LENNOX Furnace/Heater, Gas Manual L0406231
User Manual: LENNOX LENNOX Furnace/Heater, Gas Manual LENNOX Furnace/Heater, Gas Owner's Manual, LENNOX Furnace/Heater, Gas installation guides
Open the PDF directly: View PDF 
.
Page Count: 32
| Download | |
| Open PDF In Browser | View PDF |
¢:_2000 Lennox
Industries
Dallas,
INSTALLATION
INSTRUCTIONS
Inc.
Texas
G24M Series
GAS FURNACE
Technicld
_.L_PuF[T_')-bli_ations
504,1g7MSureLight_
Ignition System
02/2000
Supersedes 503.981M
:::::::::::::_::::_:_::::::_:_:::_
RETAIN THESE
FOR FUTURE
_
:
Litho USA
i:-i:,
:
, ,, ........
G24M Unit Dimensions ......................
G24M Parts Arrangement ....................
G24M Gas Furnace .........................
Shipping and Packing List ....................
Requirements ..............................
General ...................................
Combustion, Dilution& Ventilation Air ..........
Setting Equipment ..........................
Duct System ..............................
Venting ...................................
Gas Piping ................................
Electrical .................................
Unit Start-up ..............................
Gas Pressure Adjustment ...................
High Altitude Information ....................
Other Unit Adjustments .....................
Service ...................................
Repair Parts List ...........................
Ignition Control Board Diagnostic Codes ......
Troubleshooting ...........................
G24M Start-up & Performance Check Ust .....
INSTRUCTIONS
REFERENCE
WHAT TO DO IF YOU SMELL GAS:
Do not store or use gasoline or other flammable vapors and liquids In
the vicinity of this or any other appliance.
Installation
and
service
must
be
performed
by a qualified
installer,
service agency or the gas supplier.
• Do not try to light any appliance.
•
Extinguish
any open flames.
Do not touch any electrical
switch; do not
use any phone in your building.
• Immediately call your gas supplier from a
neighbor's phone. Follow the gas supplier's instructions.
•
• If you cannot reach your
the fire department.
Page 1
gas supplier,
call
i I
r
2
3
3
3
3
4
5
8
11
12
19
21
24
25
25
25
27
28
28
29
32
-
GAS PIPING
INLET
2 (51)
ELECTRICAL
INLETS
1
1
FLUE
OUTLET "
*NOTE - The supply air opening is _
with a 3/4 inch (19 n
scored flange that may
sions shown were taken after the flange was bent,
1
(25)
TOP VIEW
The double scored flange at the front of the supply air opening may be bent for a total opening dimension (front to rear)
of either 19-1/2 incheS (495 ram) or 19 inches (483 ram),
,4_
29-5/8
(752)
A -_----Ib
AIRtFLOW
F Left Side
ELECTRICAL
iNLETS
(Ei_erSide)
L
.3/4(19)
,ql'-**C_
_
(25
Opening-
FRONT VIEW
I
Model No.
19-1/2
(495)
1
(25)
II
ReturnAir_l
Opening
SIDE VIEW
A
B
C
D
E
F
G
L__
Vl r"
G24M2-45
G24M2-60
G24M3_60
G24M3-75
G24M4.75
m.
17
36-1/4
15
6-3/4
2-7/16
1%1/2
6-1/2
rnm
432
921
381
171
62
293
165
G24M3/4-100
G24M3/4.120
G24M4/5-100
G24M4/5-120
m,
20-1/2
39
18-1/2
8-3/8
4-1/4
13
8
mm
m,
G24M4fS-140
mm
521
991
470
213
108
931
203
23-1/4
39
21-1/4
9-3/4
4-1/4
12-31/32
7-3/32
591
991
540
248
108
329
180
Page 2
1
(25)
G24M
VENT ADAPTER
PARTS IDENTIFICATION
_
CABINET TOP
I_
HEAT
EXCHANGER
ASSEMBLY
FLUE BOX
COMBUSTION AIR
PRESSURE
BLOWER _
G24M
CABINET
I
PRIMARY
LIMIT _
FRONT LOUVERED
PANEL
LOW PRESSURE SWITCH
• Only)
NOx
TURBULATOR
AS_
TRANSFORMER
BURNER
SECONDARY
LIMITS
CONTROL
BOARD
CABINET
BOTTOM
BLOWER ASSEMBLY
DOOR INTERLOCK SWITCH
The G24M gas furnace is shipped ready for installation
in the upflow position. The unit can easily be converted
for installation in either downflow or horizontal applications. The furnace is shipped with a bottom seal
panel in place for side return air in upflow applications.
Package I of 1 contains:
1 - Assembled G24M unit (includes vent adapter except
for 140 kBtuh units)
1 - Vent adapter (140 kBtuh unitsonly)
The following additiona/items may be ordered separately,
ff required:
1 - Thermostat
1 - Externalfilter rack kit
1 - Hanging bracket kit
1 - Propane/LP changeover kit
Check equipment for shipping damage. If you find any
damage, immediately contact the last carder.
Lennox G24M unitsare Amedcan Gas Association (AGA)
and Canadian Gas Association (CGA) cedified.
In the USA, installation of Lennox gas central furnaces must
conform with local building codes. In the absence of local
codes, units must be installed according to the current National Fuel Gas Code (ANSI-Z223.1) in the United States.
The NationalFuel Gas Code is availablef/om the following
address:
Amedcan National Standards Institute, Inc.
11 West 42nd Street
NewYork, NY 10036
In Canada, installationmust conformwith current National
Standard of Canada CAN/CGA-B149.1 "Installation Code
for Natural Gas Burning Appliances and Equipment"and
CAN/CGA-B149.2 "Installation Cede for Propane Gas
Burning Appliances and Equipment," local plumbing or
waste water Codesand other applicable local codes.
Page 3
Adequate clearance
must be made around the air open-
ings into the vestibule area. Provisions must be made for
proper operation and for combustion air and ventilation air
supply according to the current National Fuel Gas Code or
CAN/CGA-B149
standards.
Vent installations must be according to the provided venting tables and applicable provisions of local building codes.
This furnace is AGA and CGA certified for installation clearances to combustible matedal as listedon the unit rating plate
and in the tables in figures 5, 7 and 9. Accessibility and service clearances must take precedence over fire protection
clearances.
NOTE - For installation on combustible floors, the fumaca shall
not be installed directly on carpeting, b'le,or other combustible
material other than wood flooring.
For installation in a residential garage, the fumace must be
installed so that the bumer(s) and the ignition sourceare located no tess than 18 inches (457 mm) above the floor. The
furnace must be located or protected to avcid physical darnage by vehicles. When a furnace is installed ina publicgarage,
hangar, or other building that has a hazardous atmosphere,
the furnace must be installed according to recomrnended
good practice requirements and current National Fuel Gas
Code or CAN/CGA B149.1 and B149.2 standards.
In Canada, all electrical wiring and grounding for the unit
must be installed according to the current regulations of the
Canadian Electrical Code Part I (CSA Standard C22.1)
and/or local cedes.
Field wiring connections must meet or exceed specifications of type T wire and withstand a maximum temperature
rise of 180°F (82°C).
When the furnace is installed so that supply ducts carry air
circulated by the fumace to areas outside of the space containing the furnace, retum air shall be handled by a duct(s)
sealed to the furnace casing and terminating outside space
containing furnace.
NOTE - G24M series units must not be used as a construction heater during any phase of construction. Very low return air temperatures, harmful vapors and misplacement of
the fi#ers will damage the unit and lower its efficiency.
The Lennox G24M furnace may be installed in alcoves,
closets, attics, basements, garages and utility rooms in the
upflow, downflow, or hedzontal position.
This furnace design has not been AGA or CGA certified for
installation in mobile homes, recreational vehicles, or outdoors.
AWARNING
The furnace must be adjusted to obtain a temperature dse
within the range specified on the unit rating plate.
The G24M fumace must be installed sothat electrical components are protected from water.
When the furnace is used with cooling units, it shall be
installed in parallel with, or on the upstream side of, cooling
units to avoid condensation in the heating compartment.
With a parallel flow arrangement, a damper (or other means
to control the flow of air) must adequately prevent chilled air
from entedng the furnace. If the damper is manually operated, it must be equipped to prevent operation of either the
heating or the cooling unit, unless it is in the full "HEAT" or
"COOL" setting.
When installed, the furnace must be electricallygrounded
accordingto local codes. In addition, in the United States,
installationmust conformwith the current NationalElectric
Code, ANSI/NFPA No. 70. The National Electric Code
(ANSI/NFPA No. 70) is available from the followingaddress:
National Fire Protection Association
1 Battery March Park
Quincy, MA 02269
These instructions
areintendedas a generalguideand de not
supersede localcodesin any way.Consult authoritieshaving
judsd_
before installation.
In additionto the requirementsoutlinedpreviously,the following general recommendationsshould be considered
when installingthe Lennox G24M furnace.
The furnaceshouldbe placed as close to the center of the
air distributionsystemas possible.The furnace shouldalso
be located close to the chimneyor vent terminationpoint.
Do not installthe fumaca where drafts mightblow directly
intoit. This could cause impropercombustionand unsafe
operation.
Do not block fumaca combustionair openingswith clothing, boxes, doors,etc. Combustion air is needed for proper
combustion and safe unit operation.
When the furnace is installed in an attic or other insulated
space, keep insulation away from the furnace.
Page 4
ZkWARNING
In the past,there was no problemin bringing in sufticientoutdoor air tor cembustien. Infiltrationprovidedalllie airthatwas
needed.In today'shomes,_ght _n
p_ctJcesmake it
necessary tobdngin airfrom outside forcombustion.
Takeinto
accountthat exhaust fans, appliancevents, chimneys,and
fireplaces force additionalair that couldbe usedfor oombustion out of the house. Unless outsideair is brm,'ghtintothe
housefor combustion,
negative pressure(outsidepressureis
greaterthan insidepressure)willbuildtothe pointthat a downdraft canoccurin _e fumacevent pipeor chimney.As a result,
cembustion gasesenterhe living spacecreatinga potentially
dangeroussituation.
In the absence of localcodes concerning air for combustion
and ventilation,use the guidelines and proceduresin his
sectionto installG24M furnaces to ensureefficientand safe
operation.You mustconsidercombustionair needs and requirementsfor exhaustventsend gaspiping.A portionof this
informationhas been reprinted with permission from the NationalFuel Gas Code (ANSI-7_'_3.1).This reprinted material
is not the completeand officialpositionof theANSI on the referencedsubject,whichis representedonly bythe standardin
its entirety.
In Canada, refer to the standard CAN/CGA B149.1 and
B149.2 installationcodes.
,CAUTION
AWARNING
I
All gas-firedappliancesrequire air for the combustion process. If sufficientcombustion air is not available,the furnace or other appliance will operate inefficientlyand unsafely. Enoughair must be providedto meet the needs of all
fuel-burning appliances and apptiances such as exhaust
fans whichforce air out of the house. When fireplaces, exhaust fans, or clothesdryersare used at the same timeas
the furnace, much more air is required to ensure proper
combustion and to prevent a downdraft. Insufficientair
causes incompletecombustionwhich can resultin carbon
monoxide.
In additionto providingcombustion air,fresh outdoorair dilutes contaminants in the indoor air. These contaminants
may include bleaches, adhesives, detergents, solvents
and other contaminantswhichcan corrodefurnacecomponents.
The requirementsfor providingair for combustionand ventilationdepend largely on whether the furnace is installedin
an unconfinedor a confinedspace.
Unconfined Space
An unconfinedspace is an area such as a basement or
large equipmentroomwith a volume greater than 50 cubic
feet (1.42 m3) per 1,000 Btu (.29 kW) per hour of the combined input ratingof all appliances installedin that space.
This space also includes adjacent rooms which are not
separated bya door.Thoughan area may appear to be unconfined, it might be necessary to bdng in outdoorair for
combustion if the structuredoes not provide enoughair by
infiltration.If the furnace is located in a building of tight
constructionwith weather stripping and caulkingaround
the windows and doors, follow the procedures in the air
from outside section.
Page 5
ConfinedSpace
Air from Inside
A confinedspaceis an area witha volumelessthan 50 cubic
feet (1.42 m3) par 1,000 Bto (.29 kW) par hour of the combined input rating of all appliances installed in that space. This
definition includes furnace closets or small equipment rooms.
If theconfinedspacethathouses the furnace adjoinsa space
categorized as unconfined,air can be broughtin by providing
two permanent openings between the two spaces. Each
opening must have a minimum free area of 1 square inch
(645 mm2) per 1,000 Btu (.29 kW) per hour of total input rating of all gas-fired equipment in the confined space. Each
opening must be at least 100 square inches (64516 ram2).
One opening shall be within 12 inches(305 mm) of the top of
the enclosure and one opening within 12 inches (305 ram) of
the bottom. See figure 1.
Air from Outside
When the fumace isinstalled so that supplyducts carry air circulated by the furnace to areas outside the space containing
the fumace, the retum air must be handled by ducts which are
sealed to the fumaca casing and which terminate outs;dethe
space containing the furnace. This is especially important
when thefurnaceismountedon a platformin a confined spaoe
suchas a closetor smallequipmentroom.Even a smallleak
aroundthe base of the unitat the platformor at the returnair
duct connection can cause a potentiallydangerousnegaUve
pressurecondition. Airfor combusiton and ventilationcan be
brought intothe confinedspace eitherfrom insidethe building
or from outside.
EQUIPMENT IN CONFINED SPACE
ALL AIR FROM INSIDE
CHIMNEY
G24M
FURNACE
i i
I I
II
II
Ii
i i
i i
i i
NOTE-Each opening shall have a free area of at least one square
inch (645 mmz) per 1,000 Btu (.29 kW) per hour of the total inputrating of all equipment in the enclosure, but not teas then 1O0square
inches (64516 mrn2).
FIGURE 1
If air from outsideis brought in for cornbustionand ventilation,
the confined spacemusthave two permanent openings. One
opening shall be within 12 inches (305 mm) of the top of the
enclosure and one opening within 12 inches (305 mm) of the
bottom. These openings must communicate directly or by
ducts with the outdoors or spaces (crawl or attic) that freely
communicate with the outdoors or indirectly through vertical
ducts. Each opening shall have a minimum free area of 1
square inch(645 mm2) par 4,000 Btu (1.17 kW) per hour of
total input ratingof all equipment in the enclosure.See figures
2 and 3. When communicating
with the outdoors through hodzontal ducts, each opening shall have a minimum free area
of 1 square inch(645 mm2) par 2,000 Btu (.55 kW) par total
input rating of all equipment in the enclosure. See figure 4.
When ducts are used, they shall be of the same cross-sectionalarea as the free area of the openings to which they connect. The minimum dimension of rectangular air ducts shall
be no less than 3 inches (75 mm). In calculating free area,
the blocking effect of louvers, gdlles, or screens must be
considered. If the design and free area of protective covering
is not known for calculatingthe size opening required, it may
be assumed that wood louvers will have 20 to 25 percent free
area and metal louvers and grineswill have 60 to 75 percent
free area. Louvers and grilles must be fixed in the open position or interlockedw_ the equipmentso that theyare opened
automaticallydudngequipmentoperation.
Page 6
EQUIPMENT IN CONFINED SPACE
ALL AIR FROM OUTSIDE
(Inlet Air from Crawlspace and Outlet Air to Ventilated
Attic)
CH{MNEY
GAS
VENT
OR
_1
VENTILATION LOUVERS
(EaCh end of atdc)
G24M
FURNACE
WATER
HEATER
VENTILATION
LOUVERS
(For uni_ealed craw!
rrrrn
rrrmi
NOTE- The inletand outJefairnpemngs shafteach have a free area of at least one
square _ch {645 turn2) per 4,000 Btu (1.17 kW) per hour of thetotalinput rating of
a/! equipment in the enclosure.
FIGURE 2
EQUIPMENT IN CONFINED SPACE
ALL AIR FROM OUTSIDE
(All Air Through Ventilated Attic)
VENTILATIONLOUVERS
(Eachendof ate)
G24M
FURNACE
NOTE-The inletand outJetair openings 8hall each have a
free area of at least one square inch (645 mm2) per 4,_0
Btu (1.17 kW} per hour of the total input ratingof all equipment in the enstosure.
FIGURE 3
FIGURE 4
P_e7
are provided on both sides of the furnace cabiii i i ii ii ; il; =Knockouts
iiiiiiiiiiil
net for installations with side return air. When side return air
The Lennox G24M multi-position gas furnace can be
installed as shipped in upflow or horizontal position with
right-hand or left-hand discharge. The furnace can easily be converted for downflow applications.
Select a location that allows for required clearances
listed on the unit rating plate. Also consider gas supply
connections, electrical supply, vent connection and
installation and service clearances [24 inches (610 mm)
at unit front].
is used, seal the bottom of the furnace using the panel provided.
An upflow filter rack is available and must be ordered separately. The adjustable rack can be installed beneath the furnace (flush with cabinet edges) for bottom return air ap)lications or on the side of the furnace for side return air.
Upflow Application
Installation Clearances
TOP
NOTE - 1/3 and 1/2 hp blower motors are equipped with either four flexible mounting legs or three flexible legs and
one rigid leg. The dgid leg is equipped with a shipping bolt
and a flat white plastic washer (rather than the rubber
mounting grommet used witha flexible mounting leg). This
shipping bolt and flat washer must be removed before the
furnace is put into operation. Once the shippingbolt and
washer are removed, the rigid leg will not touch the fan
housing.
LEFT
SIDE
BOTTOM
Upflow Applications
The LennoxG24M furnace is shipped in a standard upflow
position.Level_ furnaceusing shimsor levelingbolts. Four
knockoutsin thefumaca b_se panelare factory-providedfor
the installationof leveling bolts (field-provided).Allow for
clearancesto combustiblematerialsas indicatedon the unit
ratingplate.Minimumclearances for closetor alcove installationsare shownin figure5.
In upfiowapplications, returnair can be broughtin through
the bottom or either side of the furnace. If a furnace with
bottomreturnair is installedon a platform,make an airtight
seal between the bottomof the furnace and the platformto
ensure properand safe operation.
UNIT CONVERSION
RIGHT
S;DE
Vent
Connector
Twe
TOP
*FRONT
BACK
SIDES
VENT
FLOOR
Type C
Type BI
1 in. t'25 ram)
1 In. (25 mm_ I
2in.(51mm)
0
2in.(51mm}]
0
0
o
6in.(152mm)
1in.(25mm}i
0"
0"
*Front clearance in alcove Installation must be 24 in. (610
ram). Maintain a minimum of 24 in. (610 rnm) for front service
eccess.
*" For installations on a combustible floor, do not install the
furnace directly on carpeting, tile or other combustible materials other than wood flooring=
FIGURE 5
FOR DOWNFLOW
APPLICATION
REMOVE
TOPCAP
PJEINSTALL
/
SINGLE-WALLED VENT ,,.._.,..,._._
PtPE FROM COMBUSTION
AIR BLOWER FLUE
ADAPTER TO FURNACE
FLUIE OUTLET
(FumW_ed by Imta_eq
REMOVE
FOUR
SCREWS
RECONNECT
WIRE HARNESS JACK
PLUGS AND SENSOR
LEAD AT CONTROL
BOARD
'
Topc,,.-oN
UNIT BOTTOM
I I
I I
o
DISCONNECT WIRE
HARNESS JACKPLUGS
AND SENSOR LEAD
FROM CONTROL
8OARD
EXCHANGER
ROrATE HEAT&
REINSTALL
_--
REMOVE
BOTTOM
DOWNFLOWCONFIGURATION
UPFLOW CONFIGURATION
FIGURE 6
Page 8
REIN_rALL
BOTTOM ON
UNIT TOP
DownflowApplications
The LennoxG24M furnace is shippedin the upflowconfiguration and must be converted for downflow installation.
Refer tofigure 6 and the followingstepsto convertthe unit
for downflowinstallation:
1 - Place uniton its back and remove access panel.
2- Disconnect wire harness jackplugs from control
board.
3 - Disconnect sensor lead from control board.
4 - Remove four screws securing cabinet top cap to cabinet.
5 - Remove four screws holding heat exchanger assembly in place. Slide heat exchanger out through top of
cabinet.
6 - Rotate heat exchanger 180° and slide back into cabinet through top. Resecure using four screws.
7 - Remove four screws securing cabinet bottom piece
to cabinet. Replace with cabinet top cap.
8 - Use four screws to install cabinet bottom piece where
cabinet top was.
9 - Reconnect sensor lead to control board.
10- Reconnectwire harness jackptugs to control board.
11- Replace unit access panel.
12- Use cord clip located on right side of furnace to
hold wiring away from hot surfaces in heating
compartment. Install two #10 sheet metal screws in
cabinet top to provide a better air seaL
In downflowapplications,
the unitcan be installedinthree different ways: on non-combustibleflooring, on combustible
floor using an additive base, oron a reverse-flow cooling cabinet. Do not drag unit across floor.
Allow clearances to combustible materials as indicated on
unit rating plate. Minimum clearances for closet or alcove
installations are shown in figure 7.
A separate downflow filter kit is available for use in downflow applications.
A*lnstallation on Non-Combustible Flooring
1 - Cut floor opening keeping in mind the clearances
listed on the unit rating plate. Also, keep in mindgas
supply and electrical supply, vent connections and
sufficient installation and service clearances. See
table 1 for correct floor opening size.
TABLE 1
NONCOMBUSTIBLE FLOOR OPENING
Front to Rear
UNIT
In
mm
In
mm
G24M*45/60/75
19-3/4
502
15-1/4
388
G24M-1001120
19-3/4
502
18-3/4
477
G24M-140
19-3/4
502
21÷1/2
546
COTE
- Floor
opening
dimensions
listedare 1/4"(6rnm) larger
2 - Flange warm air plenum and lower into opening.
3 - Set unitover plenum.
4 - Check to see that an adequate seal is made.
B4nstallation on Combustible Flooring
1 - When unit is installedon a combustiblefloor,an additive base (ordered separately) must be installedbetween the furnace and the floor. See table 2 for opening size to cut in the floor.
TABLE 2
ADDITIVE BASE FLOOR OPENING
Front to Rear
UNIT
Side to Side
in
rnm
in
mm
G24M-45/60/75
21-7/8
556
17-5/t6
440
G24M-100/120
21-718
556
20-3/4
528
G24M.140
21-718
556
23-1/2
597
NO TE - Floor opening dimensionslisted are 1/4" (6ram) larger than addi-
(60 Hz. only)
tive base openings.
COMBUSTIBLE
LEFT
SIDE
than unit
openings.
DOWNFLOWINSTALLATIONCLEARANCES
TOP
Side to Side
RIGHT
SiDE
FLOORING
INSTALLATION
G24M
_"
SUPPLY AIR
PLENUM
BOTTOM
VENT
CONNECTOR
TYPE C
TYPE B t
TOP
•FRONT
BACK
1"I25mm_
2" I51mm)
0
1 * 125mint
2" t81mm)
0
SIDES
VENT
FLeeR
0
6" {r 52rnm'p
NC"
ADDITIVE
BASE
0
I" t25mrn_
NC"
1.
2.
3.
4.
NC - Non-combustible floor
"Front clearance In Ilcove Install_tion must be • nlln. of 24" (610rnm)
for front service IOCaKK.
"With addiUve base on combustible floor.
Cut
Set
Set
Set
correct size floor _:
additive base into opening._
supply air plenum into additive base.
unit,
FIGURE 8
FIGURE 7
Page 9
SIZED FLOOR
OPENING
2 - After opening is cut, set the additive base into opening.
See figure 10 for furnace installationson a platform.
3 - Check fiberglass strips on additive base to make sure
they are propedy glued and positioned.
NOTE - When the furnace is installed on a platform in a
crawlspace, it must be elevated enough to avoid water
damage and to allow the air conditioning coil to drain.
4 - Lower supply air plenum into additive base until plenum flanges seal against fiberglass strips.
5 - Set unit on additive base so unit flanges drop into plenum. Refer to figure 8.
Horizontal Application
Unit Installed on Platform
_IOTE-Linecontactis permissibleSeethe unitrating platefor clearances.
NOTE - Be careful not to damage fiberglass strips.
Check for tight seal
C-installation on Cooling Cabinet
1 - Refer to reverse-flow coil installationinstructions for
_VENT
correctly sized openingin floor and installationof cabinet.
PIPE
2- When cooling cabinet is in place, install furnace so
flanges drop inside cabinet opening.
3 - Seal cabinet and check for air leakage.
Horizontal Applications
The Lennox G24M furnace can be installed in horizontal
applications in either upflow or downflow configuration
(See figure 6). It is preferable to install the unit in the standard upflow configuration, if possible, because the vent
pipewill not interferewith service access for blower. Install
two #10 screws in the cabinet bottom (upflow configuration) or cabinet top (downflow configuration)to provide a
better air sea]. The unit cannot be installed on its back.
WORKING
pLATFORM
FIGURE 10
Anyone ofthefollowing methodsmay be usedtosuspendthe
furnace fiom roofraftersor floor joists:
HorizontalApplication
installation Clearances
TOP
SIDE
1-
Using Lennox hanging bracket kit catalog number 46366 Install as indicatedin the instaltationinstructions
providedwith the hanging bracket kit.
2-
Using angle iron with at least 1/4 in. diameter
rods Install as shown in figure 11.
Note - Rods must not inter[erav_h plenum or exhaustpiping; cooling coils and supplyand return
air plenums must be supported separately.
S_DE
BOTI'OM
Vem
Connector
Type
Type C
Type BI
TOP
0
o
*FRONT
2 in. (51 ram)
0
2 in. 151 ram)
0
SIDES
2 in. (51 rnm)
VENT
6 in. (152 ram)
0._
2 in. (51 ram)
1 in. (25 turn
SACK
FLOOR
0"*
*Front clearance in alcove installation must be 24 in.
(610 ram). Maintain a minimum of 24 in, (610 ram) for
front service access,
** For installations on a combustible floor, do not install
the furnace directly on carpeting, tile or other combustible materials other than wood flcorlng.
FIGURE g
Allow for clearancesto combustiblematerials as indicated
on the unit rating plate. Minimum clearances for closet or
alcove installationsare shown in figui'e9.
Furnaces may be installed in either an atticor a crawispace.
Page 10
FIGURE 11
3-
Using heavy gauge
perforated
("plumber's straps') Install as shown in figure 12.
steel
straps
I
AWARNING
Note - Straps must not interfere with plenum or exhaust I_ping; cooling coils and supply and return
air plenums must be supported separately.
Horizontal Application
Unit Suspended in Attic or Crawlspace
Using Heavy Gauge Perforated
Steel Straps
("Plumber's
Straps")
Inches (ram)
Level unit - side to side and end to end.
PLUMBER'S
Use existing blower deck screws to secure
Also use washers, if required,
2-13/16
1-1/2 (38)
SUPPLY
AIR
Atthe unit's top corners, secure each strap to the furnace, positJone_
as shown, using st least two sheetrnetal screws:
maximum screw length - 3/4 in. and minimum screw size - # 10.
1-1/2 {38)
TOP OF UNIT
/
RETURN AIR
OPENING
112
(13)
END VIEW
1-1/2 (3S)
1/2
(13)
112
(13)
TOP OF UNIT
;UPPLY AIR
OPENING
END VIEW
FIGURE 12
1/2
(13)
Use industry-approvedstandards to size and install the
supplyand rstumair duct system.This willresultin a quiet
and low-staticsystem that has uniformair distdbution.
Supply Air Plenum
Furnacesinstalledwithouta coolingcoilrequirethe instaUation of e removableaccess panel in the supplyair duct.The
accesspanelshouldbe largeenoughto permitinspection(either by smoke or reflectedlight)of the heat exchangerfor
leaks after installation.The furnace access panel mustalways be in placewhen the furnace is operatingand it must
not allowleeksintothe supplyair ductsystem.
Return Air Plenum
Return air must not be drawn from a room where this
furnace, or any other gas appliance (ie., a water heater), is installed. When return air is drawn from a room,
a negative pressure is created in the room. If a gas appliance is operating in a room with negative pressure, the
flue productscan 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.
In upfiowapplications,returnair can be brought in through
the bottomor either side of the furnace. If a furnace with
bottomreturnair is installedon a platform,make an airtight
seal between the bottomof the furnace and the platformto
ensure proper and safe operation. Use fiberglasssealing
stripsbetween the plenum and the furnace cabinet to ensure a tightseal.If a filter is installed,size the returnair duct
to fit the filterframe.
In downfiow applications,use the following steps when installing rstum air plenum:
1 - Flange bottom edge of plenum with a hemmed edge.
See figure 13.
2 - Use fiberglass sealing strips between plenum end the
unit cabinet to ensure a tight seal.
Page 11
3 - Inallcases,
secure
theplenum
tothetop flanges of the
furnace using sheet metal screws.See figure 13.
PLENUM.._._
JSECURE
._
Venting Using a Masonry Chimney
The following additional requirements apply when a lined
masonry chimney is used to vent an G24M furnace.
Masonry chimneys used to vent Category I central furnaces must be either tile-lined or lined with e listed metal
HEMMED EDGE
lining system or dedicated gas vent. Unlined masonry
chimneys are prohibited. See figures 15 and 16 for common venting.
FIGURE 13
4 - In closet installations,it may be necessary to install
sheet metalscrews from the inside.If this isthe case,
make plenum with a removable front to installscrews
as shownin figure 14.
a
SECURE FROM
,NSIDE_,_._
_
PLENUM
.jl_
A Category I appliance must never be connected to a chimney that is servicing e solid-fuel appliance. If a fireplace
chimney flue is used to vent this appliance, the fireplace
opening must be permanently sealed.
A fan-assisted fumaca may be commonly vented into an
existing lined masonry chimney if the following conditions
are met:
1 - The chimney is currently serving at least one drafthood equipped appliance.
2 - The vent connectors end chimney are sized according
to the provided venting tables for the USA, and the appropriate venting tables in the standards of CAN/CGA
B149.1 and B149.2 of the Natural Gas and Propane
Installation Code in Canada.
HEMMED EDGE
FIGURE t4
_:::_:::
:'::::iii
%::_:.
i iii::iiiiiiiiii'ii'::iiii ::
ii_ii'ii_::ii'i_=:
i i'==
:i"i_'i'i?i_i'i
i ii_i;i_ii
i'i_i'i':.:i
iiiii::%::
i":::.i i:.i'
.V: ::_:i
mg _:
................................................................................................................
...................................................
A vent adapter is factory-installed on the combustion air
blower outlet of all models, except the G24M-140. On the
G24M-140, the flue adapter is supplied with the furnace,
and must be field-installed, between the combustion air
blower flue ouUet and the vent connector, using one or two
corrosion-resistant screws. Modification of or failure to
install the adapter will cause unsafe unit operation and
will void AGA and CGA unit certification, The vent connectordoes not require insulation.
The G24M sedes units are classified as fan-assisted Category t furnaces when vertically vented according to the btest
edition of ANSI Z21.47 Central Fumaca Standard in the
USA and the current standards of CAN/CGA B149.1 and
B149.2 of the Natural Gas and Propane Installation Code in
Canada. A fan-assisted Category I furnace is an appliance
equipped with an integral mechanical means to eitherdraw
or force productsof combustion through the combustion
chamber and/or heat exchanger.
NO TE - Use these instructions as e guide. They do not supersede local codes.
The vent sizingtables in this manual were extracted from
the National Fuel Gas Code (NFPA 54 /ANSI Z223.1 ) end
are provided as a guide for proper vent installation. Proper
application,termination, construction and location of vents
must conform to local codes having jurisdiction. In the absence of local codes,the NFGC servesas the definingdocument.
Refer to the tables and the ventinginformationcontained in
these instructionsto properly size and install the venting
system.
Installthe first ventconnectorelbowa'minimumof 6 inches
(152 ram) from the furnace vent outlet.
A type B1 vent or mascnry chimney Itoershallterrninatsabove
the roofsurfacawithe listed cap or a listed roof assemblyaccordingto the terms of their respective listingsand the vent
manufacturer's
instrucfions.
Do not installa manualdamper, barometric draft regulator,
or flue restdctor between the furnace and the chimney.
If type B1 double-wall vent is used insidee chimney, no other appliance can be vented into the chimney. Outer wall of
type B1 vent pipe must not be exposed to flue products.
Insulation for the flexible vent pipe must be an encapsulated fiberglass sleeve recommended by the flexible vent
pipe manufacturer. See figure 15.
The space between the liner and the chimney wail
should NOT be insulated with puffed mica or any other
loose granular insulating material.
If B1 vent or an insulated flexiblevent pipe cannot be used
as liners, the chimney must be rebuilt to accommodate one
of these methods or some alternate approved method
must be found to vent the appliance.
When inspection reveals that an existing chimney is not safe
for_e intended purpose, it shall be rebuilt to conform to nationally recognized standards, lined or relined with suitable
materials or replaced with e gas vent or chimney suitable for
venting G24M seriesunits. The chimney passageway must
be checked periodically to ensure that it is clear and free of
obstructions.
Page 12
Common Venting Using Metal-lined Masonry Chimney
MAX. LENGTH
- SEE NOTE 1
BELOW,
i 1i
I!11
4 in, (102rmm)
EXTERLOR
CHIMNEY WITH
0.15 microamps)
I
I
YES
LOW FLAME SIGNAL
(Does not affect operation of control)
LED #1 - SLOW FLASH
LED #2 - FAST FLASH
NO_[
PRIMARY AND SECONDARY LIMIT
SWITCHES CLOSED?
;70
|
J
GAS VALVE DE-ENERGIZED.
COMBUSTION AIR BLOWER DE-ENERGIZED.
INDOOR BLOWER ON UNTIL SWITCH CLOSES.
LED #1 - SLOW FLASH. LED #2 - ON.
IS LIMIT SWITCH CLOSED?
I
I
YES
1
LIMIT SWITCH WATCHGUARD MODE.
GAS VALVE OFE COMBUSTION AIR
BLOWER OFF.
INDOOR SLOWER OFF WITH DELAY
LED #1- SLOW FLASH, LED #2 - ON.
NO L
/
I
I
/
[ INDOOR
ACC.
BLOWER
TERMINAL
ON ACB
ENERGIZED
HEAT SPEED. 1
I-.--I
l
y_S_YES
/
T
HAS CONTROL RESET IGNITION
SEQUENCE FOUR TIMES?
I--_
YES _
YES
.
/
P
FLAME SIGNAL YES
ABOVE
0.7 MICROAMPS?
_
YES _
INDOOR BLOWER ON DELAY BEGINS
/45 seconds.)
S 60-M NUTE RESET PER OD COMPLETE?
/
FLAME PRESENT?
I
ROLLOUTyEsSWITCH_
CLOSED?
COMBUSTION
AIR PRESSURE
SWITCH CLOSED?
/
YES
_
I
THERMOSTAT DEMAND SATISFIED.
YES
I
I
{,_) #1 & #2 SIMULTANEOUS SLOW FLASHES.
I
[
YES
HAS PRIMARY/SECONDARY
I
LIMIT AUTOMATIC RESET TIME I
COMPLETE? I
EXCEEDED 3 MINUTES?
,
-S
NO
GAS VALVE OFF. COMBUSTION AIR BLOWER OFF.
INDOOR BLOWER OFF WITH DELAY.
I
LED #1 - ON. LED #2 - SLOW FLASH.
LSEQUENCE HOLDS UNTIL ROLLOUT SWITCH CLOSES
f
COMB. AIR BLOWER CONTINUES 5-SECOND
POST PURGE AFTER T'STAT DEMAND IS SATISFIED.
INDOOR AIR BLOWER COMPLETES SELECTED
OFF" DELAY BEFORE SHUTT NG OFF.
IS 60-MINUTE RESET PERIOD
GAS VALVE DE-ENERGIZED.COMBUSTION AIR BLOWER ON. ]
INDOOR BLOWER OFF WITH DELAY
IYES=
LED #1 - OFF. LED #2 - SLOW FLASH.
HAS CAB SWITCH CLOSED IN 2.5 MINUTES?
|
NO
I
Page 30
5-MINUTE
PRESSURE
SWITCH
WATCHGUARD
MODE.
I
COOLINGSEQUENCEOFOPERATION
NORMAL
I
I
I
COOLING
POWER ON
COOLING
MODE
I
IGNITION CONTROL_MAIN POWER ON.
I
GAS VALVE OFF. COMBUSTION AIR BLOWER OFF.
INDOOR BLOWER OFF WITH NORMAL DELAY.
SIGNAL CIRCUIT BOARD FAILURE AT LED.
INTERRUPT MAIN POWER TO RESET CONTROL,
IS
CONTROL
CONTROL
SELF
OPERATING
DIAGNOSTIC
NORMALLY?
CHECK.
YES
I
ABNORMAL
MODE
_
TURN INDUCER ON FOR 1 SECOND.
I
i
YES _,
I
IS POLARITY REVERSED?
SIGNAL IMPROPER
GROUND AT LED.
SIGNAL HOLDS
UNTIL UNIT IS
"'"_1
PROPERLY
i=
IS THERE
I YES..I
IS VOLTAGE
_
PROPER GROUND?I_" _
ABOVE 75 VOLTS? !_1--_1
I
GROUN.DEEL
I
UoU;'
YES
I
SIGNAL POLARITY REVERSED AT LED.
-
NO
CHECKISFOR
MAIN
BURNER
FLAME
MAIN
BURNER
FLAME
OFF?SENSE.
I_1_-
GAS VALVE OFF. COMBUSTION AIR BLOWER OFF.
INDOOR BLOWER OFF WITH NORMAL DELAY,
SIGNAL CIRCUIT BOARD FAILURE AT LED,
SEQUENCE HOLDS UNTIL ROLLOUT SWITCH CLOSES.
GAS VALVE OFF, COMBUSTION AIR BLOWER OFF.
INDOOR BLOWER OFF WITH NORMAL DELAY.
SIGNAL CIRCUIT BOARD FAILURE AT LED,
SEQUENCE HOLDS UNTIL FLAME IS NOT SENSED.
I LED:
SLOW
FLABH
TEREMAINS
UNC NOED
I
THROUGHOUT COOLING CYCLE.
I
THERMOSTAT CALLS FOR COOLING.
I
COMPRESSOR CONTACTOR AND SYSTEM FAN
ENERGIZED WITH 0-SECOND DELAY.
ACB COOL SPEED ENERGIZED. ACC. TERM. ENERG ZED.
THERMOSTATOPENS.
I
COMPRESSOR
I
OF_
SYSTEM FAN AND ACC. TERM. OFF
WITH 0-SECOND DELAY.
I
I
Page 31
LOW VOLTAGE SIGNAL AT LET HOLDS
UNT L VOLTAGE R SES ABOVE 75 VOLTS.
I
I
•
.
.
..................................................................................
......................
•..........
,....................................................
..... ......................................................................................
CONTINUOUS
I
• .....................
:+_:+.:_:+:_.,..:.:.:+:,:,_._._:._::_:_
....................
LOW SPEED FAN SEQUENCE
OF OPERATION
II
LED:SLOW FLASHRATEREMAINS
UNCHANGEDTHROUGHOUT
SEQUENCE.
MANUALFANSELECTIONMADEAT THERMOSTAT.
(G) ENERGIZESSYSTEMFANAT CONTINUOUS
ACBLOWSPEED.ACC,TERM. ENERGIZED.
CONTROL
I
I
I
THERMOSTAT
CALLS
HTGACC.TERM. ENERGIZES1
WITH COMB.AIR BLOWER. I
FOR HEAT (W),
YES
I
_ NO
THERMOSTAT CALLS FOR COOLING.
SYSTEM FAN ENERGIZES ON ACB HEAT SPEED
AFTER NORMAL DELAY
_1 YES
SYSTEM FAN SWITCHED TO ACB COOL
SPEED. ACC. TERM, REMAINS ON.
I
I
THERMOSTATOPENS.
I
SYSTEM FAN OFF, ACC. TERM. OFF.
I
/AFTER OFF DELAY COMPLETED)./
THERMOSTAT OPENS.
_._
MANUAL FAN SELECTION MADE AT THERMOSTAT.
!It
CONTROL (G) ENERGIZES SYSTEM PAN AT CONTINUOUS I'i'-"-"
ACB LOW SPEED. ACC. TERM. ENERGIZED.
I
START-UP
Job Name
Job Location
AND PERFORMANCE
CHECK
LIST
Date
State/province
State/province
City
Unit Model Number
Serial Number
Service Technician
HEATING SECTION
Electrical Connections Tight? []
Supply Voltage_
Blower MotorAJ'nps
Blower Motor Horsepowedkw
Gas Piping Connections]3ght & Leaks Tested? []
Fuel Type: Natural Gas? []
LP/Propane Gas? []
Furnace Btu (kW) Input
Une Pressure
Regulator Pressure w.c.IPa - Nat.
w.c/Pa - LP/Pmpane
ConnectionsTight? []
Proper Draft? []
Fan Control Setting (45 Seconds Fixed On)
Fan Control Off Setting
Temperature Rise
FilterClean & Secure? []
Vent Clear? []
Calibrated?[]
Job Number
City
THERMOSTAT
Heat Anticipator
PropedySet? []
Page 32
Level?D
. ......
::::::::_:+_::_:::::_::_:::::_i%_::
Installer__
Source Exif Data:
File Type : PDF File Type Extension : pdf MIME Type : application/pdf PDF Version : 1.2 Linearized : No Page Count : 32 Page Layout : SinglePage Page Mode : UseNone Producer : Goby Monitor Application version 3, 2, 1, 4 Create Date : Fri Apr 20 14:18:52 2007 Author : Title : Subject :EXIF Metadata provided by EXIF.tools