Lennox G41UF?24B?045, G41UF?36B?070, G41UF?36B?045, G41UF?48C?090, G41UF?60C?090 Service Literature

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Page 1

Corp. 0303−L2

Service Literature

G41UF SERIES UNITS

G41UF series units are high−efficiency upflow gas fur naces manufactured with Lennox DuralokPlust alumi nized primary and stainless steel secondary clamshelltype heat exchangers. G41UF units are available in heating input capacities of 44,000 to 132,000 Btuh (12.9 to 38.6 kW) and cooling applications from 2 through 5 tons (7.0 through

17.6 kW). 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. All G41UF units are equipped with the Lennox SureLight® hot sur face ignition system. The gas valve is redundant to as sure safety shut−off as required by C.S.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 specifications are sub ject to change. Procedures outlined in this manual are pre sented as a recommendation only and do not supersede or replace local or state codes.

G41UF

Table of Contents

General 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Specifications 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Blower Performance Data 3. . . . . . . . . . . . . . . . . . . . . .

I−Unit Components 8. . . . . . . . . . . . . . . . . . . . . . . . . . . .

II −Placement and Installation 16. . . . . . . . . . . . . . . . . . .

III−Start−Up 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

IV−Heating System Service Checks 22. . . . . . . . . . . . . .

V−Typical Operating Conditions 26. . . . . . . . . . . . . . . . .

VI−Maintenance 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

VII−Wiring and Sequence of Operation 30. . . . . . . . . . .

VIII−Troubleshooting 35. . . . . . . . . . . . . . . . . . . . . . . . . . .

CAUTION

As with any mechanical equipment, personal injury can result from contact with sharp sheet metal edges. Be careful when you handle this equipment.

WARNING

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.

Page 1

 2003 Lennox Industries Inc.

Litho U.S.A.

Page 2

SPECIFICATIONS

Performance

Drain H

Gas Heating Performance

Output− Btuh (kW) 40,000 (11.7) 40,000 (11.7) 60,000 (17.6) 80,000 (23.4) 80,000 (23.4)

Highstatic(CSA)− in.w.g. (Pa) 0.5 0.5 0.5 0.5 0.5

Temperature rise range − _F (_C) 35 − 65 (19 − 36) 25 − 55 (14 − 31) 35 − 65 (19 − 36) 50 − 80 (28 − 44) 45 − 75 (25 − 42)

Connections in. (mm)

Condensate Drain (PVCPipe) − i.d. 1/2 (13)

Exhaust Pipe (PVC) 2 (51) 2 (51) 2 (51) 2 (51) 2 (51)

Condensate Drain (PVC Coupling) − o.d. 3/4 (19) 3/4 (19) 3/4 (19) 3/4 (19) 3/4 (19)

Indoor

Wheel nominal diameter x width −in. (mm)

Blower

Motoroutput − hp (W) 1/5 (149) 1/3 (249) 1/3 (249) 1/3 (249) 1/2 (373)

Tons(kW) ofaddoncooling 1 − 2 (3.5 − 7.0) 1 − 3 (3.5 − 10.5) 1 − 3 (3.5 − 10.5) 1 − 3 (3.5 − 10.5) 2 − 4 (7.0 − 14.0)

Shippingweight − 1 package 128 lbs. (58 kg) 131 lbs. (59 kg) 141 lbs (64 kg) 160 lbs. (73 kg) 164 lbs. (74 kg)

Electricalcharacteristics 120 volts − 60 hertz − 1 phase (less than 12 amps)

OPTIONAL ACCESSORIES – MUST BE ORDERED EXTRA

Side Return Air Filter & Rack Kit − Number & size of

filters

EZ Filter Base

Number and size of field provided filter − in. (mm) 16 x 25 x 1 (406 x 635 x 25) 20 x 25 x 1 (508 x 635 x 25)

Condensate

eat

Cable

Heat Cable

ape

High Altitude Orifice Kit − Natural Gas 47M82 47M82 47M82 47M82 47M82

High Altitude

Pressure Switch Kit

LPG/Propane Kit

Termination

Twinning Kit 15L38 15L38 15L38 15L38 15L38

Annual Fuel Utilization Efficiency based on DOE test procedures and according to FTC labeling regulations. Isolated combustion system rating for nonweatherized

furnaces.

Required for proper operation at altitudes over 4500 ft. (1370 m).

Cleanable polyurethane frame type filter.

Kits contain enough parts for two installations. Determine from venting tables proper exhaust pipe size and termination kit required.

Required for proper operation at altitudes from 7501 to 10,000 ft. (2286 to 3048 m).

NOTE − Filters and provisions for mounting are not furnished and must be field provided.

Catalog Number − Shipping Weight 73P56 − 7 lbs. (3 kg) 73P57 − 8 lbs. (4 kg)

Dimensions − H x W x D − in. (mm) 4 x 17−5/8 x 28−5/8 (102 x 448 x 727)

50 ft. (15.2 m) long 26K70 26K70 26K70 26K70 26K70

Fiberglass − 1/2 in. (38 mm) x 66 ft. (20 m)

Aluminum foil − 2 in. (25 mm) x 60 ft. (18 m)

4501−7500 ft. (1372−2286 m)

7501−10,000 ft. (2286−3048 m)

0−7500 ft. (0−2286 m) 47M83 47M83 47M83 47M83 47M83

7501−10,000 ft. (2286−3048 m) 47M81 47M81 47M81 47M81 47M81

Roof − 2 inch (51 mm)

Roof − 3 inch (76 mm)

Wall Ring − 2 inch (51 mm) 15F74 15F74 15F74 15F74 15F74

ModelNo. G41UF−24B−045 G41UF−36B−045 G41UF−36B−070 G41UF−36C−090 G41UF−48C−090

Input− Btuh (kW) 44,000 (12.9)

AFUE 90.0% 90.0% 90.0% 90.0% 90.0%

44,000 (12.9) 66,000 (19.3) 88,000 (25.8) 88,000 (25.8)

1/2 (13) 1/2 (13) 1/2 (13) 1/2 (13)

GaspipesizeIPS 1/2 (13) 1/2 (13) 1/2 (13) 1/2 (13) 1/2 (13)

10 x 7

(254 x 178)

10 x 8

(254 x 203)

10 x 8

(254 x 203)

10 x 8

(254 x 203)

10 x 10

(254 x 254)

Single 44J22 or Ten Pack 66K63 − (1) 16 x 25 x 1 in. (406 x 635 x 25 mm)

4 x 21−5/8 x 28−5/8 (102 x 549 x 727)

6 ft. (1.8 m) long 26K68 26K68 26K68 26K68 26K68

24 ft. (7.3 m) long 26K69

26K69 26K69 26K69 26K69

39G04 39G04 39G04 39G04 39G04

39G03

39G03 39G03 39G03 39G03

− − − − − − − − − 46M94 46M94

46M94

46M94 46M94 46M94 46M94

15F75 15F75 15F75 15F75 15F75

44J41

44J41 44J41 44J41 44J41

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SPECIFICATIONS

Performance

Drain H

Gas Heating Performance

Highstatic(CSA)− in.w.g. (Pa) 0.5 0.5 0.5 0.5

Temperature rise range − _F (_C) 25 − 55 (14 − 31) 50 − 80 (28 − 44) 40 − 70 (22 − 39) 45 − 75 (25 − 42)

Connections in. (mm)

Condensate Drain (PVC Pipe) − i.d. 1/2 (13)

Exhaust Pipe (PVC) 2 (51) 2 (51) 2 (51) 2 (51)

Condensate Drain (PVC Coupling) − o.d. 3/4 (19) 3/4 (19) 3/4 (19) 3/4 (19)

Indoor Blower

Wheelnominaldiameter xwidth −in. (mm) 11−1/2 x 10 (292 x 229)

Motoroutput − hp (W) 3/4 (560) 1/2 (373) 3/4 (560) 3/4 (560)

Tons(kW) ofaddoncooling 4 − 5 (14.0 − 17.5) 2 − 4 (7.0 − 14.0) 4 − 5 (14.0 − 17.5) 4 − 5 (14.0 − 17.5)

Shippingweight − 1 package 168 lbs. (76 kg) 173 lbs. (78 kg) 177 lbs. (80 kg) 194 lbs. (88 kg)

Electricalcharacteristics 120 volts − 60 hertz − 1 phase (less than 12 amps)

OPTIONAL ACCESSORIES – MUST BE ORDERED EXTRA

4,6

Air Filter and Rack Kit − Number & size of filters Single 44J22 or Ten Pack 66K63 − (1) 16 x 25 x 1 (406 x 635 x 25)

EZ Filter Base

Condensate

eat

Cable

Heat Cable

ape

High Altitude Orifice Kit − Natural Gas Only 47M82 47M82 47M82 47M82

High Altitude

Pressure Switch Kit

RAB Return Air Base RAB60C (12M71) − − − − RAB60D (12M72) RAB60D (12M72)

LPG/Propane Kit

Termination

Twinning Kit 15L38 15L38 15L38 15L38

Annual Fuel Utilization Efficiency based on DOE test procedures and according to FTC labeling regulations. Isolated combustion system rating for nonweatherized

furnaces.

Required for proper operation at altitudes over 4500 ft. (1370 m).

Cleanable polyurethane frame type filter.

Kits contain enough parts for two installations. Determine from venting tables proper exhaust pipe size and termination kit required.

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.

Required for proper operation at altitudes from 7501 to 10,000 ft. (2286 to 3048 m).

NOTE − Filters and provisions for mounting are not furnished and must be field provided.

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)

Number and size of field provided filter 20 x 25 x 1 in. (508 x 635 x 25 mm) 24 x 24 x 1 in. (610 x 610 x 25 mm)

Fiberglass − 1/2 in. (38 mm) x 66 ft. (20 m)

Aluminum foil − 2 in. (25 mm) x 60 ft. (18 m)

4501−7500 ft. (1372−2286 m) 46M94 46M94 46M94 − − −

7501−10,000 ft. (2286−3048m) 46M94

0−7500 ft. (0−2286 m) 47M83 47M83 47M83 47M83

7501−10,000ft. (2286−3048m) 47M81 47M81 47M81 47M81

Roof − 2 inch (51 mm)

Roof − 3 inch (76 mm)

Wall Ring − 2 inch (51 mm) 15F74 15F74 15F74 15F74

ModelNo. G41UF−60C−090 G41UF−48C−110 G41UF−60C−110 G41UF−60D−135

Input− Btuh (kW) 88,000 (25.8)

110,000 (32.2) 110,000 (32.2) 132,000 (38.7)

Output− Btuh (kW) 80,000 (23.4) 100,000 (29.3) 100,000 (29.3) 120,000 (35.1)

AFUE 90.0% 90.0% 90.0% 90.0%

1/2 (13) 1/2 (13) 1/2 (13)

GaspipesizeIPS 1/2 (13) 1/2 (13) 1/2 (13) 1/2 (13)

10 x 10 (254 x

254)

11−1/2 x 10 (292 x

229)

11−1/2 x 10 (292 x

229)

4 x 24−5/8 x 28−5/8 in. (102 x 625 x 727 mm)

6 ft. (1.8 m) long 26K68 26K68 26K68 26K68

24 ft. (7.3 m) long 26K69

26K69 26K69 26K69

50 ft. (15.2 m) long 26K70 26K70 26K70 26K70

39G04 39G04 39G04 39G04

39G03

39G03 39G03 39G03

46M94 46M94 46M95

15F75 15F75 15F75 15F75

44J41

44J41 44J41 44J41

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BLOWER PERFORMANCE

External Static

G41UF−24B−045 PERFORMANCE

External Static

Pressure

in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts

0.00

0.10 25 1190 560 455 990 470 355 815 385 275

0.20 50 1160

0.30

0.40 100 1070 505 395 910 430 305 755 355 245

0.50 125 1015

0.60

0.70 175 885 415 335 750 355 260 640 300 210

0.80 200 825

0.90

NOTES − All air data is measured external to unit without filter (not furnished − field provided).

0 1225 580 485 1000 470 365 820 385 290

75 1120 530 415 945 445 325 780 365 260

150 955 450 355 835 395 285 695 325 225

225 715 335 3000 600 285 220 435 205 170

Air volume based on bottom air return air. Actual air volume may vary on side return air applications.

High

545 435 970 460 340 805 380 265

480 375 865 405 295 740 350 240

390 320 695 330 245 545 255 185

G41UF−36B−045 PERFORMANCE

External Static

Pressure

in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts

0.00

0.10 25 1515 715 605 1385 655 555 1190 560 485 1020 480 415

0.20 50 1470

0.30

0.40 100 1350 640 535 1250 590 465 1120 530 410 980 465 360

0.50 125 1290

0.60

0.70 175 1145 540 460 1080 510 400 975 460 345 860 405 300

0.80 200 1050

0.90

NOTES − All air data is measured external to unit without filter (not furnished − field provided).

25 1555 735 630 1410 665 585 1190 560 520 1030 485 435

75 1410 665 555 1310 620 495 1155 545 440 1000 470 385

150 1220 575 485 1145 540 420 1020 480 365 905 430 320

225 945 445 410 900 425 345 825 390 305 730 345 270

Air volume based on bottom air return air. Actual air volume may vary on side return air applications.

High

695 580 1345 635 520 1170 550 455 1010 475 400

610 505 1205 570 450 1080 510 390 950 450 345

495 425 985 465 365 870 410 320 785 370 285

G41UF−36B−070 PERFORMANCE

External Static

Pressure

in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts

0.00

0.10 25 1600 755 635 1395 660 550 1160 545 460 1000 470 385

0.20 50 1540

0.30

0.40 100 1420 670 545 1275 605 480 1125 530 395 965 455 345

0.50 125 1360

0.60

0.70 175 1170 555 465 1085 515 385 965 430 335 860 405 295

0.80 200 1080

0.90

NOTES − All air data is measured external to unit without filter (not furnished − field provided).

0 1640 775 660 1415 665 575 1160 545 485 1005 475 410

75 1495 705 580 1345 635 505 1145 540 425 990 465 365

150 1275 600 490 1165 550 410 1025 485 350 900 425 305

225 945 445 400 840 395 320 765 360 275 710 335 245

Air volume based on bottom air return air. Actual air volume may vary on side return air applications.

High

725 605 1370 650 525 1160 545 445 995 470 375

640 525 1245 590 450 1080 510 375 945 445 325

510 440 1010 475 360 865 410 310 775 365 270

G41UF−36C−090 PERFORMANCE

External Static

Pressure

in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts

0.00

0.10 25 1680 795 700 1390 650 585 1185 560 480 1005 475 395

0.20 50 1645

0.30

0.40 100 1560 735 615 1345 635 515 1155 545 425 990 465 360

0.50 125 1495

0.60

0.70 175 1330 630 505 1205 570 435 1035 490 360 890 420 300

0.80 200 1255

0.90

NOTES − All air data is measured external to unit without filter (not furnished − field provided).

0 1705 805 730 1395 660 605 1195 555 495 1010 475 410

75 1600 755 635 1365 645 535 1165 550 445 995 470 375

150 1415 665 540 1270 600 475 1080 510 375 940 445 320

225 1135 535 450 1020 480 365 830 390 300 760 360 260

Air volume based on bottom air return air. Actual air volume may vary on side return air applications.

High

775 675 1380 650 560 1175 555 465 1000 470 390

705 580 1305 615 500 1125 530 400 970 460 345

590 485 1120 530 400 955 450 330 840 395 280

Air Volume / Watts at Different Blower Speeds

Medium Low

Air Volume / Watts at Different Blower Speeds

Medium−High Medium−Low Low

Air Volume / Watts at Different Blower Speeds

Medium−High Medium−Low Low

Air Volume / Watts at Different Blower Speeds

Medium−High Medium−Low Low

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BLOWER PERFORMANCE

External Static

G41UF−48C−090 PERFORMANCE

External Static

Pressure

in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts

0.00

0.10 25 2135 1005 885 1825 860 750 1510 710 610 1275 600 495

0.20 50 2085

0.30

0.40 100 1940 915 760 1735 820 650 1480 700 535 1250 590 440

0.50 125 1865

0.60

0.70 175 1645 775 640 1475 695 520 1290 610 450 1105 520 375

0.80 200 1540

0.90

NOTES − All air data is measured external to unit without filter (not furnished − field provided).

0 2180 1030 930 1835 865 790 1520 715 630 1280 605 510

75 2030 955 800 1775 835 685 1500 705 565 1265 595 460

150 1740 820 670 1590 750 575 1380 650 475 1175 555 410

225 1335 630 540 1170 555 440 1070 505 375 950 450 330

Air volume based on bottom air return air. Actual air volume may vary on side return air applications.

High

985 840 1810 855 720 1505 710 580 1270 600 475

880 725 1660 785 600 1430 675 505 1215 575 425

725 600 1340 630 465 1175 555 405 1020 480 355

G41UF−60C−090 PERFORMANCE − Single Side Return Air − Air volumes in bold require field fabricated transition to ac commodate 20 x 25 x 1 in. (508 x 635 x 25 mm) cleanable air filter in order to maintain proper air velocity.

External Static

Pressure

in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts

0.00

0.10 25 2460 1160 1145 2310 1090 970 2095 990 825 1780 840 660

0.20 50 2395

0.30

0.40 100 2225 1050 1050 2110 995 880 1950 920 745 1720 810 620

0.50 125 2135

0.60

0.70 175 1950 920 950 1865 880 790 1750 825 675 1535 725 555

0.80 200 1845

0.90

NOTES − All air data is measured external to unit without filter (not furnished − field provided).

0 2510 1185 1160 2350 1110 990 2145 1010 850 1785 845 670

75 2325 1095 1090 2175 1025 910 2015 950 775 1735 820 630

150 2025 955 975 1950 920 820 1820 860 700 1600 755 575

225 1730 815 885 1640 775 720 1555 735 625 1340 630 510

High Medium−High Medium−Low Low

1130 1125 2240 1060 940 2060 970 805 1760 830 650

1010 1015 2050 965 855 1900 895 725 1665 785 600

870 915 1760 830 755 1640 775 650 1450 685 530

G41UF−60C−090 PERFORMANCE − Bottom Return Air, Side Return Air with Optional RAB Return Air Base, Return Air from Both Sides or Return Air from Bottom and One Side.

External Static

Pressure

in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts

0.00

0.10 25 2525 1195 1210 2320 1095 1010 2040 960 855 1775 835 710

0.20 50 2450

0.30

0.40 100 2300 1085 1125 2155 1020 930 1970 930 800 1720 815 665

0.50 125 2210

0.60

0.70 175 2080 980 1035 1975 935 865 1805 855 730 1610 760 615

0.80 200 2000

0.90

NOTES − All air data is measured external to unit without filter (not furnished − field provided).

0 2575 1215 1235 2360 111 5 1030 2050 965 875 1790 845 720

75 2375 1120 1140 2215 1045 955 1995 940 815 1740 820 680

150 2140 1010 1030 2055 970 895 1875 885 755 1665 785 635

225 1905 900 970 1785 845 800 1640 775 675 1495 705 570

High

1155 1170 2270 1070 985 2025 955 840 1755 830 695

1045 1075 2090 985 900 1915 905 775 1700 800 650

945 1010 1890 890 830 1730 815 705 1565 740 595

G41UF−48C−110 PERFORMANCE

External Static

Pressure

in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts

0.00 0 2160 1020 880 1880 890 755 1490 705 602 1235 580 485

0.10 25 2100 990 850 1855 875 730 1480 700 585 1230 580 475

0.20 50 2035 960 805 1815 860 690 1475 695 560 1225 580 460

0.30

0.40 100 1885 890 725 1715 810 625 1465 690 510 1215 575 430

0.50 125 1780

0.60

0.70 175 1575 745 620 1410 665 505 1210 570 405 1035 490 350

0.80 200 1375

0.90

NOTES − All air data is measured external to unit without filter (not furnished − field provided).

75 1965 925 750 1755 830 650 1475 695 545 1220 575 445

150 1690 800 660 1550 735 550 1360 640 460 111 0 525 380

225 1225 580 520 1120 530 415 1050 495 365 885 420 310

Air volume based on bottom air return air. Actual air volume may vary on side return air applications.

High

840 680 1630 770 580 1420 670 490 1150 540 400

650 550 1230 580 450 1125 530 380 970 460 325

Air Volume / Watts at Different Blower Speeds

Medium−High Medium−Low Low

Air Volume / Watts at Different Blower Speeds

Medium−High Medium−Low Low

Air Volume / Watts at Different Blower Speeds

Medium−High Medium−Low Low

Page 5

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BLOWER PERFORMANCE

External Static

G41UF−60C−110 PERFORMANCE − Single Side Return Air − Air volumes in bold require field fabricated transition to ac commodate 20 x 25 x 1 in. (508 x 635 x 25 mm) cleanable air filter in order to maintain proper air velocity.

External Static

Pressure

in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts

0.00

0.10 25 2500 1180 1270 2280 1075 1050 2025 950 855 1730 815 720

0.20 50 2410

0.30

0.40 100 2280 1075 1170 2115 995 940 1910 900 790 1675 790 680

0.50 125 2195

0.60

0.70 175 1980 935 1030 1860 880 845 1705 805 700 1540 725 605

0.80 200 1895

0.90

NOTES − All air data is measured external to unit without filter (not furnished − field provided).

0 2550 1205 1300 2345 1105 1080 2055 970 895 1740 820 715

75 2350 111 0 1190 2175 1025 965 1945 920 805 1690 795 670

150 2075 980 1065 1955 925 875 1785 845 735 1585 750 630

225 1770 835 975 1640 775 770 1535 725 645 1415 670 565

High

1140 1225 2220 1050 1000 2000 945 840 1715 810 695

1035 1115 2035 960 910 1840 870 760 1630 770 650

895 1005 1770 835 810 1615 765 675 1475 695 580

G41UF−60C−110 PERFORMANCE − Bottom Return Air, Side Return Air with Optional RAB Return Air Base, Return Air from Both Sides or Return Air from Bottom and One Side.

External Static

Pressure

in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts

0.00

0.10 25 2515 1190 1295 2295 1085 1075 2040 960 880 1740 820 745

0.20 50 2450

0.30

0.40 100 2310 1090 1190 2145 1010 975 1925 910 815 1690 800 695

0.50 125 2200

0.60

0.70 175 2045 965 1065 1930 910 890 1750 825 730 1575 745 625

0.80 200 1930

0.90

NOTES − All air data is measured external to unit without filter (not furnished − field provided).

0 2580 1215 1340 2330 1100 1100 2045 965 950 1760 830 745

75 2375 1120 1225 2200 1040 1015 1965 925 835 1715 810 710

150 2130 1005 1105 2025 955 930 1825 860 770 1600 755 650

225 1820 860 980 1730 815 815 1555 735 660 1430 675 580

High

1155 1255 2255 1065 1040 2005 945 855 1735 820 730

1040 1135 2085 985 955 1870 880 780 1660 785 670

910 1025 1825 860 850 1650 780 695 1500 710 600

G41UF−60D−135 PERFORMANCE − Single Side Return Air − Air volumes in bold require field fabricated transition to ac commodate 20 x 25 x 1 in. (508 x 635 x 25 mm) cleanable air filter in order to maintain proper air velocity.

External Static

Pressure

in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts

0.00

0.10 25 2490 1175 1305 2275 1075 1100 2025 955 900 1720 810 755

0.20 50 2430

0.30

0.40 100 2285 1080 1210 2140 1010 1010 1910 900 830 1680 790 700

0.50 125 2200

0.60

0.70 175 2010 950 1075 1915 905 910 1740 820 740 1545 730 630

0.80 200 1910

0.90

NOTES − All air data is measured external to unit without filter (not furnished − field provided).

0 2550 1205 1340 2330 1100 1145 2035 960 955 1725 815 775

75 2355 111 0 1235 2180 1030 1035 1955 920 855 1700 800 715

150 2100 990 1110 1985 935 935 1815 855 780 1600 755 660

225 1815 855 1005 1735 820 835 1605 755 690 1420 670 580

High

1145 1285 2230 1050 1065 1990 940 890 1715 810 740

1040 1160 2070 975 980 1865 880 805 1645 775 675

900 1050 1845 870 875 1670 790 720 1490 705 605

G41UF−60D−135 PERFORMANCE − Bottom Return Air, Side Return Air with Optional RAB Return Air Base, Return Air from Both Sides or Return Air from Bottom and One Side.

External Static

Pressure

in. w.g. Pa cfm L/s Watts cfm L/s Watts cfm L/s Watts cfm L/s Watts

0.00

0.10 25 2530 1195 1335 2330 1100 1120 2075 980 945 1730 820 750

0.20 50 2475

0.30

0.40 100 2355 1110 1230 2185 1030 1040 1975 930 865 1680 795 695

0.50 125 2275

0.60

0.70 175 2100 990 1125 1955 925 930 1785 840 780 1550 730 635

0.80 200 1995

0.90

NOTES − All air data is measured external to unit without filter (not furnished − field provided).

0 2585 1220 1370 2355 111 0 1160 2075 980 985 1730 820 765

75 2410 1135 1260 2230 1050 1060 2010 950 890 1715 810 725

150 2190 1035 1155 2045 965 960 1850 875 805 1615 765 660

225 1860 880 1020 1750 825 835 1635 770 720 1425 670 580

High

1170 1300 2295 1085 1090 2050 970 920 1730 815 745

1075 1190 2120 1000 995 1915 905 830 1650 780 685

945 1080 1855 875 890 1715 810 745 1500 710 615

Air Volume / Watts at Different Blower Speeds

Medium−High Medium−Low Low

Air Volume / Watts at Different Blower Speeds

Medium−High Medium−Low Low

Air Volume / Watts at Different Blower Speeds

Medium−High Medium−Low Low

Air Volume / Watts at Different Blower Speeds

Medium−High Medium−Low Low

Page 6

Page 7

G41UF PARTS IDENTIFICATION

BURNER BOX

ASSEMBLY

GAS VALVE AND

MANIFOLD

COMBUSTION AIR

PROVE

(PRESSURE)

SWITCH

FLUE

COLLAR

COMBUSTION AIR

INDUCER

DuralokPlus

HEAT EXCHANGER

ASSEMBLY

TOP CAP

CABINET

WARM HEADER

(COLLECTOR)

BOX

BURNER ACCESS

PANEL

BLOWER

ACCESS

DOOR

SIGHT

GLASS

DOOR

INTERLOCK

SWITCH

CONTROL BOX

CONDENSER COIL

PRIMARY LIMIT

COLD HEADER

(COLLECTOR)

BOX

FIGURE 1

Page 7

Page 8

I−UNIT COMPONENTS

G41UF unit components are shown in figure 1. The com bustion air inducer, 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. G41UF units are designed for bottom and side re turn air.

A−MakeUp Box (Figure 2)

A field makeup box is provided for line voltage wiring. Line voltage wiring to unit is routed from the make up box. The hot" wire is connected to the door switch and then from the switch to the SureLight board. The make−up box may be installed inside or outside the unit and on the unit left or right side (right side shown figure 2).

INTERIOR MAKE−UP BOX INSTALLATION

MAKE−UP

BOX

Right Side

CLAMP LOCATION

FIGURE 2

B−Control Box Components (Figure 3)

Unit transformer (T1) and SureLight control (A92) are lo cated in the control box. In addition, a door interlock switch (S51) is located in the control box.

DOOR INTERLOCK

SWITCH (S51)

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. Door Interlock Switch (S51)

A door interlock switch rated 14A at 120VAC is located on the control box. The switch is wired in series with line volt age. When the blower door is removed the unit will shut down.

WARNING

Shock hazard. Disconnect power before servicing. Control is

not field repairable. If control is inoperable, sim ply replace entire control.

Can cause injury or death. Unsafe operation will result if repair is attempted.

3. Furnace Control (A92)

All G41UF model units are equipped with the Lennox Sur eLight ignition system. The system consists of ignition control board (figure 5 with control terminal designations in table 3), ignitor (figure 6) and sensor (figure 7). The board and ignitor work in combination to ensure furnace ignition and ignitor durability. The SureLight integrated board controls all major furnace operations. The board also features two LED lights for troubleshooting and two accessory terminals rated at (1) one amp. Tables 1 and 2 show jack plug terminal designations. See table 4 for trou bleshooting diagnostic codes. 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 suc cessfully light the burner, thus increasing the life of the ig nitor.

ELECTROSTATIC DISCHARGE (ESD)

Precautions and Procedures

CAUTION

SURELIGHT

CONTROL

BOARD

(A92)

FIGURE 3

TRANSFORMER

(T1)

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.

Page 8

Page 9

TABLE 1

SureLight BOARD J156 (J2) TERMINAL

DESIGNATIONS

PIN # FUNCTION

1 Combustion Air Inducer Line

Combustion Air Inducer Neutral

Ignitor Line

Ignitor Neutral

TABLE 2

SureLight BOARD J58 (J1) TERMINAL

DESIGNATIONS

PIN # FUNCTION

1 High Limit Output

Not Used

24V Line

Not Used

Rollout Switch In

24V Neutral

High Limit Input

Ground

Gas Valve In

Pressure Switch Out

Rollout Switch Out

Gas Valve Out

a−Electronic Ignition (See Figure 8)

On a call for heat the SureLight control monitors the com bustion air inducer prove switch. The control will not begin the heating cycle if the prove switch is closed (by−passed). Once the prove switch is determined to be open, the com bustion air inducer is energized. When the differential in the prove switch is great enough, the prove switch closes and a 15−second pre−purge begins. If the prove switch is not proven within 2−1/2 minutes, the control goes into Watch guard−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 during which the gas valve opens at 19 seconds for a 4−second trial for ignition. The ignitor stays energized during the 4 second 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 seconds. After a total of five trials for ignition (including the initial trial), the control goes into Watchguard−Flame Failure mode. After a 60−min ute 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. Each time 120V is removed and then re−applied, the control re−starts the learning process.

b−Fan Time Control

The fan on time of 45 seconds is not adjustable. Fan off time (time that the blower operates after the heat demand has been satisfied) can be adjusted by setting the dip switches located on the SureLight integrated control. The unit is shipped with a factory fan off setting of 90 seconds. For customized comfort, monitor the supply air tempera ture once the heat demand is satisfied. Note the supply air temperature at the instant the blower is de−energized. Ad just the fan−off delay to achieve a supply air temperature between 90° − 110° at the instant the blower is de−ener gized. (Longer delay times allow for lower air temperature, shorter delay times allow for higher air temperature). See figure 4.

FANOFF TIME ADJUSTMENT

60sec. 90sec.

OFF

(Black square indicates switch position)

To adjust fan−off timing, flip dip switch to desired setting.

120sec.

OFFOFF OFF

OFF

180sec.

OFF

FIGURE 4

Page 9

Page 10

SURELIGHT INTEGRATED CONTROL BOARD

XFMR–N

J156

4. Ignitor (Figure 6)

The SureLight ignitor is made of durable silicon nitride. Ig nitor longevity is enhanced by controlling voltage to the ig nitor. The board 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. Ohm value should be 10.9 to 19.7

SureLight Ignitor Location

MEASUREMENT IS TO I.D.

5/8"

OF RETENTION RING

13/32’

J58

FIGURE 5

TABLE 3

TERMINAL DESIGNATIONS

COOL−H 120V HOT Blower Cooling Speed (120VAC)

HEAT−H Blower Heating Speed−(120VAC)

EAC−H Electronic Air Cleaner (120VAC)

HUM−H Humidifier (120VAC)

XFMR−H Transformer (120VAC)

LINE−H Input (120VAC)

LINE−N 120V NEUT Input (Neutral)

HUM−N Humidifier (Neutral)

EAC−N Electronic Air Cleaner (Neutral)

XFMR−N Transformer (Neutral)

CIR−N Blower (Neutral)

PARK Alternate Blower Speeds (dead)

(FLAME SENSE) Flame Sensor

BRACKET

IGNITOR

BURNERS FRONT VIEW

FIGURE 6

5. Flame Sensor (Figure 7)

A flame sensor is located on the left side of the burner sup port. The sensor is mounted on the bottom burner box plate and the tip protrudes into the flame envelope of the left− most burner. The sensor can be removed for service with out removing any part of the burners. During operation, flame is sensed by current passed through the flame and sensing electrode. The SureLight control allows the gas valve to remain open as long as flame signal is sensed.

NOTE − The G41UF furnace contains electronic com ponents that are polarity sensitive. Make sure that the furnace is wired correctly and is properly grounded.

NORMAL FLAME SIGNAL > 0.18 MICROAMPS LOW FLAME SIGNAL < DROP OUT SIGNAL = 0.15 MICROAMPS

5/16"

0.17 MICROAMPS

FIGURE 7

Page 10

Page 11

The SureLight board is equipped with two LED lights for troubleshooting. The diagnostic codes are listed below in table 4.

TABLE 4

DIAGNOSTIC CODES

Make sure to Identify LED’S Correctly.

Refer to Installation Instructions for control board layout.

LED #1 LED #2 DESCRIPTION

SIMULTANEOUS

SLOW FLASH

SIMULTANEOUS

FAST FLASH

SLOW FLASH ON

OFF SLOW FLASH

ALTERNATING

SLOW FLASH

SLOW FLASH OFF Flame sensed without gas valve energized.

ON SLOW FLASH Rollout switch open. OR: 12pin connector improperly attached.

ON ON

ON OFF

OFF ON

FAST FLASH SLOW FLASH Main power polarity reversed. Switch line and neutral.

SLOW FLASH FAST FLASH Low flame signal. Measures below 0.18 microamps. Replace flame sense rod.

ALTERNATING

FAST FLASH

SIMULTANEOUS

SLOW FLASH

SIMULTANEOUS

FAST FLASH

ALTERNATING

SLOW FLASH

ALTERNATING

FAST FLASH

Power on − Normal operation. Also signaled during cooling and continuous fan.

Normal operation − signaled when heating demand initiated at thermostat.

Primary or secondary limit switch open. Limit must close within 3 minutes or unit goes into 1 hour Watchgurad.

Prove switch open. OR:Blocked inlet/exhaust vent; OR: Prove switch closed prior to activation of combustion air inducer.

Watchguard −− burners failed to ignite.

Circuit board failure or control wired incorrectly.

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 to control below 75 volts.

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 = 0.16−0.17 microAmps.

ON OFF

DEMAND

CAI IGNITOR GAS VALVE INDOOR BLOWER

*Blower on time will be 45 seconds after gas valve is energized. Blower off time will depend on OFF TIME" Setting.

Pre −Purge Ignitor Warmup

Trial for Ignition

Blower On"

Delay

5 SEC80

Post

Purge

FIGURE 8

Page 11

Page 12

ROLLOUT SWITCH

BURNER BOX

ASSEMBLY

G41UF HEATING COMPONENTS

LENNOX DURALOKPlust

HEAT EXCHANGER

(Assembly)

CLAMSHELL

(Each Segment)

CORBEL CUP

SURELIGHT

IGNITOR

LIMIT CONTROL

PROVE SWITCH

TUBING

BACKUP SECONDARY

LIMIT

GAS VALVE

WARM END HEADER BOX

CONDENSER COIL

COLD END HEADER BOX

ORIFICE SIZE WINDOW

COMBUSTION AIR INDUCER

COLD END HEADER BOX

FIGURE 9

Page 12

Page 13

C−Heating Components (Figure 9)

Combustion air inducer (B6), primary limit control (S10), SureLight ignitor, burners, flame rollout switch (S47), gas valve (GV1), combustion air prove switch (S18), and clam shell heat exchangers are located in the heating compart ment. The heating compartment can be accessed by re moving the burner access panel.

1. Combustion Air Inducer (B6)

All G41UF units use a combustion air inducer to move air through the burners and heat exchanger during heating op eration. The inducer uses a 120VAC motor. The motor oper ates during all heating operation and is controlled by burner ignition control A92. The inducer operates continuously while there is a call for heat. The ignition control is prevented from proceeding through the ignition sequence until combustion air inducer operation is sensed by the prove switch. The prove switch connected to the plastic cold end header box is used to prove combustion air inducer operation. The switch monitors air pressure in the channel of the cold end header box. During normal operation, the pressure in the header box is negative. If the pressure drops (becomes more positive), the pressure switch opens. When the prove switch opens, the ignition control (A92) immediately closes the gas valve to prevent burner operation.

2. Primary Limit Control (S10)

Figure 10 shows the primary limit (S10) used on G41UF units. S10 is located on the heating vestibule panel. When excess heat is sensed in the heat exchanger, the limit will open. Once the limit opens, the furnace control energizes the supply air blower and de−energizes the gas valve. The limit automati cally resets when unit temperature returns to normal. The switch is factory set and cannot be adjusted. The switch has a different setpoint for each unit model number. See Lennox Repair Parts handbook for set point.

LIMIT CONTROL (S10)

SPADE CONNECTORS

INSULATING COVER (s)

FIGURE 10

4. Burners / Gas Orifices (Figure 11)

All units use inshot burners. Burners are factory set and do not require adjustment. Burners can be removed as an assembly for service. Burner maintenance and service is detailed in the MAINTENANCE section of this manual. Each burner uses an orifice which is precisely matched to the burner input. For natural gas units the orifice size is .089" and for L.P. units .055". This size orifice is good for installation up to 7500’ (for higher altitudes see table10). The orifice is threaded into the burner manifold. The burner is supported by the orifice and will easily slide off for service. Each orifice and burner are sized specifically to the unit. A flame retention ring in the end of each burner maintains correct flame length and shape and keeps the flame from lifting off the burner head. In addition, the burner entrance to each clamshell (Figure 9) is fitted with a corbel cup (orifice) used to direct the flow of combustion prod ucts.

NOTE − Do not use threadsealing compound on the ori fices. Threadsealing compound may plug the orifices.

5. Clamshell Heat Exchanger

G41UF units use an aluminized steel primary and stain less steel secondary heat exchanger assembly. Table 5 shows how many heat exchanger clamshells are used per unit. Heat is transferred to the air stream from all sur faces of the heat exchanger. The shape of the heat ex changer ensures maximum efficiency.

The combustion air inducer pulls fresh air through the air intake box. This air is mixed with gas in the burner venturi and at the corbel orifices. The gas / air mixture is then burned at the entrance of each clamshell. Combustion gases are then pulled through the primary and secondary heat exchangers and exhausted out the exhaust vent pipe.

TABLE 5

NUMBER OF HEAT

G41UF UNIT SIZE

G41UF045 2

G41UF070 3

G41UF090 4

G41UF110 5

G41UF135 6

EXCHANGER CLAM

SHELLS / BURNERS

3. Backup Secondary Limit Control (S113) (G41UF−090, 110, 135 only)

Backup secondary limit control S113 is a N.C. auto−reset switch located on the combustion air inducer. See figure 9 for approximate location. S113 acts as a backup to primary limit S10 in the event of an indoor blower failure. S113 con tacts open when temperature on the CAI reaches 142°.

Page 13

Page 14

6. Cold End Header Box

The cold end header box on the G41UF is a single piece made of hard plastic. The box has an internal channel where the combustion air inducer (CAI) reads pressure at unit start up. The box has a single pressure tap for the CAI prove switch hose. A window is provided on the bot tom right hand side to indicate box orifice size. See figure

9. The box orifice dictates the amount of flow the CAI will draw. See table 6 for orifice size per unit. If replacement is necessary the gaskets used to seal the box to the vesti bule panel and the CAI to the box, must also be replaced.

24VAC terminals and gas control knob are located on top of the valve. All terminals on the gas valve are con nected to wires from the ignition control. 24V applied to the MV" terminals on the Honeywell (M/C or 1/2 terminals on the White Rodgers) opens the main valve.

Inlet and outlet pressure taps are located on the valve. A manifold adjustment screw is also located on the valve.

An LPG changeover kit is available. The kit includes burner orifices and a regulator conversion kit.

TABLE 6

G41UF UNIT SIZE Cold End Header Box Orifice Size

G41UF045 0.750"

G41UF070 1.0"

G41UF090 1.125"

G41UF110 1.375"

G41UF135 1.750"

7. Flame Rollout Switch (S47)

Flame rollout switch S47 is a SPST N.C. high temperature limit located on the top side of the burner box assembly (see fig ure11). S47 is wired to the burner ignition control A92. When S47 senses flame rollout (indicating a blockage in the combustion passages), the flame rollout switch trips, and the ignition control immediately closes the gas valve. Switch S47 in all G41UF units is factory preset to open at 280_F + rise. All flame rollout switches are manually reset.

BURNERS

GAS

ORIFICES

12_F (138_C + 6.7_C) on a temperature

BURNER BOX ASSEMBLY

FLAME ROLLOUT

SWITCH (S47)

HONEYWELL VR8205 SERIES GAS VALVE

MANIFOLD

PRESSURE

ADJUSTMENT

SCREW

OFF

GAS VALVE SHOWN IN OFF POSITION

WHITE RODGERS 36E GAS VALVE

MANIFOLD

PRESSURE

ADJUSTMENT

SCREW

MANIFOLD

PRESSURE

OUTLET

GAS VALVE SHOWN IN OFF POSITION

MANIFOLD

PRESSURE

OUTLET

MANIFOLD

GAS VALVE

(GV1)

FIGURE 11

8. Gas Valve (GV1)

The G41UF uses a gas valve manufactured by Honeywell or White Rodgers (see figure 12 ). The valves are internally re dundant to assure safety shutoff. If the gas valve must be re placed, the same type valve must be used.

WHITE RODGERS 36F GAS VALVE

MANIFOLD

PRESSURE

ADJUSTMENT

SCREW

MANIFOLD

PRESSURE

OUTLET

GAS VALVE SHOWN IN OFF POSITION

FIGURE 12

Page 14

Page 15

9. Combustion Air Prove Switch (S18)

G41UF series units are equipped with a combustion air prove switch located on the vestibule panel (figure 13). The switch is connected to the cold end header box housing by means of a flexible hose. It monitors negative air pressure in the cold end header box channel.

The switch is a singlepole singlethrow proving switch elec trically connected to the furnace control. The purpose of the switch is to prevent burner operation if the combustion air in ducer is not operating or if the flue becomes obstructed.

On startup, the switch senses that the combustion air in ducer is operating. It closes a circuit to the furnace control when pressure inside the cold end header box channel de creases to a certain set point. Set points vary depending on unit size. See table 7 for set point and HIGH ALTITUDE section for high altitude set point.The pressure sensed by the switch is negative relative to atmospheric pressure. If the flue becomes obstructed during operation, the switch senses a loss of negative pressure (pressure becomes more equal with atmospheric pressure) and opens the cir cuit to the furnace control and gas valve. A bleed port on the switch allows relatively dry air in the vestibule to purge switch tubing, to prevent condensate build up. The switch is factory set and is not field adjustable. It is a safety shutdown control in the furnace and must not be by− passed for any reason. If switch is closed or by−passed, the control will not initiate ignition at start up.

TABLE 7

G41UF Unit

Set Point

−045 1.95"

−070 1.95"

−090 1.95"

−110 1.95"

−135 1.60"

Measuring negative air pressure

Follow the steps below to measure negative air pressure in the channel of the cold end header box.

1 − Remove thermostat demand and allow unit to cycle

off.

2 − Disconnect hose from the prove switch and install tee

as shown in figure 14.

TEE AND 1/4"i.d. RUBBER HOSE FIELD PROVIDED

TO COLD END

HEADER BOX

TO PROVE

SWITCH

TO DRAFT GAUGE

COMBUSTION AIR PROVE SWITCH (S18)

PROVE

SWITCH S18

OFF

PROVE

SWITCH

HOSE

COLD END

HEADER

BOX

PROVE SWITCH

BRACKET

TAP

TERMINALS

FIGURE 13

FIGURE 14

3 − Install an incline manometer (draft gauge) to open end

of tee. The hose from the switch goes to the zero side of the gauge.

4 − Operate unit and observe draft gauge reading. Read

ings will change as heat exchanger warms.

Take reading after unit has reached steady state (approximately 5 minutes). This will be the negative air pressure.

The pressure differential should be greater than those listed in table 7. See table 9 for HIGH ALTITUDE set points.

5 − Remove thermostat demand and allow to cycle off.

6 − Remove draft gauge and tee. Reinstall combustion air

sensing hoses to the prove switch.

D−Blower Compartment (Figure 15)

Blower motor (B3) and capacitor (C4), are located in the blower compartment. The blower compartment can be ac cessed by removing the blower access panel.

1.Blower Motor (B3) and Capacitor (C4)

All G41UF units use single−phase direct−drive blower mo tors. All motors are 120V permanent split capacitor motors to ensure maximum efficiency. See SPECIFICATIONS table at the front of this manual for more detail. See motor name plate for capacitor ratings.

Page 15

Page 16

BLOWER

MOTOR (B3)

BLOWER COMPARTMENT

7 − Immediately after applying last coat of cement to pipe,

and while both inside socket surface and end of pipe are wet with cement, forcefully insert end of pipe into socket until it bottoms out. Turn pipe 1/4 turn during as sembly (but not after pipe is fully inserted) to distribute cement evenly.

NOTE − Assembly should be completed within 20 sec onds after last application of cement. Hammer blows should not be used when inserting pipe.

8 − After assembly, wipe excess cement from pipe at end

of fitting socket. A properly made joint will show a bead around its entire perimeter. Any gaps may indi cate a defective assembly due to insufficient solvent.

9 − Handle joints carefully until completely set.

BLOWER MOTOR

CAPACITOR (C4)

FIGURE 15

II−PLACEMENT AND INSTALLATION

Make sure unit is installed in accordance with installation in structions and applicable codes.

A−PVC Joint Cementing Procedure

All cementing of joints should be done according to the specifications outlined in ASTM D 2855.

WARNING

DANGER OF EXPLOSION!

Fumes from PVC glue may ignite during system check. Allow fumes to dissipate for at least 5 minutes before placing unit into operation.

1 − Measure and cut vent pipe to desired length.

2 − Debur and chamfer end of pipe, removing any ridges

or rough edges. If end is not chamfered, edge of pipe may remove cement from fitting socket and result in a leaking joint.

3 − Clean and dry surfaces to be joined.

4 − Test fit joint and mark depth of fitting on outside of pipe.

5 − Uniformly apply liberal coat of PVC primer for PVC or

ABS cleaner for ABS to inside socket surface of fitting and male end of pipe to depth of fitting socket.

6 − Promptly apply solvent cement to end of pipe and in

side socket surface of fitting. Cement should be ap plied lightly but uniformly to inside of socket. Take care to keep excess cement out of socket. Apply sec ond coat to end of pipe.

NOTE − Time is critical at this stage. Do not allow primer to dry before applying cement.

B−Venting Considerations

The thickness of construction through which vent pipes may be installed is 24" (610mm) maximum and 3" (76mm) minimum. If a G41UF furnace replaces a furnace which was commonly vented with another gas appliance, the size of the existing vent pipe for that gas appliance must be checked. Without the heat of the original furnace flue prod ucts, the existing vent pipe is probably oversized for the single water heater or other appliance. The vent should be checked for proper draw with the remaining appliance.

1. Use recommended piping materials for exhaust pip ing.

2. Secure all joints, including drip leg, gastight using ap proved cement.

Suspend piping using hangers at a minimum of every 5 feet (1.52m) for schedule 40 PVC and every 3 feet (.91m) for ABS−DWV, PVC− DWV, SPR−21 PVC, and SDR−26 PVC piping. A suit able hanger can be fabri cated by using metal or plastic strapping or a large wire tie.

3. In areas where piping penetrates joists or interior walls, hole must be large enough to allow clearance on all sides of pipe through center of hole using a hanger.

4. Isolate piping at the point where it exits the outside wall or roof.

5. When furnace is installed in a residence where unit is shut down for an extended period of time, such as a vacation home, make provisions for draining conden sate collection trap and lines.

Exhaust Piping

NOTE − A 2" diameter street ell is strapped to the blower deck of 60D−135 units. Street ell must be glued directly into flue collar to ensure condensate drainback during long, steady−state operation. See figure 18.

STRAPPING

(metal, plastic

or large wire

ties)

FIGURE 16

Page 16

Page 17

1. Choose the appropriate side for venting. Glue the field−provided exhaust vent pipe (or provided 2" diam eter street ell) to the flue collar. Position the exhaust pipe as close to vertical as possible before transition ing to a horizontal run of pipe. It is permissible to devi ate from vertical up to 30°; however, this may impair vent condensate drainback in some applications. All cement joints should be made according to the specifi cations outlined in ASTM D 2855. Refer to pipe and fit tings specifications and gluing procedures.

IMPORTANT

Exhaust piping and condensate trap must be installed on the same side of the unit.

2. All horizontal runs of exhaust pipe must slope back to ward unit. A minimum of 1/4" (6mm) drop for each 12" (305mm) of horizontal run is mandatory for drainage. Horizontal runs of exhaust piping must be supported ev ery 5 feet (1.52m) using hangers.

NOTE − Exhaust piping should be checked carefully to make sure there are no sags or low spots.

TYPICAL VENTING AND CONDENSATE

TRAP INSTALLATION

(Right−Hand Exit Shown)

VENT PLUG

(Must be

glued in

place)

TYPICAL G41UF−60D−135 VENTING

AND CONDENSATE TRAP

INSTALLATION

(Right−Hand Exit Shown Using

Provided 2" Diameter Street Ell

and 3" Vent Pipe)

VENT PLUG

(Must be

glued in

place)

PLUG

NOTE − Transition to larger size vent pipe must be made in a vertical run of the vent pipe as illustrated.

STREET ELL

CONDENSATE

TRAP

(Must be installed

on same side as

exhaust piping)

FIGURE 18

3. On the opposite side of the cabinet, glue the provided 2" vent plug into the unused flue collar.

4. Route piping to outside of structure. Continue with installation following instructions given in piping ter mination section.

PLUG

FIGURE 17

CONDENSATE

TRAP

(Must be installed

on same side as

exhaust piping)

CAUTION

Do not discharge exhaust into an existing stack or stack that also serves another gas appliance. If verti cal discharge through an existing unused stack is re quired, insert PVC pipe inside the stack until the end is even with the top or outlet end of the metal stack.

CAUTION

The exhaust vent pipe operates under positive pres sure and must be completely sealed to prevent leak age of combustion products into the living space.

Page 17

Page 18

Testing for Proper Venting and Sufficient Combustion Air

WARNING

CARBON MONOXIDE POISONING HAZARD!

Failure to follow the steps outlined below for each appliance connected to the venting system being placed into operation could result in carbon monox ide poisoning or death. The following steps shall be followed for each ap pliance connected to the venting system being placed into operation, while all other appliances con nected to the venting system are not in operation.

After the G41UF vent system has been completed, the fol lowing test should be conducted to ensure proper venting and sufficient combustion air has been provided to the G41UF, as well as to other gasfired appliances which are separately vented. The test should be conducted while all appliances (both in operation and those not in operation) are connected to the venting system being tested. If the venting system has been installed improperly, or if provi sions have not been made for sufficient amounts of com bustion air, corrections must be made as outlined in the previous section.

1 − Seal any unused openings in the venting system. 2 − Visually inspect the venting system for proper size and

horizontal pitch. Determine there is no blockage or re striction, leakage, corrosion, or other deficiencies which could cause an unsafe condition.

3 − To the extent that it is practical, close all building doors

and windows and all doors between the space in which the appliances connected to the venting system are lo

cated and other spaces of the building. 4 − Close fireplace dampers. 5 − Turn on clothes dryers and any appliances not con

nected to the venting system. Turn on any exhaust

fans, such as range hoods and bathroom exhausts, so

they will operate at maximum speed. Do not operate a

summer exhaust fan. 6 − Follow the lighting instruction to place the G41UF or

other appliance being inspected into operation. Adjust

thermostat so appliance will operate continuously. 7 − Test for spillage of flue gases at the draft hood relief

opening after 5 minutes of main burner operation. Use

the flame of match or candle, or smoke from a ciga

rette, cigar. 8 − If improper venting is observed during any of the

above tests, the venting system must be corrected or

sufficient combustion/makeup air must be provided.

The venting system should be resized to approach

the minimum size as determined by using the ap

propriate tables in appendix G in the current standards

of the National Fuel Gas Code ANSI−Z223.1/NPFA 54

in the U.S.A., and the appropriate Natural Gas and

Propane appliances venting sizing tables in the cur rent standard of the CSA−B149.1 Natural Gas and Propane Installation Code in Canada.

9 − After determining that each appliance remaining

connected to the common venting system properly vents when tested as indicated in step 3, return doors, windows, exhaust fans, fireplace dampers and any other gasburning appliance to their previous condition of use.

General Guidelines for Vent Terminations for NonDirect Vent Installations.

In NonDirect Vent installations combustion air is taken from indoors and the flue gases are discharged to the out doors. The G41UF is then classified as a nondirect vent, Category IV gas furnace. In NonDirect Vent installations the vent termination is limited by local building codes. In the absence of local codes, refer to the current National Fuel Gas Code ANSI Z223−1/NFPA 54 in U.S.A., and cur rent standards CSA−B149.1 of the Natural Gas and Pro pane Installation Codes in Canada for details.

Position termination ends according to locations given in figure 19. In addition, position termination ends so they are free from any obstructions and above the level of snow ac cumulation (where applicable). The termination should be at least 12 inches (305mm) from any opening through which flue products could enter the building.

At vent termination, care must be taken to maintain protective coatings over building materials (prolonged exposure to exhaust condensate can destroy protective coatings). It is recommended that the exhaust outlet not be located within 6 feet (1.8m) of a condensing unit because the condensate can damage the painted coating.

NOTE − If winter design temperature is below 32°F (0°C), exhaust piping should be insulated with 1/2" (13mm), Ar maflex or equivalent when run through unheated space. Do not leave any surface area of exhaust pipe open to out side air; exterior exhaust pipe should be insulated with 1/2" (13mm) Armaflex or equivalent. In extreme cold climate areas, 3/4" (19mm) Armaflex or equivalent may be neces sary. Insulation on outside runs of exhaust pipe must be painted or wrapped to protect insulation from deterioration. Exhaust pipe insulation may not be necessary in some specific applications.

NOTE − During extremely cold temperatures, below approximately 20°F (6.7°C), units with long runs of vent pipe through unconditioned space, even when insulated, may form ice in the exhaust termination that prevents the unit from operating properly. Longer run times of at least 5 minutes will alleviate most icing problems. Also, a heating cable may be installed on exhaust piping and termination to prevent freeze−ups. Heating cable installation kit is avail able from Lennox. See Condensate Piping section for part numbers.

Page 18

Page 19

IMPORTANT

Exhaust outlet should not be located within 6 feet (1.8m) of dryer vent or combustion air inlet or outlet of another appliance. Piping should not exit less than 3 feet (.91m) from opening into another building.

VENT TERMINATION CLEARANCES

FOR INSTALLATIONS IN THE USA AND CANADA*

IMPORTANT

Do not use screens or perforated metal in exhaust terminations. Doing so will cause freeze−ups and may block the terminations.

− G41UF VENT TERMINATION

− AIR INLET OF OTHER APPLIANCE

less than 10 ft (3.048M)

A − Clearance above grade − 12 in. (305mm) minimum. B − Clearance to window or door −

for vent installations in USA − 48 in. (1219mm) minimum horizontal and below, 12 in. (305mm) minimum above. for vent installations in Canada − 12 in. (305mm) minimum for appliances  100,000 Btuh (30 kW); 36 in. (0.9m) minimum for appliances > 100,000 Btuh (30 kW).

C − Do not position terminations directly under roof eaves. D − Clearance to electric meters, gas meters, regulators, and

relief equipment −

for vent installations in USA − 48 in (1219mm) minimum. for vent installations in Canada − see current edition of CSA

B149 Code.

* Note −

(I) Dimensions are from the current edition of The National Fuel Gas Code − ANSIZ223.1/NFPA 54 for USA installa tions and from the current edition of CSA B149 Code for Canadian installations. Local codes or regulations may re quire different clearances.

(II) In NonDirect Vent installations, combustion air is taken from indoors and the flue gases are discharged to the outdoors.

E − Clearance to non−mechanical air supply inlet

for vent installations in USA − 12 in. (305mm). for vent installations in Canada − 12 in. (305mm) minimum

for appliances  100,000 Btuh (30 kW); 36 in. (0.9m) minimum for appliances > 100,000 Btuh (30 kW).

F − Clearance to mechanical air supply inlet −−

for vent installations in USA − 36 in. minimum (914mm).

G − Clearance to mechanical air supply inlet −−

for vent installations in Canada − 72 in. (1829mm) mini mum.

H − Do not point terminations into recessed areas such as win

dow wells, stairwells, alcoves, or courtyard areas.

J − Do not position terminations directly above a walkway.

FIGURE 19

Page 19

Page 20

Details of Exhaust Piping Terminations for NonDirect Vent Installations.

Exhaust pipes may be routed either horizontally through an outside wall or vertically through the roof. In attic or closet installations, vertical termination through the roof is pre ferred. Figures 20 through 23 show typical terminations.

1. Exhaust piping must terminate straight out or up as

shown. A 2" (51mm) X 1−1/2" (38mm) reducer for 2"

(51mm) venting, 3" (76mm) x 2" (51mm) reducer for 3"

(76mm) venting is recommended for use on the ex

haust piping at the point where it exits the structure to

improve the velocity of exhaust away from any intake

piping.

2. On field supplied terminations for side wall exits, ex

haust piping should extend a maximum of 12 inches

(305mm) beyond the outside wall for 2" (51mm) pipe,

or a maximum of 20 inches (508mm) for 3" (76mm)

pipe, unless support is provided in the horizontal sec

tion. See figure 21.

Inches(mm)

12" (305mm) ABOVE AVE.

SNOW

ACCUMULATION

3" (76) OR

2" (51) PVC

PROVIDE SUPPORT

FOR EXHAUST LINES

UNCONDITIONED

ATTIC SPACE

ROOF TERMINATION KIT

(15F75) LB−49107CC for 2" (51) Venting

(44J41) LB−65678A for 3" (76) Venting

FIGURE 20

3. If exhaust piping must be run up a side wall to position above snow accumulation or other obstructions, pip ing must be supported every 3 feet (.9m) as shown in figure 16. Refer to figure 22 for proper piping method. When exhaust piping must be run up an outside wall, any reduction in exhaust pipe size must be done after the final elbow.

12" (305) Max. for 2" (51)

Inches(mm)

UNCONDITIONED

SPACE

OUTSIDE WALL

PROVIDE SUPPORT

FOR EXHAUST LINES

EVERY 36" (914)

1/2" (13) FOAM

INSULATION IN

UNCONDITIONED

SPACE

SIDE VIEW

20" (508) Max. for 3" (76) Unless Supported

12" (305) ABOVE

AVERAGE SNOW

ACCUMULATION

1/2" (13) FOAM

INSULATION

WALL RING TERMINATION

(15F74) LB−49107CB for 2" (51) Venting

FIGURE 22

G41UF VENTING IN EXISTING CHIMNEY

STRAIGHT−CUT OR

ANGLE−CUT IN DIRECTION

OF ROOF SLOPE

MINIMUM 12"

MINIMUM

12" (304mm)

(305mm) ABOVE

ABOVE AVERAGE

AVERAGE SNOW

SNOW ACCUMULATION

ACCUMULATION

INSULATE

TO FORM

SEAL

SHEET

METAL TOP

PLATE

3" − 8" (76mm− 203mm)

EXHAUST VENT

1/2" (13mm)

WEATHERPROOF

INSULATION

SHOULDER OF FITTINGS

PROVIDE SUPPORT

OF PIPE ON TOP PLATE

3" − 8"

(76mm−

203mm)

EXTERIOR

PORTION OF

CHIMNEY

12" (305) Max. for 2" (51) 20" (508) Max. for 3" (76)

1/2" (13) ARMAFLEX

INSULATION IN

UNCONDITIONED SPACE

inside

Inches (mm)

Unless Supported

PVC REDUCER

TOP VIEW

WALL RING KIT

(15F74) LB−49107CB for 2" (51) Venting

FIGURE 21

1/2" (13)

ARMAFLEX

INSULATION

outside

Page 20

NOTE − Do not discharge exhaust gases directly into any chimney or vent stack. If ver tical discharge through an existing unused chimney or stack is required, insert piping inside chimney until the pipe open end is above top of chimney and terminate as illus trated. In any exterior portion of chimney, the exhaust vent must be insulated.

FIGURE 23

Condensate Piping

This unit is designed for either right or leftside exit of con densate piping. Condensate drain line should be routed only within the conditioned space to avoid freezing of con densate and blockage of drain line. An electric heat cable should be used where condensate line is exposed to un conditioned areas.

1 − Determine which side condensate piping will exit the

unit. Remove temporary plugs from the condensate collar on the appropriate side of the unit.

Page 21

2 − Install condensate trap onto the condensate collar.

Use provided HI/LO screws to secure two upper flanges of the trap to the collar. Use provided sheet metal screw to secure bottom trap flange to side of unit. See figure 24.

NOTE − Make sure that O−rings are properly posi tioned between trap and cabinet. O−rings provide a seal between the trap and the condensate collar. It is not necessary to apply glue or sealant. NOTE − Condensate trap must be installed on the same side as exhaust piping.

cable kit may be used on the condensate trap and line. Heating cable kit is available from Lennox in various lengths; 6 ft. (1.8m) − kit no. 18K48; 24 ft. (7.3m) − kit no. 18K49; and 50 ft. (15.2m) − kit no. 18K50.

CAUTION

Do not use copper tubing or existing copper condensate lines for drain line.

5 − Glue the provided cap onto the unused condensate

drain line stub.

CAUTION

DO NOT use a power driver to tighten screws which secure condensate trap to cabinet. Screws should be hand−tightened using a screw driver to avoid the possibility of damage to the trap assembly.

CONDENSATE ASSEMBLY

(For left or right installation −− Right side shown)

HI/LO SCREWS

O−RINGS

CAP

SCREW

(DO NOT use power driver. Hand−tighten using screw driver.)

NIPPLE

COUPLING

CLEAN−OUT ACCESS

CONDENSATE TRAP

FIGURE 24

3 − Glue the field−provided coupling or pipe to the trap.

Install a tee and vent pipe near the trap.

NOTE − The condensate trap drain stubs (both sides) have an outer diamer which will accept a standard 3/4" PVC coupling. The inner diameter of each stub will ac cept standard 1/2" diameter PVC pipe.

NOTE − Vinyl tubing may be used for condensate drain. Tubing must be 1−1/4" OD X 1" ID and should be attached using a hose clamp.

4 − Glue the field−provided drain line to the tee. Route the

drain line to an open drain. As an alternate, clear vinyl tubing may be used to drain condensate away from the trap. Secure the vinyl tubing to the trap using a worm clamp. Do not overtighten the worm clamp. Condensate line must be sloped downward away from condensate trap to drain. If drain level is above con densate trap, condensate pump must be used. Con densate drain line should be routed within the condi tioned space to avoid freezing of condensate and blockage of drain line. If this is not possible, a heat

VENT

NIPPLE

TEE

(both sides)

III−STARTUP A−Preliminary and Seasonal Checks

1 − Inspect electrical wiring, both field and factory installed

for loose connections. Tighten as required.

2 − Check voltage at disconnect switch. Voltage must be with

in range listed on the nameplate. If not, consult th e power company and have voltage condition corrected be fore starting unit.

3 − Inspect condition of condensate traps and drain as

sembly. Disassemble and clean seasonally.

B−Heating StartUp

BEFORE LIGHTING the unit, smell all around the fur

nace area for gas. Be sure to smell next to the floor be cause some gas is heavier than air and will settle on the floor.

The gas valve on the G41UF may be equipped with either a gas control knob or gas control lever. Use only your hand to push the lever or turn the gas control knob. Never use tools. If the lever will not move or the knob will not push in or turn by hand, do not try to repair it. Call a quali fied service technician. Force or attempted repair may result in a fire or explosion.

Placing the furnace into operation:

G41UF units are equipped with a SureLightt ignition system. Do not

attempt to manually light burners on this furnace. Each time the thermostat calls for heat, the burners will automatically light. The ignitor does not get hot when there is no call for heat on units with SureLightt ignition system.

WARNING

If you do not follow these instructions exactly, a fire or explosion may result causing property damage, personal injury or death.

Gas Valve Operation

1 − STOP! Read the safety information at the beginning of

this section.

2 − Set the thermostat to the lowest setting.

3 − Turn off all electrical power to the unit. 4 − This furnace is equipped with an ignition device which

automatically lights the burners. Do not try to light the burners by hand.

5 − Remove the upper access panel.

Page 21

Page 22

6 − White Rodgers 36E/36F Gas Valve − Switch gas

valve lever to OFF. See figure 25 for the White Rodg ers 36F valve and figure 26 for the White Rodgers 36E valve. Honeywell VR8205 Gas Valve − Turn knob on gas

valve clockwise

to OFF. Do not force. See figure

27.

7 − Wait five minutes to clear out any gas. If you then smell

gas, STOP! Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instruc tions. If you do not smell gas go to next step.

White Rodgers 36F Series Gas Valve

MANIFOLD

PRESSURE

ADJUSTMENT

SCREW

MANIFOLD

PRESSURE

OUTLET

GAS VALVE SHOWN IN OFF POSITION

FIGURE 25

White Rodgers 36E Series Gas Valve

MANIFOLD

PRESSURE

ADJUSTMENT

SCREW

MANIFOLD

PRESSURE

OUTLET

GAS VALVE SHOWN IN OFF POSITION

FIGURE 26

Honeywell VR8205 Series Gas Valve

MANIFOLD

PRESSURE

ADJUSTMENT

SCREW

OFF

GAS VALVE SHOWN IN OFF POSITION

MANIFOLD

PRESSURE

OUTLET

FIGURE 27

8 − White Rodgers 36E/36F Gas Valve − Switch gas valve

lever to ON. See figure 25 for the White Rodgers 36F valve and figure 26 for the White Rodgers 36E valve. Honeywell VR8205 Gas Valve − Turn knob on gas

valve counterclockwise

to ON. Do not force.

9 − Replace the upper access panel.

10− Turn on all electrical power to to the unit.

11− Set the thermostat to desired setting.

NOTE − When unit is initially started, steps 1 through 11 may need to be repeated to purge air from gas line.

12− If the appliance will not operate, follow the instructions

Turning Off Gas to Unit" and call your service techni cian or gas supplier.

Turning Off Gas to Unit

1 − Set the thermostat to the lowest setting. 2 − Turn off all electrical power to the unit if service is to be

performed.

3 − Remove the upper access panel. 4 − White Rodgers 36E/36F Gas Valve − Switch gas

valve lever to OFF. Honeywell VR8205 Gas Valve − Turn knob on gas

valve clockwise

to OFF. Do not force.

5 − Replace the upper access panel.

IV−HEATING SYSTEM SERVICE CHECKS

A−C.S.A. Certification

All units are C.S.A. design certified without modifications. Refer to the G41UF Operation and Installation Instruction Manual Information.

B−Gas Piping

Gas supply piping should not allow more than 0.5"W.C. drop in pressure between gas meter and unit. Supply gas pipe must not be smaller than unit gas connection. See table 8 if gas pipe is suspect.

Compounds used on gas piping threaded joints should be resistant to action of liquefied petroleum gases.

C−Testing Gas Piping

When pressure testing gas lines, the gas valve must be dis connected and isolated. Gas valves can be damaged if subjected to more than 0.5 psig (14" W.C.). See figure 28. If the pressure is equal to or less than 0.5psig (14"W.C.), use the manual shut−off valve before pressure testing to isolate furnace from gas supply.

GAS PIPING TEST PROCEDURE (Typical)

MANUAL MAIN SHUT−OFF

VALVE WILL NOT HOLD

NORMAL TEST PRESSURE

INLET PRESSURE TAP

CAP

GAS VALVE WILL NOT HOLD TEST PRESSURE IN EXCESS

OF 0.5 PSIG (14"W.C.)

FIGURE 28

FURNACE

ISOLATE

GAS VALVE

Page 22

Page 23

Nominal Internal

Nominal

Internal

Required

Prove Switch Kit &

Required

Prove Switch Kit &

Required

Prove Switch Kit &

045

090

Iron Pipe Size

−Inches(mm)

Diameter

−Inches(mm)

GAS PIPE CAPACITY − FT

TABLE 8

/HR (kL/HR)

Length of Pipe−Feet(m)

(3.048)20(6.096)30(9.144)40(12.192)50(15.240)60(18.288)70(21.336)80(24.384)90(27.432)

100

(30.480)

1/4

(6.35)

3/8

(9.53)

1/2

(12.7)

3/4

(19.05)

(25.4)

1−1/4

(31.75)

1−1/2

(38.1)

(50.8)

2−1/2

(63.5)

(76.2)

(101.6)

.364

(9.246)

.493

(12.522)

.622

(17.799)

.824

(20.930)

1.049

(26.645)

1.380

(35.052)

1.610

(40.894)

2.067

(52.502)

2.469

(67.713)

3.068

(77.927)

4.026

(102.260)

(1.13)

(2.69)

175

(4.96)

360

(10.19)

680

(19.25)

1400

(39.64)

2100

(59.46)

3950

(111.85)

6300

(178.39)

11000

(311.48)

23000

(651.27)

(.82)

(1.84)

120

(3.40)

250

(7.08)

465

(13.17)

950

(26.90)

460

(41.34)

2750

(77.87)

4350

(123.17)

7700

(218.03)

15800

(447.39)

(.68)

(1.47)

(2.75)

200

(5.66)

375

(10.62)

770

(21.80)

1180

(33.41)

2200

(62.30)

3520

(99.67)

6250

(176.98)

12800

(362.44)

(.57)

(1.27)

(2.32)

170

(4.81)

320

(9.06)

660

(18.69)

990

(28.03)

1900

(53.80)

3000

(84.95)

5300

(150.07)

10900

(308.64)

(.51)

(1.13)

(2.07)

151

(4.28)

285

(8.07)

580

(16.42)

900

(25.48)

1680

(47.57)

2650

(75.04)

4750

(134.50)

9700

(274.67)

(.45)

(1.02)

(1.87)

138

(3.91)

260

(7.36)

530

(15.01)

810

(22.94)

1520

(43.04)

2400

(67.96)

4300

(121.76)

8800

(249.18)

(.42)

(.73)

(1.73)

125

(3.54)

240

(6.80)

490

(13.87)

750

(21.24)

1400

(39.64)

2250

(63.71)

3900

(110.43)

8100

(229.36)

NOTE−Capacity given in cubic feet of gas per hour (kilo liters of gas per hour) and based on 0.60 specific gravity gas.

(.40)

(.88)

(1.61)

118

(3.34)

220

(6.23)

460

(13.03)

690

(19.54)

1300

(36.81)

2050

(58.05)

3700

(104.77)

7500

(212.37)

(.37)

(.82)

(1.50)

110

(3.11)

205

(5.80)

430

(12.18)

650

(18.41)

1220

(34.55)

1950

(55.22)

3450

(97.69)

7200

(203.88)

(.34)

(.76)

(1.42)

103

(2.92)

195

(5.52)

400

(11.33)

620

(17.56)

1150

(32.56)

1850

(52.38)

3250

(92.03)

6700

(189.72)

D−High Altitude

TABLE 9

Conversion Kit and Prove Switch Requirements at Varying Altitudes

Altitude

Model

Input

Size

−045

−070

−090

−110

−135

Gas

Required Prove Switch Kit & Required Prove Switch Kit & Required Prove Switch Kit &

Conversion Kit

Nat. N/A No Change N/A No Change 47M82 46M94 − 1.80"

LPG 47M83* No Change 47M83* No Change 47M81* 46M94 − 1.80"

Nat. N/A No Change N/A 46M94 − 1.80" 47M82 46M94 − 1.80"

LPG 47M83* No Change 47M83* 46M94 − 1.80" 47M81* 46M94 − 1.80"

Nat. N/A No Change N/A No Change 47M82 46M95 − 1.45"

LPG 47M83* No Change 47M83* No Change 47M81* 46M95 − 1.45"

0 − 4500 ft.

(0 − 1372 m)

Set Point

Conversion Kit

Prove switch is factory set. No adjustment necessary. All models use the factory installed prove switch from 0−4500 feet (0−1370 m). *LPG/Propane conversion kit includes LP regulator.

NOTE − In Canada, certification for installations at eleva tions over 4500 feet (1372 m) is the jurisdiction of local au thorities.

The combustion air prove switches are factory−set and re quire no adjustment. Table 9 lists required prove switch changes and conversion kits at varying altitudes.The man ifold pressure may require adjustment to ensure proper op eration at higher altitudes. Refer to table 10 for proper man ifold pressure settings and gas orifice at varying altitudes.

NOTE − A natural to L.P. propane gas changeover kit is nec essary to convert this unit. Refer to the changeover kit installation instruction for the conversion procedure.

4,501 − 7500 ft.

(1373 − 2286 m)

Set Point

Conversion Kit an

7501−10,000 ft.

(2286 − 3048 m)

TABLE 10

Manifold Pressure and Gas Orifice

(Outlet) inches w.c.

Altitude (feet)

Fuel

Nat

Gas

0−4500

3.5 3.3 3.2 3.1 3.5

4501−

5500

5501−

6500

6501−

7500

Orifice .089 .081

L.P.

Gas

10.0 10.0 10.0 10.0 10.0

Orifice .055 .052

*Conversion kit required for applications at altitudes above 7501 ft. above sea level.

Set Point

7501*−

10,000

Page 23

Page 24

IMPORTANT

In case emergency shutdown is required, turn off the main shutoff valve and disconnect the main power to unit. These controls should be properly labeled by the installer.

IMPORTANT

The furnace must be isolated from the gas supply piping system by closing its individual manual shut−off valve during any pressure testing of the gas supply piping system at test pressures equal to or less than 1/2 psig (3.45 kPa). See figure 28.

The furnace and its individual shut−off valve must be disconnected from the gas supply piping sys tem during any pressure testing of the system at test pressures greater than 1/2 psig (3.45 kPa).

Left Side Piping

(Standard)

MANUAL

MAIN SHUT−OFF

VALV E

GROUND

JOINT

UNION

AUTOMATIC

GAS VALVE

(with manual

shut−off valve)

E−Testing Gas Supply Pressure

When testing supply gas pressure, connect test gauge to inlet pressure tap (field provided). Check gas line pressure with unit firing at maximum rate. Low pressure may result in erratic operation or underfire. High pressure can result in permanent damage to gas valve or overfire. For natural gas units, operating pressure at unit gas connection must be between 4.5" W.C. and 13.0" W.C. For L.P. gas units, op erating pressure at unit gas connection must be between

10.5" and 13.0" W.C.

On multiple unit installations, each unit should be checked separately, with and without units operating. Supply pres sure must fall within range listed in previous paragraph.

F−Check Manifold Pressure

After line pressure has been checked and adjusted, check manifold pressure. Move pressure gauge to outlet pres sure tap located on unit gas valve (GV1). Checks of man ifold pressure are made as verification of proper regulator ad justment.

Manifold operating pressure for the G41UF can be measured at any time the gas valve is open and is supplying gas to the unit. Normal manifold operating pressure for natural gas units is 3.5 in. W.C. +

0.3 and 10.0 in. W.C. + 0.7 for L.P.

IMPORTANT

DRIP LEG

AUTOMATIC

GAS VALVE

(with manual

shut−off valve)

Right Side Piping

(Alternate)

MANUAL

MAIN SHUT−OFF

VALV E

GROUND

JOINT

UNION

DRIP LEG

FIELD

PROVIDED

AND INSTALLED

FIGURE 29

When checking piping connections for gas leaks, use pre ferred means. Kitchen detergents can cause harmful corro sion on various metals used in gas piping. Use of a specialty Gas Leak Detector is strongly recommended. It is available through Lennox under part number 31B2001. See Corp. 8411−L10, for further details.

For safety, connect a shutoff valve between the manometer and the gas tap to permit shut off of gas pressure to the manometer.

Manifold Pressure Measurement and Adjustment

1 − Connect test gauge to outlet tap on gas valve. 2 − Start unit and allow 5 minutes for unit to reach steady

state.

3 − While waiting for the unit to stabilize, notice the flame.

Flame should be stable and should not lift from burner. Natural gas should burn blue. L.P. gas should burn mostly blue with some orange streaks.

4 − After allowing unit to stabilize for 5 minutes, adjust the

manifold pressure on the gas valve if necessary. When reading manifold pressure, regulator cap must be installed.

NOTE−Shut unit off and remove manometer as soon as an accurate reading has been obtained. Take care to re place pressure tap plug.

WARNING

Do not use matches, candles, flame or any other source of ignition to check for gas leaks.

Page 24

Page 25

G− Proper Gas Flow (Approximate)

Furnace should operate at least 5 minutes before check ing gas flow. Determine time in seconds for two revolu tions of gas through the meter. (Two revolutions assures a more accurate time.) Divide by two and compare to time in table 11 below. Adjust manifold pressure on gas valve to match time needed.

NOTE− To obtain accurate reading, shut off all other gas appliances connected to meter.

TABLE 11

GAS METER CLOCKING CHART

Seconds for One Revolution

G41UF

Unit

−45 80 160 200 400

−70 51 102 129 258

−90 40 80 100 200

−110 33 66 82 164

−135 27 53 67 134

Natural−1000 btu/cu ft LP−2500 btu/cu ft

Natural LP

1 cu ft

Dial

2 cu ft

Dial

1 cu ft

Dial

2 cu ft

DIAL

I−Flame Signal

A transducer (Part #78H5401 available from Lennox Repair Parts) is required to measure flame signal if meter used will not read a low micro amp signal. Seefigure30. The transducer converts microamps to volts on a 1:1 conversion. Flame signal for the SureLight control should read 0.18 or more microamps with a lockout signal of 0.15 microamps. A digital readout me ter must be used. The transducer plugs into most meters.

To Measure Flame Signal:

1 − Set the volt meter to the DC voltage scale. Insert

transducer into the VDC and common inputs. Ob serve correct polarities. Failure to do so results in negative (−) values.

2 − Turn off supply voltage to control.

3 − Disconnect ignition control flame sensor wire from the

flame sensor.

4 − Connect (−) lead of the transducer to flame sensor.

5 − Connect (+) lead of transducer to the ignition control sen

sor wire.

H− Proper Combustion

Furnace should operate at least 15 minutes with correct manifold pressure and gas flow rate before checking com bustions. Take sample beyond the flue outlet and compare to table 12. The maximum carbon monoxide reading should not exceed 100 ppm.

TABLE 12

CO2%

Min

Pipe

Max Pipe

G41UF

Unit

Min

Pipe

Natural

Max

Pipe

−24B−045 5.9 − 6.9 7.3 − 8.3 6.9 − 7.9 7.7 − 8.7

−36B−045 5.9 − 6.9 7.0 − 8.0 6.9 − 7.9 8.1 − 9.1

−36B−070 6.0 − 7.0 7.0 − 8.0 7.5 − 8.5 8.2 − 9.2

−36C−090 6.9 − 7.9 8.1 − 9.1 8.1 − 9.1 8.9 − 9.9

−48C−090 6.8 − 7.8 8.0 − 9.0 8.1 − 9.1 8.9 − 9.9

−60C−090 6.8 − 7.8 7.6 − 8.6 7.9 − 8.9 8.5 − 9.5

−48C−110 6.9 − 7.9 7.5 − 8.5 7.7 − 8.7 8.4 − 9.4

−60C−110 6.8 − 7.8 7.2 − 8.2 8.0 − 9.0 8.8 − 9.8

−60D−135 7.4 − 8.4 7.8 − 8.8 8.1 − 9.1 8.7 − 9.7

6 − Turn supply voltage on and close thermostat contacts to

cycle system.

7 − When main burners are in operation for two minutes, take

reading. Remember 1 DC volt = 1 DC microamp.

NOTE−MUST USE DIGITAL METER

SET DIAL TO

MEASURE VDC

TRANSDUCER PART #78H5401

RED COLLAR

INDICATES

POSITIVE

LEAD

(+) TO

IGNITION

CONTROL

SENSOR

WIRE

(+)

(−)

(−) TO

FLAME

SENSOR

FIGURE 30

Page 25

Page 26

V−TYPICAL OPERATING CHARACTERISTICS

A−Blower Operation and Adjustment

NOTE− The following is a generalized procedure and does not apply to all thermostat controls.

1 − Blower operation is dependent on thermostat control

system.

2 − Generally, blower operation is set at thermostat sub

base fan switch. With fan switch in ON position, blower operates continuously. With fan switch in AUTO position, blower cycles with demand or runs continuously while heating or cooling circuit cycles.

3 − In all cases, blower and entire unit will be off when the

system switch is in OFF position.

B−Temperature Rise

Temperature rise for G41UF units depends on unit input, blower speed, blower horsepower and static pressure as marked on the unit rating plate. The blower speed must be set for unit operation within the range of AIR TEMP. RISE °F" listed on the unit rating plate.

To Measure Temperature Rise:

1− Place plenum thermometers in the supply and return air

plenums. Locate supply air thermometer in the first hori zontal run of the plenum where it will not pick up radiant heat from the heat exchanger.

2 − Set thermostat to highest setting.

3 − After plenum thermometers have reached their high

est and steadiest readings, subtract the two readings. The difference should be in the range listed on the unit rating plate. If the temperature is too low, decrease blower speed. If temperature is too high, first check the firing rate. Provided the firing rate is acceptable, in crease blower speed to reduce temperature. To change blower speed taps see the Blower Speed Taps section in this manual.

C−External Static Pressure

1 − Measure tap locations as shown in figure 31. 2 − Punch a 1/4" diameter hole

in supply and return air ple nums. Insert manometer hose flush with inside edge of hole or insulation. Seal around the hose with perma gum. Connect the zero end of the manometer to the dis charge (supply) side of the system. On ducted sys tems, connect the other end of manometer to the return duct as above. For systems with non−ducted returns, leave the other end of the manometer open to the at mosphere.

3 − With only the blower motor running and the evaporator

coil dry, observe the manometer reading. Adjust blow er motor speed to deliver the air desired according to

the job requirements. 4 − Pressure drop must not exceed 0.5" W.C. 5 − Seal around the hole when the check is complete.

STATIC PRESSURE

TEST

G41UF UNIT

FIGURE 31

D−Blower Speed Taps Leaded Motors

Blower speed tap changes are made on the SureLight con trol board. See figure 5. Unused taps must be secured on two dummy terminals labeled "PARK" on the SureLight board. The heating tap is connected to the HEAT−H" termi nal and the cooling tap is connected to the COOL−H" termi nal. The continuous blower tap is the same as the heating tap. See table 13 for blower motor tap colors for each speed.

TABLE 13

Page 26

Page 27

G41UF BLOWER REMOVAL

To Remove Blower:

Turn off line voltage power.

1 Disconnect thermostat wiring con

nections.

2 Disconnect blower leads from control

board.

3 Loosen screws (2) and remove con

trol box from unit. Holes are slotted so screws do not need to be removed.

4. Remove screws (2) and remove blower from unit.

FIGURE 32

VI−MAINTENANCE

WARNING

ELECTRICAL SHOCK, FIRE,

OR EXPLOSION HAZARD.

Failure to follow safety warnings exactly could result in dangerous operation, serious injury, death or property damage. Improper servicing could result in dangerous opera tion, serious injury, death, or property damage. Before servicing, disconnect all electrical power to furnace. When servicing controls, label all wires prior to dis connecting. Take care to reconnect wires correctly. Verify proper operation after servicing.

At the beginning of each heating season, system should be checked as follows by a qualified service technician:

A−Blower

Check the blower wheel for debris and clean if necessary. The blower motors are prelubricated for extended bearing life. No further lubrication is needed.

WARNING

The blower access panel must be securely in place when the blower and burners are operating. Gas fumes, which could contain carbon monoxide, can be drawn into living space resulting in personal injury or death.

B−Filters

All G41UF filters are installed external to the unit. Filters should be inspected monthly. Clean or replace the filters when necessary to ensure proper furnace operation. Re placement filters must be rated for high velocity airflow.

C−Flue and Chimney

Check the flue pipe, chimney and all connections for tight ness and to make sure there is no blockage.

D−Electrical

1 − Check all wiring for loose connections. 2 − Check for the correct voltage at the furnace (furnace

operating).

3 − Check amp−draw on the blower motor.

Motor Nameplate__________Actual__________

E−Winterization and Condensate Trap Care

1 − Turn off power to the unit.

2 − Have a shallow pan ready to empty condensate water.

3 − Remove the drain plug from the condensate trap and

empty water. Inspect the trap then reinstall the drain plug.

F−Cleaning Heat Exchanger

If cleaning the heat exchanger becomes necessary, follow the below procedures and refer to figure 1 when disassem bling unit. Use papers or protective covering in front of fur nace while removing heat exchanger assembly.

1 − Turn off electrical and gas supplies to the furnace. 2 − Remove the upper and lower furnace access panels. 3 − Mark all gas valve wires and disconnect them from

valve.

4 − Remove gas supply line connected to gas valve. Re

move gas valve/manifold assembly.

Page 27

Page 28

5 − Remove sensor wire from sensor. Disconnect 2pin

plug from the ignitor. 6 − Disconnect wires from flame roll−out switch. 7 − Remove four burner box screws at the vestibule panel

and remove burner box. Set burner box assembly

aside.

NOTE − If necessary, clean burners at this time. Follow

procedures outlined in Burner Cleaning section.

8 − Loosen three clamps and remove flexible exhaust tee. 9 − Remove 3/8 inch rubber cap from condensate drain

plug and drain. Replace cap after draining. 10 − Disconnect condensate drain line from the conden

sate trap. Remove condensate trap (it may be neces

sary to cut drain pipe). Remove screws that secure

both condensate collars to either side of the furnace

and remove collars. Remove drain tubes from cold

end header collector box. 11 − Disconnect condensate drain tubing from flue collar.

Remove screws that secure both flue collars into

place. Remove flue collars. It may be necessary to cut

the exiting exhaust pipe for removal of the fittings. 12 − Disconnect the 2pin plug from the combustion air in

ducer. Remove four screws which secure combustion

air inducer to collector box Remove combustion air in

ducer assembly. Remove ground wire from vest pan

el. 13 − Disconnect combustion air pressure tubing from cold

end header collector box. 14 − Mark and remove wires from pressure switch. Re

move pressure switch. Keep tubing attached to pres

sure switch. 15 − Remove electrical junction box from the side of the fur

nace. 16 − Mark and disconnect any remaining wiring to heating

compartment components. Disengage strain relief

bushing and pull wiring and bushing through the hole in

the blower deck. 17 − Remove the primary limit from the vestibule panel. 18 − Remove two screws from the front cabinet flange at

the blower deck. Spread cabinet sides slightly to allow

clearance for removal of heat exchanger. 19 − Remove screws along vestibule sides and bottom

which secure vestibule panel and heat exchanger as

sembly to cabinet. Remove two screws from blower

rail which secure bottom heat exchanger flange. Re

move heat exchanger from furnace cabinet. 20 − Back wash heat exchanger with soapy water solution

or steam. If steam is used it must be below 275°F

(135°C) .

21 − Thoroughly rinse and drain the heat exchanger. Soap

solutions can be corrosive. Take care to rinse entire

assembly.

22 − Reinstall heat exchanger into cabinet making sure that

the clamshells of the heat exchanger assembly are resting on the support located at the rear of the cabi net. Remove the indoor blower to view this area through the blower opening.

23 − Resecure the supporting screws along the vestibule

sides and bottom to the cabinet.

24 − Reinstall cabinet screws on front flange at blower

deck.

25 − Reinstall the primary limit on the vestibule panel.

26 − Route heating component wiring through hole in blow

er deck and reinsert strain relief bushing.

27 − Reinstall prove switch and reconnect prove switch wir

ing.

28 − Connect combustion air prove switch hosing from

pressure switch to cold end header collector box.

29 − Reinstall condensate collars on each side of the fur

nace. Reconnect drain tubing to collector box.

30 − Reinstall condensate trap on same side as exhaust

pipe. Reconnect condensate drain line to the conden sate trap.

31 − Reinstall electrical junction box.

32 − Reinstall the combustion air inducer. Reconnect the

2−pin plug to the wire harness and ground wire to vest panel.

33 − Use securing screws to reinstall flue collars to either

side of the furnace. Reconnect exhaust piping and ex haust drain tubing.

34 − Replace flexible exhaust tee on combustion air induc

er and flue collars. Secure using three existing hose clamps.

35 − Reinstall burner box assembly in vestibule area.

36 − Reconnect flame roll−out switch wires.

37 − Reconnect sensor wire and reconnect 2−pin plug from

ignitor.

38 − Secure burner box assembly to vestibule panel using

four existing screws. Make sure burners line up in

center of burner ports.

39 − Reinstall gas valve manifold assembly. Reconnect

gas supply line to gas valve.

40 − Reconnect wires to gas valve.

41 − Replace the blower compartment access panel.

42 − Refer to instruction on verifying gas and electrical con

nections when re−establishing supplies.

43 − Follow lighting instructions to light and operate fur

nace for 5 minutes to ensure that heat exchanger is clean and dry and that furnace is operating properly.

44 − Replace heating compartment access panel.

Page 28

Page 29

G−Cleaning Burners

1 − Turn off electrical and gas power supplies to furnace.

Remove upper and lower furnace access panels.

2 − Mark all gas valve wires and disconnect them from the

valve.

3 − Disconnect the gas supply line from the gas valve. Re

move gas valve/manifold assembly.

4 − Mark and disconnect sensor wire from the sensor. Dis

connect 2pin plug from the ignitor at the burner box.

5 − Remove four screws which secure burner box assem

bly to vest panel. Remove burner box from the unit.

6 − Use the soft brush attachment on a vacuum cleaner to

gently clean the face of the burners. Visually inspect the inside of the burners and crossovers for any block age caused by foreign matter. Remove any blockage.

7 − Reconnect the sensor wire and reconnect the 2−pin

plug to the ignitor wiring harness.

8 − Reinstall the burner box assembly using the existing

four screws. Make sure that the burners line up in the center of the burner ports.

9 − Reinstall the gas valve manifold assembly. Reconnect

the gas supply line to the gas valve. 10 − Reconnect the gas valve wires to the gas valve. 11 − Replace the blower compartment access panel. 12 − Refer to instruction on verifying gas and electrical con

nections when re−establishing supplies. 13 − Follow lighting instructions to light and operate fur

nace for 5 minutes to ensure that heat exchanger is

clean and dry and that furnace is operating properly. 14 − Replace heating compartment access panel.

Page 29

Page 30

VII−WIRING DIAGRAM AND SEQUENCE OF OPERATION

1 − When there is a call for heat, W1 of the thermostat en

ergizes W of the furnace control with 24VAC.

2 − S10 primary limit switch and S47 rollout switch are

closed. Call for heat can continue.

3 − SureLight control (A92) energizes combustion air in

ducer B6. Combustion air inducer runs until S18 com bustion air prove switch closes (switch must close within 2−1/2 minutes or control goes into 5 minute Watchguard Pressure Switch delay). Once S18 closes, a 15−second pre−purge follows.

4 − SureLight control (A92) energizes ignitor. A 20−sec

ond warm−up period begins.

5 − Gas valve opens for a 4−second trial for ignition

6 − Flame is sensed, gas valve remains open for the heat

call.

7 − After 45−second delay, SureLight control (A92) ener

gizes indoor blower B3.

8 − When heat demand is satisfied, W1 of the indoor ther

mostat de−energizes W of the SureLight control which de−energizes the gas valve. Combustion air inducer B6 continues a 5−second post−purge period, and in door blower B3 completes a selected OFF time delay.

Page 30

Page 31

HEATING SEQUENCE OF OPERATION

NORMAL HEATING MODE

POWER ON

CONTROL SELF−CHECK OKAY?

YES

IS POLARITY REVERSED?

IS VOLTAGE

ABOVE 75 VOLTS?

YES

ROLLOUT SWITCH CLOSED?

YES

BURNER OFF?

(CONTINUOUS FLAME CHECK)

YES

NORMAL OPERATION:

LED #1 −− SLOW FLASH LED #2 −− SLOW FLASH

YES

THERMOSTAT CALLS FOR HEAT:

LED #1 −− FAST FLASH LED #2 −− FAST FLASH

YES

PRIMARY AND SECONDARY LIMIT SWITCH (if

applicable). CLOSED?

YES

IS COMBUSTION AIR

PROVE SWITCH OPEN?

YES

IS COMBUSTION AIR INDUCER

ENERGIZED?

YES

HAS COMBUSTION AIR PROVE SWITCH

CLOSED IN 2.5 MINUTES?

YES

ABNORMAL HEATING MODE

GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.

YES

(RESET CONTROL BY TURNING MAIN POWER OFF.)

THERMOSTAT. CONTROL WILL NOT RESPOND

UNTIL VOLTAGE RISES ABOVE 75 VOLTS.

GAS VALVE OFF. COMBUSTION AIR INDUCER ON.

SEQUENCE HOLDS UNTIL ROLLOUT SWITCH CLOSES.

GAS VALVE OFF. COMBUSTION AIR INDUCER ON.

PROVE SWITCH IS IN WATCHGUARD MODE.

GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.

IS 5MINUTE RESET PERIOD COMPLETE?

INDOOR BLOWER DELAY OFF.

LED #1 ON LED #2 ON

POLARITY REVERSED.

LED #1 −− FAST FLASH

LED #2 −− SLOW FLASH

LED SIGNALS WAITING ON CALL FROM

INDOOR BLOWER ON.

LED #1 −− ON. LED #2 −− SLOW FLASH.

INDOOR BLOWER ON HEATING SPEED.

LED #1 −− SLOW FLASH

LED #2 −− OFF

COMBUSTION AIR INDUCER OFF.

INDOOR BLOWER ON

LED #1 SLOW FLASH RATE

LED #2 −− ON

GAS VALVE OFF.

COMBUSTION AIR INDUCER OFF.

INDOOR BLOWER OFF WITH DELAY.

LED #1 OFF

LED #2 SLOW FLASH

(Sequence holds until pressure switch

closes or thermostat resets control.)

INDOOR BLOWER OFF WITH DELAY.

LED #1 −− OFF. LED #2 −− SLOW FLASH.

CONTINUED NEXT PAGE

Page 31

Page 32

HEATING SEQUENCE CONTINUED

NORMAL HEATING MODE ABNORMAL HEATING MODE

15SECOND COMBUSTION AIR INDUCER PREPURGE

INITIATED BY CLOSED PROVE SWITCH.

YES

IGNITOR WARMUP −− 20 SECONDS.

YES

4SECOND TRIAL FOR IGNITION.

GAS VALVE OPENS. IGNITOR ENERGIZED DURING 4

SECOND TRIAL. NO FLAME SENSED DURING THIS PERIOD.

YES

FLAME STABILIZATION PERIOD.

4 SECONDS

FLAME RECTIFICATION CURRENT

CHECK. CAN FLAME BE PROVEN WITHIN

4 SECONDS AFTER GAS VALVE OPENS?

(u0.15 microamps)

YES

FLAME PRESENT?

YES

FLAME SIGNAL 0.18 OR GREATER MICROAMPS?

YES

INDOOR BLOWER ON DELAY BEGINS

(45 seconds.)

YES

PRIMARY AND SECONDARY LIMIT

SWITCHES CLOSED?

YES

IS VOLTAGE ABOVE 75 VOLTS?

IS THERE A PROPER GROUND?

YES

IS IGNITOR INTACT AND CONNECTED?

GAS VALVE OFF. COMBUSTION AIR INDUCER ON.

HAS CONTROL FAILED TO SENSE FLAME FOR

FIVE CONSECUTIVE TRIES DURING A SINGLE

LEDs SIGNAL WATCHGUARD FAILURE CODE.

IS 60MINUTE RESET PERIOD COMPLETE?

(Does not affect operation of control)

COMBUSTION AIR INDUCER DE−ENERGIZED.

INDOOR BLOWER ON UNTIL SWITCH CLOSES.

LED #1 −− SLOW FLASH. LED #2 −− ON.

YES

INDOOR BLOWER OFF.

HEAT DEMAND?

YES

WATCHGUARD MODE. GAS VALVE OFF.

COMBUSTION AIR INDUCER OFF.

INDOOR BLOWER OFF WITH DELAY

HAS CONTROL RESET IGNITION

SEQUENCE FOUR TIMES?

LOW FLAME SIGNAL

LED #1 −− SLOW FLASH

LED #2 −− FAST FLASH

GAS VALVE DE−ENERGIZED.

IS LIMIT SWITCH CLOSED?

YES

HAS PRIMARY SECONDARY

LIMIT RESET (CLOSED)

WITHIN 3 MINUTES?

LEDS SIGNAL

ALTERNATING

FAST FLASH

YES

LIMIT SWITCH

WATCHGUARD

MODE. GAS VALVE

OFF. COMB. AIR

INDUCER OFF.

INDOOR BLOWER

OFF WITH DELAY.

LED#1−SLOW

FLASH LED#2− ON.

IS 60−MINUTE

RESET PERIOD

COMPLETE?

YES

ROLLOUT SWITCH CLOSED?

YES

COMBUSTION AIR PROVE

SWITCH CLOSED?

YES

THERMOSTAT DEMAND SATISFIED.

YES

LED #1 & #2 SIMULTANEOUS SLOW FLASHES.

YES

COMB. AIR INDUCER CONTINUES 5SECOND

POST PURGE AFTER T’STAT DEMAND IS SATISFIED.

INDOOR AIR BLOWER COMPLETES SELECTED

OFF" DELAY BEFORE SHUTTING OFF.

SEQUENCE HOLDS UNTIL ROLLOUT SWITCH IS RESET

THERMOSTAT IS CYCLED OFF/ON FOR 1 TO 20 SEC.

GAS VALVE DE−ENERGIZED.

COMBUSTION AIR INDUCER ON.

INDOOR BLOWER OFF WITH DELAY

LED #1 −− OFF. LED #2 −− SLOW FLASH.

HAS CAB SWITCH CLOSED IN 2.5 MINUTES?

5MINUTE PROVE SWITCH

GAS VALVE POWER OFF.

COMBUSTION AIR INDUCER POWER ON.

INDOOR BLOWER ON

LED #1 −− ON. LED #2 −− SLOW FLASH.

AND MAIN POWER IS INTERUPTED OR

WATCHGUARD MODE.

YES

Page 32

Page 33

COOLING SEQUENCE OF OPERATION

NORMAL COOLING MODE ABNORMAL COOLING MODE

POWER ON

IGNITION CONTROL MAIN POWER ON.

CONTROL SELF DIAGNOSTIC CHECK.

IS CONTROL OPERATING NORMALLY?

YES

IS POLARITY REVERSED?

IS VOLTAGE

ABOVE 75 VOLTS?

YES

ROLLOUT SWITCH MONITORED CONTINUOUSLY.

IS ROLLOUT SWITCH CLOSED?

YES

CHECK FOR MAIN BURNER FLAME SENSE.

IS MAIN BURNER FLAME OFF?

YES

LED: SLOW FLASH RATE REMAINS UNCHANGED

THROUGHOUT COOLING CYCLE.

THERMOSTAT CALLS FOR COOLING.

YES

GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.

INDOOR BLOWER OFF WITH NORMAL DELAY.

SIGNAL CIRCUIT BOARD FAILURE AT LED.

INTERRUPT MAIN POWER TO RESET CONTROL.

SIGNAL POLARITY REVERSED AT LED.

LED SIGNALS WAITING ON CALL FROM

THERMOSTAT. CONTROL WILL NOT RESPOND

UNTIL VOLTAGE RISES ABOVE 75 VOLTS.

GAS VALVE OFF. COMBUSTION AIR INDUCER ON.

INDOOR BLOWER ON.

SIGNAL ROLLOUT SWITCH OPEN AT LED.

SEQUENCE HOLDS UNTIL ROLLOUT SWITCH CLOSES.

GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.

INDOOR BLOWER OFF WITH NORMAL DELAY. SIGNAL UNWANTED FLAME SENSED AT LED.

SEQUENCE HOLDS UNTIL FLAME IS NOT SENSED.

COMPRESSOR CONTACTOR AND SYSTEM FAN

ENERGIZED WITH 0SECOND DELAY

(COOLING SPEED). EAC−H TERM. ENERGIZED.

THERMOSTAT OPENS.

COMPRESSOR OFF.

SYSTEM FAN AND ACC. TERM. OFF

WITH 0SECOND DELAY.

Page 33

Page 34

SURELIGHT CONTROL

CONTINUOUS HEAT SPEED FAN SEQUENCE OF OPERATION

LED: SLOW FLASH RATE REMAINS

UNCHANGED THROUGHOUT SEQUENCE.

MANUAL FAN SELECTION MADE AT THERMOSTAT.

CONTROL (G) ENERGIZES SYSTEM FAN AT HEAT−H

HEAT SPEED. EAC−H TERMINAL IS ENERGIZED.

THERMOSTAT CALLS FOR HEAT (W).

THERMOSTAT CALLS FOR COOLING.

YES

SYSTEM FAN SWITCHED TO COOL−H SPEED.

EAC−H TERM. REMAINS ON.

THERMOSTAT OPENS.

CONTROL (G) ENERGIZES SYSTEM FAN AT HEAT−H

HEAT SPEED. EAC−H TERM. ENERGIZED.

HUM−H TERM. ENERGIZES WITH COMB. AIR BLOWER.

YES

SYSTEM FAN REMAINS ON HEAT−H

HEATING SPEED.

THERMOSTAT OPENS.

HUM−H TERM. DE−ENERGIZES

WITH COMB. AIR INDUCER

SYSTEM FAN REMAINS ON HEAT−H

HEATING SPEED.

Page 34

Page 35

VIII−SURELIGHT CONTROL TROUBLESHOOTING CHART

code LED#2 Slow Flash

ACTION 1

ducer does not energize

120V field connection.

on operation

UPON INITIAL POWER UP, REMOVE ALL THERMOSTAT DEMANDS TO THE UNIT

PROBLEM: 1 UNIT FAILS TO OPERATE IN THE COOLING, HEATING, OR CONTINUOUS FAN MODE

Condition Possible Cause Corrective Action / Comments

1.1

− Both diagnostic lights fail to light up.

Main voltage 120V not supplied to unit.

1.1.1

ACTION 1 − Check 120V main voltage.

Determine cause of main power failure.

LED#1−Off LED#2−Off

1.2

− Diagnostic lights flash the roll−out

code.

LED#1−On, LED#2−Slow Flash

1.3

− On initial power−up the comb. air in .

− Diagnostic lights flash the reverse

polarity code.

1.1.2

Miswiring of furnace or improper con nections.

1.1.3

Blown fuse

1.1.4

Door interlock switch failure.

1.1.5

Transformer Failure.

1.1.6

Failed control board.

1.2.1

Roll−out switch open.

1.2.2

Roll−out switch failure.

1.2.3

Miswiring or improper connections at roll−out switch.

1.2.4

12 pin connector failure

1.3.1

120V main power polarity reversed.

ACTION 1 − Check for correct wiring of 120V to power make up box and transformer.

ACTION 2 − Check 24V wiring to control board.

ACTION 1 − Replace fuse. ACTION 2 − If fuse still blows, check for short.

ACTION 1 − Check that door switch is activated

when door is closed. ACTION 2 − Check wire connections to switch, re place loose connectors. ACTION 3 − Check continuity of switch in closed position. Replace if defective.

ACTION 1 − Check that transformer output is 24V. Replace if defective.

ACTION 1 − If all the above items have been checked, replace board.

ACTION 1 − Manually reset the roll−out switch by pushing the top button. ACTION 2 − Determine the cause of the roll−out switch activation before leaving furnace.

ACTION 1 − Check continuity across roll−out switch. Replace roll−out switch if switch is reset but does not have continuity.

− Check wiring connections to switch.

ACTION 1 − Check 12−pin connector for proper

connection to control board. ACTION 2 − Check continuity of the multi plug pin.

ACTION 1 − Check the 120V has line and neutral correctly input into control. ACTION 2 − Reverse the line and neutral at the 120V field connection.

LED#1−Fast Flash, LED#2−Slow Flash.

1.4

− On initial power up the combustion

air inducer does not energize.

− Diagnostic lights flash normal power

on o

eration.

LED#1−Slow Flash LED#2−Slow Flash

1.4.1

Open combustion air inducer motor circuit.

1.4.2

Failed combustion air inducer motor.

Page 35

ACTION 1 − Check for 120V to combustion air inducer. If no power, check wire and connec tions.

ACTION 1 − If power is present at blower, replace blower.

Page 36

PROBLEM 1: UNIT FAILS TO OPERATE IN THE COOLING, HEATING, OR CONTINUOUS FAN MODE

LED#2 Alternating Fast Flash

Diagnostic lights flash the pressure

Condition Possible Cause Corrective Action / Comments

1.5

− Diagnostic lights flash the improper

main ground.

LED#1−Alternating Fast Flash LED#2−Alternating Fast Flash

1.5.1

Improper ground to the unit.

1.5.2

4−Pin connector is improperly at

tached to the circuit board.

1.5.3

Line voltage is below 75V.

1.5.4

Open ignitor circuit.

1.5.5

Broken or failed ignitor.

ACTION 1 − Check that the unit is properly ground. ACTION 2 − Install a proper main ground to the unit

ACTION 1 − Check 4−pin connector for proper installation. Correctly insert connector into con trol.

ACTION 1 − Check that the line voltage is above 75V. Determine cause of voltage drop and supply correct voltage to the control.

ACTION 1 − Check for correct wiring and loose connections in the ignitor circuit. Check mult−plug connections for correct installation.

ACTION 1 − Unplug ignitor and read resistance across ignitor. If resistance does not read be tween 10.9 and 19.7 ohms, replace the ignitor.

PROBLEM 2: UNIT FAILS TO FIRE IN THE HEATING MODE, COMBUSTION AIR BLOWER DOES NOT

ENERGIZE

Condition Possible Cause Corrective Action / Comments

2.1

− Unit operates with a cooling or contin

uous fan demand.

− Combustion air inducer will not start with a Heating demand.

− Diagnostic lights flash the limit failure mode.

LED#1−Slow Flash, LED#2−On

2.1.1

Primary or secondary (if equipped )

limit open.

2.1.2

Miswiring of furnace or improper con

nections at limit switch(es).

ACTION 1 − Check continuity across switch(es). Switches reset automatically upon cool down. ACTION 2 − Check for restrictions on blower inlet air (including filter) and outlet air. Determine cause for limit activation before placing unit back in operation.

ACTION 1 − Check for correct wiring and loose connections. Correct wiring and/or replace any loose connections.

2.2

− Unit operates with a cooling and con tinuous fan demand.

− Combustion air inducer will not start with a Heating demand.

− Dia

nostic lights flash the pressure

switch failure code.

LED#1−Off, LED#2−Slow Flash

2.2.1

Miswiring of furnace or improper con

nections to combustion air inducer.

2.2.2

Prove switch stuck closed.

ACTION 1 − Check for correct wiring and loose connections. Correct wiring and/or replace any loose connections.

ACTION 1 − Check that the prove switch is open without the combustion air inducer operating. Re place if defective.

Page 36

Page 37

PROBLEM 2: UNIT FAILS TO FIRE IN THE HEATING MODE, COMBUSTION AIR INDUCER DOES

LED#1 Off

NOT ENERGIZE (CONT.).

Condition Possible Cause Corrective Action/Comments

2.3

− Unit operates with a cooling and con

tinuous fan demand.

− Combustion air inducer will not start

with a Heating demand.

Miswiring of furnace or improper con

nections to combustion air inducer.

2.3.1

ACTION 1 − Check for correct wiring and loose

connections. Correct wiring and/or replace any loose connections.

− Diagnostic lights flash the pressure

switch failure code 2.5 minutes after heating demand.

ACTION 1 − If there is 120V to combustion air in ducer and it does not operate, replace combus tion air inducer.

LED#1−Off,

2.3.2

Combustion air inducer failure.

LED#2−Slow Flash

PROBLEM 3: UNIT FAILS TO FIRE IN THE HEATING MODE, COMBUSTION AIR INDUCER

ENERGIZES, IGNITOR IS NOT ENERGIZED.

Condition Possible Cause Corrective Action/Comments

3.1

− Unit operates with a cooling and

continuous fan demand.

− Combustion air inducer energizes

with a heating demand.

− Diagnostic lights flash the pressure

switch failure code 2.5 minutes after heating demand.

LED#1−Off LED#2−Slow Flash

Prove switch does not close due to

incorrect routing of the pressure

Prove switch does not close due to

obstructions in the pressure lines.

Prove switch lines damaged

Condensate in prove switch line.

Prove switch does not close due to a

low differential pressure across the

Wrong prove switch installed in the

unit, or prove switch is out of calibra

Miswiring of furnace or improper con

nections at prove switch.

Prove switch failure.

3.1.1

switch lines.

3.1.2

3.1.3

3.1.4

3.1.5

prove switch.

3.1.6

tion.

3.1.7

3.1.8

ACTION 1 − Check that the prove switch lines are

correctly routed. Correctly route pressure switch lines.

ACTION 1 − Remove any obstructions from the the pressure lines and/or taps.

ACTION 1 − Check prove switch lines for leaks. Replace any broken lines.

ACTION 1 − Check prove switch lines for conden sate. Remove condensate from lines.

ACTION 1 − Check the differential pressure across the prove switch. This pressure should exceed the set point listed on the switch. ACTION 2 − Check for restricted inlet vent. Re move all blockage. ACTION 3 − Check for proper vent sizing and run length.

ACTION 1 − Check that the proper prove switch is installed in the unit. Replace prove switch if necessary.

ACTION 1 − Check for correct wiring and loose connections. Correct wiring and/or replace any loose connections.

ACTION 1 − If all the above modes of failure have been checked, the prove switch may have failed. Replace prove switch and determine if unit will operate.

Page 37

Page 38

PROBLEM 4: UNIT FAILS TO FIRE IN THE HEATING MODE, COMBUSTION AIR BLOWER

5.1

LED#1 Off

ignite code.

ENERGIZES, IGNITOR IS ENERGIZED.

Condition Possible Cause Corrective Action/Comments

4.1

− Unit operates with a cooling and continuous fan demand.

− Combustion air inducer energizes with Heating demand.

− Ignitor is energized but unit fails to light.

LED#1−Alternating Slow Flash LED#2−Alternating Slow Flash

PROBLEM 5: BURNERS LIGHT WITH A HEATING DEMAND BUT UNIT SHUTS DOWN

Condition Possible Cause Corrective Action/Comments

5.1

− Burners fire with a heating demand.

− Burners light but unit shuts off prior to satisfying T−stat demand.

− Diagnostic lights flash the pressure switch code.

LED#1−Off LED#2−Slow Flash

5.2

− Combustion air inducer energizes with a heating demand.

− Burners light but fail to stay lit.

− After 5 tries the control diagnostics flash the watchguard burners failed to ignite code.

LED#1−Alternating Slow Flash LED#2−Alternating Slow Flash

4.1.1

Check that gas is being supplied to

the unit.

4.1.2

Miswiring of gas valve or loose con

nections at multi−pin control amp

plugs or valve.

4.1.3

Defective gas valve or ignition con

trol.

PREMATURELY

5.1.1

Low pressure differential at the prove

switch.

5.1.2

Wrong concentric vent kit used for

terminating the unit.

5.1.3

Condensate drain line is not draining

properly.

5.1.4

Low pressure differential at the prove

switch.

5.2.1

Sensor or sense wire is improperly

installed.

5.2.2

Sensor or sense wire is broken.

5.2.3

Sensor or sensor wire is grounded to

the unit.

5.2.4

Control does not sense flame.

ACTION 1 − Check line pressure at the gas valve. Pressure should not exceed 13" WC for both nat ural and propane. Line pressure should read a minimum 4.5" WC for natural and 8.0"WC for pro pane.

ACTION 1 − Check for correct wiring and loose connections. Correct wiring and/or replace any loose connections.

ACTION 1 − Check that 24V is supplied to the gas valve approximately 35 seconds after heat de mand is initiated. ACTION 2 − Replace the valve if 24V is supplied but valve does not open. ACTION 3 − Replace the control board if 24V is not supplied to valve.

ACTION 1 − Check for restricted exhaust vent. Remove all blockage. ACTION 2: Check for proper vent sizing. See installation instructions.

ACTION 1 − Check vent termination kit installed. See Placement and Installation section.

ACTION 1 − Check condensate line for proper vent slope, and any blockage. Condensate should flow freely during operation of furnace. Repair or replace any improperly installed con densate lines.

ACTION 1 − Check for restricted exhaust. Re move all blockage. ACTION 2: Check for proper vent sizing. See installation instructions.

ACTION 1 − Check that sensor is properly lo cated and that the sense wire is properly at tached to both the sensor and the control.

ACTION 1 − Check for a broken sensor. ACTION 2 − Test continuity across the sense

wire. If wire or sensor are damaged replace the component.

ACTION 1 − Check for resistance between the sensor rod and the unit ground. ACTION 2 − Check for resistance between the sensor wire and the unit ground.

ACTION 3 − Correct any shorts found in circuit.

ACTION 1 − Check the microamp signal from

the burner flame. If the microamp signal is be low normal, check the sense rod for proper location or contamination. ACTION 2 − Replace, clean, or relocate flame sense rod. If rod is to be cleaned, use steel wool or replace sensor. DO NOT CLEAN ROD WITH SAND PAPER. SAND PAPER WILL CONTRIBUTE TO THE CONTAMINATION PROBLEM. NOTE: Do not attempt to bend sense rod.

Page 38

Page 39

PROBLEM 5: BURNERS LIGHT WITH HEATING DEMAND BUT UNIT SHUTS DOWN

ure.

flame failure

Condition Possible Cause Corrective Action/Comments

5.3

− Combustion air inducer energizes

with a heating demand.

− Burners light.

− Roll−out switch trips during the

heating demand.

− Diagnostic lights flash roll−out fail

ure.

LED#1−On LED#2−Slow Flash

5.4

− Combustion air inducer energizes

with a heating demand.

− Burners light roughly and the unit

fails to stay lit.

− Diagnostic lights flash watchguard

flame failure.

PREMATURELY (CONT.)

5.3.1

Unit is firing above 100% of the

nameplate input.

5.3.2

Gas orifices leak at the manifold con

nection.

5.3.3

Air leakage at the connections be

tween the primary heat exchanger,

secondary heat exchanger, and com

bustion air blower.

5.3.4

Insufficient flow through the heat ex

changer caused by a sooted or re

stricted heat exchanger.

5.3.5

Burners are not properly located in

the burner box.

5.4.1

Recirculation of flue gases. This con

dition causes rough ignitions and op

eration. Problem is characterized by

nuisance flame failures.

ACTION 1 − Check that the manifold pressure matches value listed on nameplate. See installa tion instructions for proper procedure. ACTION 2 − Verify that the installed orifice size match the size listed on the nameplate or installa tion instructions. ACTION 3 − Check gas valve sensing hose to in sure no leaks are present. ACTION 4 − Check the input rate to verify rate matches value listed on nameplate.

ACTION 1 − Tighten orifice until leak is sealed. NOTE: Be careful not to strip orifice threads. AC TION 2 − Check for gas leakage at the threaded

orifice connection. Use approved method for leak detection (see unit instructions).

ACTION 1 − Check for air leakage at all joints in the heat exchanger assembly. Condition will cause high CO2 with high CO. ACTION 2 − Seal leakage if possible, replace heat exchanger if necessary, tag and return heat exchanger to proper Lennox personnel.

ACTION 1 − Check for sooting deposits or other restrictions in the heat exchanger assembly. Clean assembly as outlined in instruction manu al.

ACTION 2 − Check for proper combustion.

ACTION 1 − Check that the burners are firing into

the center of the heat exchanger openings. Cor rect the location of the burners if necessary.

ACTION 1 − Check for proper flow of exhaust gases away from intake vent. Remove any ob stacles in front of the intake and exhaust vent which would cause recirculation. ACTION 2 − Check for correct intake and exhaust vent installation. See instructions

LED#1−Alternating Slow Flash LED#2−Alternating Slow Flash

5.4.2

Improper burner cross−overs

Page 39

ACTION 1 − Remove burner and inspect the cross−overs for burrs, or any restriction or if crossover is warped. Remove restriction or re place burners.

Page 40

PROBLEM 6: CONTROL SIGNALS LOW FLAME SENSE DURING HEATING MODE

code

Condition Possible Cause Corrective Action/Comments

6.0

− Unit operates correctly but the diag nostic lights flash low flame sense

Sensor rod is improperly located on

6.1.1

the burner.

ACTION 1 − Check the sensor rod for proper loca tion on the burner. Properly locate the sensor rod or replace if rod cannot be located correctly.

ACTION 1 − Check sensor rod for contamination or coated surface. Clean the sensor rod with steel wool or replace sensor. DO NOT USE SAND PA PER TO CLEAN ROD. SAND PAPER WILL CONTRIBUTE TO THE CONTAMINATION PROBLEM.

LED#1−Slow Flash LED#2−Fast Flash

6.1.2

Sensor rod is contaminated.

PROBLEM 7: INDOOR BLOWER FAILS TO OPERATE IN COOLING, HEATING, OR CONTINUOUS

FAN MODE

Condition Possible Cause Corrective Action/Comments

7.0

− Indoor blower fails to operate in continuous fan, cooling, or heating mode.

Miswiring of furnace or improper con

nections at control or indoor blower

120V is not being supplied to the in

door air blower or blower motor fail

7.1.1

motor.

7.1.2

ure.

ACTION 1− Correct wiring and/or replace any loose connections. Check for correct wiring and loose connections.

ACTION 1 − Check for 120V at the various calls for indoor blower by energizing "Y", "G", and "W" individually on the low voltage terminal strip. Note that when "W’ is energized, the blower is delayed 45 seconds. If there is 120V to each motor tap but the blower does not operate, replace the motor.

Condition Possible Cause Corrective Action/Comments

8.0

− AM radio interference.

7.1.3

Defective control board

7.1.4

ACTION 1 − If there is not 120V when "Y", "G", or

"W" is energized, replace the control.

ACTION 1 − Replace capacitor

Defective run capacitor

PROBLEM 8: RF STATIC DURING TIME FOR IGNITION

8.1.2

Ignitor operation

ACTION 1 − Call Technical Support, Dallas.

Page 40

Lennox G41UF?24B?045, G41UF?36B?070, G41UF?36B?045, G41UF?48C?090, G41UF?60C?090 Service Literature

Specifications and Main Features

Frequently Asked Questions

User Manual