Lennox GHR32Q Installation and operation manual

Page 1 ©2000 Lennox Industries Inc.
Litho U.S.A.
Corp. 0001−L2
GHR32Q/V
Service Literature Revised 08−2004
GHR32Q/V SERIES UNITS
This manual contains information pertaining to
GHR32−1 through −6 model units. GHR32 series units
are high−efficiency horizontal or down flow gas furnaces
manufactured with Lennox DuralokPlustaluminized and
stainless steel clamshell-type heat exchangers. GHR32Q
units are available in heating input capacities of 50,000 to
120,000 Btuh (14.7 to 35.2 kW) and cooling applications
from 2 through 5 tons (7.0 through 17.6 kW). GHR32V units
are available in heating capacities of 75,000 and 100,000 Btuh
(22.0 and 29.3 kW) and 3 and 5 tons (10.5 and 17.5) for cool-
ing. Refer to Engineering Handbook for proper sizing.
Units are factory equipped for use with natural gas. A kit is
available for conversion to LPG operation. GHR32−1
through −4 units are equipped with the Lennox SureLight
silicon nitride ignition system. GHR32−5 units are
equipped with the two stage (V models will have the vari-
able speed control) integrated control board. Each
GHR32 unit meets the California Nitrogen Oxides (NOx)
Standards and California Seasonal Efficiency require-
ments. The gas valve is redundant to assure safety
shut−off as required by A.G.A. and C.G.A.
The heat exchanger, burners and manifold assembly can be
removed for inspection and service. The maintenance section
gives a detailed description on how this is done.
Information contained in this manual is intended for
use by qualified service technicians only. All specifica-
tions are subject to change. Procedures outlined in this
manual are presented as a recommendation only and do
not supersede or replace local or state codes.
GHR32Q MODEL SHOWN
DOWN FLOW
POSITION
TABLE OF CONTENTS
General 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications Q Models 2. . . . . . . . . . . . . . . . . . . . . . . .
Blower performance Q Models 3. . . . . . . . . . . . . . . . . .
Specifications V Models 4. . . . . . . . . . . . . . . . . . . . . . . .
Blower performance V Models 5. . . . . . . . . . . . . . . . . . .
Parts Arrangement 7. . . . . . . . . . . . . . . . . . . . . . . . . . . .
I Unit Components 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
II Placement and Installation 41. . . . . . . . . . . . . . . . . . . .
III Start Up 46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IV Heating System Service Checks 47. . . . . . . . . . . . . .
V Typical Operating Characteristics 49. . . . . . . . . . . . . .
VI Maintenance 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VII Wiring Diagram and Sequence of Operation 54. . . .
GHR32Q−1 54. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GHR32Q−3 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GHR32Q−5 57. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GHR32V−1 59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GHR32V−3 60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GHR32V−4 61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GHR32V−5 63. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VIII Operating Flow Charts 65. . . . . . . . . . . . . . . . . . . . . .
IX Troubleshooting 76. . . . . . . . . . . . . . . . . . . . . . . . . . . .
X Blower Control Board Jumper Summary 87. . . . . . . .

Page 2
SPECIFICATIONS GHR32Q MODELS
Model No. GHR32Q2/3-50 GHR32Q3-75 GHR32Q4/5-100 GHR32Q4/5-120
Input  Btuh (kW)
High Fire 50,000 (14.7) 72,000 (21.1) 100,000 (29.3) 118,000 (34.6)
I
nput 
B
tu
h
(kW)
Low Fire 34,000 (10.0) 51,000 (14.9) 68,000 (19.9) 81,600 (23.9)
Output  Btuh (kW)
High Fire 47,000 (13.8) 67,000 (19.6) 93,000 (27.2) 111,000 (32.5)
O
utput 
B
tu
h
(kW)
Low Fire 31,600 (9.3) 47,000 (13.8) 63,000 (18.4) 75,900 (22.2)
A.F.U.E. 90.0%
California Seasonal Efficiency 83.7% 83.9% 85.3% 84.0%
Exhaust pipe connection (PVC) diameter  in. (mm) 2 (51)
Intake pipe connection (PVC) diameter  in. (mm) 2 (51)
Condensate drain connection (PVC)  in. (mm) 1/2 (12.7)
Temperature rise High Fire 30 − 60 (17 − 33) 40 − 70 (22 − 39) 45 − 75 (25 − 42)
Temperature
rise
range  _F (_C) Low Fire 25 − 55 (14 − 31) 35 − 65 (20 − 36) 40 − 70 (22 − 39)
High static certified by (A.G.A./C.G.A.)  in wg. (Pa) .50 (125)
Gas Piping Size I.P.S.  in. (mm) 1/2 (12.7)
Blower wheel nominal in. 10 x 8 11-1/2 x 9
Blower
wheel
nominal
diameter x width mm 254 x 203 292 x 229
Number and size of filters − in. (mm) (1) 14 x 25 x 1 (356 x 635 x 25) (1) 20 x 25 x 1 (508 x 635 x 25)
Blower motor output  hp (W) 1/3 (249) 1/2 (373) 3/4 (560)
Nominal cooling Tons 2 to 3 2 to 3.5 3.5 to 5
Nominal
cooling
that can be added kW 7.0 to 10.6 7.0 to 12.3 12.3 to 17.6
Shipping weight  lbs. (kg) 1 package 147 (67) 155 (70) 196 (89) 205 (93)
Electrical characteristics 120 volts  60 hertz  1 phase (less than 12 amps)
Optional Accessories (Must Be Ordered Extra)
LPG/Propane kit 59L81 (−1 and −2 models) 11M57 (−3 and later models)
Down-Flow Additive Base 32K52 32K53
Horizontal Support Frame Kit  Ship. Wt. − lbs. (kg.) 56J18  18 lbs. (8 kg)
Concentric Roof/Wall Termination Kits 60G77 − For 1 1/2 inch (38 mm) venting 33K97 − For 2 inch
(51 mm) venting
60L46 − For 3 inch
(76 mm) venting
Vent/
Roof
Termination
For 2 inch (51 mm) venting 15F75 Not Available
Vent/
Intake
Termination
Kits For 3 inch (76 mm) venting Not Available 44J41
Intake
Kits
Wall
Termination
Kits
For 2 inch (51 mm) venting
15F74 (ring kit) − 22G44 (close couple) − 30G28 (WTK Close Cou-
ple)
30G79 (WTKX close couple with extension riser)
Not Available
Kit
sFor 3 inch (76 mm) venting Not Available 44J40 (close couple)  81J20 (WTK close couple)
Twinning Kit 15L38 (all models)
Condensate Drain Heat Cable 26K68 6 ft. (1.8 m)  26K69 24 ft. (7.3 m)  26K70 50 ft. (15.2 m)
Heat Cable Tape 39G04 1/2 inch (13 mm) wide or 39G03 2 inch (51 mm) wide
Annual Fuel Utilization Efficiency based on U.S. DOE test procedures and FTC labeling regulations. Isolated combustion system rating for non-weatherized furnaces.
Determine from venting tables proper intake and exhaust pipe size and termination kit required.
Cleanable polyurethane frame type filter.
HIGH ALTITUDE
No gas pressure adjustment is needed when operating from 0 to 4500 ft. (0 to 1372m). See table below for correct manifold
pressure and prove switch for altitudes greater than 4500 ft. (1372m).
Manifold Pressure (outlet) in. w.g. (kPa)
Model No. Prove Switch 4501 to 5500 ft.
(1373 to 1676m)
5501 to 6500 ft.
(1677 to 1981m)
6501 to 7500 ft.
(1982 to 2286m)
GHR32−50 nat no change 3.5 (0.87) 3.5 (0.87) 3.5 (0.87)
GHR32−75 nat
GHR32−100 nat Kit #67K27 3.4 (0.85) 3.3 (0.82) 3.2 (0.80)
GHR32−120 L.P.
()
()
()
GHR32−50 L.P.
no change
10 0 (2 49)
10 0 (2 49)
10 0 (2 49)
GHR32−75 L.P. no c
h
ange
10
.
0
(2
.
49)
10
.
0
(2
.
49)
10
.
0
(2
.
49)
GHR32−100 L.P.
Kit #67K27
10.0 (2.49) 10.0 (2.49) 10.0 (2.49)
HGR32−120 L.P.
Ki
t
#67K27
9.6 (2.39) 9.3 (2.31) 9.0 (2.24)

Page 3
BLOWER PERFORMANCE DATA Q MODELS
GHR32Q2/3-50 BLOWER PERFORMANCE
External Static Air Volume and Motor Watts at Specific Blower Taps
External
Static
Pressure High Medium-High Medium-Low Low
in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts
0 0 1480 700 640 1330 630 520 1070 505 435 900 425 355
.10 25 1430 675 615 1290 610 500 1050 495 420 880 415 346
.20 50 1380 650 595 1240 585 480 1040 490 400 870 410 330
.30 75 1320 625 570 1200 565 455 1010 475 380 850 400 320
.40 100 1260 595 545 1140 540 430 980 460 370 820 385 300
.50 125 1200 565 520 1080 510 410 930 440 320 790 375 280
.60 150 1100 520 500 1000 470 385 860 405 300 740 350 265
.70 175 1000 470 470 890 420 370 750 355 290 660 310 250
.80 200 800 380 440 700 330 340 590 280 280 550 260 240
NOTE  All air data is measured external to unit with air filter in place.
GHR32Q3-75 BLOWER PERFORMANCE
External Static Air Volume and Motor Watts at Specific Blower Taps
External
Static
Pressure High Medium-High Medium-Low Low
in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts
0 0 1650 780 720 1540 725 585 1450 685 540 1230 580 450
.10 25 1590 750 660 1490 705 550 1400 660 505 1200 565 420
.20 50 1520 715 645 1430 675 520 1350 635 485 1170 550 405
.30 75 1440 680 630 1370 645 490 1300 615 450 1130 535 390
.40 100 1370 645 610 1300 615 470 1240 585 430 1090 515 370
.50 125 1300 615 590 1240 585 450 1170 550 410 1040 490 330
.60 150 1210 570 560 1170 550 430 1100 520 375 970 460 320
.70 175 1120 530 540 1080 510 410 1020 480 350 890 420 280
.80 200 1020 480 515 980 460 380 900 425 325 750 355 260
.90 225 880 415 500 820 385 350 750 355 300 600 285 240
NOTE  All air data is measured external to unit with air filter in place.
GHR32Q4/5-100 BLOWER PERFORMANCE
External Static Air Volume and Motor Watts at Specific Blower Taps
External
Static
Pressure High Medium-High Medium Medium-Low Low
in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts
0 0 2530 1195 1360 2300 1085 1210 2030 960 1050 1780 840 885 1540 725 745
.10 25 2460 1160 1290 2250 1060 1140 2010 950 1010 1760 830 850 1530 720 730
.20 50 2380 1125 1270 2200 1040 1100 1990 940 990 1740 820 830 1520 715 720
.30 75 2310 1090 1250 2150 1015 1080 1950 920 970 1720 810 805 1510 715 710
.40 100 2250 1060 1200 2090 985 1060 1910 900 950 1690 800 790 1500 710 690
.50 125 2180 1030 1150 2020 955 1020 1870 880 910 1660 785 780 1480 700 670
.60 150 2100 990 1100 1960 925 980 1810 855 870 1620 765 760 1430 675 650
.70 175 2010 950 1070 1880 885 940 1750 825 855 1570 740 730 1380 650 630
.80 200 1910 900 1040 1800 850 920 1680 795 840 1500 710 710 1320 625 615
.90 225 1800 850 1010 1700 800 890 1580 745 800 1420 670 690 1240 585 600
1.00 250 1700 800 980 1600 755 870 1500 710 780 1320 625 670 1120 530 590
NOTE  All air data is measured external to unit with air filter in place.
GHR32Q4/5-120 BLOWER PERFORMANCE
External Static Air Volume and Motor Watts at Specific Blower Taps
External
Static
Pressure High Medium-High Medium Medium-Low Low
in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts
0 0 2400 1135 1250 2270 1070 1140 2060 970 1010 1800 850 860 1560 735 720
.10 25 2350 1110 1220 2220 1050 1100 2040 965 980 1780 840 830 1550 730 705
.20 50 2290 1080 1200 2170 1025 1080 2000 945 960 1750 825 815 1540 725 685
.30 75 2220 1050 1180 2120 1000 1060 1960 925 940 1720 810 800 1520 715 675
.40 100 2150 1015 1130 2050 965 1020 1900 895 920 1680 795 770 1500 710 660
.50 125 2080 980 1100 1980 935 980 1850 875 880 1640 775 750 1460 690 650
.60 150 2000 945 1050 1910 900 940 1780 840 840 1590 750 720 1420 670 630
.70 175 1900 895 1010 1830 865 920 1710 805 810 1530 720 690 1380 650 610
.80 200 1800 850 980 1740 820 900 1630 770 790 1460 690 675 1320 625 595
.90 225 1700 800 960 1630 770 860 1540 725 770 1380 650 660 1250 590 580
1.00 250 1600 755 940 1530 720 840 1430 675 750 1300 615 640 1150 545 560
NOTE  All air data is measured external to unit with air filter in place.

Page 4
SPECIFICATIONS GHR32V MODELS
Model No. GHR32V3-75 GHR32V5-100
Inp t Bt h (kW)
High Fire 72,000 (21.1) 100,000 (29.3)
Input  Btuh (kW)
Low Fire 51,000 (14.9) 68,000 (19.9)
O tp t Bt h (kW)
High Fire 67,000 (19.6) 93,000 (27.2)
Output  Btuh (kW)
Low Fire 47,000 (13.8) 63,000 (18.4)
A.F.U.E. 90.0% 90.0%
California Seasonal Efficiency 83.9 85.3
Exhaust pipe connection (PVC) diameter  in. (mm) 2 (51)
Intake pipe connection (PVC) diameter  in. (mm) 2 (51)
Condensate drain connection (PVC)  in. (mm) 1/2 (12.7)
Tem
p
erature rise High Fire 40 − 70 (22 − 39)
Temperature
rise
range  _F (_C) Low Fire 35 − 65 (19 − 36)
High static certified by (A.G.A./C.G.A.)  in wg. (Pa) .80 (200)
Gas Piping Size I.P.S.  in. (mm) 1/2 (12.7)
Blower wheel nominal in. 10 x 8 11-1/2 x 9
Blower
wheel
nominal
diameter x width mm 254 x 203 292 x 229
Blower motor output  hp (W) 1/2 (373) 1 (746)
Number and size of filters − in. (mm) (1) 14 x 25 x 1 (356 x 635 x 25) (1) 20 x 25 x 1 ( 508 x 635 x 25)
Nominal coolin
g
Tons 2 to 3.5 3.5 to 5
Nominal
cooling
that can be added kW 7.0 to 12.3 12.3 to 17.6
Shipping weight  lbs. (kg) 1 package 160 (73) 201 (91)
Electrical characteristics 120 volts  60 hertz  1 phase (less than 12 amps)
Optional Accessories (Must Be Ordered Extra)
LPG/Propane kit 59L81
Down-Flow Additive Base 32K52 32K53
Horizontal Support Frame Kit  Ship. Wt. − lbs. (kg.) 56J18  18 lbs. (8 kg)
Concentric Roof/Wall Termination Kits 60G77 − For 1 1/2 inch (38 mm) venting 33K97 − For 2 inch (51 mm) venting
Roof
Termination
For 2 inch (51 mm) venting 15F75
Vent/
Termination
Kits For 3 inch (76 mm) venting 44J41
Vent/
Intake
Kits
Wall
Termination
Kits
For 2 inch (51 mm) venting
15F74 (ring kit)
22G44 (close couple)
30G28 (WTK Close Couple)
30G79 (WTKX close couple w/ extension riser)
15F74 (ring kit)
22G44 (close couple)
Kits
For 3 inch (76 mm) venting 44J40 (close couple)  81J20 (WTK close couple)
Condensate Drain Heat Cable 26K68 6 ft. (1.8 m)  26K69 24 ft. (7.3 m)  26K70 50 ft. (15.2 m)
Heat Cable Tape 39G04 1/2 inch (13 mm) wide or 39G03 2 inch (51 mm) wide
Annual Fuel Utilization Efficiency based on U.S. DOE test procedures and FTC labeling regulations. Isolated combustion system rating for non-weatherized furnaces.
Determine from venting tables proper intake and exhaust pipe size and termination kit required.
Cleanable polyurethane frame type filter.

Page 5
BLOWER PERFORMANCE DATA −1 through −3 V MODELS
GHR32V3-75 BLOWER PERFORMANCE
0 through 0.80 in. w.g. (0 Through 200 Pa) External Static Pressure Range
VSP2−1 Blower Control Low Speed  3
Factory Settings High Speed  4
Heat Speed  3
VSP Jumper Speed Positions
ADJUST"
Jum
p
er
LOW" Speed
(Cool, Low Heat Or Continuous Fan) HIGH" Speed (Cool) HEAT" Speed
Jumper
Setting 1 2 3 4 1 2 3 4 1 2 3 4
g
cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s
NORM 875 415 940 445 985 465 106
0500 107 0505 1130 535 127 0600 129 0610 109 0515 1175 555 128 5605 133 0630
minus 15%
less motor
speed
750 355 795 375 850 400 915 430 900 425 940 445 105
5500 1120 530 940 445 995 470 109 5515 1180 555
NOTE  The effect of static pressure and filter resistance is included in the air volumes listed.
GHR32V5-100 BLOWER PERFORMANCE
0 through 0.80 in. w.g. (0 Through 200 Pa) External Static Pressure Range
VSP2−1 Blower Control Low Speed  2
Factory Settings High Speed  4
Heat Speed  1
VSP Jumper Speed Positions
ADJUST"
Jumper
LOW" Speed (Cool Or Continuous Fan) HIGH" Speed (Cool) HEAT" Speed
Jumper
Settin
g
1 2 3 4 1 2 3 4 1 2 3 4
Setting
cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s
NORM 1100 520 1260 595 1445 680 1635 770 1670 790 1960 925 2165 1020 2285 1075 1640 775 1825 860 2150 1015 2315 1090
minus 15%
less motor
speed
935 440 1015 480 1195 565 1355 640 1335 630 1495 705 1690 800 1800 850 1360 640 1465 690 1770 835 1905 900
NOTE  The effect of static pressure and filter resistance is included in the air volumes listed.
BLOWER PERFORMANCE DATA −4 V MODELS
GHR32V3-75 BLOWER PERFORMANCE
0 through 0.80 in. w.g. (0 Through 200 Pa) External Static Pressure Range
VSP3−1 Blower Control Factory Settings ADJUST − NORM
Heat Speed − 3
Cool Speed − 4
VSP Jumper Speed Positions
ADJUST" HEAT"
ADJUST
Jumper
P iti
Low Speed High Speed
Jumper
Positions 1 2 3 4 1 2 3 4
cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s
NORM (Normal) 875 415 940 445 985 465 1060 500 1090 515 1175 555 1285 605 1330 630
" (Minus) 15% 750 355 795 375 850 400 915 430 940 445 995 470 1095 515 1180 555
ADJUST"
COOL"
ADJUST"
Jumper
Low Speed High Speed
Jumper
P
os
i
t
i
o
n
s
1 2 3 4 1 2 3 4
Positions
cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s
NORM (Normal) 875 415 940 445 985 465 1060 500 1070 505 1130 535 1270 600 1290 610
" (Minus) 15% 750 355 795 375 850 400 915 430 900 425 940 445 1055 500 1120 530
15% lower motor speed than NORM jumper setting.
NOTE − The effect of static pressure and filter resistance is included in air volumes shown.
NOTE − Continuous Fan only speed is approximately 825 cfm (390 L/s) − non adjustable.
NOTE − Lennox Harmony IItzone control applications − MAX CFM is determined by COOL jumper placement with a minimum of approximately 875 cfm (415 L/s) for all positions.
GHR32V5−100 BLOWER PERFORMANCE
0 through 0.80 in. w.g. (0 Through 200 Pa) External Static Pressure Range
VSP3−1 Blower Control Factory Settings ADJUST − NORM
Heat Speed − 2
Cool Speed − 4
VSP Jumper Speed Positions
ADJUST" HEAT"
ADJUST
Jumper
P iti
Low Speed High Speed
Jumper
Positions 1 2 3 4 1 2 3 4
cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s
NORM (Normal) 1100 520 1260 595 1445 680 1635 770 1640 775 1825 860 2150 1015 2315 1090
" (Minus) 15% 935 440 1015 480 1195 565 1355 640 1360 640 1465 690 1770 835 1905 900
ADJUST"
COOL"
ADJUST"
Jumper
Low Speed High Speed
Jumper
P
os
i
t
i
o
n
s
1 2 3 4 1 2 3 4
Positions
cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s
NORM (Normal) 1100 520 1260 595 1445 680 1635 770 1670 790 1960 925 2165 1020 2285 1075
" (Minus) 15% 935 440 1015 480 1195 565 1355 640 1335 630 1495 705 1690 800 1800 850
15% lower motor speed than NORM jumper setting.
NOTE − The effect of static pressure and filter resistance is included in air volumes shown.
NOTE − Continuous Fan only speed is approximately 1050 cfm (495 L/s) − non adjustable.
NOTE − Lennox Harmony IItzone control applications − MAX CFM is determined by COOL jumper placement with a minimum of approximately 1100 cfm (520 L/s) for all positions.

Page 6
GHR32V3−75−5 Blower Motor Performance
(For Static Pressure 0.0" to 0.8" w.g.)

Adjust
"
Blower Speed Adjustment Settings (Switches 5 and 6)
Cooling
Adjust
Jumper Low High
Jumper
Setting 12341234
g
cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s
Norm 875 415 940 445 985 465 1060 500 1070 505 1130 535 1270 600 1290 610
–750 355 795 375 850 400 915 430 900 425 940 445 1055 500 1120 530

Adjust
"
Blower Speed Adjustment Settings (Switches 7 and 8)
Heating
Adj
us
t"
Jum
p
er Low High
Jumper
Setting 12341234
g
cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s
Norm 945 446 1025 484 1125 531 1270 599 1080 510 1172 533 1286 607 1452 685
–803 379 871 411 956 451 1080 510 918 433 996 470 1093 516 1234 582
15% lower motor speed than NORM switch setting.
NOTE − The effect of static pressure and filter resistance is included in air volumes shown.
NOTE − Continuous Fan only speed is approximately 825 cfm (390 L/s) − non adjustable.
NOTE − Lennox Harmony IItzone control applications − MAX CFM is determined by COOL switch setting with a minimum of approximately 875
cfm (415 L/s) for all positions.
GHR32V5−100/125−5 Blower Motor Performance
(For Static Pressure 0.0" to 0.8" w.g.)

Adjust
"
Blower Speed Adjustment Settings (Switches 5 and 6)
Cooling
Adj
ust
"
Jum
p
er Low High
Jumper
Setting 12341234
cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s
Norm 1100 520 1260 595 1445 680 1635 770 1670 790 1960 925 2165 1020 2285 1075
–935 440 1015 480 1195 565 1355 640 1335 630 1495 705 1690 800 1800 850

Adjust
"
Blower Speed Adjustment Settings (Switches 7 and 8)
Heating
Adjust"
Jumper
Low High
Jumper
Setting 1* 2 3 4 1* 2 3 4
g
cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s cfm L/s
Norm 1100 520 1260 595 1445 680 1635 770 1640 775 1825 860 2150 1015 2315 1090
–935 440 1015 480 1195 565 1355 640 1360 640 1465 690 1770 835 1905 900
15% lower motor speed than NORM switch setting.
NOTE − The effect of static pressure and filter resistance is included in air volumes shown.
NOTE − Continuous Fan only speed is approximately 1050 cfm (495 L/s) − non adjustable.
NOTE − Lennox Harmony IItzone control applications − MAX CFM is determined by COOL switch setting with a minimum of approximately 1100
cfm (520 L/s) for all positions.

Page 7
FIGURE 1
GHR32Q−5 PARTS IDENTIFICATION
(Downflow Application Shown)
TOP CAP
CABINET
PATCH PLATE
WITH BARBED
FITTING
GAS VALVE
AND MANIFOLD
BURNER BOX
COVER
FLAME SIGHT
GLASS
DuralokPlusTM
HEAT EXCHANGER
ASSEMBLY
CONDENSER
COIL
CONTROL TRANSFORMER
CONTROL
BOX
CONTROL BOX COVER
DOOR INTERLOCK SWITCH
CONTROL VOLTAGE
CIRCUIT BREAKER
HOT END HEADER
(COLLECTOR) BOX
COLD END HEADER
(COLLECTOR) BOX
COMBUSTION
AIR INDUCER
COMBUSTION AIR
PROVING (PRES-
SURE) SWITCH
PRIMARY LIMIT
AUTO−RESET
(ALTERNATE STYLES)
SUPPLY AIR
BLOWER
BURNER BOX
ASSEMBLY
FRESH AIR
INTAKE FITTING
BURNER BOX
GASKET
BURNER BOX
TOP
FLAME SENSOR
EXHAUST TEE
COMBUSTION AIR
BLOWER MOUNTING
BRACKET
CORBELS
INTAKE AIR
GASKET
FLUE
COLLAR
CONDENSATE
COLLAR
FLAME ROLL−OUT SWITCH
(MANUAL RESET)
BACK FILTER
CLIP
SECONDARY LIMIT
AUTO−RESET
(Located on Backside
of Blower Wrapper)
GASKET
ORIFICE
CONDENSATE
TRAP
IGNITOR
SURELIGHT TWO−STAGE
INTEGRATED CONTROL

BLACK
WHITE
NEUTRAL
BROWN
J96
INSTALLING BROWN
ACCESSORY WIRE TO J96
FIGURE 5
Page 8
I−UNIT COMPONENTS
GHR32 unit components are shown in figure 1. The com-
bustion air blower, gas valve and burners can be accessed
by removing the burner access panel. The blower and con-
trol box can be accessed by removing the blower access
door.
WARNING
Before attempting to perform any service or mainte-
nance, turn the electrical power to unit OFF at dis-
connect switch
A−Make-Up Box (Figure 2)
WARNING
Unit must be grounded in accordance with national
and local codes. Electric Shock Hazaed.
Can cause injury or death.
A field make−up box (see figure 2) is provided for line voltage
wiring. Line voltage wiring to unit is done through the J96 jack
from the field make−up box to plug P96 from the control box.
The box may be installed inside or outside the unit (see figures
3 and 4) and may be installed on the unit left or right side.
FIGURE 2
MAKE-UP BOX
BOX
COVER
JACK J96
POWER ENTRY KNOCKOUT
120V LINE VOLTAGE
PIGTAIL CONNECTIONS
UNIT
GROUND
Box may be installed inside or outside unit.
FIGURE 3
INTERIOR MAKE−UP BOX INSTALLATION
J96
MAKE−UP
BOX
BUSHING P96
FIGURE 4
EXTERIOR MAKE−UP BOX INSTALLATION
P96
J96
(Shown with
accessory
wire connected)
MAKE−UP
BOX
BUSHING
An accessory (brown) output wire is provided with the make-
up box. The wire provides a 120V connection for optional ac-
cessories such as electronic air cleaner or humidifier. If
used, the wire is field installed in J96 jack plug by inserting the
pin of the brown wire into the open socket of the jack. See fig-
ure 5. 120V accessories rated up to 4 amps total may be con-
nected to this wire. The neutral
leg of the accessory is con-
nected to the neutral white wire
in the make-up box. The acces-
sory terminal is energized
whenever the indoor blower is
in operation.

Page 9
B−Control Box (Figure 6)
CAUTION
Electrostatic discharge can affect electronic
components. Take precautions during furnace
installation and service to protect the furnace’s
electronic controls. Precautions will help to avoid
control exposure to electrostatic discharge by
putting the furnace, the control and the techni-
cian at the same electrostatic potential. Neutral-
ize electrostatic charge by touching hand and all
tools on an unpainted unit surface, such as the
gas valve or blower deck, before performing any
service procedure.
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
GHR32−1 through −4 CONTROL BOX
FIGURE 6
CIRCUIT
BREAKER
VSP−2
CONTROL
(v models only)
TWO−STAGE
CONTROL
SURELIGHT
CONTROL
TRANSFORMER
DOOR INTERLOCK
SWITCH
Unit transformer (T1), circuit breaker (CB8), SureLight
control (A92), VSP−2 control (A24) and Two−stage control
(A86) are located in the control box. In addition, a door in-
terlock switch (S51) is located in the control box. Jackplugs
and a snap-off" terminal strip allow the control box to be
easily removed for blower service.
1. Control Transformer (T1)
A transformer located in the control box provides power to
the low voltage 24 volt section of the unit. Transformers on
all models are rated 40VA with a 120V primary and a 24V
secondary.
2. Circuit Breaker (CB8)
A 24V circuit breaker is also located in the control box. The
switch provides overcurrent protection to the transformer
(T1). The breaker is rated 3 amps at 32V. If the current ex-
ceeds this limit the breaker will trip and all unit operation will
shut down. The breaker can be manually reset by pressing the
button on the face (figure 7).
FIGURE 7
CIRCUIT BREAKER CB8
PRESS TO RESET
3.Door Interlock Switch (S51)
A door interlock switch rated 14 amps at 125VAC is located
on the control box. The switch is wired in series with line
voltage. When the blower door is removed the unit will shut
down.
DANGER
Shock hazard.
Disconnect power before servicing. Control is not
field repairable. If control is inoperable, simply
replace entire control.
Can cause injury or death. Unsafe operation will
result if repair is attempted.
4. SureLight Ignition System A92
All GHR32−1 through −4 units are equipped with the Len-
nox SureLight ignition system. The system consists of ig-
nitor (figure 8) and ignition control board (figure 9 and
table 3 ). The board and ignitor work in combination to en-
sure furnace ignition and ignitor durability. The SureLight
integrated board controls all major furnace operations.
Table 1 and 2 show jack plug terminal designations. shows
control board terminations. The board also features two
LED lights for troubleshooting and two accessory termi-
nals rated at (1) one amp. See table 4 for troubleshooting
diagnostic codes. Units equipped with the SureLight
board can be used with either electronic or electro−me-
chanical thermostats without modification. The SureLight
ignitor is made of durable silicon nitride. Ignitor longevity
is also enhanced by voltage ramping by the control board.
The board finds the lowest ignitor temperature which will
successfully light the burner, thus increasing the life of the
ignitor.
NOTE − Do not remove blower access panel to read
Surelight LED lights. A sight glass is provided on the
access panel for viewing.

Page 10
FIGURE 8
SURELIGHT IGNITOR
13/32’
5/8" MEASUREMENT IS TO I.D.
OF RETENTION RING
5/16"
FRONT VIEW
TOP VIEW
FIGURE 9
SURELIGHT INTEGRATED CONTROL BOARD
GHR32−1 through −4 units
TABLE 1
SureLight BOARD J156 (J2) TERMINAL
DESIGNATIONS
PIN # FUNCTION
1 Ignitor
2Not Used
3Ignitor Neutral
4Combustion Air Blower Line Voltage
5Not Used
6Combustion Air Blower Neutral
TABLE 2
SureLight BOARD J58 (J1) TERMINAL
DESIGNATIONS
PIN # FUNCTION
1Primary Limit In
2Gas Valve Common
3Roll Out Switch Out
4Gas Valve 24V
5Pressure Switch In
6Pressure Switch and Primary Limit Out
7Not Used
8Roll Out Switch In
9Ground
TERMINAL DESIGNATIONS
ACB COOL
ACB HEAT
PARK
ACB LOW
ACC
TX
HOT
HTG ACC
NEUTRALS
24VAC HOT
24VAC RTN
FLAME SENSE
Blower − Cooling Speed (Line Volt)
Blower − Heating Speed (Line Volt)
Alternate Blower Speeds (Dead)
Continuous Low Speed Blower
Accessory Terminal (Line Volt)
120VAC Hot to Transformer
120VAC Hot Input
Heat Only Accessory (Line Volt)
120VAC Neutrals
24VAC Hot from Transformer
24VAC Return from Transformer
Flame Sense Terminal
TABLE 3