Lennox G60UH Series User manual

Page 1 ©2002 Lennox Industries Inc.
Corp. 0204−L2
Revised 11−2006
G60UH(X)
Service Literature
G60UH(X) SERIES UNITS
G60UH(X) series units are mid−efficiency gas furnaces
used for upflow or horizontal applications only, manufac-
tured with Lennox Duralok Plus heat exchangers formed of
aluminized steel. G60UH(X) units are available in heating
capacities of 44,000 to 132,000 Btuh and cooling applica-
tions up to 5 tons. Refer to Engineering Handbook for prop-
er sizing.
Units are factory equipped for use with natural gas. Kits are
available for conversion to LPG operation. G60UH(X) model
units are equipped with the Two−Stage / Variable Speed Inte-
grated SureLight control. G60UH(X) unit meets the Califor-
nia Nitrogen Oxides (NOx) Standards and California Sea-
sonal Efficiency requirements. All units use a redundant gas
valve to assure safety shut−off as required by C.S.A.
All specifications in this manual are subject to change. Pro-
cedures outlined in this manual are presented as a recom-
mendation only and do not supersede or replace local or
state codes. In the absence of local or state codes, the
guidelines and procedures outlined in this manual (except
where noted) are recommendations only and do not consti-
tute code.
TABLE OF CONTENTS
Specifications Page 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Blower Data Page 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
High Altitude Page 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Identification Page 11. . . . . . . . . . . . . . . . . . . . . . . .
I Unit Components Page 12. . . . . . . . . . . . . . . . . . . . . . .
II Installation Page 24. . . . . . . . . . . . . . . . . . . . . . . . . . . .
III Start Up Page 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IV Heating System Service Checks Page 25. . . . . . . . .
V Typical Operating Characteristics Page 27. . . . . . . . .
VI Maintenance Page 28. . . . . . . . . . . . . . . . . . . . . . . . . .
VII Wiring and Sequence of Operation Page 30. . . . . .
VIII Field Wiring and Jumper Setting Page 46. . . . . . . .
IX Control Board Troubleshooting Page 50. . . . . . . . . .
G60UH−1 MODEL SHOWN
IMPORTANT
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, person-
al injury or loss of life. Installation and service must
be performed by a qualified installer, service agency
or the gas supplier.
WARNING
Electric shock hazard. Can cause injury
or death. Before attempting to perform
any service or maintenance, turn the
electrical power to unit OFF at discon-
nect switch(es). Unit may have multiple
power supplies.
WARNING
Sharp edges.
Be careful when servicing unit to avoid sharp edges
which may result in personal injury.

Page 2
SPECIFICATIONS
Gas
Heating
Performance
ModelNo. G60UH−24A−045 G60UH−24A−070 G60UH−36A−070
Low NOx Model No. G60UH−24A−045X − − − G60UH−36A−070X
Input− Btuh (kW) low fire 30,000 (8.8) 45,000 (13.2) 45,000 (13.2)
Output− Btuh (kW) low fire 24,000 (7.0) 36,000 (10.6) 36,000 (10.6)
Input− Btuh (kW) high fire 44,000 (12.9) 66,000 (19.3) 66,000 (19.3)
Output− Btuh (kW) high fire 36,000 (10.5) 54,000 (15.8) 54,000 (15.8)
AFUE 80.0% 80.0% 80.0%
California Seasonal Efficiency 73.1 74.2 73.9
Highstatic(AGA/CGA)− in.w.g. (Pa) .50 (124) .50 (124) .50 (124)
Temperature rise range − F (C) low fire 15 − 45 (8 − 25) 20 − 50 (11 − 28) 20 − 50 (11 − 28)
Temperature rise range − F (C) high fire 35 − 65 (19 − 36) 40 − 70 (22 − 39) 40 − 70 (22 − 39)
Connections Flue connection − in. (mm) round 4 (102) 4 (102) 4 (102)
GaspipesizeIPS− in. (mm) 1/2 (12.7) 1/2 (12.7) 1/2 (12.7)
Indoor
Blower
Wheelnominaldiameter xwidth −in. (mm) 10 x 7 (254 x 178) 10 x 7 (254 x 178) 10 x 8 (254 x 203)
Bl
ower
Motoroutput − hp (W) 1/5 (149) 1/5 (149) 1/3 (249)
Tons(kW) ofadd-oncooling 2 (7.0) 2 (7.0) 2 − 3 (7.0 − 10.6)
Shippingweight − 1 package 121 lbs. (55 kg) 127 lbs. (58 kg) 132 lbs. (60 kg)
Matching Coils Up−flow cased C33−18A−2F, C33−24A−2F, C33−30A−2F, C33−36A−2F, C33−38A−2F
Horizontal CH33−18A−2F, CH33−24/30A−2F, CH33−36A−2F
Electricalcharacteristics 120 volts − 60 hertz − 1 phase (less than 12 amps)
OPTIONAL ACCESSORIES −MUST BE ORDERED EXTRA
Air Filter and Rack Kit
Number and size of filters
Horizontal (end) 87L95 − (1) 14 x 25 x 1 in. (356 x 635 x 25 mm)
N
um
b
er an
d
s
i
ze o
f
filt
ers
Side Return Single (44J22) or Ten Pack (66K63) − (1) 16 x 25 x 1 in. (406 x 635 x 25 mm)
EZ Filter Base Catalog Number − Shipping Weight 73P55 − 6 lbs. (3 kg)
Dimensions − H x W x D 4 x 14−1/4 x 28−5/8 in. (102 x 362 x 727 mm)
Number and size of filter (field provided) 14 x 25 x 1 in. (356 x 635 x 25 mm)
Horizontal Support Frame Kit − Shipping Weight 56J18  18 lbs. (8 kg)
Vent Adaptor − 6 in. 152 (mm) connection size 18M79 − 2 lbs. (1 kg) 18M79 − 2 lbs. (1 kg) 18M79 − 2 lbs. (1 kg)
High Altitude See Page 10
Propane/Natural Gas Kit 0 to 7500 ft (0 − 2286m 59M87
Annual Fuel Utilization Efficiency based on DOE test procedures and according to FTC labeling regulations. Isolated combustion system rating for non-weatherized furnaces.
NOTE − Filters and provisions for mounting are not furnished and must be field provided.
The same C33 uncased models match the furnaces shown but require an optional adaptor base or field fabricated transition. See C33 coil bulletin for additional information.
Cleanable polyurethane frame type filter.

Page 3
SPECIFICATIONS Cont.
Gas
Heating
Performance
ModelNo. G60UH−36B−090 G60UH−48B−070 G60UH−48B−090 G60UH−36C−110
Low NOx Model No. − − − − − − G60UH−48B−090X − − −
Input− Btuh (kW) low fire 60,000 (17.6) 45,000 (13.2) 60,000 (17.6) 75,000 (22.0)
Output− Btuh (kW) low fire 48,000 (14.1) 36,000 (10.6) 49,000 (14.4) 61,000 (17.9)
Input− Btuh (kW) high fire 88,000 (25.8) 66,000 (19.3) 88,000 (25.8) 110,000 (32.2)
Output− Btuh (kW) high fire 72,000 (21.1) 54,000 (15.8) 72,000 (21.1) 90,000 (26.4)
AFUE 80.0% 80.0% 80.0% 80.0%
California Seasonal Efficiency 73.8% 73.1% 74.6% 74.2%
Highstatic(AGA/CGA)− in.w.g. (Pa) .50 (124) .50 (124) .50 (124) .50 (124)
Temperature rise range − F (C) low fire 20 − 50 (11 − 28) 15 − 45 (8 − 25) −1, −2 units 20 − 50
(11 − 28)
−4 units 15 − 45
(8.3 − 25)
25 − 55 (14 − 31)
Temperature rise range − F (C) high fire 40 − 70 (22 − 39) 25 − 55 (15 − 33) −1, −2 units 40 − 70
(22 − 39)
−4 units 35 − 65
(19 − 36)
50 − 80 (28 − 44)
Connections Flue connection − in. (mm) round 4 (102) 4 (102) 4 (102) 4 (102)
GaspipesizeIPS− in. (mm) 1/2 (12.7) 1/2 (12.7) 1/2 (12.7) 1/2 (12.7)
Indoor
Blower
Wheelnominaldiameter xwidth −in. 10 x 8 10 x 10 10 x 10 10 x 8
Bl
ower
mm 254 x 203 254 x 254 254 x 254 254 x 203
Motoroutput − hp (W) 1/3 (249) 1/2 (373) 1/2 (373) 1/3 (249)
Tons(kW) ofadd-oncooling 2 − 3 (7.0 − 10.6) 2 − 4 (7.0 − 14.1) 2 − 4 (7.0 − 14.1) 2 − 3 (7.0 − 10.6)
Shippingweight − 1 package 146 lbs. (66 kg) 147 lbs (67 kg) 153 lbs (69 kg) 166 lbs. (75 kg)
Matching Coils Up−flow cased C33−24B−2F, C33−30B−2F, C33−36B−2F, C33−38B−2F,
C33−42B−2F, C33−48B−2F
C33−36C−2F, C33−48C−2F,
C33−50/60C−2F,
Horizontal CH33−36B−2F, CH33−42B−2F, CH33−44/48B−2F CH33−36C−2F,
CH33−48C−2F,
CH33−50/60C−2F
Electricalcharacteristics 120 volts − 60 hertz − 1 phase (less than 12 amps)
OPTIONAL ACCESSORIES −MUST BE ORDERED EXTRA
Air Filter and Rack Kit
Number and size of filters Horizontal (end) 87L96 − (1) 18 x 25 x 1 in. (457 x 635 x 25 mm) 87L97 − (1) 20 x 25 x 1 in.
(508 x 635 x 25 mm)
Side Return Single 44J22 or Ten Pack (66K63) − (1) 16 x 25 x 1 in. (406 x 635 x 25 mm)
EZ Filter
Base
Catalog Number − Shipping Weight 73P56 − 7 lbs. (3 kg) 73P57 − 8 lbs. (4 kg)
B
ase
Dimensions − H x W x D 4 x 17−5/8 x 28−5/8 in. (102 x 448 x 727 mm) 4 x 21−5/8 x 28−5/8 in.
(102 x 549 x 727 mm)
Number & size of field provided filter 16 x 25 x 1 in. (406 x 635 x 25 mm) 20 x 25 x 1 in.
(508 x 635 x25 mm)
Horizontal Support Frame Kit − Shipping Weight 56J18 − 18 lbs. (8 kg) 56J18 − 18 lbs. (8 kg) 56J18 − 18 lbs. (8 kg) 56J18 − 18 lbs. (8 kg)
LPG/Propane Kit 4501−7500 ft. (1372−2286 m) 59M13 59M13 59M13 59M13
7501−10,000 ft. (2286−3048 m) 59M14 59M14 59M14 59M14
Vent Adaptor − 6 in. 152 (mm) connection size 18M79 − 2 lbs. (1 kg) 18M79 − 2 lbs. (1 kg) 18M79 − 2 lbs. (1 kg) 18M79 − 2 lbs. (1 kg)
High Altitude See Page 10
Propane/Natural Gas Kit 0 to 7500 ft (0 − 2286m) 59M87
Annual Fuel Utilization Efficiency based on DOE test procedures and according to FTC labeling regulations. Isolated combustion system rating for non-weatherized furnaces.
NOTE − Filters and provisions for mounting are not furnished and must be field provided.
The same C33 uncased models match the furnaces shown but require an optional adaptor base or field fabricated transition. See C33 coil bulletin for additional informa-
tion.
Cleanable polyurethane frame type filter.

Page 4
SPECIFICATIONS Cont.
Gas
Heating
ModelNo. G60UH−48C−110 G60UH−60C−110 G60UH−60D−135
Heating
Performance Low NOx Model No. − − − G60UH−60C−110X − − −
Input− Btuh (kW) low fire 75,000 (22.0) 75,000 (22.0) 90,000 (26.4)
Output− Btuh (kW) low fire 60,000 (17.6) 61,000 (17.9) 73,000 (21.4)
Input− Btuh (kW) high fire 110,000 (32.2) 110,000 (32.2) 132,000 (38.7)
Output− Btuh (kW) high fire 90,000 (26.4) 90,000 (26.4) 108,000 (31.6)
AFUE 80.0% 80.0% 80.0%
California Seasonal Efficiency 74.9 75.1 74.9
Highstatic(AGA/CGA)− in.w.g.
(Pa) .50 (124) .50 (124) .50 (124)
Temperature rise range − F (C) low fire 20 − 50 (11 − 28)
−1, −2, −3 units
25 − 55 (14 − 31)
−4 units 20 − 50 (11 − 28)
25 − 55 (14 − 31)
Temperature rise range − F (C) high fire 40 − 70 (22 − 39) 35 − 65 (19 − 36) 45 − 75 (25 − 42)
Connections Flue connection − in. (mm) round 4 (102) 4 (102) 4 (102)
GaspipesizeIPS− in. (mm) 1/2 (12.7) 1/2 (12.7) 1/2 (12.7)
Indoor
Blower Wheelnominaldiameter xwidth −in.
(mm) 10 x 10 (254 x 254) 11−1/2 x 10 (292 x 254) 11−1/2 x 10 (292 x 254)
Motoroutput − hp (W) 1/2 (373) 1 (746)
−1, −2 models 3/4 (560)
1 (746)
−1, −2 models 3/4 (560)
Tons(kW) ofadd-oncooling 2 − 4 (7.0 − 14.1) 5 (17.6) 5 (17.6)
Shippingweight − 1 package 169 lbs. (77 kg) 172 lbs. (78 kg) 192 lbs. (87 kg)
Matching Coils
Up−flow cased
C33−36C−2F,
C33−48C−2F,
C33−50/60C−2F,
C33−36C−2F, C33−48C−2F,
C33−50/60C−2F, C33−60D−2F, C33−62D−2F
Horizontal
CH33−36C−2F,
CH33−48C−2F,
CH33−50/60C−2F
CH33−36C−2F,
CH33−48C−2F,
CH33−50/60C−2F
CH33−60D−2F,
CH33−62D−2F
Electricalcharacteristics 120 volts − 60 hertz − 1 phase (less than 12 amps)
OPTIONAL ACCESSORIES −MUST BE ORDERED EXTRA
Air Filter and Rack Kit
Number and size of filters Horizontal (end) 87L97 − (1) 20 x 25 x 1 in. (508 x 635 x 25 mm)
87L97
(1) 20 x 25 x 1 in. (508 x 635 x 25 mm)
87L98
(1) 25 x 25 x 1 in.
(635 x 635 x 25 mm)
Side Return Single 44J22 or Ten Pack (66K63) − (1) 16 x 25 x 1 (406 x 635 x 25)
EZ Filter Base Catalog Number − Shipping Weight 73P57 − 8 lbs. (4 kg) 73P58 − 10 lbs. (5 kg)
Dimensions − H x W x D 4 x 21−5/8 x 28−5/8 in. (102 x 549 x 727 mm) 4 x 24−5/8 x 28−5/8 in.
(102 x 625 x 727 mm)
Number and size of field provided
filter 20 x 25 x 1 in. (508 x 635 x25 mm) 24 x 24 x 1 in. (610 x 610 x 25 mm)
Horizontal Support Frame Kit − Shipping Weight 56J18 − 18 lbs. (8 kg) 56J18 − 18 lbs. (8 kg) 56J18 − 18 lbs. (8 kg)
RAB Return Air Base Not Required RAB60C (12M71)RAB60D (12M72)
Vent Adaptor − 6 in. 152 (mm) connection size 18M79 − 2 lbs. (1 kg) 18M79 − 2 lbs. (1 kg) 18M79 − 2 lbs. (1 kg)
High Altitude See Page 10
Propane / Natural Kit 59M87
Annual Fuel Utilization Efficiency based on DOE test procedures and according to FTC labeling regulations. Isolated combustion system rating for non-weatherized furnaces.
NOTE − Filters and provisions for mounting are not furnished and must be field provided.
The same C33 uncased models match the furnaces shown but require an optional adaptor base or field fabricated transition. See C33 coil bulletin for additional information.
Cleanable polyurethane frame type filter.
 Flue connection on the unit is 4 in. (102 mm) diameter. Most applications will require 5 in. (127 mm) venting and field supplied 4 x 5 in. (102 x 127 mm) adaptor. See Venting Tables
in the Installation Instructions for detailed information.
Not for use with RAB Return Air Base or with 60C and 60D size units with air flow requirements of 1800 cfm (850 L/s) or greater. See Blower Performance Tables for additional
information.

Page 5
BLOWER DATA
G60UH−24A−045 PERFORMANCE
External Static Air Volume / Watts at Various Blower Speeds
External
Static
Pressure High Medium Low
in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts
0.00 0 1090 515 460 905 425 390 725 340 300
0.05 12 1080 510 450 900 425 390 720 340 300
0.10 25 1065 505 445 895 420 385 710 335 295
0.15 37 1050 495 435 895 420 380 700 330 290
0.20 50 1030 485 425 890 420 375 690 325 290
0.25 62 1015 480 415 875 415 370 680 320 285
0.30 75 995 470 410 860 405 365 665 315 280
0.40 100 960 455 395 840 395 350 650 305 270
0.50 125 910 430 380 795 375 335 610 290 260
0.60 150 840 395 355 750 355 315 540 255 245
0.70 175 770 365 340 665 315 295 490 230 235
0.80 200 660 310 315 555 260 275 420 200 225
0.90 225 560 265 295 480 225 260 355 170 210
NOTE − All air data is measured external to unit with 1 in. (25 mm) cleanable filter (not furnished − field provided) in place. Also see Filter Air Resistance table.
NOTE − Air volumes based on bottom return air. Actual air volume may vary on side return air applications.
G60UH−24A−070 PERFORMANCE
External Static Air Volume / Watts at Various Blower Speeds
External
Static
Pressure High Medium Low
in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts
0.00 0 1075 505 445 905 425 375 730 345 290
0.05 12 1070 505 445 900 425 375 725 340 290
0.10 25 1065 505 440 895 420 370 720 340 285
0.15 37 1060 500 435 890 420 365 715 335 285
0.20 50 1055 500 430 885 420 360 710 335 280
0.25 62 1045 495 425 880 415 360 700 330 280
0.30 75 1030 485 415 875 415 355 690 325 270
0.40 100 1010 475 400 860 405 350 675 320 270
0.50 125 975 460 390 840 395 340 660 310 265
0.60 150 940 445 375 805 380 325 640 300 255
0.70 175 890 420 360 755 355 305 605 285 240
0.80 200 830 390 340 700 330 285 565 265 225
0.90 225 765 360 305 640 300 265 515 245 205
NOTE − All air data is measured external to unit with 1 in. (25 mm) cleanable filter (not furnished − field provided) in place. Also see Filter Air Resistance table.
NOTE − Air volumes based on bottom return air. Actual air volume may vary on side return air applications.
G60UH−36A−070 PERFORMANCE
External Static Air Volume / Watts at Various Blower Speeds
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
0.00 0 1500 710 705 1290 610 565 985 465 455 830 390 375
0.05 12 1475 695 695 1275 600 555 980 465 445 820 385 365
0.10 25 1450 685 680 1255 590 545 970 460 440 810 380 360
0.15 37 1425 675 670 1240 585 535 965 455 430 805 380 355
0.20 50 1400 660 655 1225 580 525 955 450 425 795 375 350
0.25 62 1370 645 645 1205 570 510 945 445 415 790 375 345
0.30 75 1340 630 630 1180 555 500 930 440 405 780 370 335
0.40 100 1285 605 610 1140 540 475 900 425 390 745 350 325
0.50 125 1215 575 580 1080 510 450 865 410 375 705 335 310
0.60 150 1150 545 560 1015 480 430 810 380 355 655 310 290
0.70 175 1060 500 535 940 445 405 730 345 330 585 275 270
0.80 200 955 450 515 800 375 370 655 310 305 480 225 260
0.90 225 785 370 475 605 285 325 585 275 270 410 195 255
NOTE − All air data is measured external to unit with 1 in. (25 mm) cleanable filter (not furnished − field provided) in place. Also see Filter Air Resistance table.
NOTE − Air volumes based on bottom return air. Actual air volume may vary on side return air applications.

Page 6
BLOWER DATA Cont.
G60UH−36B−090 PERFORMANCE
External Static Air Volume / Watts at Various Blower Speeds
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
0.00 0 1500 710 720 1255 590 595 1040 490 460 900 425 370
0.05 12 1485 700 705 1250 590 580 1040 490 450 895 420 365
0.10 25 1465 690 685 1240 585 570 1035 490 445 890 420 360
0.15 37 1450 685 675 1235 585 555 1035 490 440 885 420 355
0.20 50 1435 675 660 1225 580 545 1030 485 435 880 415 350
0.25 62 1420 670 645 1215 575 530 1025 485 425 875 415 345
0.30 75 1400 660 630 1200 565 520 1020 480 415 870 410 340
0.40 100 1345 635 595 1170 550 495 1000 470 400 855 405 330
0.50 125 1300 615 575 1135 535 475 965 455 380 830 390 300
0.60 150 1235 585 545 1080 510 445 930 440 360 780 370 290
0.70 175 1165 550 510 1020 480 415 870 410 340 740 350 280
0.80 200 1080 510 480 940 445 385 800 380 315 670 315 260
0.90 225 985 465 445 840 395 355 710 335 290 600 285 245
NOTE − All air data is measured external to unit with 1 in. (25 mm) cleanable filter (not furnished − field provided) in place. Also see Filter Air Resistance table.
NOTE − Air volumes based on bottom return air. Actual air volume may vary on side return air applications.
G60UH−36C−110 PERFORMANCE
External Static Air Volume / Watts at Various Blower Speeds
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
0.00 0 1555 735 715 1335 630 575 1085 510 460 925 435 365
0.05 12 1540 725 705 1330 630 555 1080 510 450 920 435 360
0.10 25 1525 720 690 1320 625 545 1075 505 440 915 430 355
0.15 37 1510 715 680 1310 620 535 1070 505 430 910 430 350
0.20 50 1490 705 670 1295 610 525 1065 505 420 900 425 340
0.25 62 1465 690 655 1280 605 510 1060 500 415 890 420 335
0.30 75 1440 680 645 1260 595 495 1050 495 405 880 415 330
0.40 100 1385 655 615 1230 580 485 1030 485 390 865 410 320
0.50 125 1320 625 590 1190 560 460 995 470 375 835 395 300
0.60 150 1260 595 570 1135 535 430 960 455 355 815 385 295
0.70 175 1190 560 545 1075 505 410 915 430 345 775 365 285
0.80 200 1090 515 515 970 460 385 860 405 325 760 360 280
0.90 225 975 460 485 880 415 360 790 375 305 705 335 275
NOTE − All air data is measured external to unit with 1 in. (25 mm) cleanable filter (not furnished − field provided) in place. Also see Filter Air Resistance table.
NOTE − Air volumes based on bottom return air. Actual air volume may vary on side return air applications.
G60UH−48B−070 PERFORMANCE
External Static Air Volume / Watts at Different Blower Speeds
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
.00 0 2080 980 846 1810 855 764 1535 725 634 1295 610 519
.10 25 2030 955 810 1790 845 714 1520 715 600 1285 605 492
.20 50 1955 920 767 1760 830 675 1515 715 566 1275 600 477
.30 75 1885 890 732 1710 805 640 1505 710 555 1265 595 459
.40 100 1820 860 699 1670 790 611 1470 695 525 1255 590 443
.50 125 1740 820 664 1600 755 575 1420 670 496 1215 575 414
.60 150 1635 770 624 1530 720 544 1350 635 464 1175 555 400
.70 175 1545 730 597 1420 670 501 1270 600 432 1080 510 368
.80 200 1400 660 554 1295 610 462 1135 535 392 990 465 343
.90 225 1250 590 512 1125 530 419 1050 495 372 875 410 310
NOTES − All air data is measured external to unit with 1 in. (25 mm) cleanable filter (not furnished − field provided) in place. Also see Filter Air Resistance table.
Air volume based on bottom air return air. Actual air volume may vary on side return air applications.

Page 7
BLOWER DATA Cont.
G60UH−48B−090 PERFORMANCE
External Static Air Volume / Watts at Various Blower Speeds
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
0.00 0 1970 930 790 1810 855 735 1585 750 670 1340 630 565
0.05 12 1940 915 780 1785 840 715 1580 745 650 1335 630 555
0.10 25 1915 905 765 1760 830 695 1570 740 630 1325 625 540
0.15 37 1880 885 745 1730 815 660 1560 735 615 1325 625 530
0.20 50 1840 870 730 1700 800 620 1545 730 600 1320 625 520
0.25 62 1805 850 715 1670 790 625 1520 715 585 1310 620 510
0.30 75 1765 835 695 1640 775 625 1490 705 565 1295 610 500
0.40 100 1695 800 670 1570 740 595 1440 680 540 1260 595 480
0.50 125 1600 755 635 1490 705 560 1360 640 505 1195 565 450
0.60 150 1505 710 600 1400 660 530 1285 605 480 1140 540 425
0.70 175 1395 660 565 1265 595 485 1170 550 440 990 465 380
0.80 200 1250 590 520 1100 520 445 975 460 390 905 425 355
0.90 225 1005 475 460 870 410 385 900 425 365 810 380 325
NOTE − All air data is measured external to unit with 1 in. (25 mm) cleanable filter (not furnished − field provided) in place. Also see Filter Air Resistance table.
NOTE − Air volumes based on bottom return air. Actual air volume may vary on side return air applications.
G60UH−48C−110 PERFORMANCE
External Static Air Volume / Watts at Various Blower Speeds
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
0.00 0 2015 950 895 1620 765 780 1340 630 640 1150 545 525
0.05 12 1990 940 870 1615 760 760 1340 630 640 1150 545 525
0.10 25 1965 925 850 1610 760 745 1340 630 640 1150 545 525
0.15 37 1930 910 825 1605 755 725 1335 630 630 1150 545 525
0.20 50 1895 895 805 1600 755 710 1335 630 615 1150 545 525
0.25 62 1860 880 785 1590 750 695 1330 630 605 1150 545 520
0.30 75 1820 860 765 1580 745 675 1330 630 590 1145 540 515
0.40 100 1740 820 725 1530 720 635 1320 625 560 1140 540 490
0.50 125 1665 785 695 1475 695 600 1285 605 525 1120 530 470
0.60 150 1575 745 650 1405 665 555 1230 580 490 1075 505 445
0.70 175 1475 695 610 1310 620 515 1165 550 470 1015 480 415
0.80 200 1350 635 560 1210 570 485 1080 510 430 930 440 380
0.90 225 1210 570 520 1070 505 430 870 410 365 740 350 325
NOTE − All air data is measured external to unit with 1 in. (25 mm) cleanable filter (not furnished − field provided) in place. Also see Filter Air Resistance table.
NOTE − Air volumes based on bottom return air. Actual air volume may vary on side return air applications.
G60UH−60C−110 with 3/4 hp PERFORMANCE − Bottom Return Air, Side Return Air with Optional RAB Return Air Base, Re-
turn Air from Both Sides or Return Air from Bottom and One Side.
External Static Air Volume / Watts at Various Blower Speeds
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
0.00 0 2450 1155 1220 2300 1085 1060 2056 970 905 1725 815 735
0.05 12 2410 1135 1205 2265 1070 1045 2040 965 895 1715 810 725
0.10 25 2370 1120 1195 2230 1050 1030 2020 955 890 1710 810 720
0.15 37 2325 1095 1175 2200 1040 1015 1995 940 875 1700 800 715
0.20 50 2280 1075 1165 2170 1025 1005 1975 935 870 1695 800 710
0.25 62 2245 1060 1150 2130 1005 990 1950 920 855 1680 795 705
0.30 75 2205 1040 1135 2095 990 975 1925 910 845 1665 785 700
0.40 100 2115 995 1105 2010 950 940 1860 875 820 1625 770 685
0.50 125 2025 955 1060 1945 920 920 1810 855 805 1605 755 675
0.60 150 1910 900 1015 1850 875 885 1715 810 780 1540 730 670
0.70 175 1835 865 1005 1775 840 865 1655 780 765 1495 705 655
0.80 200 1745 825 975 1655 780 835 1540 725 730 1400 660 635
0.90 225 1610 760 945 1540 725 805 1475 695 715 1310 620 615
NOTE − All air data is measured external to unit with 1 in. (25 mm) cleanable filter (not furnished − field provided) in place. Also see Filter Air Resistance table.

Page 8
BLOWER DATA Cont.
G60UH−60C−110 with 3/4 hp PERFORMANCE − Single Side Return Air − Air volumes in bold require field fabricated transi-
tion to accommodate 20 x 25 x 1 in. (508 x 635 x25 mm) cleanable air filter in order to maintain proper air velocity across
the filter.
External Static Air Volume / Watts at Various Blower Speeds
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
0.00 0 2395 1130 1230 2260 1065 1085 2015 950 920 1730 815 750
0.05 12 2365 1115 1220 2230 1050 1070 1985 935 905 1720 810 745
0.10 25 2330 1100 1205 2200 1040 1060 1960 925 890 1705 805 750
0.15 37 2285 1080 1190 2170 1025 1045 1030 485 880 1695 800 740
0.20 50 2245 1060 1170 2135 1010 1030 1905 900 870 1675 790 735
0.25 62 2200 1040 1160 2100 990 1020 1890 890 860 1665 785 730
0.30 75 2170 1025 1145 2070 980 1005 1870 880 850 1655 780 720
0.40 100 2085 985 1110 1990 940 975 1825 860 835 1610 760 705
0.50 125 1980 935 1075 1910 900 945 1755 830 810 1555 735 690
0.60 150 1890 890 1045 1835 865 915 1670 790 780 1515 715 680
0.70 175 1800 850 1020 1725 815 885 1615 760 770 1445 685 655
0.80 200 1700 805 995 1645 775 855 1525 720 745 1380 650 645
0.90 225 1590 750 980 1520 720 820 1410 665 710 1300 615 625
NOTE − All air data is measured external to unit with 1 in. (25 mm) cleanable filter (not furnished − field provided) in place. Also see Filter Air Resistance table.
G60UH−60D−135 with 3/4 hp PERFORMANCE − Bottom Return Air, Side Return Air with Optional RAB Return Air Base, Re-
turn Air from Both Sides or Return Air from Bottom and One Side.
External Static Air Volume / Watts at Various Blower Speeds
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
0.00 0 2465 1165 1205 2325 1100 1060 2155 1015 930 1895 895 780
0.05 12 2430 1145 1195 2295 1085 1050 2125 1000 920 1875 885 770
0.10 25 2395 1130 1180 2265 1070 1040 2095 990 910 1855 875 765
0.15 37 2350 1110 1165 2230 1050 1025 2070 975 900 1830 865 755
0.20 50 2310 1090 1150 2195 1035 1010 2045 965 890 1805 850 745
0.25 62 2265 1070 1135 2155 1015 995 2010 950 875 1785 840 735
0.30 75 2220 1050 1120 2115 1000 980 1975 930 865 1765 830 730
0.40 100 2120 1000 1080 2035 960 950 1915 905 845 1715 810 720
0.50 125 2050 970 1055 1955 925 925 1830 865 815 1645 775 700
0.60 150 1930 910 1015 1860 880 895 1745 825 795 1585 745 680
0.70 175 1835 865 985 1775 840 870 1655 780 770 1530 720 670
0.80 200 1720 810 955 1645 775 830 1560 735 745 1445 685 650
0.90 225 1595 755 925 1535 725 800 1455 685 720 1310 620 620
NOTE − All air data is measured external to unit with 1 in. (25 mm) cleanable filter (not furnished − field provided) in place. Also see Filter Air Resistance table.
G60UH−60D−135 with 3/4 hp PERFORMANCE − Single Side Return Air − Air volumes in bold require field fabricated transi-
tion to accommodate 20 x 25 x 1 in. (508 x 635 x25 mm) cleanable air filter in order to maintain proper air velocity across
the filter.
External Static Air Volume / Watts at Various Blower Speeds
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
0.00 0 2350 1110 1180 2225 1050 1035 2055 970 905 1855 875 775
0.05 12 2310 1090 1170 2195 1035 1025 2035 960 895 1835 865 765
0.10 25 2275 1075 1155 2165 1020 1010 2010 950 885 1815 855 760
0.15 37 2235 1055 1140 2130 1005 1000 1980 935 875 1795 845 755
0.20 50 2195 1035 1130 2100 990 985 1945 920 865 1775 835 750
0.25 62 2155 1020 1115 2055 970 970 1915 905 855 1750 825 740
0.30 75 2115 1000 1100 2010 950 950 1885 890 845 1725 815 735
0.40 100 2010 950 1055 1940 915 930 1830 865 830 1665 785 720
0.50 125 1930 910 1035 1860 880 905 1745 825 805 1600 755 705
0.60 150 1830 865 1005 1770 835 880 1655 780 775 1530 720 685
0.70 175 1735 820 985 1655 780 845 1595 755 765 1480 700 675
0.80 200 1645 775 955 1545 730 815 1480 700 735 1375 650 650
0.90 225 1515 715 925 1435 675 785 1385 655 710 1290 610 630
NOTE − All air data is measured external to unit with 1 in. (25 mm) cleanable filter (not furnished − field provided) in place. Also see Filter Air Resistance table.

Page 9
BLOWER DATA Cont.
G60UH−60C−110 with 1 hp PERFORMANCE − Bottom Return Air, Side Return Air with Optional RAB Return Air Base, Re-
turn Air from Both Sides or Return Air from Bottom and One Side.
External Static Air Volume / Watts at Different Blower Speeds
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
.00 0 2555 1205 1378 2300 1085 1027 1985 935 863 1655 780 678
.10 25 2490 1175 1354 2265 1070 1002 1980 935 839 1640 775 667
.20 50 2420 1140 1330 2225 1050 980 1975 930 832 1635 770 660
.30 75 2355 1110 1300 2175 1025 957 1945 915 810 1625 765 653
.40 100 2275 1075 1265 2115 1000 934 1915 905 785 1620 765 639
.50 125 2175 1025 1229 2040 960 903 1860 875 762 1595 750 623
.60 150 2085 985 1199 1965 925 873 1800 850 733 1565 740 608
.70 175 1990 940 1140 1870 880 843 1730 815 714 1525 720 590
.80 200 1890 890 1105 1770 835 807 1630 770 676 1455 685 567
.90 225 1760 830 1067 1655 780 777 1535 725 649 1370 645 541
NOTE − All air data is measured external to unit with 1 in. (25 mm) cleanable filter (not furnished − field provided) in place. Also see Filter Air Resistance table.
G60UH−60C−110 with 1 hp PERFORMANCE − Single Side Return Air − Air volumes in bold require field fabricated transition
to accommodate 20 x 25 x 1 in. (508 x 635 x25 mm) cleanable air filter in order to maintain proper air velocity.
External Static Air Volume / Watts at Different Blower Speeds
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
.00 0 2385 1125 1296 2185 1030 981 1915 905 836 1650 780 686
.10 25 2330 1100 1274 2150 1015 961 1900 895 815 1635 770 677
.20 50 2255 1065 1234 2095 990 930 1885 890 794 1625 765 664
.30 75 2190 1035 1207 2035 960 902 1855 875 769 1620 765 651
.40 100 2115 1000 1179 1970 930 876 1820 860 751 1605 755 639
.50 125 2055 970 1156 1905 900 853 1760 830 725 1575 745 622
.60 150 1985 935 1141 1830 865 827 1705 805 704 1525 720 602
.70 175 1910 900 1119 1745 825 797 1635 770 680 1475 695 582
.80 200 1810 855 1088 1650 780 772 1560 735 659 1430 675 571
.90 225 1715 810 1058 1570 740 751 1485 700 638 1355 640 549
NOTE − All air data is measured external to unit with 1 in. (25 mm) cleanable filter (not furnished − field provided) in place. Also see Filter Air Resistance table.
G60UH−60D−135 with 1 hp PERFORMANCE − Bottom Return Air, Side Return Air with Optional RAB Return Air Base, Re-
turn Air from Both Sides or Return Air from Bottom and One Side.
External Static Air Volume / Watts at Different Blower Speeds
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
.00 0 2715 1280 1407 2255 1065 1070 1910 900 850 1660 785 674
.10 25 2640 1245 1403 2250 1060 1030 1900 895 834 1645 775 668
.20 50 2540 1200 1355 2245 1060 1006 1890 890 821 1630 770 665
.30 75 2480 1170 1319 2200 1040 975 1890 890 781 1625 765 656
.40 100 2390 1125 1282 2155 1015 940 1885 890 775 1615 760 642
.50 125 2320 1095 1251 2085 985 904 1860 875 758 1605 755 631
.60 150 2205 1040 1210 2020 955 876 1815 855 731 1595 750 611
.70 175 2080 980 1161 1935 915 839 1760 830 707 1545 730 588
.80 200 2010 950 1122 1855 875 810 1690 795 679 1495 705 568
.90 225 1880 885 1071 1755 830 781 1585 745 646 1430 675 545
NOTE − All air data is measured external to unit with 1 in. (25 mm) cleanable filter (not furnished − field provided) in place. Also see Filter Air Resistance table.

Page 10
BLOWER DATA Cont.
G60UH−60D−135 with 1 hp PERFORMANCE − Single Side Return Air − Air volumes in bold require field fabricated transition
to accommodate 20 x 25 x 1 in. (508 x 635 x25 mm) cleanable air filter in order to maintain proper air velocity.
External Static Air Volume / Watts at Different Blower Speeds
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
.00 0 2455 1160 1336 2170 1025 1019 1850 875 829 1555 735 673
.10 25 2380 1125 1299 2140 1010 974 1840 870 812 1550 730 664
.20 50 2305 1085 1266 2105 995 947 1830 865 791 1545 730 656
.30 75 2235 1055 1234 2045 965 914 1820 860 774 1540 725 642
.40 100 2160 1020 1240 1985 935 886 1800 850 755 1540 725 628
.50 125 2065 975 1170 1925 910 863 1745 825 726 1535 725 614
.60 150 1990 940 1146 1870 880 844 1700 800 706 1505 710 599
.70 175 1895 895 1111 1775 835 808 1655 780 689 1465 690 573
.80 200 1805 850 1074 1680 790 779 1565 740 656 1425 670 562
.90 225 1695 800 1042 1590 750 752 1480 700 630 1335 630 533
NOTE − All air data is measured external to unit with 1 in. (25 mm) cleanable filter (not furnished − field provided) in place. Also see Filter Air Resistance table.
HIGH ALTITUDE
HIGH ALTITUDE / MANIFOLD PRESSURE INFORMATION
Altitude Manifold Pressure
tllltitd
Model
Input
Gas
0 − 4500 ft.
(0 − 1372 m)
4,501 − 7500 ft.
(1373 − 2286 m)
7501−10,000 ft.
(2286 − 3048 m)
at all altitudes
Input
Size
G
as
Required
Conversion
Pressure Required
Conversion
1Pressure Required
Conversion
1Pressure Low Fire High Fire
C
onversion
Kit
Pressure
Switch
C
onversion
Kit
Pressure
Switch
C
onversion
Kit
Pressure
Switch in. w.g. kPa in. w.g. kPa
045/070−1 Nat. N/A N/A N/A N/A 59M16 18M64 1.7 0.42 3.5 0.87
045/070−1
to −6 LPG 59M13 N/A 59M13 N/A 59M14 18M64 4.9 1.22 10.0 2.5
045/070−7 Nat. N/A N/A N/A N/A 59M17 18M64 1.7 0.42 3.5 0.87
045/070−7
and later LPG 59M13 N/A 59M13 N/A 59M14 18M64 4.9 1.22 10.0 2.5
090 1 to 6
Nat. N/A N/A N/A 18M61 59M16 18M64 1.7 0.42 3.5 0.87
090−1 to −6 LPG 59M13 N/A 59M13 18M61 59M14 18M64 4.9 1.22 10.0 2.5
090−7 and Nat. N/A N/A N/A 18M61 59M17 18M64 1.7 0.42 3.5 0.87
090−7
and
later LPG 59M13 N/A 59M13 18M61 59M14 18M64 4.9 1.22 10.0 2.5
110/135−1 Nat. N/A N/A N/A 18M63 59M16 18M61 1.7 0.42 3.5 0.87
110/135−1
to −6 LPG 59M13 N/A 59M13 18M63 59M14 18M61 4.9 1.22 10.0 2.5
110/135−7 Nat. N/A N/A N/A 18M63 59M17 18M61 1.7 0.42 3.5 0.87
110/135−7
and later LPG 59M13 N/A 59M13 18M63 59M14 18M61 4.9 1.22 10.0 2.5
Pressure switch is factory set. No adjustment necessary. All models use the factory installed pressure switch from 0−4500 feet (0−1372 m).
1 − Conversion requires 2 pressure switches

Page 11
*Flame rollout switches are located
on brackets on the inner sides.
FIGURE 1
PARTS ARRANGEMENT
NOTE − G60UH−1, −2 and −3 unit models are
equipped with a fully enclosed burner box.
See figure 19.
Flue
Transition
Combustion Air Inducer
Combustion Air
Orifice
Combustion Air
Pressure Switch Assembly
(two switches)
Flue
Collector
Box
Heat Exchanger
NOxInsert
Primary
Limit
Door Interlock Switch
Two−Stage Integrated
Control Board
Control Transformer
Circuit Breaker
Gasket
Flue Box Gasket
Limit Shield
Secondary Limit(s)
(NOxUnits Only)
Air Deflector
G60UH−60C−110
Units Only
Blower Motor
Capacitor
Flame Sensor
Gas Valve
Burners
Ignitor
Flame Rollout Switches*
Flame Rollout Bracket
Gas Orifices
Ignitor Bracket
Burner Bottom Shield

Page 12
I−UNIT COMPONENTS
G60UH(X) unit components are shown in figure 1. The gas
valve, combustion air inducer and burners can be ac-
cessed by removing the burner access panel. Electrical
components are in the control box (figure 2) found in the
blower section.
G60UH(X) units are factory equipped with a bottom return air
panel in place. The panel is designed to be field removed as
required for bottom air return. Markings are provided for side
return air and may be cut out in the field.
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 dis-
charge by putting the furnace, the control and
the technician at the same electrostatic poten-
tial. Neutralize electrostatic charge by touching
hand and all tools on an unpainted unit surface,
such as the gas valve or blower deck, before per-
forming any service procedure.
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
1. Control Transformer (T1)
A transformer located in the control box provides power to
the low voltage section of the unit. Transformers on all
models are rated 40VA with a 120V primary and a 24V sec-
ondary.
2. Door Interlock Switch (S51)
A door interlock switch rated 14A at 125VAC is wired in se-
ries with line voltage. When the blower door is removed the
unit will shut down.
FIGURE 2
CONTROL BOX G60UH(X)
Door Interlock Switch
Two−Stage Integrated
Control Board
Control Transformer
Circuit Breaker
3. Circuit Breaker (CB8)
A 24V circuit breaker is also located in the control box.
The switch provides overcurrent protection to the trans-
former (T1). The breaker is rated 3A at 32V. If the current
exceeds this limit the breaker will trip and all unit opera-
tion will shutdown. The breaker can be manually reset
by pressing the button on the face. See figure 3.
FIGURE 3
CIRCUIT BREAKER CB8
PRESS TO RESET
WARNING
Shock hazard.
Disconnect power before servicing. Integrated
Control Board 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. Integrated Control Board(A92)
SureLihgt®Board 18M34
All G60UH units are equipped with the Lennox Two−Stage
Integrated control board. The system consists of a igni-
tion control board (figure 4 with control terminal designa-
tions in tables 3, 4 and 5). and ignitor (figure 7). The board
and ignitor work in combination to ensure furnace ignition
and ignitor durability. The board controls all major furnace
operations. The board features two LED lights, DS1 and
DS2 for troubleshooting. The board also has two accesso-
ry terminals rated at (1) one amp. See table 6 for trouble-
shooting diagnostic codes.
Electronic Ignition
At the beginning of the heat cycle, SureLight control moni-
tors the first stage and second stage combustion air induc-
er prove switch. The control will not begin the heating cycle
if the first stage prove switch is closed (by−passed). Like-
wise the control will not begin the second stage heating
cycle if the second stage prove switch is closed, and will al-
low first stage heat only. However if the second stage prove
switch closes during the first stage pre−purge, the control
will respond to second stage heat. Once the first stage
prove switch is determined to be open, the combustion air
inducer is energized on low (first stage) heat speed. When
the differential in the prove switch is great enough, the
prove switch closes and a 15−second pre−purge begins. If
the switch is not proven within 2−1/2 minutes, the control
goes into Watchguard−Pressure Switch mode for a 5−min-
ute re−set period.
After the 15−second pre−purge period, the SureLight ignitor
warms up for 20 seconds after which the gas valve opens
for a 4−second trial for ignition. The ignitor energizes during
the trial until flame is sensed. If ignition is not proved during
the 4−second period, the control will try four more times with
an inter purge and warm−up time between trials of 35

Page 13
seconds. After a total of five trials for ignition (including the
initial trial), the control goes into Watchguard−Flame Fail-
ure mode. After a 60−minute reset period, the control will
begin the ignition sequence again.
The SureLight control board has an added feature that pro-
longs the life of the ignitor. After a successful ignition, the
SureLight control utilizes less power to energize the ignitor
on successive calls for heat. The control continues to ramp
down the voltage to the ignitor until it finds the lowest
amount of power that will provide a successful ignition. This
amount of power is used for 255 cycles. On the 256th call
for heat, the control will again ramp down until the lowest
power is determined and the cycle begins again.
Two Stage Operation / Thermostat Selection Jumper
The control can be utilized in two modes: SINGLE−STAGE
thermostat or TWO−STAGE thermostat. The thermostat
selection jumper E20, located just below dip switches 1
through 4 (figure 4), must be positioned for the particular
application. The jumper is factory set on TWO" for use
with a two−stage thermostat with two stage heat. Re−posi-
tion jumper to SINGLE" for use with a single stage thermo-
stat with two stage heat.
While in the single−stage thermostat mode (single jumper
setting), the burners will always fire on first−stage heat. The
combustion air inducer will operate on low speed and in-
door blower will operate on low heat speed. After a 10 min-
ute recognition period, the unit will switch to second stage
heat. While in the two−stage thermostat mode (two jumper
setting) the burners will fire on first−stage heat. The com-
bustion air inducer will operate on low speed and indoor
blower will operate on low heat speed. The unit will switch
to second−stage heat on call from the indoor thermostat. If
there is a simultaneous call for first and second stage heat,
the unit will fire on first stage heat and switch to second
stage heat after 30 seconds of operation. See Sequence of
Operation flow charts in the back of this manual for more
detail.
Dip Switch Settings
Dip Switches 1 and 2 − Heating Fan off Delay − The fan on
time of 45 seconds is not adjustable. Fan off time (time that
the blower operates after the heat demand has been satis-
fied) can be adjusted by flipping the dip switches 1 and 2
located on the SureLight integrated control. The unit is
shipped with a factory fan off setting of 90 seconds. Fan off
time will affect comfort and is adjustable to satisfy individual
applications. For customized comfort, monitor the supply
air temperature once the heat demand is satisfied. Note the
supply air temperature at the instant the blower is de−ener-
gized. Adjust the fan−off delay to achieve a supply air tem-
perature between 90° − 110° at the instant the blower is de−
energized. (Longer delay times allow for lower air tempera-
ture, shorter delay times allow for higher air temperature).
See table 1 for dip switch settings.
TABLE 1
Heating Fan Off Delay
Delay (Seconds) Switch 1 Switch 2
60 Off Off
90 Off On
120 On Off
180 On On
Switch 3 − Second Stage Delay (Used with Single−Stage
Thermostat Only) −− This switch is used to determine the
second stage on delay when a single−stage thermostat is
being used. The switch is factory−set in the ON position,
which provides a 10−minute delay before second−stage
heat is initiated. If the switch is toggled to the OFF position,
it will provide a 15−minute delay before second−stage heat
is initiated. This switch is only activated when the thermo-
stat selector jumper is positioned for SINGLE−stage ther-
mostat use.
Switch 4 − Cooling Fan off Delay − The fan on delay time
of 2 seconds is not adjustable. Fan off time (time that the
blower operates after the cool demand has been satisfied)
can be adjusted by flipping dip switch 4. The unit is shipped
with a factory fan off setting of 45 seconds. Fan off time will
affect comfort and is adjustable to satisfy individual ap-
plications. See table 2 for cool fan off time settings.
TABLE 2
Cooling Fan Off Delay
Delay (Seconds) Switch 4
2 Off
45 On
Diagnostic LED’s (DS1 and DS2)
Two diagnostic LED’S are located on the two−stage inte-
grated control board. See figure 4. These light flashes cor-
respond with the codes detailed in table 6.
Factory Installed Jumper Y1 to Y2
A factory−installed jumper from Y1 to Y2 terminals on the
integrated control board terminal strip must be clipped for
two−stage cooling.

Page 14
CONTROL BOARD 18M34
FIGURE 4
THERMOSTAT CONNECTIONS (TB1)
DIP
SWITCHES
1 − 4
LEDs
FACTORY−
INSTALLED
JUMPER
DIP SWITCH(ES) FUNCTION
1 and 2 Blower Off Delay (Heating Mode)
3 Second Stage ON Delay (Single−stage t’stat)
4 Blower Off Delay (Cooling Mode)
TABLE 3
Integrated Control Board Terminals
120VAC Neutral
LINE Line
XFMR Transformer
EAC Electronic Air Cleaner
CIRC Indoor Blower
HUM Humidifier
120VAC Line
HUM Humidifier
XMFR Transformer
LINE Line
PARK For Unused Leads
COOL Cooling Speed
EAC Electronic Air Cleaner
HI HEAT HIigh Heat Speed
LO HEAT Low Heat, Low Cool and Continuous Fan
Speed
TABLE 4
Integrated Control Board 5 Pin Terminal
PIN # Function
1 Ignitor
2Combustion Air Inducer High Speed
3Combustion Air Inducer Low Speed
4Combustion Air Inducer Neutral
5Ignitor Neutral
TABLE 5
Integrated Control Board 12Pin Terminal
PIN # Function
1Gas Valve 2nd Stage (High Fire)
2Second Stage Prove Switch
3Not Used
4 Ground
524V Hot
6Primary Limit In
7Gas Valve 1st stage (Low Fire)
8Gas Valve Common
924V Neutral
10 Ground
11 Primary Limit Out
12 1st Stage Prove Switch

Page 15
TABLE 6
DIAGNOSTIC CODES
Diagnostic LEDs are labeled DS1 and DS2. See figure 4 for location of diagnostic LEDs.
DS1 DS2 DESCRIPTION
SIMULTANEOUS
SLOW FLASH
SIMULTANEOUS
SLOW FLASH
Power on − Normal operation.
Also signaled during cooling and continuous fan.
SIMULTANEOUS
FAST FLASH
SIMULTANEOUS
FAST FLASH
Normal operation − signaled when heating demand initiated at thermostat.
SLOW FLASH ON Primary, secondary or rollout limit switch open. Limits must close within 3 minutes
or unit goes into 1 hour Watchguard.
OFF SLOW FLASH
Low pressure switch open;
OR: Blocked inlet/exhaust vent;
OR: Low pressure switch closed prior to activation of combustion air inducer.
OFF FAST FLASH
High pressure switch open;
OR: Blocked inlet/exhaust vent;
OR: High pressure switch closed prior to activation of combustion air inducer.
ALTERNATING
SLOW FLASH
ALTERNATING
SLOW FLASH
Watchguard −− burners failed to ignite; OR limit open more than 3 minutes;
OR lost flame sense 5 times in one heating cycle;
OR pressure switch opened 5 times in one heating cycle.
SLOW FLASH OFF Flame sensed without gas valve energized.
ON ON
ON
ON
ON
OFF Circuit board failure or control wired incorrectly. Check 24 and 115 volts to board.
OFF ON
Circuit
board
failure
or
control
wired
incorrectly.
Check
24
and
115
volts
to
board.
FAST FLASH SLOW FLASH Main power polarity reversed. Switch line and neutral.
SLOW FLASH FAST FLASH Low flame signal. Measures below 0.23 microAmps. Replace flame sense rod.
ALTERNATING
FAST FLASH
ALTERNATING
FAST FLASH
The following conditions are sensed during the ignitor warm−up period only:
1) Improper main ground;
2) Broken ignitor; OR: Open ignitor circuit;
3) Line voltage below 75 volts.
(If voltage lower than 75 volts prior to ignitor warm-up, control will signal waiting on
call from thermostat, and will not respond.
NOTE − Slow flash rate equals 1 Hz (one flash per second). Fast flash rate equals 3 Hz (three flashes per second).
Low flame sense current = 0.17−0.22 microAmps.

Page 16
WARNING
Shock hazard.
Disconnect power before servicing. Integrated
Control Board 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.
5. Integrated Control Board(A92)
SureLight Board 100869
G6OUH units are equipped with the Lennox two−stage in-
tegrated SureLight control board. The system consists of
a ignition / blower control board (figure 5) with control pin
designations in tables 8 and 9 and and ignitor (figure 8).
The board and ignitor work in combination to ensure fur-
nace ignition and ignitor durability. The SureLight inte-
grated board controls all major furnace operations. The
board features a red LED light, for furnace status and trou-
bleshooting. The LED flashes in X" + Y" codes. For ex-
ample using table 10 under PRESSURE SWITCH
CODES", if the red LED flashes 2 times, then off for 2 sec-
onds then flashes 3 times, the low pressure switch is failed
open. The board also has two 120 volt accessory termi-
nals rated at (1) one amp each and one 24 volt accessory
terminal rated at 0.5.
Electronic Ignition
At the beginning of the heat cycle the SureLight control
monitors the first stage and second stage combustion air
inducer prove switch. The control will not begin the heating
cycle if the first stage prove switch is closed (by−passed).
Likewise the control will not begin the second stage heating
cycle if the second stage prove switch is closed, and will re-
main in first stage heat. However, if the second stage prove
switch closes during the first stage heat pre−purge, the con-
trol will allow second stage heat. Once the first stage prove
switch is determined to be open, the combustion air induc-
er is energized on low (first stage) heat speed. When the
differential in the prove switch is great enough, the prove
switch closes and a 15−second pre−purge begins. If the
switch is not proven within 2−1/2 minutes, the control goes
into Watchguard−Pressure Switch mode for a 5−minute re−
set period.
After the 15−second pre−purge period, the SureLight ignitor
warms up for 20 seconds after which the gas valve opens
for a 4−second trial for ignition. The ignitor energizes during
the trial until flame is sensed. If ignition is not proved during
the 4−second period, the control will try four more times with
an inter purge and warm−up time between trials of 35 sec-
onds. After a total of five trials for ignition (including the ini-
tial trial), the control goes into Watchguard−Flame Failure
mode. After a 60−minute reset period, the control will begin
the ignition sequence again.
NOTE − Board 100869 DOES NOT ramp down voltage
to the ignitor. A regulated 95 volts is provided to the ig-
niter at ignition.
Two Stage Operation / Thermostat Selection Jumper
The control can be utilized in two modes: SINGLE−STAGE
thermostat or TWO−STAGE thermostat. The thermostat
selection is made using a dip switch (figure 4) and must be
positioned for the particular application. The dip switch is
factory set on TWO" for use with a two−stage thermostat
with two stage heat. Re−position dip switch to SINGLE" for
use with a single stage thermostat with two stage heat.
While in the single−stage thermostat mode (single dip
switch setting), the burners will always fire on first−stage
heat. The combustion air inducer will operate on low speed
and indoor blower will operate on low heat speed. After a
10 minute recognition period, the unit will switch to second
stage heat. While in the two−stage thermostat mode (two
dip switch setting) the burners will fire on first−stage heat.
The combustion air inducer will operate on low speed and
indoor blower will operate on low heat speed. The unit will
switch to second−stage heat on call from the indoor thermo-
stat. If there is a simultaneous call for first and second stage
heat, the unit will fire an first stage heat and switch to sec-
ond stage heat after 30 seconds of operation. See Se-
quence of Operation flow charts in the back of this manual
for more detail.

Page 17
DIP Switch Settings
Switch 1 −− Thermostat Selection −− This unit may be used
with either a single−stage or two−stage thermostat. The
thermostat selection is made using a DIP switch which
must be properly positioned for the particular application.
TheDIP switch is factory−positioned for use with a two−
stage thermostat. If a single−stage thermostat is to be used,
the DIP switch must be repositioned.
a − Select OFF" for two−stage heating operation con-
trolled by a two−stage heating thermostat (factory set-
ting);
b − Select ON" for two−stage heating operation con-
trolled by a single−stage heating thermostat. This set-
ting provides a timed delay before second−stage heat
is initiated.
Switch 2 −− Second Stage Delay (Used with Single−
Stage Thermostat Only) −− This switch is used to deter-
mine the second stage on delay when a single−stage ther-
mostat is being used. The switch is factory−set in the OFF
position, which provides a 10−minute delay before second−
stage heat is initiated. If the switch is toggled to the ON
position, it will provide a 15−minute delay before second−
stage heat is initiated. This switch is only activated when
the thermostat selector jumper is positioned for SINGLE−
stage thermostat use.
Switches 3 and 4 −− Heating Blower−Off Delay −− The
heating blower−on delay of 45 seconds is not adjustable.
The heating blower−off delay (time that the blower operates
after the heating demand has been satisfied) can be ad-
justed by moving switches 3 and 4 on the integrated control
board. The unit is shipped from the factory with a heating
blower−off delay of 90 seconds. The heating blower off
delay affects comfort and is adjustable to satisfy individual
applications. Adjust the blower off delay to achieve a sup-
ply air temperature between 90° and 110°F at the exact
moment that the blower is de−energized. Longer off delay
settings provide lower supply air temperatures; shorter set-
tings provide higher supply air temperatures.Table 7 pro-
vides the blower off timings that will result from different
switch settings.
TABLE 7
Heating Blower−Off Delay Switch Settings
Blower Off Delay
(Seconds) Switch 3 Switch 4
60 Off On
90 Off Off
120 On Off
180 On On
Switch 5 −− Cooling Blower−Off Delay −− The cooling
blower−off delay (time that the blower operates after the
cooling demand has been satisfied) can be adjusted by
moving switch 5 on the integrated control board. The
switch is factory−set in the OFF position, which provides a
cooling blower−off delay of 45 seconds. If the switch is
toggled to the ON position, it will provide a 2−second cool-
ing blower−off delay
On−Board Jumper W951
On−board jumper W951, which connects terminals R and O
on the integrated control board, must be cut when the fur-
nace is installed in applications which include a heat pump
unit and a thermostat which features dual fuel use. If the
jumper is left intact, terminal O" will remain energized elim-
inating the HEAT MODE in the heat pump.
On−Board Jumper W915
On−board jumper W915, which connects terminals Y1 and
Y2 on the integrated control board, must be cut if two−stage
cooling will be used. If the jumper is not cut the outdoor unit
will operate in first−stage cooling only.

Page 18
CONTROL BOARD 100869
FIGURE 5
THERMOSTAT CONNECTIONS (TB1)
1/4" QUICK CONNECT TERMINALS
DIP SWITCH FUNCTIONS
DIP
SWITCHES
DIAGNOSTIC
LEDs
ON−BOARD
JUMPERS 1= ERROR CODE RECALL
H= 24V HUMIDIFIER OUTPUT
L= LENNOX SYSTEM OPERATION MONITOR
SENSE = 120 VAC OUTPUT TO FLAME SENSER
NEUTRALS= 120 VAC NEUTRAL
PARK = DEAD TERMINAL FOR UNUSED BLOWER LEAD
HEAT LOW = 120 VAC OUTPUT TO CIRC BLWR −− LOW HT SPEED
HEAT HIGH/ COOL LOW = 120 VAC OUTPUT TO CIRC BLWR −−
HIGH HEAT AND LOW COOL SPEED
COOL HIGH = 120 VAC OUTPUT TO CIRC BLWR −− HIGH COOL SPEED
DIP SWITCH(ES) FUNCTION
1 −− 2 Stage T’stat Selects t/stat type (single or two−stage)
2 −− 2nd Stage Delay Second stage ON delay (single−stage t’stat)
3 & 4 −− Heat Off Delay Heating fan OFF delay
5 −− Cool Off Delay Cooling fan OFF delay
W915
W951
FUTURE USE
TABLE 8
SureLight Board 5 Pin Terminal Designation
PIN # Function
1 Ignitor
2Combustion Air Inducer High Speed
3Combustion Air Inducer Low Speed
4Combustion Air Inducer Neutral
5Ignitor Neutral
TABLE 9
SureLight Board 12Pin Terminal Designation
PIN # Function
1Gas Valve High Fire
2Second Stage Prove Switch
3Rollout In
4 Ground
524V Hot
6Primary Limit In
7Gas Valve Low Stage
8Gas Valve Common
924V Neutral
10 Ground
11 Rollout Switch Out
12 1st Stage Prove Switch

Page 19
TABLE 10
FLASH CODE
(X + Y) STATUS / ERROR DESCRIPTION
FLASH CODE DESCRIPTIONS
Pulse A 1/4 second flash followed by four seconds of off time.
Heartbeat Constant 1/2 second bright and 1/2 second dim cycles.
X + Y LED flashes X times at 2Hz, remains off for two seconds, flashes Y times at 2Hz, remains off for four
seconds, then repeats.
Pulse Power on − Standby.
Heartbeat Normal operation − signaled when heating demand initiated at thermostat.
FLAME CODES
1 + 2 Low flame current −− run mode.
1 + 3 Flame sensed out of sequence −− flame still present.
PRESSURE SWITCH CODES
2 + 3 Low pressure switch failed open.
2 + 4 Low pressure switch failed closed.
2 + 5 High pressure switch failed open.
2 + 6 High pressure switch failed closed.
2 + 7 Low pressure switch opened during ignition trial or heating demand.
LIMIT CODE
3 + 1 Limit switch open.
WATCHGUARD CODES
4 + 1 Watchguard −− Exceeded maximum number of retries.
4 + 2 Watchguard −− Exceeded maximum number of retries or last retry was due to pressure switch opening.
4 + 3 Watchguard −− Exceeded maximum number of retries or last retry was due to flame failure.
4 + 5 Watchguard −− Limit remained open longer than three minutes.
4 + 6 Watchguard −− Flame sensed out of sequence; flame signal gone.
4 + 7 Ignitor circuit fault −− Failed ignitor or triggering circuitry.
4 + 8 Low line voltage.
HARD LOCKOUT CODES
5 + 1 Hard lockout −− Rollout circuit open or previously opened.
5 + 2 Control failed self check, internal error (control will restart if error recovers).
5 + 3 No Earth ground (control will restart if error recovers).
5 + 4 Reversed line voltage polarity (control will restart if the error recovers).
5 + 6 Low secondary (24VAC) voltage.
Error Code Storage
The ignition control stores the last ten error codes in
memory. The codes are retained in case of power loss.
Error Code Review
1 − Short R (2) to (1). Within 1/2 second, the STATUS LED
will stay lit continuously to indicate that the short was
sensed.
2 − Continue to hold the short between R (2) to (1). After 5
seconds, STATUS LED will go from being continuously
lit to off. This indicates that error code review is pend-
ing.
3 − Remove R (2) to (1) short within ten seconds of STA-
TUS LED turning off. This activates error code review.
4 − Last ten error codes will be flashed on the STATUS
LED.
5 − After final error code is indicated, STATUS LED will
flash to indicate normal operation.
Clearing Error Codes
1 − Short R (2) to (1). Within 1/2 second, the STATUS LED
will stay lit continuously to indicate that the short was
sensed.
2 − Continue to hold the short between R (2) to (1). After 5
seconds, STATUS LED will go from being continuously
lit to off.
3 − Continue to hold the short between R (2) to (1) beyond
ten seconds after STATUS LED has turned off. STA-
TUS LED will turn on, indicating that error codes have
been cleared.
4 − Remove R (2) to (1) short. STATUS LED will flash to in-
dicate normal operation.

Page 20
6. Blower Motors and Capacitors
All G60UH(X) units use direct drive blower motors. All mo-
tors are 120V permanent split capacitor motors to ensure
maximum efficiency. Ratings for capacitors will be on motor
nameplate. See SPECIFICATIONS section for motor speci-
fications.
NOTE − Shafts on 1 HP motors have 2 flat sides and are
matched with blower wheels with 2 set screws.
FIGURE 6
SUPPLY AIR BLOWER
AND SECONDARY LIMIT (S)
SECONDARY
LIMIT (S)
CAPACITOR
MOTOR/BLOWER
ASSEMBLY
To Remove Blower From Unit: Disconnect Power, Remove Control
Box, Remove Bolts and Unplug Motor Wires From Control Board.
Then Slide Out Front of Unit.
7. Ignitor
The SureLight ignitor is made of durable silicon nitride. Ig-
nitor longevity is enhanced by controlling voltage to the ig-
nitor. Board 18M34 finds the lowest ignitor temperature
which will successfully light the burner, thus increasing the
life of the ignitor. Due to this feature of the board, voltage
cannot be measured so ignitor must be ohmed. Board
100869 provides a regulated 95 volts to the ignitor for con-
sistent ignition and long ignitor life. Ohm value for ignitors
with SureLight board 18M34 should be 10.9 to 19.7. Ohm
value for ignitors with board 100869 should be 25 to 47.
See figure 7 and 8 (make note of control board used) for
ignitor location.
NOTE − The G60UH(X) furnace contains electronic
components that are polarity sensitive. Make sure that
the furnace is wired correctly and is properly grounded.
8. Flame Sensor
A flame sensor is located on the left side of the burner sup-
port. See figure 9 and 10 (make note of control board used).
The sensor is mounted on the flame rollout plate and the tip
protrudes into the flame envelope of the left−most burner.
The sensor can be removed for service without removing
any part of the burners. During operation, flame is sensed
by current passed through the flame and sensing elec-
trode. The SureLight control allows the gas valve to remain
open as long as flame signal is sensed.