Lennox G61MPV Series Guide

06/03
*2P0603*
504,809M
*P504809M*
G61MPV
SERIES
Litho U.S.A.
504,809M
6/2003
E 2003 Lennox Industries Inc.
Dallas, Texas, U A

WHAT TO DO IF YOU SMELL GAS:
Do not store or se gasoline or other
flammable vapors and liq ids in the
vicinity of this or any other appliance.
Installation and service m st be perĆ
formed by a q alified installer, serĆ
vice agency or the gas s pplier.
DDo not try to light any appliance.
DDo not to ch any electrical switch; do not
se any phone in yo r b ilding.
DImmediately call yo r gas s pplier from a
neighbor's phone. Follow the gas s pplier's
instr ctions.
DIf yo cannot reach yo r gas s pplier, call
the fire department.
FIRE OR EXPLOSION HAZARD.
Fail re to follow safety warnings exactĆ
ly co ld res lt in serio s inj ry, death,
or property damage.
WARNING
DLeave the b ilding immediately.
GAS FURNACE

Page 2
G61MPV Parts Identification
DURALOKTM HEAT
EXCHANGER
ASSEMBLY
UPPER ACCESS
PANEL
BURNERS
BLOWER
MOTOR
CABINET
CONTROL BOX
GAS VALVE AND
MANIFOLD
COMBUSTION AIR
PROVING
(PRESSURE)
SWITCHES
COMBUSTION AIR
INDUCER
BLOWER ACCESS
PANEL
FLUE
COLLAR
TOP CAP
SURELIGHT®
CONTROL BOARD
FIGURE 1
WARNING
Prod ct contains fiberglass wool.
Dist rbing the ins lation in this prod ct d ring
installation, maintenance, or repair will expose yo
to fiberglass wool. Breathing this may ca se l ng
cancer. (Fiberglass wool is known to the State of CalĆ
ifornia to ca se cancer.)
Fiberglass wool may also ca se respiratory, skin,
and eye irritation.
To red ce expos re to this s bstance or for f rther
information, cons lt material safety data sheets
available from address shown below, or contact yo r
s pervisor.
Lennox Ind stries Inc.
P.O. Box 799900
Dallas, TX 75379-9900
NOTE - This manual must be left with the equipment
user.
WARNING
Do not set thermostat below 60°F (16°C) in heating
mode. Setting thermostat below 60°F (16°C) red ces
the n mber of heating cycles. Damage to the nit
may occ r that is not covered by the warranty.
WARNING
If overheating occ rs or if gas s pply fails to sh t off,
sh t off the man al gas valve to the f rnace before
sh tting off electrical s pply.
CAUTION
Before attempting to perform any service or mainteĆ
nance, t rn the electrical power to nit OFF at the
disconnect switch.

Page 3
WARNING
Do not se this f rnace if any part has been nderĆ
water. A flood-damaged f rnace is extremely danĆ
gero s. Attempts to se the f rnace can res lt in
fire or explosion. Immediately call a q alified serĆ
vice technician to inspect the f rnace and to replace
all gas controls, control system parts, and electrical
parts that have been wet or to replace the f rnace,
if deemed necessary.
IMPORTANT
Any additions, changes, or conversions req ired in
order for the appliance to satisfactorily meet the apĆ
plication needs m st be made by a Lennox service
technician sing factory specified and approved
parts.
WARNING
Improper installation, adj stment, alteration, service
or maintenance can ca se property damage, personĆ
al inj ry or loss of life. Installation and service m st
be performed by a q alified installer, service agency
or the gas s pplier.
Safety Instr ctions
1 - Keep the furnace area clear and free of combustible
material, gasoline, and other flammable vapors and
liquids. If it is installed in an insulated area, the furnace
must be kept free of insulating material. Insulating maĆ
terial may be combustible.
2 - DO NOT obstruct air flow to unit. Unit must receive an
unobstructed flow of combustion and ventilating air.
DO NOT block or obstruct air openings on the furnace
or air openings to the area in which the furnace is
installed. Take care to maintain established clearĆ
ances surrounding the furnace.
3 - DO NOT store chlorine or fluorine products near unit
or introduce these products into the combustion air.
These products can cause furnace corrosion.
4 - DO NOT draw ret rn air from a room where this f rĆ
nace, or any other gas appliance (ie., a water heatĆ
er), is installed. When return air is drawn from a room,
a negative pressure is created in the room. If a gas apĆ
pliance is operating in a room with negative pressure,
the flue products can be pulled back down the vent
pipe and into the room. This reverse flow of the flue
gas may result in incomplete combustion and the
formation of carbon monoxide gas. This toxic gas
might then be distributed throughout the house by the
furnace duct system.
WARNING
The blower door m st be sec rely in place when the
blower and b rners are operating. Gas f mes, which
co ld contain carbon monoxide, can be drawn into
the living space res lting in personal inj ry or death.
Yo r f rnace is a gas appliance. It is critical that the gas
supplied to the unit be completely burned to avoid the proĆ
duction of carbon monoxide gas. Complete combustion of
the gas requires, but is not limited to, correct gas pressure
and gas flow rate, adequate combustion, air, and proper
venting.
WARNING
Carbon monoxide gas is invisible, odorless and
toxic.
Exposure to carbon monoxide gas can cause personal injuĆ
ry and even death to all occupants, including pets. Any item
that is powered by or gives off heat from a combustion proĆ
cess (including lawn mowers, automobiles, and fireplaces)
has the potential to produce carbon monoxide gas. Because
of this, Lennox recommends the se of a carbon monoxĆ
ide detector in yo r home, even if yo do not own gas
appliances. Reliable detectors are available at reasonable
retail prices. Contact your Lennox dealer for more details
about this investment in your safety.
Your furnace is designed to meet standards set by nationĆ
al agencies, and to operate safely when properly installed
and maintained. However, the unit's performance can be
greatly impacted by the individual installation and the opĆ
erating environment. It is your responsibility to ensure that
this appliance is maintained. Proper maintenance is critiĆ
cal for your safety and the satisfactory operation of the
product. Lennox strongly recommends ann al inĆ
spection and maintenance of this appliance. Contact
your Lennox dealer for an inspection by a qualified service
technician.
Lighting Information & Operation
WARNING
If yo do not follow these instr ctions exactly, a fire
or explosion may res lt ca sing property damage,
personal inj ry or death.
BEFORE LIGHTING the nit, smell all around the apĆ
pliance area for gas. Be sure to smell next to the floor beĆ
cause some gas is heavier than air and will settle on the
floor.

Page 4
The gas valve on the G61MPV may be equipped with eiĆ
ther a gas control knob or gas control lever. Use only your
hand to push the lever or turn the gas control knob. Never
use tools. If the the lever will not move or the knob will not
push in or turn by hand, do not try to repair it. Call a qualiĆ
fied service technician. Force or attempted repair may
result in a fire or explosion.
Placing the G61MPV f rnace into operation:
G61MPV units are equipped with a ureLight® ignition
system. Do not attempt to manually light burners on this
furnace. Each time the thermostat calls for heat, the
burners will automatically light. The ignitor does not get
hot when there is no call for heat on units with ureLight®
ignition system.
Operating the Gas Valve (Fig res 3 and 4)
1 - STOP! Read the safety information at the beginning of
this section.
2 - et the thermostat to the lowest setting. ee figure 2.
3 - Turn off all electrical power to the unit.
THERMOSTATS
FIGURE 2
4 - This furnace is equipped with an ignition device which
automatically lights the burners. Do not try to light the
burners by hand.
5 - Remove the upper access panel.
6 - White Rodgers 36E Gas Valve - witch gas valve leĆ
ver to OFF.
Honeywell VR8205 Gas Valve - Turn knob on gas
valve clockwise to OFF. Do not force. ee figure
4.
7 - Wait five minutes to clear out any gas. If you then smell
gas, STOP! Immediately call your gas supplier from a
neighbor's phone. Follow the gas supplier's instrucĆ
tions. If you do not smell gas go to next step.
8 - White Rodgers 36E Gas Valve - witch gas valve lever to
ON. ee figure 3 for the White Rodgers 36E valve.
Honeywell VR8205 Gas Valve - Turn knob on gas valve
counterclockwise to ON. Do not force.
FIGURE 3
WHITE RODGERS 36E SERIES GAS VALVE
GAS VALVE SHOWN IN OFF POSITION
FIGURE 4
HONEYWELL VR8205 SERIES GAS VALVE
GAS VALVE SHOWN IN OFF POSITION
9 - Replace the upper access panel.
10 - Turn on all electrical power to to the unit.
11 - et the thermostat to desired setting.
NO E - When unit is initially started, steps 1 through 11
may need to be repeated to purge air from gas line.
12- If the appliance will not operate, follow the section
Turning Off Gas to the Unit" and call your service techĆ
nician or gas supplier.
T rning Off Gas to the Unit
1 - et the thermostat to the lowest setting.
2 - Turn off all electrical power to the unit if service is to be
performed.
3 - Remove the upper access panel.
4 - White Rodgers 36E Gas Valve - witch gas valve leĆ
ver to OFF.
Honeywell VR8205 Gas Valve - Turn knob on gas
valve clockwise to OFF. Do not force.
5 - Replace the upper access panel.

Page 5
Filters
All G61MPV filters are installed external to the unit. Filters
should be inspected monthly. Clean or replace the filters
when necessary to ensure proper furnace operation. ReĆ
placement filters must be rated for high velocity airflow.
Table 1 lists recommended filter sizes.
A filter must be in place whenever the unit is operating.
TABLE 1
F rnace Filter Size
F rnace
Cabinet Size Side Ret rn Bottom Ret rn
17-1/2" 16 X 25 X 1 (1) 16 X 25 X 1 (1)
21" 16 X 25 X 1 (1) 20 X 25 X 1 (1)
24-1/2" 16 X 25 X 1 (2) 24 X 25 X 1 (1)
Maintenance
A qualified service technician should inspect the complete
system each season (heating and cooling). The following
maintenance procedures should only be conducted by a
qualified service technician. Do not attempt to service
the nit in any way.
WARNING
ELECTRICAL SHOCK, FIRE,
OR EXPLOSION HAZARD.
Fail re to follow safety warnings exactly co ld res lt
in dangero s operation, serio s inj ry, death or
property damage.
Improper servicing co ld res lt in dangero s operaĆ
tion, serio s inj ry, death, or property damage.
Before servicing, disconnect all electrical power to
f rnace.
When servicing controls, label all wires prior to disĆ
connecting. Take care to reconnect wires correctly.
Verify proper operation after servicing.
Venting System
WARNING
Asphyxiation Hazard
The exha st vent for this f rnace m st be sec rely
connected to the f rnace fl e collar at all times.
For yo r safety and to f lfill the terms of the limited
warranty, a q alified service technician m st ann alĆ
ly inspect this f rnace and its vent system.
Annually (before heating season) inspect furnace venting
system, vent cap, heat exchanger, and burners for corroĆ
sion, deterioration, or deposits of debris. Remove any obĆ
structions.
Inspect the furnace for obvious signs of deterioration.
Inspect the furnace venting system to make sure it is in
place, physically sound, and without holes, corrosion, or
blockage.
Vent pipe must be clear and free of obstructions and must
slope upward away from the furnace.
Inspect the furnace return air duct connection to ensure
duct is sealed to the furnace and terminates outside the
space containing the furnace.
Inspect the physical support of the furnace to guarantee
that it is sound without sagging, cracks or gaps around
base and it maintains seal between base and support.
Inspect and clean the condensate trap and drain.
During a seasonal check the service technician will inspect
the indoor blower, burner flames and electrical connections
along with the venting system.
Blower
Check the blower wheel for debris and clean if necessary.
The blower motors are prelubricated for extended bearing
life. No further lubrication is needed.
WARNING
The blower access panel m st be sec rely in place
when the blower and b rners are operating. Gas
f mes, which co ld contain carbon monoxide, can
be drawn into living space res lting in personal inj Ć
ry or death.
B rner Flame
CAUTION
To ens re proper operation, a q alified technician
sho ld ann ally check the b rner flame.
Electrical
1 - Check all wiring for loose connections.
2 - Check for the correct voltage at the furnace (furnace
operating).
3 - Check amp-draw on the blower motor.
Motor Nameplate__________Actual__________

Page 6
Service Reminder
Call your Lennox service technician if the unit will not operĆ
ate. Before calling, always check the following to be sure
service is required:
1 - Check that electrical disconnect switches are ON.
2 - Check room thermostat for proper setting.
3 - Replace any blown fuses or reset circuit breakers.
4 - Gas valve should be ON.
5 - Air filter should not be plugged, which will limit air flow.
6 - Is gas turned on at meter?
7 - Is manual main shut-off valve open?
Record the model and serial number of the furnace. These
numbers are on the unit nameplate, which is located on the
blower deck below the combustion air inducer.
erial Number __________________
Model Number __________________
Safety Preca tions
If yo discover any of the following, sh t down yo r
nit, and contact a Lennox dealer for an inspection by
a q alified technician.
DIf you repeatedly hear any new or unfamiliar sounds
while your unit is operating, there may be a problem. For
example, poorly performing burners can produce unfaĆ
miliar noises.
DIf you smell any unusual odors, your unit may be operatĆ
ing improperly. For example, units can give off unfamilĆ
iar odors if components are required to operate in abĆ
normal conditions.
DLook for visible signs of a malfunctioning unit. Examples
include unusual amounts of condensate on windows inĆ
side your house, visibly burnt components or unusual
dirt or rust accumulations on the vent pipe or in the unit.
DIf you experience headache, nausea, fatigue, or dizziĆ
ness, the cause could be exposure to carbon monoxide
gas. This is often misdiagnosed as the flu because
symptoms are similar. If you suffer from flu-like sympĆ
toms that are exaggerated at home, but seem to subĆ
side while you are away from the house, exposure to
carbon monoxide could be the cause.
Your vigilance may pay off in early detection of a problem
before either personal injury or property damage occurs.
Do not hesitate to contact a qualified service technician as
an investment in your well being.
Planned Service
You should expect a service technician to check the followĆ
ing items during an annual inspection. Power to the unit
must be shut off for the service technician's safety.
Fresh air grilles and lo vers (on the unit and in the room
where the furnace is installed) - Must be open and unobĆ
structed to provide combustion air.
B rners - Must be inspected for rust, dirt, or signs of water.
Vent pipe - Must be inspected for signs of water, damaged
or sagging pipe, or disconnected joints.
Unit appearance - Must be inspected for rust, dirt, signs
of water, burnt or damaged wires, or components.
Blower access door - Must be properly in place and proĆ
vide a seal between the return air and the room where the
furnace is installed.
Ret rn air d ct - Must be properly attached and provide
an air seal to the unit.
Operating performance - Unit must be observed during
operation to monitor proper performance of the unit and the
vent system.
Comb stion gases - Flue products must be analyzed and
compared to the unit specifications.
Problems detected during the inspection may make it necĆ
essary to temporarily shut down the furnace until the items
can be repaired or replaced.
Pay attention to yo r f rnace. ituations can arise beĆ
tween annual furnace inspections that may result in unsafe
operation. For instance, items innocently stored next to the
furnace may obstruct the combustion air supply. This could
cause incomplete combustion and the production of carĆ
bon monoxide gas.

Page 7
Repair Parts List
The following repair parts are available through Lennox dealers. When ordering parts, include the complete furnace model
number listed on the C A International nameplate -- Example: G61MPV-36B-045-1.
Cabinet Parts
Upper access panel
Blower access panel
Top Cap
Control Panel Parts
Transformer
ureLight® integrated control board
Door interlock switch
Circuit Breaker
Blower Parts
Blower wheel
Motor
Blower housing cutoff plate
Heating Parts
Flame ensor
Heat exchanger assembly
Gas manifold
Combustion air inducer
Gas valve
Main burner cluster
Main burner orifices
Pressure switches
Ignitor
Primary limit control
econdary limit
Flame rollout switches
Backup secondary limit