOSTAT (OPTIONAL)
JUNCTION BOX
BLACK
W
GR
120 V
AC
WALL MOUNTED CONFIGURATION FOR FAN SWITCH (OPTIONAL)
BK
R
WIRING DIAGRAM MILLIVOLT GAS VALVES
THERMOPILE
GAS VALVE
FAN
(OPTIONAL)
WIRING DIAGRAMS
Wiringdiagramsareprovidedhereforreference
purposesonly. Thisinformationisalsoprovided
onschematicsattacheddirectlytotheappliance
on a pullout panel located within the control
compartment.
CAUTION: LABEL ALL WIRES
PRIOR TO DISCONNECTION WHEN
SERVICING CONTROLS. WIRING
ERRORS CAN CAUSE IMPROPER
AND DANGEROUS APPLIANCE
OPERATION.
ATTENTION : AU MOMENT DE
L'ENTRETIEN DES COMMANDES,
ÉTIQUETEZ TOUS LES FILS AVANT
DE LES DÉBRANCHER. DES
ERREURS DE CÁBLAGE PEU-VENT
ENTRAÎNER UN FONCTIONNEMENT
INADÉQUAT ET DANGEREUX.

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
ACCESSORY COMPONENTS
Product Reference Information
Cat.
No.
Model Ship.
Weight
Ship.
Volume
H7514 MLDVTCD-35NM 86 lb. 10.61 cu. ft.
H7515 MLDVTCD-35NE 86 lb. 10.61 cu. ft.
Remote Control Kit, Standard
Cat. No. Model No. Description
H0249 RCL Remote Control System
(Standard)
Remote Control Kit, Deluxe
Cat. No. Model No. Description
H0251 RCL-STAT Remote Control System
(Deluxe)
Digital Wall Thermostat
The wall thermostat kit provides temperature control
for optimum comfort.
Wall Thermostat, Millivolt
Cat. No. Model No. Description
H4635 DWTK Wall Thermostat Kit,
White
Rocker Switch Kit
Cat. No. Model No. Description
80L41 FRS Rocker Switch Kit
Unit-Mountable Rocker Switch
This rocker switch kit can be installed directly in
the gas valve mounting bracket (millivolt gas valve
equipped fireplaces) to provide On/Off operation in
lieu of a wall switch.
Standard Remote Control System
The Model RCL (Standard) Remote Control System,
features a simplistic OFF/ON control function for the
fireplace. Thismodelincludesahand-heldtransmitter,
a remote receiver with wall-mount cover plate and
all hardware required to install the unit. The remote
receiver can be wall or hearth mounted.
The transmitter has ON and OFF functions that are
activated by pressing either button on the face of
the transmitter. When a button on the transmitter
is pressed, a signal light illuminates briefly to verify
that a signal has been sent.
The Model RCL is designed to operate with all mil-
livolt ignition systems, as well as electronic ignition
systems. It may be installed with use for either
natural gas or propane gas appliances. The RCL
offers ease of installation and allows you to execute
on-off commands to the fireplace effortlessly with
one simple motion.
The Model RCL comes complete with detailed operat-
ing instructions.
Deluxe Remote Control System
The Model RCL-T (Deluxe) Remote Control System
has all of the features of the standard system along
withanaddedeasytoreadLCDscreenwhichpresents
access to many enhancements, including; battery
power level indicator, timer, mode of operation,
thermostatic display including room temperature in
either metric of English units, flame indicator and
clock. Fully programmable, the Model RCL-T allows
for virtual command over nearly all operational and
temperature variables, using the hand held remote
control transmitter.
The Model RCL-T (Deluxe) remote control system is
installed in the same manner as the standard system,
maybeoperatedwith electronicandmillivoltsystems
with either natural gas or propane gas. The RCL-T
comescompletewithdetailedoperatinginstructions.
OFF/ON Wall Switch Kit
The OFF/ON wall switch kit may be used to control
theoperationofthefireplaceburnerorblower. Install
the OFF/ON wall switch in a convenient location near
the fireplace.
White Wall Switch Kit
Cat. No. Model No. Description
85L87 FWSK OFF/ON Wall Switch Kit
Variable Speed Wall Switch
Provides variable speed control if optional blower
kit is purchased.
Variable Speed Wall Switch
Cat. No. Model No. Description
045571H VSWS Rocker Switch Kit
(ref. Kit Instruction P/N 750127M) (ref. Kit Instruction P/N 750129M)
17
(ref. Kit Instruction P/N 750037M)

18
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
ACCESSORY COMPONENTS CONTINUED
Screen Panel Kits
Cat. No. Model No. Models Where Used
H6113 PSFPKM35 MLDVTCD-35
Pull Screen Panel Kit
This easy to install optional decorative screen kit
installs over the standard glass enclosure panel.
These screen kits cannot be used in conjunction with
the arch door kits or door frame kits.
Style View Screen Doors -
These Style View doors are easy to install and will not require hardware to attach them to the standard glass door frame. The Style View door installs over the standard
glass enclosure panel and provides a barrier to prevent direct contact with the hot glass surface. The door includes heavy duty magnet door latches and functional
twin-pane screen doors.
Arch Pane Design Square Pane Design
ARCH PANE DESIGN KITS
Cat. No. Model Description Model Series
35” Arch Pane Door, Charcoal
35” Arch Pane Door, Satin Pewter
MLDVTCD-35
H6106 APDML35C
H6107 APDML35SP
SQUARE PANE DESIGN KITS
Cat. No. Model Description Model Series
35” Square Pane Door, Charcoal
35” Square Pane Door, Satin Pewter
MLDVTCD-35
H6098 SPDML35C
H6099 SPDML35SP
Contemporary Facade Kits
Cat. No. Model No. Description
H7732 CDFBBK-35 Facade Base, Black
H7733 CDFBSS-35 Facade Base, Stainless
H7730 CDFFBK-35 Facade Frame, Black
H7731 CDFFSS-35 Facade Frame, Stainless
H7727 CDTKBK-35 Facade Trim, Black
H7728 CDTKSS-35 Facade Trim, Stainless
H7729 CDTKBR-35 Facade Trim, Polished Brass
Base
Trim
Frame
Contemporary Facade Kit
ThiseasytoinstalloptionalContemporaryFacade
kit installs over the front face of the MLDVTCD-35
fireplace.
Barrier Screen Panel Kits
Cat. No. Model No. Models Where Used
H6095 35MSPK MLDVTCD-35
Barrier Screen Panel Kit
This easy to install optional screen panel installs over
the standard glass enclosure panel and provides a
barrier to prevent direct contact with the hot glass
surface. These screen panels cannot be used in
conjunction with the arch door kits or door frame kits.
(ref. Kit Instruction P/N 750215M)
(ref. Kit Instruction P/N 750042M)
(ref. Kit Instruction P/N 506019-40)

19
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
Forced Air Kit
TheFBK-100blowerprovidesconstantvelocityforced
air circulation. The FBK-200 assembly with variable
speed,wall-mountableswitchprovidesvariablespeed
forced air circulation.
Forced Air Blower Kits
Cat.
No.
Model No. Description
80L84 FBK-100 Blower, Standard
(single speed)
80L85 FBK-200 Blower, Variable Speed
(w/wall-mounted switch)
Refractory Panel Kit
Cat.
No.
Model No. Description
H7581 MBLPK-35ZG Zen Garden MLDVTCD-35
Refractory Panel Kit
The Zen Garden Refractory Panel Kit includes panels
similar in appearance to the illustration. The panels
have vertical design features in relief.
ACCESSORY COMPONENTS CONTINUED
Bag of Contemporary Media
(Stone, Sand or Glass)
Replacement contemporary materials or beach sand
are available for use with these appliances. Order kits
as part of the periodic maintenance of the appliance.
Touch-Up Paint Kit
Repair of minor scratches and discoloration of the
appliance black painted surfaces may be accomplished
with the touch-up paint kit.
Touch-Up Paint Kits
(all models)
Cat. No. Model No. Description
90L73 TPK-B Touch-Up Paint (Black)
P
A
I
N
T
Termination Guard Kits
(all models)
Cat. No. Model No. Description
H5820 4.5HTSK Termination Shroud
87L02 SV4.5HGS Termination Guard,
Deluxe
17M52 SV4.5HGS-1 Termination Guard,
Square
Termination Guard Kits
Theventtermination guards maybeusedto cover the
vent termination on the exterior of the home to mini-
mize exposure to the hot surface of the termination.
Replacement Contemporary Media
Cat. No. Model No. Description
H7536 MTRS Tumbled River Stone
(ref. Kit Instruction P/N 506019-29)
H7538 MBSK Contemoporary Beach Sand
(ref. Kit Instruction P/N 506019-31)
H7537 MCCG-OB Contemoporary Glass,
Obsidian Black
(ref. Kit Instruction P/N 506019-30)
H7578 MCCG-DW Contemoporary Glass,
Diamond White
(ref. Kit Instruction P/N 506019-30)
H7579 MCCG-SB Contemoporary Glass,
Deep Sea Blue
(ref. Kit Instruction P/N 506019-30)
(ref. Kit Instruction P/N 506019-36)
(ref. Kit Instruction P/N 750028M)
(ref. Kit Instruction P/N 750050M)
(ref. Kit Instruction
P/N 750246M)
(ref. Kit Instruction
P/N 750055M)
(ref. Kit Instruction
P/N 750109M)
Square Termination
Guard (Fits 94L10)
Deluxe Termination
Guard (Fits 94L10)
Termination Shroud
(Fits H1968)

20
LENNOX HEARTH PRODUCTS • MERIT® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
LIGHTING INSTRUCTIONS – MILLIVOLT GAS VALVE
FOR YOUR SAFETY READ BEFORE LIGHTING
A. This appliance has a pilot which must be lighted with a piezo
igniter. When lighting the pilot, follow these instructions
exactly.
B. BEFORE LIGHTING smell all around the appliance area for gas.
Be sure to smell next to the floor because some gas is heavier
than air and will settle on the floor.
WHAT TO DO IF YOU SMELL GAS
•Do not try to light any appliance.
•Do not touch any electric switch; do not use any phone in your
building.
TO TURN OFF GAS TO APPLIANCE
1. Turn remote wall switch “OFF.” The pilot will remain lit for nor-
mal service.
2. For complete shutdown, turn remote wall switch to “OFF.”
3. Access the lower control compartment.
4. Depress gas control knob slightly and turn clockwise
to “OFF.” Do not force.
5. Close lower control compartment.
LIGHTING INSTRUCTIONS
6. Wait five (5) minutes to clear out any gas. Then smell for gas, includ-
ing near the oor. If you smell gas, STOP! Follow “B” in the safety
information above (to the left) on this label. If you don’t smell gas, go
to the next step.
7. Push in gas control knob slightly and turn counterclockwise
to “PILOT.”
8. Push in control knob all the way and hold in. Immediately light the
pilot by triggering the spark igniter (pushing the button) until pilot
lights. Continue to hold the control knob in for about 1-1/2 minutes
after the pilot is lit. Release knob and it will pop back up. Pilot should
remain lit. If it goes out, repeat steps 5 through 8.
• If knob does not pop up when released, stop
and immediately call your service
technician or gas supplier.
•If pilot will not stay lit after several
tries, turn the control knob to “OFF”
and call your service technician or
gas supplier.
9. Turn gas control knob counterclockwise
to “ON.”
10. Close lower control compartment.
11. If the appliance will not operate, follow the instructions "To Turn Off
Gas To Appliance" and call your service technician or gas supplier.
•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.
C. Use only your hand to push in or turn the gas control knob.
Never use tools. If the knob will not push in or turn by hand,
do not try to repair it, call a qualified service technician. Force
or attempted repair may result in a fire or an explosion.
D. Do not use this appliance if any part has been under water.
Immediately call a qualified service technician to inspect the
appliance and to replace any part of the control system and
any gas control which has been under water.
Note: Knob cannot be turned from “PILOT” to “OFF”
unless the knob is pushed in slightly. Do not force.
H
I
L
O
W
TPTH TP TH
P
I
L
O
T
P
I
L
O
T
O
N
it
O
F
F
OUT
IN
WARNING: IF YOU DO NOT FOLLOW THESE INSTRUCTIONS EXACTLY, A FIRE OR EXPLOSION MAY
RESULT CAUSING PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE.
1. STOP! Read the safety information above on this page.
2. Access the lower control compartment.
3. Turn remote wall switch to “OFF.”
4. Verify main line shut-off valve is open.
5. Push in gas control knob slightly and turn clockwise
to “OFF.”
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.