WARNING: IF THE INFORMATION IN THIS MANUAL
IS NOT FOLLOWED EXACTLY, A FIRE OR EXPLOSION MAY RESULT CAUSING PROPERTY DAMAGE,
PERSONAL INJURY OR LOSS OF LIFE.
FOR YOUR SAFETY: Do not store or use gasoline
or other fl ammables or liquids in the vicinity of
this or any other appliance.
FOR YOUR SAFETY: What to do if you smell gas:
• DO NOT light any appliance.
• DO NOT touch any electrical switches.
• Do not use any phone in your building.
• Immediately call your gas supplier from a
neighbor’s phone. Follow your gas suppliers
instructions.
• If your gas supplier cannot be reached, call
the fi re department.
Installation and service must be performed by
a qualifi ed installer, service agency or the gas
supplier.
04-01-05
RETAIN THESE INSTRUCTIONS
FOR FUTURE REFERENCE
A French manual is available upon request. Order P/N 875,025CF
Ce manuel d’installation est disponible en francais, simplement en
faire la demande. Numéro de la pièce 875,025CF
Listing Agency
OTL Report No. 116-F-28-5
CONGRATULATIONS!
In selecting this LENNOX Direct-Vent Gas Appliance you have chosen the fi nest and most
dependable fi replace to be found anywhere. Its a beautiful, prestigious alternative
to a wood burning fi replace. Welcome to a Family of tens of thousands of satisfi ed
LENNOX Fireplace Owners.
Please carefully read and follow all of the instructions found in this manual. Please pay
special attention to the safety instructions provided in this manual. The Homeowner's
Care and Operation Instructions included here will assure that you have many years
of dependable and enjoyable service from your LENNOX product.
Replacement Parts List .....................Page 20
INTRODUCTION
The Fireplace models covered in this manual
are Direct-Vent sealed combustion gas fi replace
heaters designed for residential application.
Direct-Vent appliances operate with the combustion chamber completely isolated from 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 provides
safe, effi cient operation. 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 an electronic
intermittent pilot system provides safe, effi cient
operation. External electrical power is required
to operate these appliances.
2
These appliances comply with National Safety
Standards and are tested and listed by OMNITest Laboratories, Inc. (Report No.116-F-28-5)
to ANSI Z21.88a-2003 (in Canada, CSA-2.33a-
2003), and CAN/CGA-2.17-M91 in both USA and
Canada, as vented gas fi replace heaters.
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
Propane Installation Code, CSA B149.1-latest
edition. The appliance, when installed, must
be electrically grounded in accordance with
local codes or, in the absence of local codes,
the latest edition of the National Electrical Code,
ANSI/NFPA 70, or the Canadian Electrical Code,
CSA C22.1 - latest editions.
GENERAL INFORMATION
Note: Installation and repair should be performed by a qualifi ed service person. The
appliance should be inspected annually by a
qualifi ed professional service technician. More
frequent inspections and cleanings may be
required due to excessive lint from carpeting,
bedding material, etc.
IMPORTANT
It is imperative that the control
compartment, burners and circulating air passage ways of appliance be kept clean. See Maintenance instructions on Page 5.
Provide adequate clearances around air openings and adequate accessibility clearance for
service and proper operation. Never obstruct
the front openings of the appliance.
Due to high temperatures the appliance should
be located out of traffi c and away from furniture
and draperies. Locate furniture and window
coverings accordingly.
These fi replaces are designed as supplemental heaters. Therefore, it is advisable to have
an alternate heat source when installed in a
dwelling.
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
These appliances are designed to operate on natural
gas or propane gas only. The use of other fuels or
combination of fuels will degrade the performance
of this system and may be dangerous.
Millivolt Models - BTU Input
Millivolt models come standard with the manually-modulated gas valve; fl ame appearance and
heat output can be controlled at the gas valve.
The BTU Input for millivolt models is shown
in Table 1:
Input (BTU) Manually-Modulated Gas
Valves (millivolt models)
ModelsFuel
Type
MPD35ST-NMNat. Gas
MPD35ST-PMPropane
Input Rate
(BTU / HR)
30,000 high
23,000 low
28,000 high
22,000 low
Table 1
Electronic Models -
Electronic models have a fi xed rate gas valve.
The BTU Input for electronic models is shown
in Table 2:
Input (BTU) - Fixed Rate
(electronic models)
ModelsFuel
Type
MPD35ST-NENat. Gas30,000
MPD35ST-PE
(if fi eld converted)
Pro. Gas28,000
Input Rate
(BTU / HR)
Table 2
Gas Pressure -
Tables 3, 4 and 5 show the appliances' gas
pressure requirements.
Inlet Gas Supply Pressure
(all models)
Fuel #MinimumMaximum
Natural Gas
Propane
5.0" WC
(1.24 kPa)
11.0" WC
(2.74 kPa)
10.5" WC
(2.61 kPa)
13.0" WC
(3.23 kPa)
Table 3
Manifold Gas Supply Pressure
(millivolt models)
Fuel #LowHigh
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 4
Manifold Gas Supply Pressure
(electronic models)
Fuel #Fixed
Natural Gas
Propane
Table 5
Test gauge connections are provided on the
front of the millivolt gas control valve, identifi ed
IN for the inlet and OUT for the manifold side
(see Figure 2 on Page 4 ). A 1/8" NPT Test
gauge connection is provided at the inlet and
outlet (manifold) ports on the electronic gas
control valve (see Figure 3 on Page 5 ).
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).
Orifi ce Sizes - Sea Level to High Altitude
(All Models)
These appliances are tested and approved for
installations at elevations of 0-4500 feet (0-1372
meters) above sea level using the standard burner
orifice sizes (marked with an "*" in Table 6 ). At
the time of installation, it must be determined
if the appliance needs to be derated. Contact
your local gas supplier for deration requirements
for your area.
Deration - At higher elevations, the amount of
BTU fuel value delivered must be reduced by
either using gas that has been derated by the gas
company or by changing the burner orifi 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 CAN1-B149.1 and .2
codes - latest edition.
Burner Orifi ce Sizes (all models)
Elevation
Feet (meters)
0-4500
(0-1372)
* Standard size installed at factory
• Part /Cat. Number
Table 6
Natural
Gas
drill size (inches)
#37 (.104")
24M1001 •
3.5" WC
(.87 kPa)
10.0" WC
(2.49 kPa)
*
Propane
Gas
drill size (inches)
1.55
mm
(.061")
42M7901 •
*
Burn-in Period
During the fi rst few fi res of this appliance there
will be some odor due to the curing of the
paint and burning off of lubricants used in the
manufacturing process.
Depending on your use, the burn-in period may
take a few hours or a few days.
KEEP YOUR HOUSE WELL VENTILATED
DURING THE CURING PROCESS. THE ODOR
AND HAZE EMITTED DURING THE CURING
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.
A white fi lm may develop on the glass front
during the fi rst few fi res as part of the curing
process. The glass should be kept clean during
the fi rst two weeks of use to prevent the fi lm from
baking on (making it very diffi cult to remove).
See Cleaning Glass on Page 5.
WARNING
If the information in this
manual is not followed
exactly, a fi re or explosion
may result causing property damage, personal
injury or loss of life.
WARNING
Failure to comply with the installation and operating instructions
provided in this document will
result in an improperly installed
and operating appliance, voiding
its warranty. 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 fi re, burns, explosion
or carbon monoxide poisoning.
IMPORTANT
These appliances must not be
connected to a chimney or fl ue
serving a separate solid fuel
burning appliance.
WARNING
Do not use these appliances if
any part has been under water.
Immediately call a qualifi ed,
professional service technician
to inspect the appliances and to
replace any parts of the control
system and any gas controls
which have been under water.
WARNING
Do not attempt to alter or modify
the construction of the appliance or its components. Any
modifi cation or alteration may
void the warranty, certifi cation
and listings of this unit.
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 qualifi ed installer, service
agency or the gas supplier.
WARNING
These fireplaces are vented
heaters. Do not burn wood or
other material in these appliances.
WARNING
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 certifi ed
kit is used.
WARNING
Do not place clothing or other
fl ammable materials on or near
this appliance.
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
3
WARNING
Carbon monoxide poisoning:
early signs of carbon monoxide
poisoning are similar to the fl u
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 qualifi ed professional, as it may not
be operating correctly.
WARNING
Children and adults should be
alerted to the hazards of high
surface temperatures. Use caution around the appliance to
avoid burns or clothing ignition.
Young children should be carefully
supervised when they are in the
same room as the appliance.
Note: An Optional Screen Heat
Guard for the glass is available
(see Page 14 for ordering information).
WARNING
Any safety guard or screen
removed for servicing the appliance must be replaced prior to
operating the appliance.
Gas Control Compartment Access
The gas controls can be found behind the control
compartment access panel.
To open the control compartment access panel,
actuate the spring-loaded magnetic catches
securing the panel. First, depress the outer top
right corner of the panel until the catch "pops"
the door free. Then, gently pull the door forward
until the left top corner "pops" free, allowing the
panel to swing out and down to open.
On millivolt systems, the piezo igniter, HI/LO
fl 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.
To ease door closure, depress the catches to
place them in their retracted position, then
close the door.
4
OFF/PILOT/ON (gas control knob)
HI/LO (fl ame height
control knob)
OFF/ON Switch
Hinge Pin
Control
Compartment Access panel
Piezo Igniter
Figure 1 - Gas Control Compartment Access
OPERATION AND CARE OF YOUR
APPLIANCE
The standard controls for appliance operation
are located behind the hinged drop-down panel
below the appliance front glass enclosure panel
(see Figure 1). Optional control switches are
also available (see Page 12 - Remote Wall Switch, Remote Control or Wall Thermostat).
Operation of millivolt and electronic gas control systems are different. Before lighting and
operating your appliance determine if you have
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 fi tted with the gas
control valve shown in Figure 2.
Electronic Appliances - Appliances with
electronic systems will be fi tted with the
electronic valve shown in Figure 3.
Millivolt Appliances -
To light millivolt appliances refer to the detailed
lighting instructions found on Page 15 . Millivolt
appliance lighting instructions may also be
found on the pull out lighting instruction labels
attached to the gas control valve.
Millivolt appliances are fi tted with an OFF/ON
Rocker Switch located behind the control
compartment access panel, below the appliance front glass enclosure panel (see Figure 1
for location). Once the pilot is lit, the OFF/ON
rocker switch will control the appliance OFF/ON
burner operation. 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 or wall thermostat) and the pilot is lit,
the appliance main burner may be turned on
and off using the optional switch. When using
an optional remote switch, turn off the standard
OFF/ON switch.
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
Note:The gas supply
line must be installed
in accordance with
building codes by a
qualifi ed installer
approved and/or
licensed as requed
by the locality. In
the Commonwealth
of Massachusetts,
installation must
be performed
by a licensed
Gas Flex Line
Gas Valve
plumber or gas
fi tter.
SIT Millivolt Gas Valve
HI/LO Variable
Flame Height
Adjustment
T
P
HT
TPT
H
Pilot Adjustment
Screw
Gas
Outlet
Terminals
TPTH,TP & TH
Figure 2
Manifold Pressure Tap
P
I
L
O
T
OFF/ON
ON
OFF
(burner)
Note: The piezo igniter and burner
OFF/ON switch are located below
glass panel (see Figure 1).
Note: To prevent excessive resistance in burner
circuit (which can cause burner operation problems), only one burner control switch should be
wired to valve. Therefore, if an optional control
switch is installed, the standard Off/On switch
and wires should be removed.
Electronic Appliances -
To light electronic appliances refer to the detailed
lighting instructions found on Page 16.Elec-
tronic appliance lighting instructions may also be
found on the pull out lighting instruction labels
attached to the gas control valve.
Inlet Pressure Tap
I
H
L
O
W
Main Gas
Control Knob
OFF/PILOT/ON
TPTH TP TH
HI/LO Variable
Flame Height
Adjustment
OUT
F
F
O
P
I
L
it
O
T
O
N
Control Knob
OFF/PILOT/ON
IGNITER
IN
Gas
Inlet
Main Gas
Once the pilot is lit, if your electronic appliance is
equipped with an optional burner control switch
kit the appliance main burner may be turned on
and off using the optional switch (See optional
accessories on Page 12 - Wall Switch, Wall
Thermostat Or Remote Control Receiver).
WARNING
Turn off gas and electrical power
before servicing the appliance.
IMPORTANT
Do not use abrasive cleaners
on glass. Never clean the glass
when it is hot.
variable gas control valve. Flame height for
these models may be adjusted through a
range between fi xed low and high settings
while the appliance is in operation. Adjust
the fl ame height as desired after lighting the
appliance by rotating the variable adjustment
control knob (HI/LO) located on the front of
the valve (refer to Figure 2 ).
2. During the fi rst initial burns of these appli-
ances, there will be some odor emitted (see
Burn-In Period on Page 3 ).
3. Keep the lower control compartment clean
by vacuuming or brushing at least twice a
year. More frequent cleaning may be required
due to excessive lint from carpeting, bedding
materials, pet hair, etc. It is very important
that the control compartments, burners
and circulating air passageways of the
appliance are kept clean.
4. Always turn off gas to the pilot (millivolt
appliances) and let the appliance cool down
before cleaning. Before re-lighting, refer
to the lighting instructions in this manual.
Lighting instructions may also be found
on the pull out lighting instruction labels
attached to the gas control valve.
5. Always keep the appliance area clear and
free from combustible materials, gasoline
and other fl ammable liquids.
6. Remember, Millivolt appliances have a continu-
ous burning pilot fl ame. Exercise caution when
using products with combustible vapors.
MAINTENANCE
(See Maintenance Schedule, Page 17)
Refer to the maintenance schedule for maintenance
tasks, procedures, periodicity and by whom they
should be performed. Always verify proper operation of the appliance after servicing.
CAUTION
Wear gloves and safety Glasses
for protection while doing
required maintenance
.
IMPORTANT
Always verify proper operation
after servicing.
Before re-lighting the fi replace, refer to the
lighting instructions in this manual. Instructions are also found on pull-out panels
located below the glass door 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 qualifi ed service technician
(inspection should include ensuring that exhaust
or intake passages are unobstructed and vent
components are properly assembled and not
damaged). If the venting system is disassembled
for any reason, a qualifi ed 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.
Clean Lower Control Compartment
Keep lower control compartment clean by
vacuuming or brushing it out at least twice a
year (also clean the air venturi with a brush or
wire). More frequent cleaning may be required
due to accumulation of lint from carpeting,
bedding materials, pet hair, spider webs, etc. It
is very important that control compartments,
burners, circulating air passageways and air
venturi on the appliance are NOT obstructed
in any way.
Cleaning Glass
(see Front Glass Enclosure Panel, Removal
and Installation on Page 6) Note: Clean glass
after fi rst two weeks of operation (after Burn-In
period is over) and then only when necessary
and when the fi replace is cool. Wipe surface
with clean, dampened, soft cloth. Follow with
dry, soft towel as desired. Take care not to
scratch the glass surface.
The viewing glass should be cleaned periodically to remove any build-up caused from the
following:
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
• During start-up, it is normal for condensation to form on the inside of the glass (this
condensation and fog will usually disappear
in a few minutes). The moisture can cause
lint, dust and other airborne particles to cling
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 fi lm
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 & water
• gas fi 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 fi rmly.
Clean Logs And Burner
Carefully remove the logs (use care when handling the fi ber logs, as they become quite fragile
after curing). Vacuum out any foreign matter
(lint, carbon, etc.) on the burner. Ensure the
burner ports are “open.” Remove any carbon
deposits from the under side of the logs using
a vacuum cleaner, or a soft bristled brush (i.e.
paint brush). Note: Improper positioning of
logs can create carbon build-up and will alter
the performance of the appliance.
Replacing Logs -
If the logs become damaged by accident or
improper handling and need replacement, use
only the proper replacement logs from manufacturer (see Page 20 for ordering information).
Re-Install Embers, Logs and Vermiculite
- Carefully follow placement instructions on
Pages 7 to 9 ). All logs should fi t onto corresponding pins and/or log stoppers. This will
ensure a proper fl ame and safe combustion.
Inspect Wiring
Refer to wiring diagrams on Page 11.
WARNING
Label all wires prior to disconnection when servicing controls. Wiring errors can cause
improper and dangerous operation. Verify proper operation
after servicing.
5
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 fl ame shown in Figure 13 and as
described in Flame Appearance and Sooting on
Page 9. The Homeowner must contact a quali-
fi ed service technician at once if any abnormal
condition is observed.
Small Area Paint Touch-up
The fi nish of the appliance is a high quality powdercoat. Only use factory supplied
powdercoat paint kit for touch-ups. Paint is
available at your local authorized Lennox Hearth
Products dealer (cat. no. 90L74). Never attempt
to paint a hot fi replace.
Do not attempt to repaint the appliance until the
fi nish is completely cured (see Burn-In Period
on Page 3 ). If the surface later becomes stained
or marred, it may be lightly sanded and touched
up with spray paint.
Front Glass Enclosure Panel, Removal
and Installation
WARNING
Do not operate appliance with the
glass front removed, cracked or
broken. Replacement of the glass
should be done by a licensed or
qualifi ed service technician.
WARNING
Do not attempt to substitute the
materials used on this door, or
replace cracked or broken glass
with any materials other than
those provided by the appliance
manufacturer.
WARNING
Do not attempt to touch the front
enclosure glass with your hands
while the fi replace is in use.
WARNING
The glass door of this appliance must only be replaced as a
complete unit as provided by the
manufacturer. Do not attempt to
replace broken, cracked or chipped
glass separately.
These are direct-vent appliances. They are
designed to operate only when the front glass
enclosure panel is installed. Generally the front
glass enclosure panel should not be removed
except to gain access to the components within
the fi rebox, and the appliance may only be operated without the front glass enclosure panel
in place for very brief periods of time during
appliance checkout and adjustment. Note: The
fl ame appearance will be diminished while the
front glass enclosure panel is removed.
During this appliance checkout and adjustment period, a potential safety hazard exists
- EXERCISE EXTREME CAUTION to prevent
the occurrence of any burn injuries from the
exposed fl ames or hot surfaces. Also note, that
while the front glass enclosure panel (or any of
the panels) is removed, the fl ame appearance
will appear to be smaller than normal.
Lower Compartment
Door and Hinge
Top Flange on
Glass Door
Glass Door
Removing Glass Enclosure Panels
(see Figure 4)
1. Remove the top louver assembly or radiant
panel by pulling it out and off.
2. Open the control compartment access panel.
by actuating the spring-loaded magnetic
catches securing the panel (gently depress the
outer top corners of the louvered or radiant
panel until the catches "pop" the door free,
allowing it to swing out and down to the open
position).
3. Locate the two (2) latches at the top of the
control compartment. To disengage the two
latches from the bottom vee-fl ange of the
glass enclosure panel, reach for the handles
located towards the back of the latches and
pull the handles down toward the front of
the appliance.
4. Swing the bottom of the door out and raise
it slightly to lift the top fl ange of the door
frame away from the appliance.
Installing Glass Enclosure Panels
(see Figure 4 )
1. Visually inspect the gasket on the backside of
the panels. The gasket surface must be clean,
free of irregularities and seated fi rmly.
2. Position the glass enclosure panel in front of
the fi rebox opening at a 45 degree angle and
engage the top fl ange over the lip at the top
of the fi rebox opening. See Figure 4.
3. Swing the glass enclosure panel down and
back. Ensure the gasket seats evenly as the
panel draws shut. Engage the Vee-fl ange at
the bottom of the panel with the latches and
close the latches to secure the panel.
4. Close the bottom control compartment
access panel.
WARNING
Handle this glass with extreme
care! Tempered glass is susceptible to damage – do not scratch
or handle roughly while reinstalling the glass door frame.
6
Bottom Vee-fl ange
Glass Door
Glass Door Latch
Firebox Floor
Figure 4 - INSTALLING GLASS DOOR
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
INSTALL GRATE, VERMICULITE, GLOWING EMBERS AND LOGS
LOG SET - IDENTIFICATION
LOG SET
Catalog Number
* Item
A
B
C
D
E
F
* Item "letters" above correspond to photos on right
REFERENCE
Firebox Accessories / Parts
Cat. No.Model No.Description
88L53FGEBag of Glowing Embers
42363
H3210
Description
Log, Center
Log, Left Rear
Log, Left Front
Log, Right Rear
Log, Top Center
Log, Front Center
(1 oz. rockwool)
Vermiculite, Bag (2 liters)
Bottom View of Logs (in packaging)
C
A
B
F
D
E
Top View of Logs
B
E
WARNING
The size and position of the log
set was engineered to give the
appliance a safe, reliable and
attractive fl ame pattern. Any
attempt to use a different log
set in the fi replace will void
the warranty and will result in
incomplete combustion, sooting, and poor fl ame quality.
Glowing Embers
Separate into Quarter
Size (separate) Pieces
Bag of Glowing
Embers (rockwool)
D
A
C
F
Top View of Logs - Installed
B
D
E
C
Figure 5
(Valve Access Side)
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
F
A
7
READ LOG WARNINGS ON PAGE 9 BEFORE PROCEEDING
8. Place Log (B) as shown in Figure 8.
1. Remove front glass enclosure panel from appliance.
a. Open Control Compartment Access Panel (see Control Compart-
ment Access Instructions on Page 4.).
b. Remove the glass panel enclosure (see Removing Glass Enclosure
Panel instructions on Page 6.
2. Remove the following from fi rebox; log set, embers (rockwool) and
vermiculite. Handle logs carefully to prevent breakage.
3. Ensure the Grate is properly installed in the fi rebox with the 4 legs
of the grate fi tting into the 4 dimples on the fi rebox fl oor.
4. Install Vermiculite - Place some vermiculite on the fi rebox fl oor around
the grate (the entire bag of vermiculite will NOT be used). See Figure 13
on Page 9. DO NOT PLACE ANY VERMICULITE ON THE BURNER.
6. Placement of Glowing Embers -
Separate the Embers (rockwool) into pieces about the size of a quarter
(see Figure 5 on Page 7 ). Keep the pieces fl uffed up, not matted.
Distribute these pieces over the surface of the burner, as shown in
Figure 6. Do not use more than is necessary. Ensure that the main
burner ports remain uncovered by the ember material.
Note: This appliance is provided with enough Glowing Embers for
several applications, do not use all that is in a new bag at one time. For
best glowing effect, replace the ember material annually. Replacement
Glowing Embers are available (order Catalog Number 88L53).
Place Embers on burner as shown.
Position Log (B) Against The Back Of
The Grate Here
B
Position Groove at The Bottom Of Log (B) Over The Grate
Here And Slide It Against The Back Of The Grate
Figure 8
9. Place Log (C) as shown in Figure 9.
(Valve Access Side)
Log (C) Lays Over Logs (A) and (B)
Figure 6
DO NOT PLACE EMBERS OVER
GAS PORTS / AREAS CIRCLED
7. Place Log (A) on the grate as shown in Figure 7.
A
B
C
Position The Groove in The Back of Log (C)
Figure 9
Against The Grate
10. Place Log (D) as shown in Figure 10.
Position And Slide Log (D) Against The
The Grate
Back Of
A
A
(Valve Access Side)
Position Groove At The Bottom Of
Log (A) Over The Log Support Here
Figure 7
8
Position The Groove At The Bottom Of
Log (A) Over The Grate And Slide It
Forward Against The Grate Here
(Valve Access Side)
(Valve Access Side)
Figure 10
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
D
Place Log (D) Over The
Flat Spot On Log (A)
Here
10. Place Log (E) as shown in Figure 11.
Position round end of log (E) against the notch of
log (D) here. Two charred spots face the front
E
D
C
Position Small End of
Log (E) on The Notch of
Log (C) Here
11. Place Log (F) as shown in Figure 12.
Log (F) sits in front of the grate
(Valve Access Side)
WARNING
(Valve Access Side)
Figure 11
Figure 12
F
This appliance is not designed
to burn wood. Any attempt to
do so could cause irreparable
damage to appliance and prove
hazardous to your safety.
WARNING
If logs are not installed according
to the log installation instructions,
fl ame impingement and improper
combustion could occur and result
in soot and/or excessive production of carbon monoxide (CO), a
colorless, odorless, toxic gas.
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.
WARNING
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 and logs.
BURNER ADJUSTMENTS (QUALIFIED TECHNICIANS ONLY)
If the air shutter openings closed too far, sooting may develop. Sooting is indicated by black puffs
developing at the tips of very long orange fl ames. 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 fl ames and lack of combustion air entering the air shutter
opening. To achieve a warm yellowish-orange fl ame 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, fi rst check the log set positioning to ensure that the fl ames 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 fl ames that appear blue
and transparent. These weak, blue and transparent fl ames are termed anemic.
• Propane models may exhibit fl 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 fl ame normalizes and the fl ames do not appear sooty.
Flame Appearance & Sooting
Proper fl ame appearance is a
fl ame which is blue at the base
and becomes yellowish-orange in
the body of the fl ame. When the
appliance is fi rst lit, the entire fl ame
may be blue and will gradually turn
yellowish-orange during the fi rst
15 minutes of operation. If after
period the fl ame stays lowered
blue, or if the fl ame is orange with
evidence of sooting (black tip), the
air shutter opening may need to
be adjusted.
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
WARNING
Air shutter adjustment should
only be performed by a qualifi ed
professional service technician.
WARNING
Ensure front glass panels are in
place and sealed during adjustment.
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
Figure 13 *- Burner Flame Appearance
Vermiculite
CAUTION
The air shutter door and nearby
:
Air Shutter
Adjustment
Air shutter
gap should be
increased
Air shutter
gap should be
decreased
appliance surfaces are hot. Exercise caution to avoid injury while
adjusting fl ame appearance.
CAUTION
Carbon 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.
Burner Air Shutter Adjustment Procedure
1. Locate adjustment rod and adjust air shutter
to the standard setting as shown in Figure
14 (adjustment rod is located in the lower
control compartment). Note: Rotating the
adjustment rod counterclockwise decreases
air and clockwise increases air.
9
2. Light appliance (follow lighting procedure on
lighting label in control compartment or see
homeowners manual).
3. Allow the burner to operate for at least 15 min-
utes while observing the fl ame continuously
to ensure that the proper fl ame appearance
has been achieved (see Figure 13 ). If the
following conditions are present, adjust
accordingly.
• If flame appears weak or sooty, adjust
the air shutter, incrementally, to a more
open position until the proper fl ame
appearance is achieved.
• If fl ame stays lowered blue, adjust the
air shutter, incrementally, to a more
closed position until the proper fl ame
appearance is achieved.
4. Leave the control knob (off/pilot/on) in the
ON position and the burner OFF/ON switch
OFF (& remote switches, if applicable).
5. When satisfi ed that the burner fl ame appear-
ance is normal, close the lower control
compartment door.
Decrease Shutter Opening
In This Direction
Air Shutter
Adjusting
Rod
Increase Shutter Opening
In This Direction
Note - Burners are
omitted in this
view for clarity.
Orifi ce
Millivolt Appliance Checkout
The pilot fl ame should be steady, not lifting
or fl oating. 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 fl ame. The fl ame should
project 1" (25 mm) beyond the hood at all three
ports. See Figure 15.
To light the burner, refer to the lighting instructions on Page 15.
MILLIVOLT PILOT ASSEMBLY
Proper Pilot Flame Appearance
Hood
Thermocouple
Pilot
Nozzels
Thermopile
Igniter Rod
3/8" Min.
(9 mm)
Figure 15
Electronic Appliance Checkout
To light the burner, refer to the lighting instructions on Page 16. Ensure the igniter lights the
pilot. The pilot fl ame should engulf the fl ame
sensor as shown in Figure 16.
ELECTRONIC PILOT ASSEMBLY
Proper Pilot Flame Appearance
Proper Flame
Adjustment
Pilot
Nozzels
3/8" to 1/2"
(9 -13 mm)
Ground
Electrode
Flame Rod
Hot Surface
Igniter
Figure 16
With proper care and maintenance, your appliance will provide many years of enjoyment. If
you should experience any problem, fi rst refer
to the troubleshooting guide in this manual.
If problem persists, contact your Lennox
distributor.
Main Burner Factory Air Shutter
Opening Setting - All Models
ModelNatural
Gas
MPD35ST
Figure 14
1/8”
3.2mm
Adjustment Rod Positions
(when viewed from above)
Propane
Gas
1/4”
6.4mm
10
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
WIRING DIAGRAMS
Wiring diagrams are provided here for reference purposes only. This information is also
provided on schematics attached directly to the
appliance on a pullout panel located within the
control compartment.
CAUTION
Label all wires prior to disconnection when servicing con-
J-Box Wiring when
using unit mounted
relay module.
BK
W
G
Junction Box
Relay Module C/W FBK-250 only. Plug blower
into J-Box receptacle for FBK-100 or FBK-200
application. View A for J-Box wiring.
C
AV
02
1
*OFF/ON Switch
(Integral with
Gas Valve)
Schematic Representation Only
Optional Blower
trols. Wiring errors can cause
improper and dangerous appliance operation.
Millivolt Wiring Diagram
Schematic Representation Only
If any of the original wire as supplied must
be replaced, it must be replaced with Type
AWM105 C - 18 gage wire.
TH
TP
TP
TH
Thermopile
*Opt.
Switch
Field Wired
Standard OFF/ON Switch
Factory
Wired
* Optional Kits Installed - OFF/ON wall switch,
wall thermostat or remote control receiver.
Note: Turn the appliance-mounted OFF/ON
burner control switch to the OFF position if
any of these kits are installed.
Figure 17
Your Fireplace's Model Number ________________________________________
BL
BL
BK
Optional Control Switch
Figure 18
WARRANTY
Your gas appliance is covered by a limited
twenty year warranty. You will fi 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
documents for future reference.
PRODUCT REFERENCE INFORMATION
We recommend that you record the following
important information about your fi replace.
Please contact your Lennox dealer for any
questions or concerns. For the number of
your nearest Lennox dealer, please call 800731-8101
Igniter
Connector
Honeywell
Electronic
Gas
Valve
BK
Transformer
BL
R
BK = BLACK BL = BLUE
BK
R = RED W = WHITE
W
G = GREEN
24 V
Secondary
Wall Mounted Blower Speed Control Switch or
ON/OFF Switch for Blower Kit (optional)
Outlet Box Green
Ground Screw
BK
120
W
VAC
G
G
Break off Tab
Junction
Box
White Wire
to Opposite
Side (neutral)
GROUND
120 VAC
Primary
Field Wired
Factory
Wired
Hot side
of Outlet
* Leave the OFF/ON switch, which is
integral with the gas valve, in the ON
position.
** Optional Control Switches: Wall
Switch, Wall Thermostat or Remote
Control Receiver.
Notes:
1. If any of the original wire as supplied
must be replaced, use Type AWM 105°C
- 18 gage wire ONLY.
2. 120 VAC, 60 Hz - Less than 3 Amps.
Caution: label all wires prior to
disconnection when servicing controls.
Wiring errors can cause improper and
dangerous operation.
REPLACEMENT PARTS
A complete parts list is found at the end of
this manual. Use only parts supplied from the
manufacturer.
Normally, all parts should be ordered through
your Lennox distributor or dealer. Parts will be
shipped at prevailing prices at time of order.
When ordering repair parts, always give the
following information:
1. The model number of the appliance.
2. The serial number of the appliance.
3. The part number.
4. The description of the part.
5. The quantity required.
6. The installation date of the appliance.
If you encounter any problems or have any questions concerning the installation or application
of this system, please contact your distributor,
or Lennox directly:
BK
R
Your Fireplace's Serial Number ________________________________________
The Date On Which Your Fireplace Was Installed ___________________________
The Type of Gas Your Fireplace Uses ____________________________________
Your Dealer's Name ________________________________________________
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
LENNOX HEARTH PRODUCTS
1110 West Taft Avenue
Orange, CA 92865
11
ACCESSORY COMPONENTS
Product Reference Information
Cat. No.ModelShip.
Weight
H3201MPD35ST-NM220 lbs46W x 26D x
H3202MPD35ST-PM220 lbs46W x 26D x
H3203MPD35ST-NE220 lbs46W x 26D x
Ship.
Volumn
43H (30 cu.ft.)
43H (30 cu.ft.)
43H (30 cu.ft.)
Wall Thermostat, Millivolt
Cat. No.Model No.Description
89L36WTKWall Thermostat Kit,
White
Wall Thermostat
The wall thermostat kit provides temperature control
for optimum comfort.
Remote Control Kit, Standard
Cat. No.Model No.Description
H0249RCLRemote Control System
(Standard)
(ref. Form # 750,127M)
Standard Remote Control System
The Model RCL (Standard) Remote Control System,
features a simplistic OFF/ON control function for the
fi replace. This model includes a hand-held transmitter,
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 briefl y to verify
that a signal has been sent.
The Model RCL is designed to operate with all millivolt 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 fi replace effortlessly with
one simple motion.
The Model RCL comes complete with detailed operating instructions.
Remote Control Kit, Deluxe
Cat. No.Model No.Description
H0251RCL-STATRemote Control System
(Deluxe)
(ref. Form # 750,129M)
Deluxe Remote Control System
The Model RCL-T (Deluxe) Remote Control System
has all of the features of the standard system along
with an added easy to read LCD screen which presents
access to many enhancements, including; battery
power level indicator, timer, mode of operation,
thermostatic display including room temperature in
either metric of English units, fl ame 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, may be operated with electronic and millivolt systems with either natural gas or propane gas.
The RCL-T comes complete with detailed operating
instructions.
White Wall Switch Kit
Cat. No.Model No.Description
85L87FWSKOFF/ON Wall Switch Kit
OFF/ON Wall Switch Kit
The OFF/ON wall switch kit may be used to control
the operation of the fi replace burner. Install the
OFF/ON wall switch in a convenient location near
the fi replace.
12
Decorative Firebox Accessories
Cat. No.Model No.Description
88L53FGEBag of Glowing Embers
80L42FDVS
(FDVS ref. Form #750,010M)
(1 oz. rockwool)
Bag of Decorative
Volcanic Stone
Bag of Glowing Embers
Bag of Volcanic Stone
Replacement ember materials or volcanic stone are
available for use with these appliances. Order kits as
part of the periodic maintenance of the appliance.
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
Brickaded Wall Liner Kits
Cat. No.Model No.Description
H3207MBLK-35ST Interior Brick Liner Kit
(ref. Form # 750,160M)
Brickaded Panel Liner Kit
The brickaded liner kits include ceramic panels as
shown here. The panels have brick-like features
in relief.
ACCESSORY COMPONENTS
Note: Door & Trim Kits are for 1 side only. If set is desired, order 2 kits.
Arch
Design
Arch Pane
Design
Square
Design
Square
Pane
Design
Style View Doors -
Style View Doors come in 4 beautiful styles. They
are easy to install and will not require hardware to
attach them to the standard glass door frame. The
door includes heavy duty magnet door latches and
functional twin-pane doors.
Arch Pane Design Kits
H0930APD35C 35” Arch Pane Doors, Char.
H0931APD35TI 35” Arch Pane Doors, Text. Iron
H0932APD35SP 35” Arch Pane Doors, Satin Pew.
H0933APD35AB 35” Arch Pane Doors, Ant. Brass
Arch Design Kits
Cat. No.ModelDescription
H0858AD35C35” Arch Doors, Charcoal
H0859AD35TI35” Arch Doors, Textured Iron
H0860AD35SP 35” Arch Doors, Satin Pewter
H0861AD35AB 35” Arch Doors, Antique Brass
Square Design Kits
Cat. No.ModelDescription
H0946SD35C35” Sq. Doors, Charcoal
H0947SD35TI35” Sq. Doors, Textured Iron
H0948SD35SP 35” Sq. Doors, Satin Pewter
H0949SD35AB 35” Sq. Doors, Antique Brass
Square Pane Design Kits
H0962SPD35C35” Sq. Pane Doors, Char.
H0963SPD35TI35” Sq. Pane Doors, Text. Iron
H0964SPD35SP 35” Sq. Pane Doors, Satin Pew.
H0965SPD35AB 35” Sq. Pane Doors, Ant. Brass
(ref. Form # 775,169M)
2-Piece Louver Kits
Cat. No.Model No.Description
96L052LVR35PB
96L092LVR35BS
(ref. Form # 504,224M)
2 Pc. Louver Kit,
Polished Brass
2 Pc. Louver Kit,
Brushed Stainless
2-Piece Polished Brass and Brushed Stainless
Louvers Kits
These louvers are designed to replace either the middle
charcoal louver of each set or the charcoal louver in
each set closest to the glass door. These kits include
two narrow louvers. They provide a touch of elegance
to these appliances. These kits can be retrofi tted to
previously installed appliances.
Clean Face Charcoal Radiant Panel Kits
Cat. No.Model No.Description
88L36RAD35C-2Clean Face Panel Kit
(ref. Form # 504,223M)
Clean Face Panel Kits
Clean faced panel kits are available to convert the standard louvered fi replaces to radiant models which are
more suited for fi nishing around the fi rebox opening
with non-combustible materials, such as tile.
4 Piece Trim Kit
Cat. No.Model No.Description
96K17 TK35PB435” 4 Piece Finish Trim Kit,
(ref. Form # ii-9299)
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
Polished Brass
3 Piece Trim Kit
Cat. No.Model No.Description
96K21TK35PB335” 3 Piece Finish Trim Kit,
(ref. Form # 750,147M)
Polished Brass
Polished Brass 3-Piece Trim Kit
This kit contains brass trim pieces used to fi nish the
gaps between the wall board and the fi replace, providing the appliance a brass perimeter highlight. This kit
contains the trim pieces and these instructions.
35" Assembled Louver Kits
Cat. No.Model No.Description
88L28LVR35PB-2
88L32LVR35BS-2
(ref. Form # 750,119M)
Louver Kit, Polished
Brass
Louver Kit, Brushed
Stainless
Polished Brass & Brushed Stainless Louvers Kits
Decorative louvers are available for use with all
Multi-Open Series appliances.These kits include a
top 3-piece assembly and a bottom 3-piece assembly.
They provide a touch of elegance to any Multi-Open
Series appliance. These kits can be retrofi tted to
previously installed appliances.
2-Piece Door Frame Kits
These kits are designed
to attach directly to
the front face of the
appliance at the glass
enclosure panel’s top
and bottom edges.
2 Piece Trim Kit
Cat. No.Model No.Description
26M88 2DFK35PB35” Door Trim Kit, Polished
26M91 2DFK35BS35” Door Trim Kit, Brushed
(ref. Form # 750,098M)
Brass (2 Piece, Top and
Bottom)
Stainless (2 Piece, Top and
Bottom)
13
ACCESSORY COMPONENTS
* 35" Eyebrow Hood Kits
Cat. No.Model No.Description
96K67EB35PB
88L49EB35BS
* These hood kits replace the standard hood that
comes with these fi replaces.
(ref. Form #504,142M)
Polished Brass & Brushed Stainless Hood Kits
Attractive hoods are available in two styles to be used
on the Multi-Open Series appliances. These hoods
are designed to be fi tted to the glass viewing sides of
the appliance. In addition to providing an aesthetically
pleasing appearance to your appliance installation,
the hood reduces heat effects to decorative mantles
and fi nish materials located above the fi replace
opening. The hood kit replaces the standard hood
that comes with these appliances and snaps into
place. These kits can be retrofi tted to previously
installed appliances.
Hood Kit, Polished
Brass
Hood Kit, Brushed
Stainless
* 35" Screen Heat Guard Kit
Cat. No.Model No.Description
26M48HG35M 35" Screen Heat Guard Kit
* Order 2 for set if desired.
(ref. Form # 750,101M)
Screen Heat Guard Kit
This easy to install optional screen heat guard installs
over the standard glass enclosure panel to provide
protection from the hot glass surface. These screen
heat guard panels cannot be used in conjunction
with the arch door kits or door frame kits. Order 2
if a set is desired (for front face and rear face glass
surfaces).
* 35" Arch Door Kits
Cat. No.Model No.Description
26M43 ADK35CMPB Arch Door, Polished Brass
26M44 ADK35CMBS Arch Door, Brushed Stainless
* Order 2 for set if desired.
(ref. Form # 750,021M)
Arch Door Kits
Two types of arch door kits are available for the MultiOpen Series. Both types of kits are easy to install
and do not require hardware to attach them to the
standard door frame. These kits can be retrofi tted to
previously installed Multi-Open Series appliances. The
decorative arch kits can not be used in conjunction
with the screen panel kit.
4 Piece Door Trim Kits
Cat. No.Model No.Description
26M824DFK35PBDoor Trim, Polished Brass
26M854DFK35BSDoor Trim, Brushed Stainless
(ref. Form # 750,098M)
Door Frame Kits
A decorative door frame kit is available for use with
these appliances. It is designed to attach directly to
the front face of the appliance at the four edges of
the glass enclosure panel resulting in the appearance
of a picture frame.
Forced Air Kit
The FBK-100 blower provides constant velocity forced
air circulation. The FBK-200 assembly with variable
speed, wall-mountable switch provides variable speed
forced air circulation. The FBK-250 assembly with
variable speed unit-mountable switch, also provides
variable speed forced air circulation.
P
T
A
N
I
Forced Air Blower Kits
Cat.
Model No.Description
No.
80L84FBK-100Blower, Standard
80L85FBK-200Blower, Variable Speed
80L86FBK-250Blower, Variable Speed
94L89FBK-100-36Blower, Standard, 36 Pack
94L90FBK-200-36Blower Kit - Variable Speed
H0543FBK-250-36Blower Kit - Variable Speed
(ref. Form # 750,028M & 750,029M)
Cat. No.Model No.Description
90L74TPK-CTouch-Up Paint (Charcoal)
98K67TPK-TTouch-Up Paint (Tan)
(TPK-C ref. Form # 504,216M)
(single speed)
(w/wall-mounted switch)
(w/unit-mounted switch)
with Wall Switch 36 Pack
with Thermo Snap Switch
36 Pack
Touch-Up Paint Kits
Touch-Up Paint Kit
Repair of minor scratches and discoloration of the
appliance charcoal painted surfaces may be accomplished with the touch-up paint kit.
14
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
LIGHTING INSTRUCTIONS – MILLIVOLT GAS VALVE
it
OUT
IN
FOR YOUR SAFETY READ BEFORE LIGHTING
WARNING: IF YOU DO NOT FOLLOW THESE INSTRUCTIONS EXACTLY, A FIRE OR EXPLOSION
MAY RESULT CAUSING PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE.
A. This appliance has a pilot which must be lit with a piezo
igniter. When lighting the pilot, follow these instructions
exactly.
B. BEFORE OPERATING smell all around the appliance area for
gas. Ensure to smell next to the fl oor because some gas is
heavier than air and will settle on the fl oor.
WHAT TO DO IF YOU SMELL GAS
• Extinguish any open fl ame.
• Open windows.
• Do not light any appliance.
• Do not touch any electrical switches.
LIGHTING INSTRUCTIONS
1. STOP! Read the safety information above on this page.
2. Access the lower control compartment.
3. Turn OFF/ON switch to “OFF” (and remote wall switch, if appli-
cable).
4. Verify main line shut-off valve is open.
5. Push in gas control knob slightly and turn clockwise
to “OFF.”
SIT Millivolt Gas Valve
IN
PIEZO
IGNITER
OUT
F
F
O
P
I
L
it
O
T
O
N
GAS CONTROL
KNOB
TP/TH
TP
TH
TPTH TPTH
BURNER
OFF/ON SWITCH
I
H
L
W
O
P
I
L
O
T
- LO / HI +
• Do not use any phone in your building.
• Immediately call your gas supplier from a neighbor’s
phone.
• If your gas supplier cannot be reached, call the fi re depart-
ment.
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 qualifi ed service technician. Force
or attempted repair may result in a fi re or an explosion.
D. Do not use this appliance if any part has been under water.
Immediately call a qualifi ed service technician to inspect the
appliance and to replace any part of the control system and
any gas control which has been under water.
6. Wait fi ve (5) minutes to clear out any gas. If you then smell gas,
STOP! Follow “B” in the safety information above on this page. If you
do not 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.
Millivolt Pilot
9. Turn gas control knob counterclockwise
to “ON.”
10. Close lower control compartment.
ON
OFF
Note: Knob cannot be turned from “PILOT” to “OFF”
unless the knob is pushed in slightly. Do not force.
TO TURN OFF GAS TO APPLIANCE
1. Turn remote wall switch “OFF.” The pilot will remain lit for
normal service.
2. For complete shutdown, turn remote wall switch to “OFF.”
3. Access the lower control compartment.
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
4. Depress gas control knob slightly and turn clockwise
to “OFF.” Do not force.
5. Close lower control compartment.
15
LIGHTING INSTRUCTIONS — ELECTRONIC
FOR YOUR SAFETY READ BEFORE LIGHTING
WARNING: IF YOU DO NOT FOLLOW THESE INSTRUCTIONS EXACTLY, A FIRE OR EXPLOSION
MAY RESULT CAUSING PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE.
A. When lighting the appliance, follow these instructions
exactly.
B. BEFORE OPERATING smell all around the appliance area
for gas. Be sure to smell next to the fl oor because some
gas is heavier than air and will settle on the fl oor.
WHAT TO DO IF YOU SMELL GAS
• Extinguish any open fl ame.
• Open windows.
• Do not light any appliance.
• Do not touch any electrical switches.
• Do not use any phone in your building.
LIGHTING INSTRUCTIONS
1. STOP! Read the safety information above on this page.
2. Turn remote wall switch to “OFF.”
3. Open lower control compartment door.
4. Verify main line shut-off valve is open.
Honeywell Electronic Gas Control Valve
ON / OFF Switch
C
O
N
T
R
NO
O
FFO
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N
I
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ER
Front View
NI
I
PS
• Immediately call your gas supplier from a neighbor’s
phone.
• If your gas supplier cannot be reached, call the fi re
department.
C. Use only your hand to turn the gas control lever. Never
use tools. If the lever will not turn by hand, do not try
to repair it, call a qualifi ed service technician. Force or
attempted repair may result in a fi re or an explosion.
D. Do not use this appliance if any part has been under
water. Immediately call a qualifi ed service technician
to inspect the appliance and to replace any part of the
control system and any gas control which has been under
water.
5. Turn the OFF/ON switch to “OFF”. Do not force.
6. Wait fi ve (5) minutes to clear out any gas. If you then
smell gas, STOP! Follow “B” in the safety information
above on this page. If you do not smell gas, go to the
next step.
7. Turn the OFF/ON switch to “ON”. Do not force.
8. Turn “ON” all electrical power to appliance (remote wall
or appliance switch).
9. Close lower control compartment door.
TO SHUT OFF
1. Turn off all electrical power to the appliance (remote wall
switch).
16
TO TURN OFF GAS TO APPLIANCE
1. For complete shut-down, turn remote wall switch to
“OFF.”
2. Open lower control compartment door.
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
3. Turn the OFF/ON switch to “OFF”. Do not force.
4. Close the main line shut-off valve.
5. Close lower control compartment door.
MAINTENANCE SCHEDULE
Annually (Before the onset of the Burning Season)
MAINTENANCE TASKACCOMPLISHING PERSONPROCEDURE
Inspecting/Cleaning Burner, Logs
and Controls
Check Flame Patterns and Flame
Height
Inspecting/Cleaning Pilot and BurnerQualifi ed Service Technician
Checking Vent SystemQualifi ed Service TechnicianInspect the vent system at the top and at the base (within the
Appliance CheckoutQualifi ed Service TechnicianPerform the appropriate appliance checkout procedure detailed
Qualifi ed Service TechnicianInspect valve and ensure it is properly operating. Check piping
for leaks. Vacuum the control compartment, fi replace logs and
burner area.
Qualifi ed Service Technician
Refer to Figure 13 on Page 9 and verify the fl ame pattern and
height displayed by the appliance conforms to the picture. Flames
must not impinge on the logs. Ensure fl ames are steady (not
lifting or fl oating).
Refer to Figure 15 and Figure 16 on Page 10. Remove any
surface build-up on pilot and burner assembly. Wipe the pilot
nozzles, igniter/fl ame rod and hood. Ensure the pilot fl ame
engulfs the fl ame sensor as shown.
fi rebox) for signs of blockage or obstruction. Look for any signs
of dislocation or deterioration of the vent components. Note:
Excessive condensation can cause corrosion of caps, pipe &
fi ttings (excessive condensation can be caused by long lateral
runs, too many elbows and/or exterior portions of the system
being exposed to cold weather). Also inspect wall straps or
plumbers's tape to ensure it is secure and in place.
in this manual.
Replacing Rockwool Ember MaterialsHomeowner/Qualifi ed Service
Technician
Periodically (After the Burning Season)
Remove old ember materials (rockwool) and vacuum the ember
placement area. Place new embers as described in Step 6 on
Page 8.
MAINTENANCE TASKACCOMPLISHING PERSONPROCEDURE
Cleaning Firebox InteriorHomeownerCarefully remove logs, rockwool, volcanic stone and vermiculite.
Vacuum out interior of the fi rebox. Clean fi rebox walls and log
grate. Replace logs, Rockwool and volcanic stone as detailed
in this manual.
Check Flame Patterns and Flame
Height
Checking Vent SystemHomeownerInspect the vent system at the top and at the base (within the
Cleaning Front Glass Enclosure PanelHomeownerClean as necessary following the directions provided in this
Homeowner
Refer to Figure 13 on Page 9 and verify the fl ame pattern and
height displayed by the appliance conforms to the picture. Flames
must not impinge on the logs.
fi rebox) for signs of blockage or obstruction. Look for any signs
of dislocation of the vent components.
manual. DO NOT TOUCH OR ATTEMPT TO CLEAN GLASS WHILE HOT.
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
17
TROUBLESHOOTING
Note: Before troubleshooting the gas control system, Ensure external gas shut off valve, located at gas supply inlet, (and wall switch, iff applicable), is
in the “ON” position.
Important: Valve system troubleshooting should only be accomplished by a qualifi ed service technician.
TROUBLESHOOTING GUIDE - MILLIVOLT GAS CONTROL SYSTEM
SYMPTOMPOSSIBLE CAUSESCORRECTIVE ACTION
1. Spark igniter will not light pilot after
repeated triggering of igniter button.
2. Pilot will not stay lit after
carefully following the lighting
instructions.
3. Pilot burning, no gas to burner, Valve
knob “ON,” and the (standard) burner
OFF/ON switch is “ON." Read important note below.
IMPORTANT NOTE: If an optional
*remote switch is used for burner
operation, if the standard burner
OFF/ON switch is still installed on
appliance it must be in the "OFF"
position.
*Optional remote switch kits - wall
switch, wall thermostat or remote
control.
4. Frequent pilot/burner outage prob-
lem.
A. Defective igniter
(no spark at electrode).
B. Defective or misaligned electrode at pilot
(spark at electrode).
C. Gas supply pressure errant.
D. Pilot orifi ce plugged.
A. Defective pilot generator
(thermocouple).
A. Wall switch or wires defective.
B. Thermopile may not be generating suf-
fi cient millivolts.
C. Plugged burner orifi ce.
D. OFF/ON Switch & *Remote Switch are in
the "ON" position resulting in excessive
resistance.
A. Pilot fl ame may be too low or blowing (high)
causing the pilot/valve safety to drop out.
Check for spark at electrode and pilot; if no spark and
electrode wire is properly connected, replace igniter.
Using a match, light pilot. If pilot lights, turn off pilot
and trigger the igniter button again. If pilot lights, an
improper gas mixture caused the bad lighting and
a longer purge period is recommended. If pilot will
not light – check gap at electrode and pilot – should
be 1/8" to have a strong spark. If gap measures 1/8",
replace pilot (see Figure 15 on Page 10).
Check inlet gas pressure. It should be within the limits
as marked on the rating plate.
Clean or replace pilot orifi ce.
Check pilot fl ame, it must impinge on thermocouple
(see Figure 15 on Page 10). Clean and/or adjust pilot
for maximum fl ame impingement on thermocouple.
Ensure that the connection between the valve and
thermocouple are tight and secure.
Check wall switch and wires for proper connections.
Jumper wire across terminals at wall switch, if burner
comes on, replace defective wall switch. If okay, jumper
wires across wall switch wires at valve, if burner comes
on, wires are faulty or connections are bad.
Check thermopile with millivolt meter. Take reading
at thermopile terminals of gas valve. Should read
325 millivolts minimum with optional wall switch
“OFF.” Replace faulty thermopile if reading is below
specifi ed minimum.
Check burner orifi ce for blockage and remove.
When turning on the burner using a *remote switch,
ensure that the standard OFF/ON switch is in the "OFF"
position. If both switches are in the ON position, it
may result in excessive resistance (& millivolt drainage) and the burner may not come on.
Clean and/or adjust pilot fl ame for maximum fl ame
impingement on thermocouple (see Figure 15 on
Page 10).
TROUBLESHOOTING GUIDE - ELECTRONIC IGNITION SYSTEM
SYMPTOMPOSSIBLE CAUSESCORRECTIVE ACTION
1. Burner will not light.A. Faulty Valve System.
B. “OFF/ON” or wall switch defective.
2. Burners come “ON,” then turns “OFF.”A. Burner orifi ce plugged.
B. Obstructed vent system.
18
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
See Below.
Disconnect the two black wires from the wire nuts.
Test switch(s) for continuity with a multimeter. If
continuity is not indicated, switch(s) is defective and
must be replaced.
Note: Before replacing “OFF/ON” switch, Ensure to
check wiring for loose connections or broken wires
and repair as needed.
Check main burner orifi ce(s) for blockage. Clean
or replace.
Check vent system for obstructions.
TROUBLESHOOTING PROCEDURE - ELECTRONIC IGNITION SYSTEM
STARTCHECK
• Turn Off Gas Supply.
• Ensure Valve Switch Is In ON Position.
• Disconnect Control Harness.
• Set Thermostat To Call For Heat.
Insert A
End View of Control Harness Connector
• Check for proper voltage at control harness
(see insert A). Voltage
2
should be 24V between
thermostat or pressure
switch and 24V common
and 24V hot.
YES
• Plug control harness into
valve. Wait for internal check
delay.
NO
• Line voltage power
• Low voltage transformer
• Limit controller
• Thermostat
• Wiring
24 Volt Hot
Common
24 Volt
Switched
Check For Damaged or Missing
Terminals in Connector
Insert B
Igniter Terminals
24 Volt
• With pilot burner cable con-
1
• Igniter warms up and glows
red.
NO
nected, measure voltage at
valve HSI element output. 24V
2
nominal. (See insert B)
YES
YES• Replace igniter/fl ame rod
1
assembly.
YES
• Check that pilot gas is fl owing. Wait
• Turn on gas supply.
• Pilot burner lights.
NO
to ensure pilot gas tubing is purged.
Recycle call for heat if necessary.
YES
• Measure voltage between 24V hot and
24V common leads to valve control.
Must measure at least 19.5 VAC with
igniter powered (see insert A). To
YES
identify proper lead, this check must
be done with the valve control connected and igniter powered.
YES
• Replace Pilot Assembly.
• Check that pilot fl ame makes good
contact with pilot burner fl ame rod.
• Main valve opens and main
burner lights.
• Check for good electrical connection
NO
through the pilot tubing.
• If both of the above are good, replace
igniter/fl ame rod assembly.
YES YES
• System Is okay.• Cycle thermostat off and back on.
NO
• Replace valve.
NO
• Replace valve.
• Check transformer and
NO
line volt supply.
Igniter will cycle off and
1
back on once during the 90
second ignition trial. All
voltage measurements must
be taken while the igniter is
powered.
When measuring voltage
2
at connections, use care
to ensure terminals are
not damaged.
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
• Main burner lights.
NO
• Replace valve.
19
REPLACEMENT PARTS - MPD35ST
Item Part/Cat.No. QtyDescription Where Used
SIT Millivolt Only
1H33571Gas Train Assembly, NG, MVMPD35ST-NM
1H33551Gas Train Assembly, LP, MVMPD35ST-PM
Honeywell Electronic Only
2H33561Gas Train Assembly, NG, Elecrtr.MPD35ST-NE
342J321Transformer
Misc. Replacement Parts
4
5
6
7
H3351
H3352
H3353
LB-91941BY
Brickaded Side PanelsAll
2
Burner, PanAll
1
* Electrical kitAll
1
Eyebrow PanelAll
2
893L321Flex Line Gas Connector, FFGCAll
9
LB-92398B
2Glass Enclosure AssemblyAll
1042363Vermiculite, Bag ofAll
11H33581Grate AssemblyAll
1269L21014Latch, Glass Enclosure PanelAll
H3354
13
Note: Ordering information for Volcanic Stone, Glowing Embers and Touch-up Paint can be found on
Page 12
* Electrical Outlet Kit consists of a junction box, 2 screws, an receptacle outlet, an OFF/ON rocker switch
and a snap bushing. Note: All the components in the electrical kit will Not be used by every model.
4
7
15
8
10
25
20
6
13
5
15
9
11
16
21
12
18
19
22
1
9
17
22
2
Complete Log Set Available Only
14
8
3
8
LENNOX reserves the right to make changes at any time, without notice, in design,
materials, specifi cations, prices and also to discontinue colors, styles and products.
Consult your local distributor for fi replace code information.