Lennox G20RQ3XE-75, G20RQ3E-75, G20RQ4E-75, G20RQ4XE-75, G20RQ5E-100 Installation Instructions Manual
...
INSTALLATION
PRODUCT LITERATURE
1997 Lennox Industries Inc.
Dallas, Texas
INSTRUCTIONS
G20R SERIES UNITS
GAS UNITS
503,560M
2/97
Supersedes 11/96
TABLE OF CONTENTS
UNIT DIMENSIONS 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PARTS ARRANGEMENT 3. . . . . . . . . . . . . . . . . . . . . . . . . . . .
REQUIREMENTS 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COMBUSTION, DILUTION AND VENTILATION AIR 5. . . .
INSTALLATION–Setting Equipment 7. . . . . . . . . . . . . . . . . . .
RETURN AIR OPENING GUIDELINES 8. . . . . . . . . . . . . . . .
DUCT SYSTEM 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VENTING 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GAS PIPING 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ELECTRICAL 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
UNIT START–UP 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
HIGH ALTITUDE INFORMATION 15. . . . . . . . . . . . . . . . . . . .
GAS PRESSURE ADJUSTMENT 15. . . . . . . . . . . . . . . . . . . .
OTHER UNIT ADJUSTMENTS 15. . . . . . . . . . . . . . . . . . . . . .
SERVICE 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REPAIR PARTS 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
START–UP AND PERFORMANCE CHECK LIST 19. . . . . .
BCC TROUBLESHOOTING 20. . . . . . . . . . . . . . . . . . . . . . . .
Litho U.S.A.
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.
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.
RETAIN THESE INSTRUCTIONS
FOR FUTURE REFERENCE
WARNING
WHAT TO DO IF YOU SMELL GAS:
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 gas supplier, call
the fire department.
Page 1
G20R UNIT DIMENSIONS–INCHES (MM)
1Ć1/16
(27)
B
1Ć1/16
17Ć3/4
(451)
RETURN
AIR
OPENING
(27)
26Ć1/8
(664)
FLUE OUTLET
(center side to side)
N O T E Ċ Supply air opening is equipped with a 5/8 in. (16 mm) flange on
E
sides and rear of furnace and may be bent 90 for plenum connecĆ
tion or to help in alignment with cooling coil.
ă*Dimensions before flanges are bent (as shipped).
**Dimensions after flanges are bent.
Dimension after flange (furnished) is field installed on unit.
A
WHISPER HEAT
Model No.
CONTROL VOLTAGE
(Left Side)
LINE VOLTAGE
(Both Sides)
CONTROL VOLTAGE
(Right Side)
GAS PIPING INLET
(Both Sides)
2Ć5/8
(67)
ă8 (203) Right Side
53
(1346)
AIR FLOW
11 (279) Left Side
*19Ć5/8 (498)
**20Ć1/4 (541)
Supply Air
Opening
26Ć1/8
(664)
3Ć3/8
(86)
2Ć3/8
(60)
D
C
Supply Air
Opening
A B *C **C *D **D E
inch mm inch mm inch mm inch mm inch mm inch mm inch mm
G20RQ2/3(X)EĆ50
G20RQ3(X)EĆ75
16Ć1/4 413 14Ć1/8 359 10Ć3/4 273 12 305 1Ć1/2 38 2Ć1/8 54 3Ć1/8 79
G20RQ4(X)EĆ75 21Ć1/4 540 19Ć1/8 486 15Ć3/4 400 17 432 1Ć1/2 38 2Ć1/8 54 3Ć1/8 79
G20RQ3/4(X)EĆ100 21Ć1/4 540 19Ć1/8 486 15Ć3/4 400 17 432 1Ć1/2 38 2Ć1/8 54 3Ć1/4 83
G20RQ5(X)EĆ100
G20RQ3(X(EĆ125
26Ć1/4 667 24Ć1/8 613 18Ć3/4 475 20 508 2Ć1/2 64 3Ć1/8 79 3Ć5/16 84
G20RQ4/5(X)EĆ125
G20RQ4/5EĆ150 31Ć1/4 794 29Ć1/8 740 22 559 24Ć1/4 616 2Ć7/8 73 3Ć1/2 89 3Ć1/2 89
Page 2
G20R PARTS ARRANGEMENT
PARTS IDENTIFICATION
(G20R Unit Shown)
LOWER
ACCESS
PANEL
PILOT/ELECTRODE
ASSEMBLY
FLUE TRANSITION
UPPER ACCESS
PANEL
DRAFT
HOOD
MANIFOLD
GAS VALVE
GAS
FILTER ACCESS
PRIMARY
LIMIT
CONTROL
ROLL-OUT
SWITCH
DOOR
DOOR
INTERLOCK
SWITCH
BCC
CONTROL
BLOCKED VENT
SHUT-OFF
SWITCH
BURNER BOX
BURNERS
.
.
EXCHANGER
IGNITION
CONTROL
CABINET
REMOVABLE STRIP
HEAT
ROLL-OUT
SWITCH
REMOVABLE
BURNER BOX TOP
BURNER BOX
DAMPER ASSEMBLY
SWITCH COVER
FIGURE 1
DAMPER BOX PARTS ARRANGEMENT
(G20R Units Shown)
DAMPER
SWITCH
SPRING
DAMPER
PATC H
PLATE
BURNER
BOX
DAMPER
PATCH PLATE
FIGURE 2
DAMPER
MOTOR/GEAR
Page 3
REQUIREMENTS
In the US, installation of Lennox gas central furnaces
must conform with local building codes or, in the abĆ
sence of local codes, with the current National Fuel Gas
Code (ANSI-Z223.1). The National Fuel Gas Code is
available from:
American National Standards Institute, Inc.
1430 Broadway
New York, NY 10018
All G20R units are A.G.A. (American Gas Association)
and C.G.A (Canadian Gas Association) certified.
NOTE-G20RXE series units (units equipped with flame
rods) are certified for use with natural gas only.
Air supply for combustion and ventilation must conĆ
form to the methods outlined in the current National
Fuel Gas Code.
WARNING
Product contains fiberglass wool.
Disturbing the insulation in this product during
installation, maintenance, or repair will expose you
to fiberglass wool. Breathing this may cause lung
cancer. (Fiberglass wool is known to the State of
California to cause cancer.)
Fiberglass wool may also cause respiratory, skin,
and eye irritation.
To reduce exposure to this substance or for further
information, consult material safety data sheets
available from address shown below, or contact
your supervisor.
Lennox Industries Inc.
P.O. Box 799900
Dallas, TX 75379-9900
The furnace is certified for installation clearances to
combustible material as listed on the appliance rating
plate and in table 1:
TABLE 1
Clearances Location Inches (mm)
Service access
To combustible
materials
From draft hood relief
opening
NOTE-Service access clearance must be maintained.
* If tight installation, front service clearance may be 24" (610mm).
** Clearance is 1" (25mm) for type B1 vent.
Accessibility and service clearances must take preceĆ
dence over fire protection clearances.
Vent installations shall be in accordance with the curĆ
rent GAMA/A.G.A. venting tables manual (502,567M),
or applicable provisions of local building codes. Vent
connectors serving appliances vented by natural draft
shall not be connected into any portion of mechanical
draft systems operating under positive pressure.
Front
Top, side and rear
Flue
Front
36 in. (914mm)*
1 in. (25mm)
6 in. (152mm)**
6 in. (152mm)
NOTE-For installation on combustible floors, appliance
shall not be installed directly on carpeting, tile, or other
combustible material other than wood flooring.
For installation in a residential garage, unit must be
installed so that burner(s) and ignition source are loĆ
cated no less than 18 in. (457 mm) above floor. Furnace
must be located or protected to avoid physical damage
by vehicles.
Unit must be adjusted to obtain a temperature rise
within the range specified on appliance rating plate.
The draft hood shall be installed in the same atmospheric
pressure zone as the combustion air inlet to the furnace.
G20R unit must be installed so that electrical compoĆ
nents are protected from water.
When furnace is used in conjunction with cooling
units, it shall be installed in parallel with, or on the upĆ
stream side of, cooling units to avoid condensation in
the heating element. With a parallel flow arrangement,
damper (or other means to control the flow of air) shall
be adequate to prevent chilled air from entering the
furnace and, if manually operated, must be equipped
with means to prevent operation of either unit, unless
damper is in the full heat" or cool" position.
When installed, furnace must be electrically grounded
in accordance with local codes or, in the absence of loĆ
cal codes, with the current National Electric Code,
ANSI/NFPA No. 70. The National Electric Code (ANSI/
NFPA No. 70) is available from:
National Fire Protection Association
470 Atlantic Avenue
Boston, MA 02210
Field wiring connection with unit must meet or exceed
specifications of type T wire and withstand a 63F
(17C) temperature rise. When furnace is installed so
that supply ducts carry air circulated by furnace to
areas outside space containing furnace, return air shall
be handled by a duct(s) sealed to the furnace casing
and terminating outside space containing furnace.
This furnace is certified for installation clearances to
combustible material as listed on appliance rating plate
and in table 1. Accessibility and service clearances must
take precedence over fire protection clearances.
n Canada, installation of C.G.A. certified units must conĆ
form with current Standard CAN/CGA-B149.1 Installation
Code for Natural Gas Burning Appliances and Equipment"
and CAN/CGA-B149.2 In s t a l l a t i o n C o d e f o r P r o p a n e G a s
Burning Appliances and Equipment," local plumbing or
waste water codes and other applicable local codes. AuĆ
thorities having jurisdiction should be consulted before
installation. Adequate clearance shall be made around air
Page 4
openings into the vestibule area. Provisions shall be made
for proper operation and for combustion air and ventilaĆ
tion air supply according to the current CAN/CGA-B149
standards.
All electrical wiring and grounding for the unit must be
in accordance with the current regulations of the CanaĆ
dian Electrical Code Part I (C.S.A. Standard C22.1) and/
or local codes.
NOTE Ċ G20R series units must
not be used as a construction
heater" at any time during any
phase of construction. Very low return air temperaĆ
tures, harmful vapors and misplacement of the filters
will damage the unit and its efficiency.
GENERAL
These instructions are intended as a general guide
and do not supersede local codes in any way. AuthoriĆ
ties having jurisdiction should be consulted before
installation.
A-Shipping and Packing List
1-Rubber grommet (for electrical make-up)
1-Base bottom angle
2-Sheet metal screws
B-Shipping Damage
Check unit for shipping damage. Receiving party
should contact last carrier immediately if any shipping
damage is found.
COMBUSTION, DILUTION & VENTILATION AIR
Until recently, there was no problem in bringing in suffiĆ
cient amounts of outdoor air for combustion -- infiltration
provided all the air that was needed and then some. In
today's homes built with energy conservation in mind,
tight construction practices make it necessary to bring in
air from outside for combustion. Consideration must also
be given to the use of exhaust fans, appliance vents, chimĆ
neys and fireplaces because they force additional air that
could be used for combustion out of the house. Unless
outside air is brought into the home for combustion, negĆ
ative pressure (pressure outside is greater than inside
pressure) will build to the point that a down draft can ocĆ
cur in the furnace vent pipe or chimney. Combustion
gases enter the living space creating a potentially dangerĆ
ous situation.
In the absence of local codes concerning air for combusĆ
tion and ventilation, this section outlines guidelines and
recommends procedures for installing G20R furnaces in
a manner that ensures efficient and safe operation. SpeĆ
cial consideration must be given to combustion air needs
as well as requirements for exhaust vents and gas pipĆ
ing. A portion of this information has been reprinted with
permission from the National Fuel Gas Code (ANSIZ223.1). This reprinted material is not the complete and
official position of the ANSI on the referenced subject,
which is represented only by the standard in its entirety.
In Canada, refer to the standard CAN/CGA-B149.1 and
-B149.2 installation codes.
Combustion Air Requirements
CAUTION
Insufficient combustion air can cause headaches,
nausea, dizziness or asphyxiation. Excessive exĆ
posure to contaminated combustion air will result
in safety and performance related problems. Avoid
exposure to the following substances in the comĆ
bustion air supply:
Permanent wave solutions;
Chlorinated waxes and cleaners;
Chlorine base swimming pool chemicals;
Water softening chemicals;
De-icing salts or chemicals;
Carbon tetrachloride;
Halogen type refrigerants;
Cleaning solvents (such as perchloroethylene);
Printing inks, paint removers, varnishes, etc.;
Hydrochloric acid;
Cements and glues;
Antistatic fabric softeners for clothes dryers; and
Masonry acid washing materials.
All gas-fired appliances require air to be used for the
combustion process. If sufficient amounts of combusĆ
tion air are not available, the furnace or other appliance
will operate in an inefficient and unsafe manner.
Enough air must be provided to meet the needs of all
fuel-burning appliances, as well as appliances such as
exhaust fans which force air out of the home. When fireĆ
places, exhaust fans, or clothes dryers are used at the
same time as the furnace, much more air is required to
ensure proper combustion and to prevent a down-draft
situation. Insufficient amounts of air also cause incomĆ
plete combustion which can result in carbon monoxide.
The requirements for providing air for combustion and
ventilation depend largely on whether the furnace is
installed in an unconfined or confined space.
Unconfined Space
An unconfined space is an area such as a basement or
large equipment room with a volume greater than 50
cubic feet per 1,000 Btu per hour of the combined input
rating of all appliances installed in that space. This
space also includes adjacent rooms which are not sepĆ
arated by a door. Though an area may appear to be unĆ
confined, it might be necessary to bring in outdoor air
for combustion if the structure does not provide
enough air by infiltration. If the furnace is located in a
Page 5
building of tight construction with weather stripping
and caulking around the windows and doors, follow
the procedures outlined for using air from the outside
for combustion and ventilation.
Confined Space
A confined space is an area with volume less than 50 cuĆ
bic feet per 1,000 Btu per hour of the combined input ratĆ
ing of all appliances installed in that space. This definiĆ
tion includes furnace closets or small equipment rooms.
When the furnace is installed so that supply ducts carry
air circulated by the furnace to areas outside the space
containing the furnace, the return air must be handled
by ducts which are sealed to the furnace casing and
which terminate outside the space containing the furĆ
nace. This is especially important when the furnace is
mounted on a platform in a confined space such as a
closet or small equipment room. Even a small leak
around the base of the unit at the platform or at the reĆ
turn air duct connection can cause a potentially danĆ
gerous negative pressure condition. Air for combusĆ
tion and ventilation can be brought into the confined
space either from inside the building or from outside.
Air from Inside
If the confined space housing the furnace adjoins space
categorized as unconfined, air can be brought in by proĆ
viding two permanent openings between the two
spaces. Each opening must have a minimum free area of
1 square inch per 1,000 Btu per hour of total input rating
of all gas-fired equipment in the confined space. Each
opening must be at least 100 square inches. One opening
shall be within 12 inches of the top of the enclosure and
one opening within 12 inches of the bottom. See figure 3.
EQUIPMENT IN CONFINED SPACE
CHIMĆ
NEY OR
GAS
VENT
ALL AIR FROM INSIDE
Air from Outside
If air from outside is brought in for combustion and venĆ
tilation, the confined space must have two permanent
openings. One opening shall be within 12 inches of the
top of the enclosure and one within 12 inches of the botĆ
tom. These openings must communicate directly or by
ducts with the outdoors or spaces (crawl or attic) that freeĆ
ly communicate with the outdoors or indirectly through
vertical ducts. Each opening shall have a minimum free
area of 1 square inch per 4,000 Btu per hour of total input
rating of all equipment in the enclosure. See figures 4 and
5. When communicating with the outdoors through horiĆ
zontal ducts, each opening shall have a minimum free
area of 1 square inch per 2,000 Btu per total input rating of
all equipment in the enclosure. See figure 6.
EQUIPMENT IN CONFINED SPACE
ALL AIR FROM OUTSIDE
CHIMNEY
OR GAS
VENT
G20R
FURNACE
VENTILATION
LOUVERS
(For unheated crawl space)
NOTE-The inlet and outlet air openings shall each have a
free area of at least one square inch per 4,000 Btu per hour
of the total input rating of all equipment in the enclosure.
(Inlet Air from Crawl Space and Outlet
VENTILATION LOUVERS
(Each end of attic)
Air to Ventilated Attic)
OUTLET
AIR
WATER
HEATER
INLET
AIR
FIGURE 4
EQUIPMENT IN CONFINED SPACE
CHIMNEY
OR GAS
VENT
ALL AIR FROM OUTSIDE
(All Air Through Ventilated Attic)
VENTILATION LOUVERS
(Each end of attic)
G20R
FURNACE
NOTE-Each opening shall have a free area of at least one
square inch per 1,000 Btu per hour of the total input rating of all
equipment in the enclosure, but not less than 100 square inches.
WATER
HEATER
FIGURE 3
OPENINGS
(To Adjacent
Room)
Page 6
OUTLET
AIR
G20R
FURNACE
NOTE-The inlet and outlet air openings shall each have a free area of
at least one square inch per 4,000 Btu per hour of the total input rating
of all equipment in the enclosure.
INLET AIR
(Ends 12" above
bottom)
WATER
HEATER
FIGURE 5
When ducts are used, they shall be of the same crosssectional area 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. In calculating
free area, the blocking effect of louvers, grilles, or
screens must be considered. If the design and free area
of protective covering is not known for calculating the
size opening required, it may be assumed that wood
louvers will have 20 to 25 percent free area and metal
louvers and grilles will have 60 to 75 percent free area.
Louvers and grilles must be fixed in the open position
or interlocked with the equipment so that they are
opened automatically during equipment operation.
EQUIPMENT IN CONFINED SPACE
ALL AIR FROM OUTSIDE
CHIMNEY
OR GAS
VENT
WATER
HEATER
OUTLET AIR
G20R
FURNACE
INLET AIR
NOTE-Each air duct opening shall have a free area of at least one
square inch per 2,000 Btu per hour of the total input rating of all equipĆ
ment in the enclosure. If the equipment room is located against an outĆ
side wall and the air openings communicate directly with the outdoors,
each opening shall have a free area of at least one square inch per
4,000 Btu per hour of the total input rating of all other equipment in the
enclosure.
FIGURE 6
INSTALLATION–Setting Equipment
The G20R series units can be installed in three different
ways: on non-combustible flooring, on combustible
floor using an additive base, or on a reverse-flow coolĆ
ing cabinet. Do not drag unit across floor.
A-Installation on Non-Combustible Flooring
1- Cut floor opening keeping in mind the clearances
listed on the unit rating plate. Also, keep in mind gas
supply and electrical supply, vent connections and
sufficient installation and service clearances. See
table 2 for correct floor opening size.
TABLE 2
NONCOMBUSTIBLE FLOOR
UNIT
Q2/3-50, Q3-75
Q4-75, Q3/4-100
Q5-100, Q3-125, Q4/5-125
Q4/5-150
NOTE-Floor opening dimensions listed are 1/4" (6mm) larger
than unit openings.
Front to Rear Side to Side
in mm in mm
20-1/2
20-1/2
20-1/2
20-1/2
520
520
520
520
12-1/4
17-1/4
22-1/4
27-1/4
311
438
565
692
2- Flange warm air plenum and lower into opening.
3- Use duckbill pliers to bend
unit flanges out from openĆ
INSTALLING
BASE ANGLE
ing. Install provided base
bottom angle (shipped in
vestibule panel) to outside of
base into provided holes.
See illustration at right. SeĆ
cure with screws provided.
4- Set unit over plenum.
5- Check to see that an adequate seal is made.
B-Installation on Combustible Flooring
1- When unit is installed on a combustible floor, an addiĆ
tive base (ordered separately) must be installed beĆ
tween the furnace and the floor. See table 3 for openĆ
ing size to cut in the floor.
TABLE 3
ADDITIVE BASE FLOOR OPENING
UNIT
Q2/3-50, Q3-75
Q4-75, Q3/4-100
Q5-100, Q3-125, Q4/5-125
Q4/5-150
NOTE-Floor opening dimensions listed are 1/4" (6mm) larger
than unit openings.
Front to Rear Side to Side
in mm in mm
22-7/8 581
22-7/8
22-7/8
22-7/8
581
581
581
14-5/8
19-5/8
24-5/8
29-5/8
371
498
625
752
2- After opening is cut, set the additive base into opening.
3- Check fiberglass strips on additive base to make sure
they are properly glued and positioned.
4- Lower supply air plenum into additive base until pleĆ
num flanges seal against fiberglass strips.
5- Use duckbill pliers to bend
unit flanges out from openĆ
INSTALLING
BASE ANGLE
ing. Install provided base
bottom angle (shipped in
vestibule panel) to outside of
base into provided holes.
See illustration at right. SeĆ
cure with screws provided.
6- Set unit on additive base so unit flanges drop into pleĆ
num. Refer to figure 7.
NOTE-Be careful not to damage fiberglass strips.
Check for tight seal.
1. Cut correct size floor opening
2. Set additive base into opening.
G20R UNIT
PROPERLY
SIZED
FLOOR
OPENING
3. Set supply air plenum into
additive base.
4. Set unit.
SUPPLY AIR
PLENUM
ADDITIVE
BASE
FIGURE 7
Page 7
Loading...