Lennox G43UF SERIES Guide

0312009
LENNOX)
~ 20G4 LennoJ( IndU&lrioa Inc.
Oall8l, Teus, USA
S04.8Q8M
G43UF
SERIES
SuplllSlldes 02/2004
GAS FURNACE
f'Jl')jj) Technlcsl
lll.JPu~lioelions
Litho U.S.A.
Do notstore or use gasoline or other
flammable vapors and liquids in the
vicinity
of this or any other ap-
pliance.
Installation and sen/ice must
be
performed by a qualified installer
. '
servIce agency or the gas supplier.
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.
•
leave the building immediately.
• 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.
03/09 504,89BM
1111111111111111111111111111111111111111
11111111111111111.11111111111111111111 \~1I11111111
l 'd 6H8 'oN
sa)!flns I'eJ!u'epa~ J!'el8 ~~tS:8 OlOl '8l'
da
S
'1"'Mlftlzt~_

UPPER ACCESS
PANEL
COMBUSTION AIR
PROVING
(PRESSURE)
SWITCH
INTEGRATED
CONTROL
BLOWER ACCESS
PANEL
DURALOKnI HEAT
EXCHANGER
ASSEMBLY
GAS VALVE
AND MANIFOLD
FLUE:
COLLAR
COMBUSTION AIR
INDUCER
BLOWER
MOTOR
CONTROL BOX
FIGURE 1
NOTE -This manu.1 is the property of the homeowner
lind must be left with the eqlJlpment user.
This furnace is equipped With safety devices that protect
you and your property. If one or more of these devices is
activated, furnace operation will stop. Ifyour home is left
unattended
for an exlended period of time, equipment op·
eralion must
be checked periodically. If this is not possible,
the water supply to the house should be shut off and the
pipes should be drained. This will prevent problems associ-
ated with a NO HEAT condition (frozen pipes, ele.)
AWARNING
Product contains fiberglass wool.
Distllrbing the insulation in this product during
installation. IlHlintenance,
or repair will ellpose you
to fiberglass wool.
Breathing this may cause lung
canc~r. (Fiberglass wool is known to the State of Cal-
ifornia to cause c;Jncer.)
Fiberglass wool
rnOlY also cause respiratory, skin.
and eye irritation.
To reducc ~llPOSUre to this substance or for further
information,
consult material safely data sheets
available from
~dctress sllown helow, or contactyour
supervisor.
Lennox Indu!itries Inc.
PO. Box 799900
Dallas, TX 75379·9900
Page 2
saJ!AJas l~J!U~YJa~ J !~l8
~~~S:8 OlOl '8l'
da
S
£ 'd
6H8 'ol~
'['J',*~""

A WARNING
NOTICE
Any additions, ch,mges, or Conyer sions required in
order for the <tppliancc to satisfactorily meet the ap-
plic<ltion needs must
be m<lde I)y a licensed profes-
sional installer
(or equivalent) lIsing f3ctory-speci.
fied and approved pat1s.
AWARNING
1 - Keep the furnace area clear and free ofcombustible
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 rna.
tarial may be combustible,
2 - After any heavy snow, ice or frozen fog event, the fur-
nace vent pipes may become restricted. Always checK
the vent system and remove any snow or ice that may
be obstructing the plastic intake or e)(haust pipes,
3· DO NOT obstruct air flow to unit. Unit must receive an
unobstructed now 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. Taka care to maintain established clear-
ances surrounding the furnace.
4 -
DO NOT store chlorine or fluorine products near unit
or introduce these products into the combustion air.
These products can cause furnace corrosion.
S- DO NOT drawreturn aIr from aroom where this fur·
nace, orany other gas appliance
(Ie., awater heat·
er). Is Installed. When return air is drawn from a room,
a negative pressure is created in the room. Ifa gas ap-
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.
A WARNING
Yourfurnace is a gas appliance. It is critical that the gas
supplied to the unit be completely burned 'to avoid lhe pro-
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.
Exposure to carbon monoxide gas can cause personal in-
jury
and even death to all occupants, including pets, Any
item that is powered by or gives off heat from a combustion
process (including lawn mowers. automobiles. and fire-
places) has the potential to produce carbon monOXide gas.
Because or this, Lennox recommends the use of a car-
bon monoxide detector in your home, even if you do
not own gas appliances. Reliable detectors are available
at reasonable retail prices. Contact your Lennox dealer for
more details aboul this investment in your safely.
Your
furnace is designed to meet standards sel by national
agencies. and to operata safely when properly installed
and maintained, However, the unit's performance can be
greatly impacted by the individual installation and the oper·
ating environment. It is your responsibility to ensure that
this appliance is maintained. Proper maintenance is critical
for your safety and the satisfactory operation of th6 prod-
uct. Lennox strongly recommends annual inspection
and maIntenance of this appliance. Contact your Len-
nox dealer for an inspection by a licensed professional ser-
vice technician (or equivalent).
Page 3
sn!~JaS l'e~!u'e4H~ J!'elS
~~SS:8 OlOl '8l'
da
S
17 'd
6H8 'oN
1~'I!t1!Il'k '1l",,*I..,

BEFORE LIGHTING the untt. smell all around the ap-
pliance area for gas. Be SUre to smell next to the noor be-
cause soma gas is heavier than air and will settle on the
noor.
The gas valve on the G43UF will be equipped with a gas
control sWitch. Use only your hand to move the switch, Nev-
er use tools. If the sWitch will not move by hand, do not try to
repair it. Call a licensed professional service technician (or
equivalent). Force or attempted repair may result in a fire or
explosion.
Placing the G43UF furnace into operation:
G43UF units are equipped with an ignition system. Do not
allempt to manually light burners On this furnace. Each
time the thermostat calls for heat, the burners will automati-
cally light. The ignitor does not get hot when there is no call
for heat on units With this ignition system.
Operating the Gas Valve (Figures 2 and 3)
1- STOP! Read the safety information at the beginning of
this section.
2 -
Set the thermostat to the lowest setting.
3 - Turn off all electrical power to the unit.
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 36G Gas Valve - Move gas valve
switch to OFF. See figure 2 for the White Rodgers 36G
valve.
Honeywell VR8205 GflS Valve - Move switch on gas
valve to OFF. See figure 3 for Honeywell VR8205
valve.
7 - Wait five minutes to clear out any gas. If you then smell
gas, STOPI Immediately call your gas supplier from a
neighbor's
phone. Follow the gas supplier's instruc-
tions, If you do not smell gas go to next step.
S- White Rodgers 36G Gas Valve - Move gas valve
switch to ON. See figure 2 for the While Rodgers 36G
valve.
Honeywell VR8205 Gas Valve - Move SWitch on gas
valve to ON. See figure 3 for Honeywell VR8205 valve.
White Rodgers 36G Series Gas Valve
MANIFOLD
PRE88U~E
ADJUSTMENT
SCREW
INLET
t==i_~·PRESSURE
POST
OUTLET
PRESSURE
POST
--."....<kI=::::l:~
GAS VAlVf: SHOWN IN OFF POSITION
FIGURE 2
Honeywell
VR8205 Series Gas Valve
MANIFOLD MANIFOLD
PRESSURE PRES8UR~
ADJUSTMEN OUTLET
SCREW
GAS VALVE SHOWN IN ON POSITION
FIGURE J
9 - Replace the upper access panel.
. 10 - Turn on all electrical power to to the unit.
11 -Selthe thermostat to desired setting.
NOTE - When unit Is Initially started. steps 1 through 11
mayneed to be repeated to purge air from gas lina.
12- If the appliance will not operate, follow the section
"Turning Off Gas to the Unit" and call your licensed pro-
fessIonal service technician (or equivalent).
Turning Off Gas to the Unit
1-
Set 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 36G Gas Valve • Move gas valve
switch to OFF.
Honeywell VR8205 Gas Valve - Move 5witch on gas
valve OFF.
5- Replace the upper aCcess panel.
Page 4
SdJ!AJaS l'e:l!u'e4:l
aWJ!'el8

All G43UF fillers are installed e)(ternal. to the unit. Filters
should
be Inspected monthly. Clean or replace the filters
when necessary to ensure proper furnace operation. Re-
placement filters must be rated for high velocity
alr1low.
Table 1lists recommended filter sizes.
A
filter must be in place when Ihe unit is operating.
TABLE 1
Furnace Filter Size
Cabinet Width
SIde Return
Bottom Return
17-1/2"
16 X 25 X 1 (1)
16 X 25 X 1 (1)
21"
16X25X1 (1)
20 X 25 X 1 (1)
24-1/2"
16X25X 1 (2) 24 )( 25 )( 1 (1)
A licensed professional service technician (or eqUivalent)
should inspect the complete system each season (heating
and cooling). The following maintenance procedures
should only
be conducted by a licensed professional ser-
vice technician (or eqUivalent).
Do not attempt to service
the
unit in any way.
AWARNING
ELECTRICAL SHOCK, FIRE.
OR EXPLOSION HAZARD.
Annually (before heating season) inspect furnace venting
system, vent cap, heat exchanger, and burners for corro-
sion, deterioration, or deposits
of debris. Remove any ob-
structions.
Inspect the furnace ror 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 the condensate drain and trap
for leaks and cracks.
The
dr~in and trap must also be cleaned and the trap must
be filled with water.
During a seasonal check the service technician will
con~
duct a combustion analysis. The technician will also in-
spect the indoor blower, burner flames, electrical connec-
tions and the venting system.
810wer
Check the blower wheel for debris
and clean if necessary.
The blower motors are prelubricated for extended bearing
life.
No further lubrication is needed.
Failure
to follow safety warnings eXilctly could result
in
dangerous operation, serious injmy, death or
property damage.
Improper servicing could result in dangerous oper~
tion. serious injury. c1eath, or properly damage.
Before servicing,
disconnect all electrical power to
fUl'I1ace.
When
servicing controls, label <III wires prior to dis-
connecting. Take cart' to reconnect wires correctly.
Verify
proper operation after serVicing.
Venting
System
A WARNING
Asphyxiation HClzard
The exhaust vent for this furnace must be Innk·free
and
must be securely connected to the furnilce flue
collar
<:It all times.
For your sClfety and to ftllfjll the term::; of the limited
warranty, a licensed
professional service technician
(or eqUivalent) Illust annually inspect this furnace
Jnd its vent system
AWARNING
The blower access panellTlusl be securely in place
when the
blower and burners are operating. Gas
fumes. willet\ could contam carbon monoxide, can
be drawn 11110 living space resulting in personal inju-
ry 01 cleCltll
Burner Flame
A CAUTION
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 5
9 'd
6H8 'ON
sa)!AJas l~)!u~~)a~ J !~18
~~SS:8 OlOl '8l'
da
S
"''':&'17&_

,:Q"'".';,l'''
:l~~~~ Ih
Call your Lennox selVice technician if the unit will not oper-
ate. Before calling, always check the following to be sure
salVice is required;
1 - Check that electrical disconnect switches are ON.
2 -
Check room thermostat for proper setting.
3 - Replace any blown fuses Or reset circuli breakers.
4 - Gas valve should be ON.
5 - Air filler should not be plugged, which will limit air now.
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.
Serial Number
Model Number
!'Cfliil{ '''.1' «P' ';"~" ·1
~~'~11"'~ ;1\1,'!'~ i~"',
If you discover any of the following, shut down your
unit,
and contact a lennolC dealer foran inspection by
a licensed professional service technician (or equIva-
lent).
• If
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 unfa-
miliar noises.
• If you smell any unusual odors, your unit may be operat-
ing Improperly. For example. units can give off unfamil-
iar odors if components are required to operate in ab-
normal conditionS.
• Look (or Visible signs of a malfunctioning unit. Examples
include unusual amounts of condensate on windows in-
side your house, vIsibly burnt components or unusual
dirt or rust accumulations on the vent pipe or in the unit.
• If you experience headache. nausea, fatigue, or dizzi-
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 symp-
toms that are exaggerated at home, but seem to sub-
side while you are away from the house, exposure to
carbon monoxide could be the cause.
Your vigilance may payoff in early detection of a problem
before either personal injUry or property damage occurs,
Do not hesitate to conlact a qualified service technician as
an investment in your well being.
~,I,: .... , ';~~: ... 1Il:::: .. :.:"
You should expect a selVice technician to check the follow-
ing items during an annual inspection. Power to the unit
must be shut off for the service technician's safety.
Fresh air grilles and louvers (on the unit and in the room
Where the furnace is installed) - Must be open and unob-
structed to provide combustion air.
Burners- 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 waler, burnt or damaged wires. or components.
Blower access door- Must be properly in place and pro-
vide a seal between the return air and the room where the
furnace is installed.
Return air duct -Musl be properly attached and proVide
an air seal to the unit.
operating performance. Unit must be observed during
operation to tnonilor proper performance of the unit and the
vent system.
Combustion gase8 - Flue products must be analyzed and
compared to the unit speclflcations.
Problems detected during Ihe inspection may make it nec-
essary to temporarily shut down the furnace unlil the Items
can be repaired or replaced.
Pay attention to your furnace. Situations can arise be-
tween annual fumace inspections that may result in unsafe
operation. For instance. items innocently stored ne>rt to the
fumace may obstruct the combustion air supply. This could
cause incomplete combustion and the production 01 car-
bon monOXide gas.
Page 6
sa)!hJaS l'eJ!u'e4H~ J!'el8
L .d
6HS 'oN
.,.n£lt's:tst~ ..

The following repair paris are available through Lennox dealers. When ordering parts, include the complete furnace model
number listed on the CSA International nameplate - Example: G43UF-24B-045-2. All service must be done byalicensed
professional Installer (or equivalent), 8 service agency, or the gas supplier.
Cabinet Parts
Upper access panel
Blower access panel
Top Cap
Control Panel Parts
Transformer
Integrated control
Door interlock switch
Blower Parts
Blower wheel
Motor
Motor mounting frame
Motor capacitor
Blower housing cutoff plate
Heating Parts
Flame Sensor
Heat exchanger assembly
Gas manifold
Combustion air inducer
Gas valve
Main burner cluster
Main burner orifices
Pressure switch
Ignitor
Primary limil control
Secondary limit
Flame rollout switches
Combustion air inducer auxiliary limit
Page 7
Sa)!AJ~S IF)!UF4H~ )!FI8
~VSS:8 alae 'Sl'das
8 'd
6VL8 'ON

[Jj)[f!)[fif rmJ~4\ iJfWjffJ
LENNOX)
13ACX
Corp, 0612·L2
Revised AuguBl11. 2010
Service Literature
411
l.OUVERED
NON·LOUVERED
A WARNING
ImprOPt'r im;lallalioll, adjustment, alt~ratl()n. i;f:;rvil.:\: or
mamtenanr.p. can Cllll~;e pcr:;oll.:llilljury. loss olliff!, Of
dam3gA tn properly
In~~IClII;1tion ;.lClI.1 ~;(~rVICl) IlIllst be perform8d by ;'1 liC;;;r1~;'.ic.1
prnff:i;$iIHltll in~;I'.lllcr (or equivalent) or ;'\ ~8rVIr:e ;.I!Jt.~!lC.:Y.
A IMPORTANT
ThiS IlIlil !nu'.;l be IllEllclled wiltl 311 incloClI r:od m;
specified in LAnnnx EIIU1f1l,l,:,nnn H~lndl)l)ok. Coils
pr oviou31y c:llarged willi HCFC 22 rt'1I,1~.;1 he flushed.
TABLE OF CONTENTS
Model Number Identification "
Typical Serial Number Idenlification
Specifications ,
Electrical
Data
Unit Dimensions , , . ,
Typical Unit Parts Arrangement
Operating Gauge Set
and Service Valves
Unit Placement, . ' , . '
Removing
and Installing Louvers ,
Newor Replacement Line
Set .. ,
,.,., 2
,, , 2
, ,., .. ... 2
"
Brazing Connections ,. . .. . .. ..
.. . .. ..
Flushing Line
Set and Indoor Coil ... ,, ... , ,. 15
Installing Indoor Metering Device. . . . ... .. .. .. . .. 16
Leak Test Line Set and Indoor Coil, , .. , .. .. 17
Evacuating Line Sel and IMoor Coil , ,.,.. 18
Electrical Connections " , "", 19
Servicing Unit Void of Charge , 21
Unit Start-Up, , .. ,.. , ., , ,,. , , 21
System Refrigerant , ., , .. , ' .. ,. , ,.. . .. 21
System Operation ,.", , .. ,." , " 28
Maintenance , . , , .. ,, . , .. ,, ' , .. ,, ,. 28
start·Up and Perlormance Checklist ,., .. , ... 29
Sequence ofOperations
.... ,. , .... ,. , , , .. , ,. 30
13ACX Air Conditioners. which will also be referred to in
this instruction 8S the outdoor unit, uses HFC-4 1 OA
refrigerant. This outdoor unit must be installed with a
matching indoor unit
and line set 8S outlined In the Lennox
13ACX Engineering Handbook.
This outdoor unitls designed for use in systems that use
one of the following refrigerant metering devices:
Thermal expansion valve (TXV)
• Fixed orifice
A IMPORTANT
Thf~ Clc"ln Air Act or 1 mJO bans !lle mlAnliol);'ll velllirJ(j {If
rdllt~",ranl (CF(>.;. HCFCs and HI Cs) <IS of July 1, 1992.
Approved rnelho<b r)r r~(;(Iv(';ry. rt.'cycling or rc:c
l
ail11l1lg
mw;1 he followed. 1-11l8S ElIl(J/Qr incarceration may t>~
II~vwl.1 for nOllcompll.:mce.
.. ,..... 4
,. ,.. , . .. 6
, .. ,... 7
, ' . .
.. 7
,, .. ,.... .. 9
10
'" 11
13
Page 1
6 'd
6VLB 'ON
UFlftJllllb "("t,*~-a,
;"··,*Is:el$t~.

:=]
1 X-024 - t-13
Nominal SEER ~ T Minar Revilion NumberD
Voltage
Unit Type 230;; 208/230V·1phase-60h:z
AC ;; Air Conditioner Cooling Cepaclty - Tons
018'" 1.5
Refrlgeranl-----------l
024;; 2
030'" 2.5
X'" R-410A
036'" 3
042;;3.5
048 "'4
060" 5
location Code
19'"
Saltillo, Mellic_----'
58 =Marshalltown. IA
L '(or 6) Dlgl' "",que "urn"'"
Year CodI Month
Code
06;; 2008 A'" January
09'" 2009 B'" February
10'" 2010 ....J C"'March
Model Number
Page 2
ol 'd
6PLB 'ON
.,
""",,*~_1'
iu,I'mles):.

Un~
OuldoorFan
Model Nl,I\l1ber
13ACX-060·230-12
~~1: .' !t~ .. ,. .n :';' .
SOl,lnd RIIUnQ Number
(dB~
Number 01 Blada;
Diameler -Inches.
1 Tesllild according to AHRI Stundard 270·2006 test GOn(lilions.
2 Refrigerant chargo $ulficianl for 15 feel length of refrillllranl ~nlIs.
Page 3
13ACXSERIES
II 'd
6VL8 'oN
,
.[tI'ItI~1a,