Lennox G60DF series User manual

Page 1 ©2002 Lennox Industries Inc.
Corp. 0210−L3 G60DF(X)
Service Literature Revised 08−2007
G60DF(X) SERIES UNITS
G60DF series units are mid−efficiency gas furnaces used
for downflow applications only, manufactured with Lennox
Duralok Plus heat exchangers formed of aluminized steel.
Units are available in heating capacities of 44,000 to
132,000 Btuh and cooling applications up to 5 tons. Refer
to Engineering Handbook for proper sizing.
Units are factory equipped for use with natural gas. Kits are
available for conversion to LPG operation. G60DF model
units are equipped with the Lennox two−stage integrated
SureLight control. G60DF units meets the California Nitro-
gen Oxides (NOx) Standards and California Seasonal Effi-
ciency 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 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
High Altitude Page 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Identification Page 9. . . . . . . . . . . . . . . . . . . . . . . . .
I Unit Components Page 10. . . . . . . . . . . . . . . . . . . . . . .
II Installation Page 23. . . . . . . . . . . . . . . . . . . . . . . . . . . .
III Start Up Page 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IV Heating System Service Checks Page 24. . . . . . . . .
V Typical Operating Characteristics Page 26. . . . . . . . .
VI Maintenance Page 27. . . . . . . . . . . . . . . . . . . . . . . . . .
VII Wiring and Sequence of Operation Page 30. . . . . .
VIII Field Wiring and Jumper Settings Page 46. . . . . . .
IX Control Board Troubleshooting Page 50. . . . . . . . . .
G60DF−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 G60DF(X) Models
Gas
Heating
Performance
ModelNo. G60DF−24A−045 G60DF−36A−070 G60DF−36B−090 G60DF−48C−090
Low NOxModel No. G60DF−24A−045X G60DF−36A−070X − − − G60DF−48C−090X
Input− Btuh (kW) low fire 30,000 (8.8) 45,000 (13.2) 60,000 (17.6) 60,000 (17.6)
Output− Btuh (kW) low fire 24,000 (7.0) 36,000 (10.5) 48,000 (14.1) 49,000 (14.4)
Input− Btuh (kW) high fire 44,000 (12.8) 66,000 (19.3) 88,000 (25.8) 88,000 (25.8)
Output− Btuh (kW) high fire 36,000 (10.5) 54,000 (15.8) 72,000 (21.1) 72,000 (21.1)
AFUE 80.0% 80.0% 80.0% 80.0%
California Seasonal Efficiency 73.3% 74.5% 75.0% 74.4%
Highstatic− in.w.g. (Pa) .50 (124) .50 (124) .50 (124) .50 (124)
Temperature rise range − F (C) low fire 15 − 45 (8 − 25) −1, −2, units
20 − 50 (11 − 28)
−4 units 15 − 45
(6 − 25)
−1, −2, units
25 − 55 (14 − 31)
−4 units 20 − 50
(11 − 28)
20 − 50 (11 − 28)
Temperature rise range − F (C) high fire 30 − 60 (17 − 33) 35 − 65 (19 − 36) 45 − 75 (25 − 42) 35 − 65 (19 − 36)
Connections GaspipesizeIPS− in. (mm) 1/2 (12.7) 1/2 (12.7) 1/2 (12.7) 1/2 (12.7)
Flue connection − in. (mm) round 4 (102) 4 (102) 4 (102) 4 (102)
Indoor
Blower
Wheelnominaldiameter xwidth −in. 10 x 8 10 x 8 10 x 8 10 x 10
mm 254 x 203 254 x 203 254 x 203 254 x 254
Motoroutput − hp (W) 1/5 (149) 1/3 (249) 1/3 (249) 1/2 (373)
Tons(kW) ofadd-oncooling 1.5 − 2 (5.3 − 7.0) 1.5 − 3 (5.3 − 10.6) 1.5 − 3 (5.3 − 10.6) 2 − 4 (7.0 − 14.1)
Shippingweight − 1 package 121 lbs. (55 kg) 132 lbs. (60 kg) 146 lbs. (66 kg) 153 (69)
Matching Coils CR26−18N−F,
CR26−30N−F,
CR26−36N−F
CR26−18N−F,
CR26−30N−F,
CR26−36N−F
CR26−36W−F,
CR26−48N−F
CR26−36W−F,
CR26−48N−F,
CR26−60N−F
Electricalcharacteristics 120 volts − 60 hertz − 1 phase (less than 12 amps)
OPTIONAL ACCESSORIES −MUST BE ORDERED EXTRA
Down−Flow Additive Base − Shipping Weight − lbs. (kg) 11M59 − 9 (4) 11M59 − 9 (4) 11M60 − 10 (5) 11M61 − 11 (5)
High Altitude See Page 8
Propane/Natural Gas Kit 0 to 7500 ft. (0 to 2286 m) 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.

Page 3
SPECIFICATIONS Cont.
Gas
Heating
Performance
ModelNo. G60DF−48C−110 G60DF−60C−110 G60DF−60D−135
Low NOxModel No. − − − − G60DF−60C−110X − − − −
Input− Btuh (kW) low fire 75,000 (22.0) 75,000 (22.0) 90,000 (26.4)
Output− Btuh (kW) low fire 61,000 (17.9) 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) 91,000 (26.7) 109,000 (31.9)
AFUE 80.0% 80.0% 80.0%
California Seasonal Efficiency 75.4% 74.6% 75.3%
Highstatic− in.w.g. (Pa) .50 (124) .50 (124) .50 (124)
Temperature rise range − F (C) low fire −1, −2 units
25 − 55 (14 − 31)
−4 units 20 − 50 (11 − 28)
20 − 50 (11 − 28) 25 − 55 (14 − 31)
Temperature rise range − F (C) high fire 45 − 75 (25 − 42) 30 − 60 (17 − 33) 40 − 70 (22 − 39)
Connections GaspipesizeIPS− in. (mm) 1/2 (12.7) 1/2 (12.7) 1/2 (12.7)
Flue connection − in. (mm) round 4 (102) 4 (102) 4 (102)
Indoor
Blower
Wheelnominaldiameter xwidth −in. 10 x 10 11−1/2 x 10 11−1/2 x 10
mm 254 x 254 292 x 254 292 x 254
Motoroutput − hp (W) 1/2 (373) 3/4 (560) 3/4 (560)
Tons(kW) ofadd-oncooling 2 − 4 (7.0 − 14.1) 4 − 5 (14.1 − 17.6) 4 − 5 (14.1 − 17.6)
Shippingweight − 1 package 169 lbs. (77 kg) 169 lbs. (77 kg) 192 lbs. (87 kg)
Matching Coils CR26−36W−F,
CR26−48N−F,
CR26−60N−F
CR26−48N−F,
CR26−60N−F
CR26−48W−F,
CR26−60W−F
Electricalcharacteristics 120 volts − 60 hertz − 1 phase (less than 12 amps)
OPTIONAL ACCESSORIES −MUST BE ORDERED EXTRA
Down−Flow Additive Base − Shipping Weight − lbs. (kg) 11M61 − 11 (5) 11M61 − 11 (5) 11M62 − 13 (6)
High Altitude See Page 8
Propane/Natural Gas Kit 0 to 7500 ft. (0 to 2286 m) 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.

Page 4
SPECIFICATIONS Cont.
Gas
Heating
Performance
ModelNo. G60DF−60C−110 G60DF−60D−135
Low NOxModel No. G60DF−60C−110X − − − −
Input− Btuh (kW) low fire 75,000 (22.0) 90,000 (26.4)
Output− Btuh (kW) low fire 61,000 (17.9) 73,000 (21.4)
Input− Btuh (kW) high fire 110,000 (32.2) 132,000 (38.7)
Output− Btuh (kW) high fire 91,000 (26.7) 109,000 (31.9)
AFUE 80.0% 80.0%
California Seasonal Efficiency 74.6% 75.3%
Highstatic− in.w.g. (Pa) .50 (124) .50 (124)
Temperature rise range − F (C) low fire 20 − 50 (11 − 28) 25 − 55 (14 − 31)
Temperature rise range − F (C) high fire 30 − 60 (17 − 33) 40 − 70 (22 − 39)
Connections GaspipesizeIPS− in. (mm) 1/2 (12.7) 1/2 (12.7)
Flue connection − in. (mm) round 4 (102) 4 (102)
Indoor
Blower
Wheelnominaldiameter xwidth −in. 11−1/2 x 10 11−1/2 x 10
mm 292 x 254 292 x 254
Motoroutput − hp (W) 1 (746)
−1, −2 models 3/4 (560)
1 (746)
−1, −2 models 3/4 (560)
Tons(kW) ofadd-oncooling 4 − 5 (14.1 − 17.6) 4 − 5 (14.1 − 17.6)
Shippingweight − 1 package 172 lbs. (78 kg) 195 lbs. (88 kg)
Matching Coils CR26−48N−F,
CR26−60N−F
CR26−48W−F,
CR26−60W−F
Electricalcharacteristics 120 volts − 60 hertz − 1 phase (less than 12 amps)
OPTIONAL ACCESSORIES −MUST BE ORDERED EXTRA
Down−Flow Additive Base − Shipping Weight − lbs. (kg) 11M61 − 11 (5) 11M62 − 13 (6)
High Altitude See Page 8
Propane/Natural Gas Kit 0 to 7500ft (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.
BLOWER DATA
G60DF−24A−045 PERFORMANCE
External Static
Pressure
Air Volume / Watts at Different Blower Speeds
High Medium Low
in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts
0.00 0 1202 565 417 1058 500 367 828 390 278
0.05 12 1185 560 410 1041 490 360 819 385 274
0.10 25 1167 550 402 1024 482 353 809 380 270
0.15 37 1147 540 396 1008 475 346 793 375 265
0.20 50 1127 530 390 991 470 338 776 365 260
0.25 62 1104 520 382 979 460 335 764 360 257
0.30 75 1081 510 374 966 455 331 752 355 254
0.40 100 1018 480 357 922 435 319 712 335 244
0.50 125 960 455 342 873 410 306 651 305 234
0.60 150 901 425 330 811 385 290 618 290 231
0.70 175 815 385 313 691 325 272 564 265 221
0.80 200 685 325 289 619 290 259 465 220 203
0.90 225 558 265 271 510 240 238 395 185 190
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 5
BLOWER DATA Cont.
G60DF−36A−070 PERFORMANCE
External Static
Pressure
Air Volume / Watts at Different Blower Speeds
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 1475 695 616 1343 635 554 1151 545 495 989 465 415
0.05 12 1449 685 606 1321 625 543 1139 540 481 983 465 407
0.10 25 1423 670 595 1298 615 532 1127 530 466 976 460 398
0.15 37 1397 660 585 1276 600 521 1115 525 452 970 460 390
0.20 50 1371 645 574 1253 590 510 1103 520 437 963 455 381
0.25 62 1345 635 563 1228 580 494 1090 515 428 953 450 371
0.30 75 1318 620 552 1203 570 478 1077 510 418 943 445 360
0.40 100 1249 590 528 1151 545 455 1039 490 395 918 435 346
0.50 125 1200 565 508 1094 515 432 998 470 374 882 415 331
0.60 150 1112 525 475 1033 490 409 951 450 354 831 390 313
0.70 175 1032 485 455 968 455 390 856 405 338 722 340 280
0.80 200 959 455 434 876 415 359 737 350 299 666 315 266
0.90 225 770 365 389 715 335 321 667 315 278 591 280 244
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.
G60DF−36B−090 PERFORMANCE
External Static
Pressure
Air Volume / Watts at Different Blower Speeds
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 1598 755 608 1408 665 526 1166 550 436 963 455 355
0.05 12 1579 745 599 1398 660 518 1164 550 428 966 455 351
0.10 25 1559 735 589 1388 655 509 1161 550 420 968 455 346
0.15 37 1528 720 573 1369 645 497 1156 545 413 966 455 341
0.20 50 1497 705 556 1350 635 485 1150 545 406 964 455 335
0.25 62 1465 690 544 1326 625 473 1137 535 398 955 450 329
0.30 75 1432 675 532 1301 615 460 1124 530 389 945 445 323
0.40 100 1370 645 509 1248 590 438 1093 515 373 933 440 313
0.50 125 1294 610 482 1198 565 420 1055 500 355 902 425 302
0.60 150 1213 575 456 1141 540 397 1012 480 343 862 405 285
0.70 175 1139 540 437 1054 495 371 917 435 313 802 380 272
0.80 200 1002 475 401 948 445 342 850 400 295 728 345 251
0.90 225 901 425 374 822 390 313 740 350 272 − − − − − − − − −
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 6
BLOWER DATA Cont.
G60DF−48C−090 PERFORMANCE
External Static
Pressure
Air Volume / Watts at Different Blower Speeds
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 2039 960 749 1852 875 657 1595 755 562 1325 625 466
0.05 12 1998 945 727 1826 860 638 1576 745 547 1338 632 460
0.10 25 1956 925 704 1800 850 619 1556 735 532 1351 640 453
0.15 37 1921 905 692 1770 835 602 1541 725 518 1340 630 441
0.20 50 1885 890 679 1739 820 585 1526 720 503 1329 625 428
0.25 62 1844 870 662 1701 805 568 1502 710 488 1301 615 414
0.30 75 1802 850 645 1663 785 551 1477 695 473 1272 600 399
0.40 100 1693 800 606 1583 745 517 1415 670 448 1226 580 378
0.50 125 1600 755 570 1491 705 485 1334 630 414 1170 550 360
0.60 150 1494 705 540 1406 665 457 1248 590 389 1110 525 337
0.70 175 1378 650 509 1300 615 426 1166 550 367 1026 485 316
0.80 200 1248 590 478 1161 550 390 1027 485 331 − − − − − − − − −
0.90 225 1097 520 439 1028 485 360 925 435 307 − − − − − − − − −
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.
G60DF−48C−110 PERFORMANCE
External Static
Pressure
Air Volume / Watts at Different Blower Speeds
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 2034 960 846 1790 845 712 1508 710 595 1226 580 477
0.05 12 2001 945 825 1761 830 694 1493 705 581 1224 580 470
0.10 25 1968 930 803 1731 815 675 1477 695 567 1222 575 463
0.15 37 1924 910 781 1708 805 657 1470 695 555 1219 575 455
0.20 50 1879 885 758 1685 795 638 1463 690 542 1216 575 447
0.25 62 1837 865 736 1654 780 618 1442 680 528 1201 565 437
0.30 75 1794 845 714 1623 765 597 1420 670 514 1186 560 427
0.40 100 1681 795 669 1548 730 564 1361 640 483 1134 535 400
0.50 125 1622 765 630 1445 680 524 1280 605 447 1065 505 371
0.60 150 1447 685 592 1312 620 479 1165 550 404 1000 470 343
0.70 175 1289 610 545 1178 555 434 1056 500 369 907 430 319
0.80 200 1157 545 502 1067 505 406 956 450 348 816 385 296
0.90 225 1012 480 472 931 440 372 840 395 320 690 325 265
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.
G60DF−60C−110 with 3/4 hp PERFORMANCE
External Static
Pressure
Air Volume / Watts at Different Blower Speeds
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 2450 1155 1170 2355 1110 1005 2145 1015 840 1845 870 705
.05 10 2430 1150 1165 2340 1105 995 2130 1005 835 1840 870 695
.10 25 2380 1120 1145 2315 1090 985 2105 995 825 1830 865 690
.15 35 2350 1110 1135 2260 1065 965 2085 985 815 1815 855 680
.20 50 2300 1085 1115 2235 1055 955 2060 975 805 1805 850 675
.25 60 2270 1070 1105 2205 1040 945 2015 950 785 1780 840 665
.30 75 2245 1060 1100 2150 1015 925 1995 940 775 1770 835 655
.40 100 2135 1010 1060 2070 975 895 1925 910 750 1730 815 640
.50 125 2055 970 1035 1990 940 870 1855 875 725 1695 800 625
.60 150 1975 930 1010 1910 900 845 1785 845 705 1650 775 605
.70 175 1870 880 980 1830 865 820 1695 800 680 1575 745 585
.80 200 1760 830 950 1720 815 795 1605 755 655 1505 710 570
.90 225 1625 765 915 1560 735 755 1515 715 640 1435 675 555
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 7
BLOWER DATA Cont.
G60DF−60D−135 with 3/4 hp PERFORMANCE
External Static
Pressure
Air Volume / Watts at Different Blower Speeds
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 2845 1345 1143 2692 1270 961 2451 1155 818 2054 970 686
0.05 12 2774 1310 1128 2628 1240 948 2354 1110 809 2022 955 680
0.10 25 2702 1275 1112 2564 1210 935 2256 1065 799 1989 940 674
0.15 37 2629 1240 1095 2494 1175 918 2203 1040 784 1933 910 666
0.20 50 2556 1205 1077 2424 1145 901 2150 1015 769 1877 885 657
0.25 62 2471 1165 1061 2309 1090 890 2089 985 759 1835 865 649
0.30 75 2385 1125 1045 2194 1035 878 2028 955 749 1792 845 640
0.40 100 2184 1030 1022 2066 975 851 1900 895 727 1697 800 626
0.50 125 2019 955 990 1917 905 830 1779 840 707 1584 750 602
0.60 150 1865 880 957 1760 830 796 1630 770 676 1491 705 583
0.70 175 1697 800 927 1592 750 768 1475 695 656 1364 645 557
0.80 200 1513 715 897 1485 700 740 1378 650 627 1266 600 538
0.90 225 1385 655 863 1305 615 712 1206 570 598 1120 530 516
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.
G60DF−60C−110 with 1 hp PERFORMANCE
External Static
Pressure
Air Volume / Watts at Different Blower Speeds
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 2475 1170 1276 2280 1075 987 1995 940 845 1690 795 698
.10 25 2390 1125 1248 2235 1055 955 1990 940 829 1675 790 690
.20 50 2330 1100 1223 2180 1030 945 1975 930 809 1665 785 675
.30 75 2245 1060 1192 2125 1000 911 1940 915 786 1660 785 657
.40 100 2175 1025 1187 2050 965 880 1895 895 757 1650 780 636
.50 125 2085 985 1145 1970 930 849 1835 870 734 1625 765 619
.60 150 2020 955 1129 1880 885 815 1750 825 695 1580 745 599
.70 175 1920 905 1094 1775 835 785 1660 785 669 1525 720 579
.80 200 1785 840 1052 1685 795 762 1585 745 645 1440 680 556
.90 225 1670 790 1020 1600 755 741 1520 715 633 1370 645 538
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.
G60DF−60D−135 with 1 hp PERFORMANCE
External Static
Pressure
Air Volume / Watts at Different Blower Speeds
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 2660 1255 1379 2325 1095 1059 1960 925 864 1655 780 684
.10 25 2560 1210 1353 2310 1090 1030 1945 915 840 1640 775 667
.20 50 2490 1175 1325 2280 1075 1000 1940 915 824 1630 770 661
.30 75 2415 1140 1293 2225 1050 972 1930 910 801 1625 765 649
.40 100 2345 1105 1264 2170 1025 941 1910 900 779 1620 760 638
.50 125 2265 1070 1235 2115 1000 918 1870 880 754 1615 760 624
.60 150 2165 1020 1199 2020 955 880 1830 865 733 1585 745 604
.70 175 2050 965 1160 1940 915 854 1755 830 705 1570 740 604
.80 200 1955 920 1112 1865 880 828 1680 790 683 1515 715 584
.90 225 1865 880 1096 1760 830 797 1605 755 656 1465 690 567
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.
FILTER AIR RESISTANCE
cfm L/s in. w.g. Pa cfm L/s in. w.g. Pa
0 0 0.00 0 1400 660 0.15 35
200 95 0.01 0 1600 755 0.19 45
400 190 0.03 5 1800 850 0.23 55
600 285 0.04 10 2000 945 0.27 65
800 380 0.06 15 2200 1040 0.33 80
1000 470 0.09 20 2400 1130 0.38 95
1200 565 0.12 30 2600 1225 0.44 110
Data is for 1 inch (25 mm) cleanable filter (field provided).
HIGH ALTITUDE / MANIFOLD PRESSURE INFORMATION
Model
Input
Size
Gas
Altitude Manifold Pressure
at all altitudes
0 − 4500 ft.
(0 − 1372 m)
4,501 − 7500 ft.
(1373 − 2286 m)
7501−10,000 ft.
(2286 − 3048 m)
Required
Conversion
Kit
Pressure
Switch
Required
Conversion
Kit
1Pressure
Switch
Required
Conversion
Kit
1Pressure
Switch
Low Fire High Fire
in. w.g. kPa in. w.g. kPa
045/070−1 to
−6
Nat. no change no change no change N/A 59M16 18M64 1.7 0.42 3.5 0.87
LPG 59M13 59M13 N/A 59M14 18M64 4.9 1.22 10.0 2.5
045/070−7
and later
Nat. no change no change no change N/A 59M17 18M64 1.7 0.42 3.5 0.87
LPG 59M13 59M13 N/A 59M14 18M64 4.9 1.22 10.0 2.5
090−1 to −6 Nat. no change no change no change 18M61 59M16 18M64 1.7 0.42 3.5 0.87
LPG 59M13 59M13 18M61 59M14 18M64 4.9 1.22 10.0 2.5
090−7 and
later
Nat. no change no change no change 18M61 59M17 18M64 1.7 0.42 3.5 0.87
LPG 59M13 59M13 18M61 59M14 18M64 4.9 1.22 10.0 2.5
110/135−1 to
−6
Nat. no change no change no change 18M63 59M16 18M61 1.7 0.42 3.5 0.87
LPG 59M13 59M13 18M63 59M14 18M61 4.9 1.22 10.0 2.5
110/135−7
and later
Nat. no change no change no change 18M63 59M17 18M61 1.7 0.42 3.5 0.87
LPG 59M13 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 9
FIGURE 1
Blower Assembly
Blower Motor
Capacitor
Internal Flue Pipe
Assembly
Flue Box Gasket
Flue Collector Box
Gasket
Combustion Air Inducer
Gasket
Primary
Limit
Heat Exchanger
Combustion Air
Prove Switch
Assembly
(Two Switches)
Combustion
Air Orifice
Transformer
SureLight®Two−Stage
Integrated Control Board
Flue
Chase
Gasket
Door
Interlock Switch Limit
Shield
Circuit Breaker
Flame Sensor
Gas Valve
Burners
Ignitor
Flame Rollout Switches*
Flame Rollout Bracket
Gas Orifices
Ignitor Bracket
Burner Bottom Shield
*Flame rollout switches are
located on brackets on the
inner sides.
PARTS ARRANGEMENT
NOTE − G60DF−1, −2 and −3 model units are
equipped with a fully covered burner box.

Page 10
I−UNIT COMPONENTS
Unit components are shown in figure 1. The gas valve,
combustion air inducer and burners can be accessed by re-
moving the burner access panel. Electrical components
are in the control box (figure 2) found in the blower section.
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
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 G60DF
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)
SureLight®Board 18M34
All G60DF units are equipped with the Lennox two−stage
integrated SureLight control board. The system consists
of a ignition control board (figure 4 with control terminal
designations in tables 3, 4 and 5) and ignitor (figure 8).
The board and ignitor work in combination to ensure fur-
nace 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 accessory terminals rated at (1) one amp each.
See table 6 for troubleshooting diagnostic codes.
Electronic Ignition
At the beginning of each heat cycle, SureLight control mon-
itors 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 still 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.