Lennox G61MP User Manual

Corp. 0308−L6

Service Literature

Revised 10−2004

G61MP SERIES UNITS

G61MP series units are high−efficiency multi−position (upflow, downflow, horizontal right and left) gas furnaces manufactured with Lennox Duralok Plust heat exchangers formed of aluminized steel. G61MP units are available in heating capacities of 44,000 to 132,000 Btuh (13.0.0 to

38.6 kW) and cooling applications from 2 to 5 tons (7.0 kW to 17.5 kW)) up to 5 tons. Refer to Engineering Handbook for proper sizing.

Units are factory equipped for use with natural gas. Kits are available for conversion to LPG operation. G61MP model units are equipped with the Two−Stage Integrated SureLight control. All G61MP units meet the California Nitrogen Oxides (NO quirements. All units use a redundant gas valve to assure safety shut−off as required by C.S.A.

) Standards and California Seasonal Efficiency re-

G61MP

All specifications in this manual are subject to change. Procedures outlined in this manual are presented as a recommendation only and do not supersede or replace local or state codes. In the absence of local or state codes, the guidelines and procedures outlined in this manual (except where noted) are recommendations only and do not constitute code.

TABLE OF CONTENTS

Introduction 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

Blower Data 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Parts Identification 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

II Installation 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

III Start Up 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

IV Heating System Service Checks 31. . . . . . . . . . . . . .

V Typical Operating Characteristics 34. . . . . . . . . . . . . .

IMPORTANT

Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal 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 disconnect switch(es). Unit may have multiple power supplies.

VI Maintenance 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

VII Wiring and Sequence of Operation 38. . . . . . . . . . . .

VIII Field Wiring and Jumper Setting 46. . . . . . . . . . . . .

IX Control Board Troubleshooting 48. . . . . . . . . . . . . . . .

Page 1

WARNING

Sharp edges. Be careful when servicing unit to avoid sharp edges which may result in personal injury.

SPECIFICATIONS

Blower

Gas Heating Performance

High

Fire

ModelNo. G61MP−36B−045 G61MP−36B−070 G61MP−48C−090 G61MP−60C−090

Input− Btuh (kW) 44,000 (12.9) 66,000 (19.3) 88,000 (25.8) 88,000 (25.8)

Output− Btuh (kW) 41,000 (12.0) 62,000 (18.2) 83,000 (24.3) 84,000 (24.6)

Temperature rise range − _F (_C) 25 − 55 (14 − 31) 35 − 65 (21 − 39) 35 − 65 (21 − 39) 25 − 55 (14 − 31)

Low

Fire

Input− Btuh (kW) 30,000 (8.8) 45,000 (13.2) 60,000 (17.6) 60,000 (17.6)

Output− Btuh (kW) 28,000 (8.2) 43,000 (12.6) 57,000 (16.7) 58,000 (17.0)

Temperature rise range − _F (_C) 10 − 40 (6 − 24) 20 − 50 (12 − 30) 25 − 55 (14 − 31) 15 − 45 (9 − 27)

AFUE 94.1% 94.1% 94.1% 94.1%

California Seasonal Efficiency 83.5% 86.0% 87.3% 84.4%

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

Connections in.

Intake Pipe (PVC) 2 2 2 2

Exhaust Pipe (PVC) 2 2 2 2

Condensate Drain Trap (PVC pipe) −

i.d.

with field supplied (PVC coupling) − o.d. 3/4 3/4 3/4 3/4

hose with hose clamp − i.d. x o.d. 1−1/4 x 1 1−1/4 x 1 1−1/4 x 1 1−1/4 x 1

GaspipesizeIPS 1/2 1/2 1/2 1/2

Indoor Blower

Wheel nominal diameter x width −in.

(mm)

Motoroutput − hp (W) 1/3 (249) 1/3 (249) 1/2 (373) 1 (746)

Tons(kW) ofadd-oncooling 2.5 − 3 (8.8 − 10.5) 2.5 − 3.5 (8.8 − 12.3) 3 − 4 (10.5 − 14.0) 4 − 5 (14.0 − 17.5)

ShippingData lbs. (kg) − 1 package 136 (62) 146 (66) 168 (76) 176 (80)

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

OPTIONAL ACCESSORIES − MUST BE ORDERED EXTRA

Air Filter and Rack Kit

Size of filter

Condensate Drain Heat Cable

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

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

EZ Filter Base

Catalog Number − Ship. Weight − lbs.

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

Size of field provided filter − in. (mm) 16 x 25 x 1

Down−Flow Additive Base 11M 60 11M 60 11M 61 11M 61

High Altitude Orifice Kit − Natural Gas 59M16 59M16 59M16 59M16

High Altitude Pressure Switch Kit − Order two each

7501−10,000ft. (2286−3048m

Horizontal Support Frame Kit − Ship. Weight − lbs. (kg) 56J18 − 18 (8) 56J18 − 18 (8) 56J18 − 18 (8) 56J18 − 18 (8)

LPG/Propane Kit

7501−10,000 ft. (2286−3048 m) 59M14 59M14 59M14 59M14 Natural to LPG/Propane Kit 59M87 59M87 59M87 59M87

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

Termination Kits

Direct Vent

Concentric

Applications Only

Wall

Close Couple − 2 inch (51 mm) 22G44 22G44 − − − − − −

Close Couple WTK − 2 inch (51 mm) 30G28 30G28 − − − − − −

5,6

Termination Kits

Roof Direct Vent or Non−Direct Vent

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

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

Determine from venting tables proper exhaust pipe size and termination kit required.

Cleanable polyurethane frame type filter.

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

See Installation Instructions for specific venting information.

Kits contain enough parts for two, non−direct vent installations.

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

Horizontal (end) 87L96 − 18 x 25 x 1 in.

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

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

24 ft. (7.3 m) 26K69 26K69 26K69 26K69

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

(kg)

0−7500 ft. (0−2286 m) 59M13 59M13 59M13 59M13

1−1/2 inch (38 mm) 60G77 60G77 − − − − − −

2 inch (51 mm) − − − − − − 33K97 33K97 3 inch (76 mm) − − − − − − 60L46 60L46

3 inch (76 mm) 44J40 44J40 44J40 44J40

2 inch (51 mm) 15F75 15F75 15F75 15F75 3 inch (76 mm) 44J41 44J41 44J41 44J41

1/2 1/2 1/2 1/2

10 x 8 (254 x 203) 10 x 8 (254 x 203) 10 x 10 (254 x 254) 11−1/2 x 10 (292 x 229)

(457 x 635 x 25 mm)

87L97 − 20 x 25 x 1 in.

(508 x 635 x 25 mm)

39G04 39G04 39G04 39G04

39G03 39G03 39G03 39G03

73P56 − 7 (3) 73P56 − 7 (3) 73P57 − 8 (4) 73P57 − 8 (4)

(102 x 448 x 727)

(406 x 635 x 25)

4 x 17−5/8 x 28−5/8

(102 x 448 x 727)

16 x 25 x 1

(406 x 635 x 25)

4 x 21−5/8 x 28−5/8

(102 x 549 x 727)

20 x 25 x 1

(508 x 635 x 25)

4 x 21−5/8 x 28−5/8

(102 x 549 x 727)

20 x 25 x 1

(508 x 635 x 25)

− − − 56M06 − − − − − −

Page 2

SPECIFICATIONS

Perf

Applications

Direct Ven t

Gas Heating

ormance

High Fire

Temperature rise range − _F (_C) 45 − 75 (25 − 42) 35 − 65 (21 − 39) 40 − 70 (24 − 42)

Low Fire

Temperature rise range − _F (_C) 30 − 60 (18 − 36) 25 − 55 (14 − 31) 30 − 60 (18 − 36)

California Seasonal Efficiency 88.4% 87.0% 87.7%

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

Connections in.

Exhaust Pipe (PVC) 2 2 3

Condensate Drain Trap (PVC pipe) − i.d. 1/2 1/2 1/2

with field supplied (PVC coupling) − o.d. 3/4 3/4 3/4

hose with hose clamp − i.d. x o.d. 1−1/4 x 1 1−1/4 x 1 1−1/4 x 1

Indoor Blower

Wheelnominaldiameter xwidth −in. (mm) 10 x 10 (254 x 254) 11−1/2 x 10 (292 x 229) 11−1/2 x 10 (292 x 229)

Motoroutput − hp (W) 1/2 (373) 1 (746) 1 (746)

Tons(kW) ofadd-oncooling 3 − 4 (10.5 − 14.0) 4 − 5 (14.0 − 17.5) 4 − 5 (14.0 − 17.5)

ShippingData lbs. (kg) − 1 package 178 (81) 186 (84) 206 (93)

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

ModelNo. G61MP−48C−110 G61MP−60C−110 G61MP−60D−135

Input− Btuh (kW) 110,000 (32.2) 110,000 (32.2) 132,000 (38.7)

Output− Btuh (kW) 104,000 (30.5) 104,000 (30.5) 124,000 (36.3)

Input− Btuh (kW) 75,000 (22.0) 75,000 (22.0) 90,000 (26.4)

Output− Btuh (kW) 72,000 (21.1) 72,000 (21.1) 86,000 (25.2)

AFUE 94.1% 94.1% 94.1%

Intake Pipe (PVC) 2 2 3

GaspipesizeIPS 1/2 1/2 1/2

OPTIONAL ACCESSORIES − MUST BE ORDERED EXTRA

3, 4

Air Filter and Rack Kit −

Size of filter

Condensate Drain Heat Cable

Heat Cable Tape

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

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

EZ Filter Base

Catalog Number − Shipping Weight 73P57 − 8 lbs. (4 kg) 73P58 − 10 lbs. (5 kg) 73P58 − 10 lbs. (5 kg)

Dimensions − H x W x D − in. (mm) 4 x 21−5/8 x 28−5/8

Size of field provided filter − in. (mm) 20 x 25 x 1

Down−Flow Additive Base 11M 61 11M 61 11M 62

High Altitude Orifice Kit − Natural Gas Only 59M16 59M16 59M16

High Altitude Pressure Switch Kit − Order two each

4501−10,000 ft. (1372−3048 m)

Horizontal Support Frame Kit − Ship. Weight − lbs. (kg) 56J18 − 18 (8) 56J18 − 18 (8) 56J18 − 18 (8)

LPG/Propane Kit 0−7500 ft. (0−2286 m) 59M13 59M13 59M13

7501−10,000ft. (2286−3048m) 59M14 59M14 59M14

Natural to LPG/Propane Kit 59M87 59M87 59M87

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

Termination Kits −

Direct Vent

Concentric Roof/Wall

Wall Close−Coupled 3 inch (76 mm) 44J40 44J40 44J40

7,8

Termination Kits

Roof

Direct Vent or Non−

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

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

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

Determine from venting tables proper exhaust pipe size and termination kit required.

Cleanable polyurethane frame type filter.

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).

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

See Installation Instructions for specific venting information.

Kits contain enough parts for two, non−direct vent installations.

Non−direct vent applications only.

Horizontal (end) 87L97 − 20 x 25 x 1 in. (508 x 635 x 25 mm) 87L98 − 25 x 25 x 1 in.

(635 x 635 x 25 mm)

Side Return

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

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

24 ft. (7.3 m) 26K69 26K69 26K69

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

39G04 39G04 39G04

39G03 39G03 39G03

(102 x 549 x 727)

(508 x 635 x 25)

4 x 24−5/8 x 28−5/8

(102 x 625 x 727)

24 x 24 x 1

(610 x 610 x 25)

4 x 24−5/8 x 28−5/8

(102 x 625 x 727)

24 x 24 x 1

(610 x 610 x 25)

− − − − − − 56M93

2 inch (51 mm) 33K97 33K97 − − −

3 inch (76 mm) 60L46 60L46 60L46

2 inch (51 mm) 15F75 15F75 − − −

3 inch (76 mm) 44J41 44J41 44J41

15F74

Page 3

BLOWER DATA

External Static

G61MP−36B−045 PERFORMANCE (Less Filter)

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 695 580 1345 635 520 1170 550 455 1010 475 400

0.30 75 1410 665 555 1310 620 495 1155 545 440 1000 470 385

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

0.50 125 1290 610 505 1205 570 450 1080 510 390 950 450 345

0.60 150 1220 575 485 1145 540 420 1020 480 365 905 430 320

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

0.80 200 1050 495 425 985 465 365 870 410 320 785 370 285

0.90 225 945 445 410 900 425 345 825 390 305 730 345 270

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

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

High Medium−High Medium−Low Low

G61MP−36B−070 PERFORMANCE (Less Filter)

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

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

0.20 50 1540 725 605 1370 650 525 1160 545 445 995 470 375

0.30 75 1495 705 580 1345 635 505 1145 540 425 990 465 365

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

0.50 125 1360 640 525 1245 590 450 1080 510 375 945 445 325

0.60 150 1275 600 490 1165 550 410 1025 485 350 900 425 305

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

0.80 200 1080 510 440 1010 475 360 865 410 310 775 365 270

0.90 225 945 445 400 840 395 320 765 360 275 710 335 245

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

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

High Medium−High Medium−Low Low

G61MP−48C−090 PERFORMANCE (Less Filter)

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

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

0.20 50 2085 985 840 1810 855 720 1505 710 580 1270 600 475

0.30 75 2030 955 800 1775 835 685 1500 705 565 1265 595 460

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

0.50 125 1865 880 725 1660 785 600 1430 675 505 1215 575 425

0.60 150 1740 820 670 1590 750 575 1380 650 475 1175 555 410

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

0.80 200 1540 725 600 1340 630 465 1175 555 405 1020 480 355

0.90 225 1335 630 540 1170 555 440 1070 505 375 950 450 330

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

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

High Medium−High Medium−Low Low

G61MP−48C−110 PERFORMANCE (Less Filter)

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

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

0.50 125 1780 840 680 1630 770 580 1420 670 490 1150 540 400

0.60 150 1690 800 660 1550 735 550 1360 640 460 111 0 525 380

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

0.80 200 1375 650 550 1230 580 450 1125 530 380 970 460 325

0.90 225 1225 580 520 1120 530 415 1050 495 365 885 420 310

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

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

High Medium−High Medium−Low Low

Air Volume / Watts at Different Blower Speeds

Page 4

BLOWER DATA

External Static

G61MP−60C−090 PERFORMANCE (Less Filter) − Single Side Return Air − Air volumes in bold require field fabricated transition to accommodate 20 x 25 x 1 in. (508 x 635 x 25 mm) 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 2835 1335 1495 2340 1105 1155 1800 850 895 1440 680 695

0.10 25 2785 1315 1475 2345 1105 1135 1805 855 865 1515 715 690

0.20 50 2715

0.30

0.40 100 2550 1205 1350 2230 1055 1015 1845 870 815 1620 765 670

0.50 125 2450 1155 1305 2175 1025 990 1850 870 790 1615 765 655

0.60 150 2365 1115 1270 2130 1005 940 1830 865 775 1615 760 640

0.70 175 2240 1060 1205 2070 975 915 1815 855 760 1595 755 620

0.80 200 2185 1030 1190 1965 925 865 1775 840 745 1555 735 605

0.90 225 2015 950 1150 1820 860 820 1690 800 715 1440 680 580

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

75 2620 1235 1380 2260 1065 1035 1840 870 825 1600 755 680

High Medium−High Medium−Low Low

1280 1435 2275 1075 1080 1825 860 845 1560 735 685

G61MP−60C−090 PERFORMANCE (Less Filter) − 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 2840 1340 1450 2345 1105 1105 1895 895 900 1515 715 700

0.10 25 2765 1305 1415 2365 1115 1080 1950 920 885 1580 745 700

0.20 50 2695 1270 1385 2345 1105 1050 1985 935 870 1620 765 695

0.30 75 2605 1230 1335 2315 1090 1030 1990 940 850 1645 775 690

0.40 100 2530 1195 1300 2265 1070 990 1990 940 825 1665 785 675

0.50 125 2420 1140 1260 2210 1045 955 1970 930 800 1675 790 665

0.60 150 2330 1100 1220 2145 1010 925 1930 910 775 1665 785 650

0.70 175 2250 1060 1190 2050 965 885 1875 885 745 1645 775 630

0.80 200 2135 1010 1140 2000 945 865 1810 855 715 1620 765 615

0.90 225 2030 960 1090 1885 890 830 1720 810 685 1560 735 590

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

High Medium−High Medium−Low Low

Air Volume / Watts at Different Blower Speeds

G61MP−60C−110 PERFORMANCE (Less Filter) − Single Side Return Air − Air volumes in bold require field fabricated transition to accommodate 20 x 25 x 1 in. (508 x 635 x 25 mm) 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 2625 1240 1350 2310 1090 1080 1885 890 885 1515 715 700

0.10 25 2570 1215 1330 2325 1095 1060 1910 900 865 1575 745 700

0.20 50 2410 1135 1305 2285 1080 1035 1930 910 845 1620 765 690

0.30 75 2425 1145 1265 2230 1055 990 1925 905 825 1635 770 675

0.40 100 2335 1100 1220 2175 1025 950 1910 900 810 1640 775 660

0.50 125 2270 1070 1195 2120 1000 935 1895 895 785 1640 775 640

0.60 150 2170 1025 1155 2045 965 885 1860 875 765 1630 770 630

0.70 175 2110 995 1130 1950 920 855 1795 845 730 1590 750 610

0.80 200 2035 960 1090 1885 890 820 1745 825 705 1540 725 580

0.90 225 1900 895 1055 1760 830 780 1665 785 680 1470 695 565

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

High Medium−High Medium−Low Low

Air Volume / Watts at Different Blower Speeds

Page 5

BLOWER DATA

G61MP−60C−110 PERFORMANCE (Less Filter) − 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 2720 1285 1385 2410 1135 1090 2055 970 935 1620 765 710

0.10 25 2665 1255 1355 2385 1125 1075 2025 955 885 1730 815 735

0.20 50 2585 1220 1315 2350 1110 1015 2030 955 865 1680 795 690

0.30 75 2505 1180 1275 2290 1080 990 2025 955 840 1695 800 675

0.40 100 2435 1150 1250 2235 1055 940 2030 960 830 1695 800 660

0.50 125 2350 1110 1205 2170 1025 930 1975 930 790 1735 820 665

0.60 150 2255 1065 1185 2100 990 895 1915 905 765 1720 810 650

0.70 175 2160 1020 1150 2005 945 840 1865 880 730 1680 795 635

0.80 200 2020 955 1090 1905 900 825 1810 855 710 1625 765 610

0.90 225 1910 900 1050 1820 860 795 1705 805 675 1540 725 590

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

High Medium−High Medium−Low Low

G61MP−60D−135 PERFORMANCE (Less Filter) − Single Side Return Air − Air volumes in bold require field fabricated transition to accommodate 20 x 25 x 1 in. (508 x 635 x 25 mm) 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 2665 1260 1440 2325 1095 1100 1865 880 890 1410 665 690

0.10 25 2615 1235 1405 2310 1090 1065 1915 905 865 1465 690 685

0.20 50 2530 1195 1370 2280 1075 1055 1925 910 850 1570 740 675

0.30 75 2470 1165 1330 2235 1055 1015 1920 905 825 1590 750 670

0.40 100 2380 1125 1290 2175 1025 985 1910 900 805 1590 750 655

0.50 125 2310 1090 1265 2120 1000 965 1890 890 790 1595 755 645

0.60 150 2200 1035 1230 2055 970 935 1835 865 765 1580 745 630

0.70 175 2120 1000 1190 1970 930 900 1790 845 740 1545 730 605

0.80 200 2025 955 1160 1890 890 875 1720 810 710 1515 715 590

0.90 225 1930 910 1110 1800 850 835 1655 780 685 1440 680 570

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

High Medium−High Medium−Low Low

Air Volume / Watts at Different Blower Speeds

G61MP−60D−135 PERFORMANCE (Less Filter) − 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 2730 1290 1465 2425 1145 1125 2055 970 915 1560 735 680

0.10 25 2670 1260 1440 2400 1135 1100 2065 975 890 1590 750 675

0.20 50 2600 1225 1400 2365 1115 1070 2045 965 865 1620 765 665

0.30 75 2525 1190 1360 2315 1095 1045 2035 960 845 1615 760 655

0.40 100 2445 1155 1325 2260 1065 1015 2020 955 820 1615 760 645

0.50 125 2360 1115 1280 2195 1035 985 1960 925 790 1610 760 635

0.60 150 2290 1080 1255 2130 1005 965 1900 895 755 1600 755 615

0.70 175 2205 1040 1220 2035 960 910 1825 860 730 1570 740 600

0.80 200 2110 995 1195 1945 915 880 1765 830 710 1540 725 580

0.90 225 1970 930 1120 1835 865 830 1680 795 690 1540 725 545

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

High Medium−High Medium−Low Low

Air Volume / Watts at Different Blower Speeds

Page 6

G61MP PARTS ARRANGEMENT

TOP CAP

BURNER BOX

ASSEMBLY

GAS VALVE

AND MANIFOLD

FLUE

COLLAR

COMBUSTION

AIR PROVE PROVE

SWITCHES*

COMBUSTION AIR

INDUCER

DuralokPlus

HEAT EXCHANGER

ASSEMBLY

CABINET

WARM HEADER

(COLLECTOR)

BOX

CONDENSER COIL

BURNER

ACCESS

PANEL

BLOWER

ACCESS

DOOR

*G61MP−090 shown.

G61MP−045 and −070

are equipped with

two switches.

SIGHT

GLASS

DOOR

INTERLOCK

SWITCH

PRIMARY LIMIT

COLD HEADER

(COLLECTOR)

BOX

SECONDARY

LIMITS (2)

BLOWER

ASSEMBLY

CONTROL BOX

FIGURE 1

Page 7

I−UNIT COMPONENTS

G61MP unit components are shown in figure 1. The gas valve, combustion air inducer and burners can be accessed by removing the burner access panel. Electrical components are in the control box (figure 2) found in the blower section. G61MP units are factory equipped with a bottom return air

panel in place. The panel is designed to be field removed as required for bottom air return. Markings are provided for side return air and may be cut out in the field.

ELECTROSTATIC DISCHARGE (ESD)

Precautions and Procedures

3. Circuit Breaker (CB8)

A 24V circuit breaker is also located in the control box. The switch provides overcurrent protection to the transformer (T1). The breaker is rated 3A at 32V. If the current exceeds this limit the breaker will trip and all unit operation will shutdown. The breaker can be manually reset by pressing the button on the face. See figure 3.

CIRCUIT BREAKER CB8

PRESS TO RESET

CAUTION

Electrostatic discharge can affect electronic components. Take precautions during furnace installation and service to protect the furnace’s electronic controls. Precautions will help to avoid control exposure to electrostatic discharge by putting the furnace, the control and the technician at the same electrostatic potential. Neutralize 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.

A−Control Box

1. Control Transformer (T1)

A transformer located in the control box provides power to the low voltage section of the unit. Transformers on all models are rated 40VA with a 120V primary and a 24V secondary.

2. Door Interlock Switch (S51)

A door interlock switch rated 14A at 125VAC is wired in series with line voltage. When the blower door is removed the unit will shut down.

CONTROL BOX G61MP

CIRCUIT BREAKER

DOOR INTERLOCK

SWITCH

SURELIGHT

CONTROL

BOARD

FIGURE 2

TRANSFORMER

FIGURE 3

WARNING

Shock hazard. Disconnect power before servicing. Integrated

Control Board is not field repairable. If control is inoperable, simply replace entire control.

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

4. Integrated Control Board (A92)

All G61MP units are equipped with the Lennox Two−Stage Integrated control board. The system consists of a ignition control board (figure 4 with control terminal designations in tables 3, 4 and 5) and ignitor (figure 7). The board and ignitor work in combination to ensure furnace ignition and ignitor durability. The board controls all major furnace operations. The board features two LED lights, DS1 and DS2 for troubleshooting. The board also has two accessory terminals rated at (1) one amp. See table 6 for troubleshooting diagnostic codes.

Electronic Ignition

At the beginning of the heat cycle, SureLight control monitors the first stage and second stage combustion air inducer prove switch. The control will not begin the heating cycle if the first stage prove switch is closed (by−passed). Likewise the control will not begin the second stage heating cycle if the second stage prove switch is closed, and will allow first stage heat only. However if the second stage prove switch closes during the first stage pre−purge, the control will respond to second stage heat. Once the first stage prove switch is determined to be open, the combustion air inducer is energized on low (first stage) heat speed. When the differential in the prove switch is great enough, the prove switch closes and a 15−second pre−purge begins. If the switch is not proven within 2−1/2 minutes, the control goes into Watchguard−Pressure Switch mode for a 5−minute re−set period. After the 15−second pre−purge period, the SureLight ignitor warms up for 20 seconds after which the gas valve opens for a 4−second trial for ignition. The ignitor energizes during the trial until flame is sensed. If ignition is not proved during the 4−second period, the control will try four more times with an inter purge and warm−up time between trials of 35 sec-

Page 8

onds. After a total of five trials for ignition (including the initial trial), the control goes into Watchguard−Flame Failure mode. After a 60−minute reset period, the control will begin the ignition sequence again. The SureLight control board has an added feature that prolongs the life of the ignitor. After a successful ignition, the SureLight control utilizes less power to energize the ignitor on successive calls for heat. The control continues to ramp down the voltage to the ignitor until it finds the lowest amount of power that will provide a successful ignition. This amount of power is used for 255 cycles. On the 256th call for heat, the control will again ramp down until the lowest power is determined and the cycle begins again.

Two Stage Operation / Thermostat Selection Jumper

The control can be utilized in two modes: SINGLE−STAGE thermostat or TWO−STAGE thermostat. The thermostat selection jumper E20, located just below dip switches 1 through 4 (figure 4), must be positioned for the particular application. The jumper is factory set on TWO" for use with a two−stage thermostat with two stage heat. Re−position jumper to SINGLE" for use with a single stage thermostat with two stage heat. While in the single−stage thermostat mode (single jumper setting), the burners will always fire on first−stage heat. The combustion air inducer will operate on low speed and indoor blower will operate on low heat speed. After a 10 minute recognition period, the unit will switch to second stage heat. While in the two−stage thermostat mode (two jumper setting) the burners will fire on first−stage heat. The combustion air inducer will operate on low speed and indoor blower will operate on low heat speed. The unit will switch to second−stage heat on call from the indoor thermostat. If there is a simultaneous call for first and second stage heat, the unit will fire on first stage heat and switch to second stage heat after 30 seconds of operation. See Sequence of Operation flow charts in the back of this manual for more detail.

Dip Switch Settings

Dip Switches 1 and 2 − Heating Fan off Delay − The fan on

time of 45 seconds is not adjustable. Fan off time (time that the blower operates after the heat demand has been satisfied) can be adjusted by flipping the dip switches 1 and 2 located on the SureLight integrated control. The unit is shipped with a factory fan off setting of 90 seconds. Fan off time will affect comfort and is adjustable to satisfy individual applications. For customized comfort, monitor the supply air temperature once the heat demand is satisfied. Note the supply air temperature at the instant the blower is de−energized. Adjust the fan−off delay to achieve a supply air temperature between 90° − 110° at the instant the blower is de− energized. (Longer delay times allow for lower air temperature, shorter delay times allow for higher air temperature). See table 1 for dip switch settings.

TABLE 1

Heating Fan Off Delay

Delay (Seconds)

60 Off Off

90 Off On

120 On Off

180 On On

Switch 3 − Second Stage Delay (Used with Single−Stage

Thermostat Only) −− This switch is used to determine the

second stage on delay when a single−stage thermostat is

being used. The switch is factory−set in the ON position,

which provides a 10−minute delay before second−stage

heat is initiated. If the switch is toggled to the OFF position,

it will provide a 15−minute delay before second−stage heat

is initiated. This switch is only activated when the thermo-

stat selector jumper is positioned for SINGLE−stage ther-

mostat use.

Switch 4 − Cooling Fan off Delay − The fan on delay time

of 2 seconds is not adjustable. Fan off time (time that the

blower operates after the cool demand has been satisfied)

can be adjusted by flipping dip switch 4. The unit is shipped

with a factory fan off setting of 45 seconds. Fan off time will

affect comfort and is adjustable to satisfy individual ap-

plications. See table 2 for cool fan off time settings.

Cooling Fan Off Delay

Delay (Seconds) Switch 4

2 Off

45 On

Diagnostic LED’s (DS1 and DS2)

Two diagnostic LED’S are located on the two−stage inte-

grated control board. See figure 4. These light flashes cor-

respond with the codes detailed in table 6.

Factory Installed Jumper Y1 to Y2

A factory−installed jumper from Y1 to Y2 terminals on the

integrated control board terminal strip must be clipped for

two−stage cooling.

Switch 1 Switch 2

TABLE 2

Page 9

TWO−STAGE INTEGRATED CONTROL BOARD

LEDs

DIP

SWITCHES

1 − 4

W915 FACTORY INSTALLED JUMPER

(MUST CLIP FOR 2 STAGE COOL)

THERMOSTAT CONNECTIONS (TB1)

TABLE 3

Integrated Control Board Terminals

120VAC Neutral

LINE Line

XFMR Transformer

EAC Electronic Air Cleaner

CIRC Indoor Blower

HUM Humidifier

120VAC Line

HUM Humidifier

XMFR Transformer

LINE Line

PARK For Unused Leads

COOL Cooling Speed

EAC Electronic Air Cleaner

HI HEAT HIigh Heat Speed

LO HEAT Low Heat, Low Cool and Continuous Fan

Speed

TABLE 4

Integrated Control Board 5 Pin Terminal

PIN # Function

1 Ignitor

2 Combustion Air Inducer High Speed

3 Combustion Air Inducer Low Speed

4 Combustion Air Inducer Neutral

5 Ignitor Neutral

DIP SWITCH(ES) FUNCTION

1 and 2 Blower Off Delay (Heating Mode)

3 Second Stage ON Delay (Single−stage t’stat) 4 Blower Off Delay (Cooling Mode)

FIGURE 4

TABLE 5

Integrated Control Board 12Pin Terminal

PIN # Function

1 Gas Valve 2nd Stage (High Fire)

2 Second Stage Prove Switch

3 Not Used

4 Ground

5 24V Hot

6 Primary Limit In

7 Gas Valve 1st stage (Low Fire)

8 Gas Valve Common

9 24V Neutral

10 Ground

11 Primary Limit Out

12 1st Stage Prove Switch

Page 10

TABLE 6

ONONON

Circuit board failure or control wired incorrectly. Check 24 and 115 volts to board.

DIAGNOSTIC CODES

Diagnostic LEDs are labeled DS1 and DS2. See figure 4 for location of diagnostic LEDs.

DS1 DS2 DESCRIPTION

SIMULTANEOUS

SLOW FLASH

SIMULTANEOUS

FAST FLASH

SLOW FLASH ON

OFF SLOW FLASH

OFF FAST FLASH

ALTERNATING

SLOW FLASH

SLOW FLASH OFF Flame sensed without gas valve energized.

ON ON

OFF ON

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

SLOW FLASH FAST FLASH Low flame signal. Measures below 0.23 microAmps. Replace flame sense rod.

ALTERNATING

FAST FLASH

SIMULTANEOUS

SLOW FLASH

SIMULTANEOUS

FAST FLASH

ALTERNATING

SLOW FLASH

OFF

ALTERNATING

FAST FLASH

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

Normal operation − signaled when heating demand initiated at thermostat.

Primary, secondary, backup secondary or rollout limit switch open. Limits must close within 3 minutes or unit goes into 1 hour Watchguard. Low prove switch open; OR: Blocked inlet/exhaust vent; OR: Low prove switch closed prior to activation of combustion air inducer.

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

Watchguard −− burners failed to ignite; OR limit open more than 3 minutes; OR lost flame sense 5 times in one heating cycle; OR pressure switch opened 5 times in one heating cycle.

Circuit board failure or control wired incorrectly. Check 24 and 115 volts to board.

The following conditions are sensed during the ignitor warm−up period only:

1) Improper main ground;

2) Broken ignitor; OR: Open ignitor circuit;

3) Line voltage below 75 volts. (If voltage lower than 75 volts prior to ignitor warm-up, control will signal waiting on call from thermostat, and will not respond.

NOTE − Slow flash rate equals 1 Hz (one flash per second). Fast flash rate equals 3 Hz (three flashes per second). Low flame sense current = 0.17−0.22 microAmps.

B−Blower Compartment

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

SUPPLY AIR BLOWER

AND SECONDARY LIMITS

All G61MP units use direct drive blower motors. All motors are 120V permanent split capacitor motors to ensure maximum efficiency. Ratings for capacitors will be on motor nameplate. See SPECIFICATIONS section for motor specifications.

NOTE − Shafts on 1 HP motors have 2 flat sides and are matched with blower wheels with 2 set screws.

2. Secondary Limit Controls (S21)

The secondary limits (S21) on G61MP units are located in the blower compartment on the back side of the blower housing. See figure 5. All G61MP units are equipped with two secondary limts. When excess heat is sensed in the blower compartment, the limit will open. If the limit is open, the furnace control

CAPACITOR

To Remove Blower From Unit: Disconnect Power, Remove Control

Box, Remove Bolts and Unplug Motor Wires From Control Board.

Then Slide Out Front of Unit.

FIGURE 5

SECONDARY

LIMIT (S)

MOTOR/BLOWER

ASSEMBLY

energizes the supply air blower and closes the gas valve. The limit automatically resets when unit temperature returns to normal. The switch is factory set to open at 125°F and cannot be adjusted.

Page 11

C−Heating Components

3. Flame Sensor

A flame sensor is located on the left side of the burner support. See figure 6. The sensor is mounted through the bottom of the burner box and the tip protrudes into the flame envelope of the left−most burner. The sensor can be removed for service without removing any part of the burners. During operation, flame is sensed by current passed through the flame and sensing electrode. The SureLight control allows the gas valve to remain open as long as flame signal is sensed.

NORMAL FLAME SIGNAL > 0.23 MICROAMPS LOW FLAME SIGNAL < 0.22 MICROAMPS DROP OUT SIGNAL = 0.16 MICROAMPS

5/16"

FIGURE 6

4. Ignitor

The SureLight ignitor is made of durable silicon nitride. Ignitor longevity is enhanced by controlling voltage to the ignitor. 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. Ohme value should be 10.9 to 19.7. See 7 for ignitor location.

NOTE − The G61MP furnace contains electronic components that are polarity sensitive. Make sure that the furnace is wired correctly and is properly grounded.

5. Burners (Figure 7)

All units use inshot burners. Burners are factory set and do not require adjustment. The manifold brackets are slotted so 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 and is threaded into the burner manifold. All G61MP natural gas units are fitted with .089" sized orifices. See SPECIFICATIONS" tables for LP kits and high altitude. 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 is fitted with a corbel cup (orifice) used to direct the flow of combustion products.

13/32’

IGNITOR

MEASUREMENT IS TO I.D.

5/8"

OF RETENTION RING

SureLight Ignitor Location

5/16"

BRACKET

BURNERS TOP VIEWBURNERS FRONT VIEW

FIGURE 7

Page 12

6. Clamshell Heat Exchanger

G61MP units use an aluminized steel primary and stainless steel secondary heat exchanger assembly. Heat is transferred to the air stream from all surfaces of the heat exchanger. The shape of the heat exchanger 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.

7. Flame Rollout Switches (S47)

Flame rollout switch S47 is a high temperature limit located on each side of the burner box. Each furnace is equipped with two identical switches. The limit is a N.C. SPST manual-reset limit connected in series with the primary limit S10. When S47 senses rollout, the circuit breaks and the ignition control immediately stops ignition and closes the gas valve. If unit is running and flame rollout is detected, the gas valve will close and ignition control will be disabled. Rollout can be caused by a blocked heat exchanger, flue or lack of combustion air. The switch is factory set to trip (open) at 250°F and cannot be adjusted. The switch can be manually reset. To manually reset a tripped switch, push the reset button located on the control.

8. Primary Limit Control (S10)

Figure 8 shows the primary limit (S10) used on G61MP units located in the heating vestibule panel. S10 is provided with a shield on some models (figure 8) and must not be removed. Note orientation of shield and limit if limit is replaced. 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 automatically resets when unit temperature returns to normal. The switch is factory set and cannot be adjusted.

9. Backup Secondary Limit Control (S113) (G61MP−090, 110, 135 only)

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

10. Gas Valve (GV1)

The G61MP uses a two−stage gas valve manufactured by Honeywell (figure 35) or White Rodgers (figure 36). The valves are internally redundant to assure safety shut−off. If the gas valve must be replaced, the same type valve must be used.

24VAC terminals and gas control knob or switch are located on the valve. All terminals on the gas valve are connected to wires from the electronic ignition control. 24V applied to the terminals energizes the valve.

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

LPG change over kit s are available from Lennox. Kits include burner orifices and a gas valve regulator conversion kit.

The burner box is sealed and operates under a negative pressure. A pressure hose is connected from the burner box to the gas valve. The gas valve senses the pressure in the burner box and changes gas valve outlet (manifold) pressure based on changes in the burner box pressure. The intent is to compensate for different vent configurations which can greatly affect the rate of the unit.

PRIMARY LIMIT LOCATION

limit shield

090, −110 and

−135 only

limit faces shield

FIGURE 8

11. Combustion Air Inducer Prove Switch (S18)

All G61MP units are equipped with combustion air prove switches located on the combustion air inducer housing. G61MP−045 and −070 (figure 10) units have two combustion air proving switches. G61MP−090, −110 and −135 units are equipped with two dual prove switch assemblies" consisting of two switches acting as one. See figure 9. The switches are connected to the cold end header box by means of a flexible hose that monitors negative air pressure in the cold end header box.

The switches are a single-pole single-throw proving switch electrically connected to the furnace control. The purpose of the switch is to prevent burner operation if the combustion air inducer is not operating or if the flue becomes obstructed.

Page 13

On heat demand (first or second stage) the switch senses that the combustion air inducer is operating. It closes a circuit to the furnace control when pressure inside the cold end header box decreases to a certain set point. Set points vary depending on unit size. See tables 8, 9 and

10. The pressure sensed by the switch is negative. If the air intake vent pipe or outlet vent pipe becomes obstructed during operation, the switch senses a change of negative pressure and opens the circuit 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.

1 − Remove thermostat demand and allow unit to cycle

off.

2 − Install a tee in the negative (−) line and a tee in the positive

(+) line running from one of the prove switches to the cold end header box.

3 − Install a manometer with hose from the negative (−)

side of the manometer to the tee installed in the negative (−) line and with hose from the positive (+) side of the manometer to the tee in the positive (+) line.

NOTE − Both sides of the cold end header box are negative. However the (+) port reads less negative pressure than the (−) port.

CAI & COLD END HEADER BOX ASSEMBLY

(−045 & 070 SHOWN)

DUAL COMBUSTION AIR PROVE SWITCH

G61MP−090, −110 & −135

first stage

negative

pressure

second stage

positive

pressure

FIGURE 9

To troubleshoot the prove switches, temporarily jumper them. The unit will not fire with the switches jumpered. Therefore, the prove switches must be bypassed after the combustion air inducer is activated. This will determine if the prove switches and furnace are operating properly. However, this may not indicate if the sealed combustion system is operating properly.

Checks of pressure differential can aid in troubleshooting. When measuring the pressure differential, readings should be taken at the prove switch. Lack of differential usually indicates problems in the intake or exhaust piping, bu t ma y indicat e problems in the heat exchanger, condensing coil, header boxes, combustion inducer or other components.

Measuring pressure differential

The differential pressure is the difference in pressure measured across the cold end header box orifice.

Install tee’s in the

negative line and positive line then connect hoses to

manometer.

cold end header box

prove switches

orifice size

FIGURE 10

4 − Operate unit and observe manometer reading. Read-

ings will change as heat exchanger warms.

a. Take one reading immediately after start-up. b. Take a second reading after unit has reached steady state (approximately 5 minutes). This will be the pressure differential.

The pressure differential should be greater than those listed in table 8, 9 or 10.

5 − Remove thermostat demand and allow to cycle off.

6 − Remove manometer and tee’s. Reinstall combustion air

sensing hoses to the prove switch.

7 − Repeat steps 1 through 6 for the other prove switch.

Page 14

12. Combustion Air Inducer (B6)

0.95"

0.85"

0.50"

0.95"

All G61MP units use a combustion air inducer to move air through the burners and heat exchanger during heating operation. The blower uses a PSC 120VAC motor. The motor operates during all heating operation and is controlled by the ignition control A3. Blower operates continuously while there is a call for heat. The burner ignition control will not proceed with the ignition sequence until combustion air inducer operation is sensed by the proving switches.

The CAI is installed on the cold end header box. The cold end header box is a single piece made of hard plastic. The box has an internal channel where the combustion air inducer creates negative pressure at unit start up. The channel contains an orifice used to regulate flow created by the CAI. The box has pressure taps for the CAI prove switch hoses.

The prove switches measure the pressures across the CAI orifice or difference in the channel and the box. A window is provided on the bottom right hand side of the box to indicate orifice size. See figure 10. See table 7 for orifice size per unit. If replacement is necessary the

gaskets used to seal the box to the vestbule panel and the CAI to the box, must also be replaced.

TABLE 7

G61MP Unit C.A.I. Orifice Size

−045 .719"

−070 .938"

−090 1.063"

−110 1.313"

−135 1.688"

TABLE 8

0’ to 4500’

G61MP Unit

Set Point

Second Stage

Set Point

First Stage

−045

−070

−090

−110

−135 0.60" 0.35"

TABLE 9*

4501’ to 7500’

G61MP Unit

Set Point

Second Stage

Set Point

First Stage

−045

−070

−090 0.75" 0.50"

−110 0.85" 0.50"

−135 0.55" 0.35"

*Unit may require conversion kit at this altitude. See High Altitude table.

TABLE 10*

7501’ to 10,000’

G61MP Unit

Set Point

Second Stage

Set Point

First Stage

−045 0.95" 0.95"

−070 0.85" 0.85"

−090 0.60" 0.35"

−110 0.85" 0.50"

−135 0.55" 0.35"

*Unit may require conversion kit at this altitude. See High Altitude table.

Page 15

II−PLACEMENT AND INSTALLATION

36B−045

36B−070

60C−090

60D−135

OUTDOOR TERMINATION KITS AND CORRESPONDING EQUIVALENCIES

Outdoor Exhaust

Accelerator

(Dia. X

Length)

UNIT

MODEL

VENT

PIPE

DIA. (in.)

1−1/2" X 12"

2 4

2−1/2 5

3 7

4 14

2 4

2−1/2 5

3 8

4 14

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

60C−110

2−1/2

*Requires field−provided and installed 1−1/2" exhaust accelerator. **Requires field−provided and installed 2" exhaust accelerator. ***For use only in non−direct vent applications, when snow riser is

Outdoor Exhaust

Accelerator

(Dia. X

1−1/2"

Concen-

tric Kit

Length)

2" X 12" 71M80 60M29 60L46 22G44

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

TABLE 11

Vent Pipe Length Equivalency (feet)

2" Con-

centric

Allowed

3" Con-

centric

Kit

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

3 3

6 6

12 12

6 6

12 12

Not

Kit

Not

2" Wall

Plate Kit

3" Wall

Plate Kit

44J40 81J20

4 4* 4 4

5 5* 5 5

7 7* 7 7

14 14* 14 14

4 4* 4 4

5 5* 5 5

8 8* 8 8

14 14* 14 14

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

2" Wall

Kit with

Vent Ex-

tension

30G28 15F74

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

Not

Allowed

not required. Requires field−provided and installed 2" exhaust accelerator.

2" Wall

Ring Kit

1**

2**

4**

2***

4***

6***

10***

Page 16

A−Vent Piping Guidelines

The G61MP can be installed as either a Non−Direct Vent or a Direct Vent gas central furnace.

NOTE − In Non-Direct Vent installations, combustion air is taken from indoors and flue gases are discharged outdoors. In Direct Vent installations, combustion air is taken from outdoors and flue gases are discharged outdoors.

Intake and exhaust pipe sizing in Direct Vent applications and exhaust pipe sizing in Non-Direct Vent applications −−

Size pipe according to tables 12 and 13. Table 12 lists the minimum equivalent vent pipe lengths permitted. Table 13 lists the maximum equivalent pipe lengths permitted.

Maximum vent length is defined as:

Total length (linear feet) of pipe,

Plus Equivalent length (feet) of fittings, Plus Equivalent length (feet) of termination. NOTE − Include ALL pipe and ALL fittings, both in doors and outdoors.

Regardless of the diameter of pipe used, the standard roof and wall terminations described in section Exhaust Piping Terminations should be used. Exhaust vent termination pipe is sized to optimize the velocity of the exhaust gas as it exits the termination. Refer to table 14.

*NOTE − The exhaust pipe should be offset a minimum of 12 inches to avoid the possibility of water droplets being released from the exhaust termination. The minimum exhaust vent length is 15 ft. Shorter exhaust vent lengths may result in the discharge of water droplets from the exhaust termination, in spite of the 12−inch vertical offset.

Each 90° elbow (including those provided with the furnace) of any diameter is equivalent to 5 feet (1.52m) of vent pipe of the same diameter. Two 45° elbows are equivalent to one 90° elbow of the same diameter. One 45° elbow is equal to 2.5 feet (.76m) of vent pipe of the same diameter.

In some applications which permit the use of several different sizes of vent pipe, a combination vent pipe may be used. Contact the Application Department for assistance in sizing vent pipe in these applications.

NOTE − The flue collar on all models is sized to accommodate 2" Schedule 40 flue pipe. When vent pipe which is larger than 2" must be used in an upflow application, a 2" elbow must be applied at the flue collar in order to properly transition to the larger diameter flue pipe. This elbow must be added to the elbow count used to determine acceptable vent lengths. Assign an equivalent feet value to this elbow according to the larger size pipe being used. Contact the Application Department for more information concerning sizing of vent systems which include multiple pipe sizes.

12" Min.

Upflow and Downflow Application

Rooftop Termination

12" Min.

Horizontal Application

Rooftop Termination

Exhaust Pipe Offset

12" Min.

Upflow and Downflow Application

Side Wall Termination

12" Min.

Horizontal Application

Side Wall Termination

FIGURE 11

Page 17

Use the following steps to correctly size vent pipe diameter.

ALTITUDE

MODEL

1371 m)

(1372−2286 m)

1 − Determine the vent termination and its corresponding

equivalent feet value according to table 11.

2 − Determine the number of 90° elbows required for both

indoor and outdoor (e.g. snow riser) use. Calculate the corresponding equivalent feet of vent pipe.

3 − Determine the number of 45° elbows required for both

indoor and outdoor use. Calculate the corresponding equivalent feet of vent pipe.

4 − Determine the length of straight pipe required.

5 − Add the total equivalent feet calculated in steps 1

through 4 and compare that length to the maximum values given in table 12 for the proposed vent pipe diameter. If the total equivalent length required exceeds the maximum equivalent length listed in the appropriate table, evaluate the next larger size pipe.

TABLE 12

MINIMUM VENT PIPE LENGTHS

G61MP

MODEL

045, 070,

090

110**

135***

*Any approved termination may be added to the minimum equivalent length listed.

**G61MP−48C−110 and G61MP−60C−110 must have 90° street ell (supplied) installed directly into unit flue collar.

***G61MP−60D−135 must have 3" to 2" reducing ell (supplied) installed directly into unit flue collar.

MIN. EQUIV.

VENT LENGTH

15 ft.*

EXAMPLE

5 ft. plus 2 elbows of 2", 2−1/2", 3"

or 4" diameter pipe

5 ft. plus 2 elbows of 2−1/2" 3" or 4"

diameter pipe

5 ft. plus 2 elbows of 3" or 4"

diameter pipe

TABLE 13

MAXIMUM VENT PIPE LENGTHS

ALTITUDE

0 − 4500

−

4501−7500

7501 − 10000

(2287 − 3048 m)

n/a −− Not allowed. *G61MP−48C−110 and G61MP−60C−110 must have 90° street ell (supplied) installed directly into unit flue collar. **G61MP−60D−135 must have 3" to 2" reducing ell (supplied) installed directly into unit flue collar. ***90° elbows used in configuration of G61MP−60D−135 vent, must be limited to 3" sweep elbows.

G61MP

045 59 65 77 234 070 59 65 78 214 090 26 42 72 204

110* n/a 32 72 179

135** n/a n/a ***61 160

045 59 65 77 234 070 59 65 78 214 090 26 42 72 204

110* n/a 32 72 179

135** n/a n/a ***46 160

045 59 65 77 234 070 59 65 78 214 090 26 42 72 204

110* n/a 32 72 179

135** n/a n/a ***46 160

MAXIMUM EQUIVALENT VENT

LENGTH FEET

2" dia. 2−1/2" dia. 3" dia. 4" dia.

B−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 prim-

er to dry before applying cement.

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.

Page 18

C− Venting Practices

The thickness of construction through which vent pipes may be installed is 24" (610mm) maximum and 3" (76mm) minimum. If a G61MP 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 products, 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 piping.

2. Secure all joints so that they are gas-tight using approved 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 suitable hanger can be fabricated by using metal or plastic strapping or a large wire tie.

STRAPPING (metal, plastic

or large wire

ties)

FIGURE 12

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 in order to prevent transmission of vibration to the structure.

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 condensate collection trap and lines.

Exhaust Piping

NOTE − A 2" diameter street ell is strapped to the blower deck of 48C−110 and 60C−110 units. Street ell must be glued directly into the unit flue collar. See figure 13. A 3" to 2" reducing ell is strapped to the blower deck of the 60D−135 units. In upflow or downflow applications, the reducing ell must be glued directly into the unit flue collar.

1. Choose the appropriate side for venting in upflow or downflow positions. Exhaust piping exits from the top of the unit in horizontal air discharge applications. Glue the field−provided exhaust vent pipe (or provided street ell or reducing ell in upflow or downflow applications) to the flue collar. All cement joints should be made according to the specifications outlined in ASTM D 2855. Refer to pipe and fittings specifications and gluing procedures.

TYPICAL EXHAUST PIPE CONNECTIONS AND CONDENSATE TRAP INSTALLATION

IN UPFLOW OR DOWNFLOW DIRECT OR NON-DIRECT VENT APPLICATIONS

PLUG PLUG

VENT PLUG

(Must be

glued in

place)

PLUG

*2" diameter street elbow provided.

**3" diameter reducing elbow provided.

***Limit pipe length to 2".

(Right-Hand Exit in Upflow Application Shown)

2”

CONDENSATE

TRAP

(Must be installed

on same side as

exhaust piping)

2”

2−1/2", 3", OR

REDUCER

2"***

2"*

G61MP−110 with 2−1/2", 3", OR 4"

vent pipe

2−1/2", 3", OR

REDUCER

2”

G61MP−045, 070

or 090 with 2−1/2",

2”

3", or 4" vent pipe

2”

REDUCER

(use only if

4" pipe is required)

G61MP−135 with

3" OR 4" vent pipe

3"**

FIGURE 13

Page 19

TYPICAL EXHAUST PIPE CONNECTIONS

HORIZONTAL DIRECT OR NON-DIRECT VENT

APPLICATIONS

(Horizontal Right-Hand Air

Discharge Application Shown)

*Limit pipe length to 2" in G61MPV−110 and

−135 applications.

DO NOT transition from smaller to larger pipe size in horizontal runs.

2−1/2", 3", OR

REDUCER

2"*

G61MP−36B−045

G61MP−36B−070 G61MP−48C−090 G61MP−60C−090

G61MP−48C−110* G61MP−60C−110* G61MP−60C−135*

G61MP−36B−045

G61MP−36B−070 G61MP−48C−090 G61MP−60C−090

FIGURE 14

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 toward 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 every 5 feet (1.52m) using hangers.

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

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 termination section.

CAUTION

Do not discharge exhaust into an existing stack or stack that also serves another gas appliance. If vertical discharge through an existing unused stack is required, 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 pressure and must be completely sealed to prevent leakage of combustion products into the living space.

Intake Piping

The G61MP furnace may be installed in either direct vent or non−direct vent applications. In non−direct vent applica- tions, when intake air will be drawn into the furnace from the surrounding space, the indoor air quality must be considered and guidelines listed in Combustion, Dilution and Ventilation Air section must be followed.

The G61MP unit is designed for either left−side or right−side air intake connections in either upflow or downflow applications. In horizontal applications, air intake must be brought in through the top. Intake air piping is independent of exhaust piping.

Follow the next four steps when installing the unit in direct vent applications, where combustion air is taken from outdoors and flue gases are discharged outdoors. The pro-

vided air intake screen must not be used in direct vent applications.

1 − Cement intake piping in slip connector located on the

side of the burner box.

2 − Use a #7 sheet metal screw to secure the intake pipe to

the connector, if desired. A pilot indentation is provided in the slip connector to assist in locating and starting the fastener.

3 − Glue the provided 2" plug into the unused air intake con-

nector on the opposite side of the cabinet.

4 − Route piping to outside of structure. Continue with instal-

lation following instructions given in general guide lines for piping terminations and in intake and exhaust piping terminations for direct vent sections. Refer to figure 15 for pipe sizes.

Page 20

TYPICAL AIR INTAKE PIPE CONNECTIONS

UPFLOW OR DOWNFLOW DIRECT VENT APPLICATIONS

(Right-Hand Exit in Upflow Application Shown)

2

PLUG

(Must be

glued in

place)

G61MP−36B−045

G61MP−36B−070 G61MP−48C−090 G61MP−60C−090

*Limit pipe length to 2" in G61MP−110 and

−135 applications.

TYPICAL AIR INTAKE PIPE CONNECTIONS

HORIZONTAL DIRECT VENT APPLICATIONS

(Horizontal Right-Hand Air Discharge Application Shown)

REDUCER

G61MP−48C−110* G61MP−60C−110*

FIGURE 15

Follow the next three steps when installing the unit in NonDirect Vent applications where combustion air is taken

from indoors and flue gases are discharged outdoors.

2−1/2",

3" OR

4

2*

G61MP−36B−045 G61MP−36B−070 G61MP−48C−090 G61MP−60C−090

2

2−1/2",

3" OR

4

REDUCER

2"*

G61MP−36B−045 G61MP−36B−070 G61MP−48C−090

G61MP−60C−090 G61MP−48C−110* G61MP−60C−110* G61MP−60C−135*

*Limit pipe length to 2" in G51MP−110 and −135 applications.

G61MP−36B−045 G61MP−36B−070 G61MP−48C−090

G61MP−60C−090 G61MP−48C−110* G61MP−60C−110*

G61MP−60C−135*

G61MP−36B−045 G61MP−36B−070 G61MP−48C−090

G61MP−60C−090 G61MP−48C−110* G61MP−60C−110*

G61MP−36B−045 G61MP−36B−070 G61MP−48C−090 G61MP−60C−090

2-1/2”,

3” OR 4”

TYPICAL AIR INTAKE PIPE CONNECTIONS

UPFLOW OR HORIZONTAL NON-DIRECT

VENT APPLICATIONS

(Right-Hand Exit in Upflow Application Shown)

REDUCER

2”*

2-1/2”,

REDUCER

3” OR 4”

2”

PLUG

(Must be

glued in

place)

2”

2”*

2”

6 in. Max.

INTAKE

DEBRIS

SCREEN

(Provided)

NOTE − Debris screen and elbow may be rotated, so that screen may be positioned to face forward, backward or downward.

FIGURE 16

FIGURE 17

Page 21

TYPICAL AIR INTAKE PIPE CONNECTIONS

DOWNFLOW NON-DIRECT VENT APPLICATIONS

(Right-Hand Exit in Downflow Applications Shown)

2" SWEEP

ELL

INTAKE

DEBRIS

SCREEN

(Provided)

PLUG

(Must be

glued in

place)

6 in. Max.

INTAKE DEBRIS

SCREEN

(Provided)

Downflow

Evaporator

Coil

FIGURE 18

1 − Use field−provided materials and the factory−provided

air intake screen to route the intake piping as shown in figures 17 and 18. Maintain a minimum clearance of 3" (76mm) around the air intake opening. The air intake opening (with the protective screen) should always be directed either downward or straight out. Use 2" pipe and fittings only and make sure that the air intake does not extend more than 6" beyond the G61MP cabinet.

The air intake connector must not be located near the floor. To avoid this complication in downflow applications which do not include a downflow evaporator coil, the intake air routing should be modi-

fied as shown in figure 18.

2 − Use a #7 sheet metal screw to secure the intake pipe to

the connector, if desired. A pilot indentation is provided in the slip connector to assist in locating and starting the fastener.

3 − Glue the provided 2" plug into the unused air intake con-

nector on the opposite side of the cabinet.

PLUG

(Must be

glued in

place)

Downflow Additive Flloor Base

NOTE − Debris screen and sweep ell may be rotated, so that screen may be positioned to face forward, backward or to the side.

2" SWEEP ELL

18 in.

Testing for Proper Venting and Sufficient Combustion Air

(Non−Direct Vent Applications Only)

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 monoxide poisoning or death. The following steps shall be followed for each appliance connected to the venting system being placed into operation, while all other appliances connected to the venting system are not in operation.

After the G61MP gas furnace has been started, the following test should be conducted to ensure proper venting and sufficient combustion air has been provided to the G61MP, 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 provisions have not been made for sufficient amounts of combustion 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 restriction, leakage, corrosion, or other deficiencies which could cause an unsafe condition.

Page 22

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 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 Natural Gas and Pro-

pane Installation Codes 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 applications, combustion air is taken from indoors and the flue gases are discharged to the outdoors. The G61MP is then classified as a non-direct vent, Category IV gas furnace. In Non-Direct Vent applications, 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 current CSA−B149 Natural Gas and Propane Installation Codes in Canada for details.

Position termination end according to location given in figure 19. In addition, position termination end so it is free

from any obstructions and above the level of snow accumulation (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), Armaflex or equivalent when run through unheated space. Do not leave any surface area of exhaust pipe open to outside 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 necessary. 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 available from Lennox. See Condensate Piping section for part numbers.

IMPORTANT

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

IMPORTANT

For Canadian Installations Only: In accordance to CSA International B149 installation codes, the minimum allowed distance between the combustion air intake inlet and the exhaust outlet of other appliances shall not be less than 12 inches (305mm).

Page 23

VENT TERMINATION CLEARANCES

FOR INSTALLATIONS IN THE USA AND CANADA*

− G61MP 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 that may be opened −

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

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 installations. In Canada, refer to current edition of CSA B149 installation codes. Local codes or regulations may require 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 or outlet

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).

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) minimum.

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

dow wells, stairwells or alcoves.

J − Do not position terminations directly above a walkway.

FIGURE 19

Page 24

Details of Intake and Exhaust Piping Terminations for Direct Vent Installations

NOTE − In Direct Vent installations, combustion air is taken from outdoors and flue gases are discharged to outdoors.

Intake and 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 preferred. Figures 20 through 28 show typical terminations.

1. Exhaust and intake exits must be in same pressure

zone. Do not exit one through the roof and one on the

side. Also, do not exit the intake on one side and the

exhaust on another side of the house or structure.

2. Intake and exhaust pipes should be placed as close

together as possible at termination end (refer to il-

lustrations). Maximum separation is 3" (76mm) on roof

terminations and 6" (152mm) on side wall termina-

tions.

3. If necessary, install a field−provided reducer to adapt

larger vent pipe size to termination pipe size.

4. On roof terminations, the intake piping should termi-

nate straight down using two 90° elbows (See figure

20).

5. Exhaust piping must terminate straight out or up as

shown. In rooftop applications, a reducer may be re-

quired on the exhaust piping at the point where it exits

the structure to improve the velocity of exhaust away

from the intake piping. See table 14.

NOTE − Care must be taken to avoid recirculation of exhaust back into intake pipe.

6. On field supplied terminations for side wall exits, ex-

haust piping should extend a minimum of 12 inches

(305mm) beyond the outside wall. Intake piping

should be as short as possible. See figure 21.

7. On field supplied terminations, a minimum separation

distance between the end of the exhaust pipe and the

end of the intake pipe is 8 inches (203mm).

8. If intake and exhaust piping must be run up a side wall

to position above snow accumulation or other obstruc-

tions, piping must be supported every 3 ft. (.9m) as

shown in figure 12. Refer to figure 24 for proper piping

method. In addition, WTK wall termination kit must be

extended for use in this application. See figure 27.

When exhaust and intake piping must be run up an

outside wall, the exhaust piping is reduced to 1−1/2"

(38mm) after the final elbow. The intake piping may be

equipped with a 90° elbow turndown. Using turndown

will add 5 feet (1.5m) to the equivalent length of the

pipe.

9. Based on the recommendation of the manufacturer, a multiple furnace installation may use a group of up to four termination kits WTK assembled together horizontally, as shown in figure 26.

TABLE 14

EXHAUST PIPE TERMINATION SIZE REDUCTION

G61MP

MODEL

045 and 070 2", 2−1/2", 3" or 4" 1−1/2"

090 2", 2−1/2", 3" or 4" 2" 110 2−1/2", 3" or 4" 2"* 135 3" or 4" 2"*

*Approved 3" concentric termination kit terminates with 2−5/8" ID pipe.

Inches(mm)

8" (203) MIN

12" (305) ABOVE

AVERAGE SNOW

ACCUMULATION

3" (76) OR

2" (51) PVC

PROVIDE SUPPORT

FOR INTAKE AND

EXHAUST LINES

Exhaust Pipe Size Termination Pipe Size

3(76) MAX.

DIRECT VENT ROOF TERMINATION KIT

(15F75 or 44J41)

SIZE TERMINATION

PIPE PER TABLE 14.

UNCONDITIONED

ATTIC SPACE

1/2" (13) FOAM

INSULATION IN

UNCONDITIONED

SPACE

FIGURE 20

12" (305) MAX.

1/2" (13) ARMAFLEX

INSULATION IN

UNCONDITIONED SPACE

FIELD−

PROVIDED

REDUCER MAY

BE REQUIRED

TO ADAPT

LARGER VENT

PIPE SIZE TO

TERMINATION

OUTSIDE

WALL

2" (51) PVC

COUPLING

TOP VIEW WALL RING KIT

(unless supported)

6" (152)

MAXIMUM

MINIMUM

(15F74)

8" (203)

1/2" (13)

ARMAFLEX

INSULATION

SIZE

TERMINATION

PIPE PER

TABLE 14.

Inches (mm)

FIGURE 21

Page 25

EXHAUST

TERMINATION

INTAKE

TERMINATION

12" (305) ABOVE

AVERAGE SNOW

ACCUMULATION

Inches (mm)

INTAKE

VENT

EXHAUST VENT

Front View

FIELD−PROVIDED

REDUCER MAY BE REQUIRED

TO ADAPT LARGER VENT

PIPE SIZE TO TERMINATION

EXHAUST

INTAKE

DIRECT VENT CONCENTRIC ROOFTOP TERMINATION

(71M80, 69M29 or 60L46)

FIGURE 22

Inches (mm)

EXHAUST

INTAKE

FIELD−PROVIDED

REDUCER MAY

BE REQUIRED TO

ADAPT LARGER VENT PIPE SIZE

TO TERMINATION

DIRECT VENT CONCENTRIC WALL TERMINATION

(71M80, 69M29 or 60L46)

INTAKE

TERMINATION

EXHAUST

TERMINATION

12" (305) Min.

above grade.

FIGURE 23

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

Inches(mm)

UNCONDITIONED

SPACE

OUTSIDE WALL

PROVIDE SUPPORT

FOR INTAKE AND

EXHAUST LINES EVERY

36" (914)

FIELD−PROVIDED

REDUCER MAY

BE REQUIRED TO

ADAPT LARGER

VENT PIPE SIZE

TO TERMINATION

1/2" (13) FOAM

INSULATION IN

UNCONDITIONED

SPACE

(unless supported)

8 (203)

MIN.

12" (305) ABOVE

AVERAGE SNOW

ACCUMULATION

1/2" (13) FOAM

INSULATION

SIZE

TERMINATION

PIPE PER

TABLE 14.

SIDE VIEW

DIRECT VENT WALL RING TERMINATION

(15F74)

See venting table 12 for maximum venting lengths with this arrange-

ment.

FIGURE 24

1/2" (13) Foam Insulation

in Unconditioned Space

FIELD−

PROVIDED

REDUCER MAY

BE REQUIRED

TO ADAPT

LARGER VENT

PIPE SIZE TO

TERMINATION

Side View

EXHAUST VENT

INTAKE VENT

Inches (mm)

OUTSIDE WALL

DIRECT VENT WALL TERMINATION KIT

(22G44, 44J40, 30G28 or 81J20)

FIGURE 25

EXHAUST

VENT

INTAKE

VENT

Inches (mm)

(127)

18" MAX.

(457)

12"

(305)

5−1/2"

(140)

Front View

EXHAUST VENT

INTAKE

VENT

Side View

OPTIONAL VENT TERMINATION FOR MULTIPLE UNIT

INSTALLATION OF DIRECT VENT WALL TERMINATION KIT WTK

FIGURE 26

Page 26

INTAKE

AIR

GRADE

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

(unless supported)

8" (203)

Minimum

Side View

Inches (mm)

EXHAUST

AIR

12" (305)

Minimum

ABOVE GRADE

INTAKE

AIR

(127)

12"

(305)

5-1/2"

(140)

COVER EXHAUST

VENT WITH

1/2" (13)

FOAM

INSULATION

EXHAUST

AIR

12" MIN.

(305)

Above Grade

GRADE

DIRECT VENT TERMINATION

WALL TERMINATION KIT (22G44, 44J40, 30G28 or 81J20) EXTENDED VENT FOR GRADE CLEARANCE

FIGURE 27

Front View

G61MP DIRECT VENT APPLICATION

USING EXISTING CHIMNEY

3" − 8"

8" − 12"

(203mm − 305mm)

INTAKE PIPE

INSULATION (optional)

SHEET

METAL TOP

PLATE

MINIMUM 12"

(305mm) ABOVE

ROOF

INSULATE

TO FORM

SEAL

*SIZE TERMINATION PIPE PER TABLE 14.

NOTE − Do not discharge exhaust gases directly into any chimney or vent stack. If vertical 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 illustrated. In any exterior portion of chimney, the exhaust vent must be insulated.

(76mm−

203mm)

STRAIGHT−CUT OR

ANGLE−CUT IN DIRECTION

OF ROOF SLOPE *

EXHAUST VENT

1/2" (13mm)

WEATHERPROOF

INSULATION

SHOULDER OF FITTINGS

PROVIDE SUPPORT

OF PIPE ON TOP PLATE

3" − 8" (76mm− 203mm)

ALTERNATE INTAKE PIPE

EXTERIOR

PORTION OF

CHIMNEY

FIGURE 28 Details of Exhaust Piping Terminations for Non-Direct Vent Applications

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 preferred. Figures 29 through 32 show typical terminations.

1. Exhaust piping must terminate straight out or up as

shown. The termination pipe must be sized as listed in table 14.The specified pipe size ensures proper velocity required to move the exhaust gases away from the building.

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

haust piping should extend a maximum of 12 inches (305mm) beyond the outside wall, unless support is provided in the horizontal section. See figure 30.

Inches(mm)

12" (305mm)

ABOVE AVE.

SNOW

ACCUMULATION

3" (76) OR

2" (51) PVC

PROVIDE SUPPORT

FOR EXHAUST LINES

NON−DIRECT VENT ROOF TERMINATION KIT

1/2" (13) ARMAFLEX

INSULATION IN

UNCONDITIONED SPACE

FIELD−PROVIDED

REDUCER MAY

BE REQUIRED TO

ADAPT LARGER

VENT PIPE SIZE

TO TERMINATION

Inches (mm)

NON−DIRECT VENT WALL RING KIT

(15F75 or 44J41)

FIGURE 29

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

TOP VIEW

(15F74)

FIGURE 30

SIZE TERMINATION

PIPE PER TABLE

14.

UNCONDITIONED

ATTIC SPACE

1/2" (13)

ARMAFLEX

INSULATION

PVC REDUCER

SIZE TERMINATION

PIPE PER TABLE 14.

Page 27

3. If exhaust piping must be run up a side wall to position above snow accumulation or other obstructions, piping must be supported every 3 feet (.9m) as shown in figure 12. Refer to figure 31 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.

Horizontal

left and

optional

downflow

CONDENSATE TRAP LOCATIONS

(Unit shown in upflow position)

Horizontal

right and

optional

downflow

Inches(mm)

UNCONDITIONED

SPACE

OUTSIDE WALL

PROVIDE SUPPORT

FOR EXHAUST LINES

EVERY 36" (914)

FIELD−PROVIDED

REDUCER MAY BE

REQUIRED TO

ADAPT LARGER

VENT PIPE SIZE TO

TERMINATION

1/2" (13) FOAM

INSULATION IN

UNCONDITIONED

SPACE

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

SIZE TERMINATION PIPE PER TABLE 14.

12" (305) ABOVE AVERAGE SNOW ACCUMULATION

1/2" (13) FOAM

INSULATION

SIDE VIEW

NON−DIRECT VENT WALL RING TERMINATION

(15F74)

FIGURE 31

G61MP NON−DIRECT VENT APPLICATION

USING EXISTING CHIMNEY

SIZE TERMINATION

PIPE PER TABLE 14.

3" − 8"

(76mm−

MINIMUM 12"

MINIMUM

12" (304mm)

(305mm) ABOVE

ABOVE AVERAGE

AVERAGE SNOW

SNOW ACCUMULATION

ACCUMULATION

METAL TOP

INSULATE TO FORM

SEAL

203mm)

SHEET

PLATE

STRAIGHT−CUT OR

ANGLE−CUT IN DIRECTION

OF ROOF SLOPE

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

FIGURE 32

Condensate Piping

This unit is designed for either right- or left-side exit of condensate piping in either upflow or downflow applications; however, it must be installed on the same side of the unit as the exhaust piping. In horizontal applications, the condensate trap should extend below the unit. A 5−1/2" service clearance is required for the condensate trap. Refer to figure for condensate trap locations.

Optional

upflow

Optional

upflow

FIGURE 33

1 − Determine which side condensate piping will exit the

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

NOTE − The condensate trap is factory−shipped with two rubber O−rings and two rubber clean−out caps installed. Check to make sure that these items are in place before installing the trap assembly.

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 34.

NOTE − In upflow and downflow applications, condensate trap must be installed on the same side as exhaust piping.

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.

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 diameter which will accept a standard 3/4" PVC coupling. The inner diameter of each stub will accept 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 to the drain stubs on the trap 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 drain stubs on the trap using a hose clamp. Do not overtighten the

Page 28

hose clamp. Condensate line must be sloped downward away from condensate trap to drain. If drain level is above condensate trap, condensate pump must be used. Condensate drain line should be routed within the conditioned space to avoid freezing of condensate and blockage of drain line. If this is not possible, a heat 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 − If unit will be started immediately upon completion of

installation, prime trap per procedure outlined in Unit Start−Up section.

6 − Glue the provided cap onto the unused condensate

drain line stub.

CONDENSATE ASSEMBLY

O−RINGS

HI/LO SCREWS (DO NOT use power driver. Hand−tighten using screw driver.)

VENT

NIPPLE

TEE

CAP

NIPPLE

COUPLING

CLEAN−OUT ACCESS

(both sides)

CONDENSATE TRAP

SCREW

FIGURE 34

Page 29

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

within range listed on the nameplate. If not, consult the power company and have voltage condition corrected before starting unit.

B−Heating Start-Up

FOR YOUR SAFETY READ BEFORE OPERATING

WARNING

Shock and burn hazard.

G61MP units are equipped with a hot surface ignition system. Do not attempt to light manually.

BEFORE LIGHTING the unit, smell all around the fur-

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

The gas valve on the G61MP 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 the lever will not move or the knob will not push in or turn by hand, do not try to repair it. Force or attempted repair may result in a fire or explosion.

Placing the furnace into operation:

G61MP units are equipped with a SureLight® 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 SureLight ignition system.

Priming Condensate Trap

The condensate trap should be primed with water prior to start−up to ensure proper condensate drainage. Either pour 10 fl. oz. (300 ml) of water into the trap, or follow these steps to prime the trap:

1 − Follow the lighting instructions to place the unit into op-

eration.

2 − Set the thermostat to initiate a heating demand.

3 − Allow the burners to fire for approximately 3 minutes. 4 − Adjust the thermostat to deactivate the heating de-

mand.

5 − Wait for the combustion air inducer to stop. Set the

thermostat to initiate a heating demand and again allow the burners to fire for approximately 3 minutes.

6 − Adjust the thermostat to deactivate the heating de-

mand and again wait for the combustion air inducer to stop. At this point, the trap should be primed with sufficient water to ensure proper condensate drain operation.

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 (Figures 35 and 36)

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.

6 − Honeywell VR8205 Gas Valve − Turn knob on gas

valve clockwise to OFF. Do not force. See figure

35.

White Rodgers 36E Gas Valve − Switch gas valve le-

ver to OFF. See figure 36 for the White Rodgers 36E

valve.

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.

HONEYWELL VR8205 Series Gas Valve

REFERENCE TO

HIGH FIRE

ADJUSTMENT

SCREW

(under cap)

lOW FIRE

ADJUSTMENT

SCREW

(under cap)

GAS VALVE SHOWN IN OFF POSITION

BURNER BOX

hose barb in place of cap

iNLET PRESSURE TAP

FIGURE 35

MANIFOLD

PRESSURE

TAP

Page 30

WHITE RODGERS 36E SERIES GAS VALVE

HIGH FIRE

MANIFOLD

PRESSURE

ADJUSTMENT

ON SIDE

(under cap)

IV−HEATING SYSTEM SERVICE CHECKS A−C.S.A. Certification

All units are C.S.A. (formally A.G.A. and C.G.A. combined) design certified without modifications. Refer to the G61MP Installation Instruction.

B−Gas Piping

MANIFOLD

PRESSURE

TAP ON SIDE

INLET PRESSURE

TAP ON SIDE

GAS VALVE SHOWN IN OFF POSITION

8 − Honeywell VR8205 Gas Valve − Turn knob on gas

valve counterclockwise to ON. Do not force. White Rodgers 36E Gas Valve − Switch gas valve lever to ON. See figure 36 for the White Rodgers 36E valve.

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 technician 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 − Honeywell VR8205 Gas Valve − Turn knob on gas

valve clockwise to OFF. Do not force.

White Rodgers 36E Gas Valve − Switch gas valve le-

ver to OFF. 5 − Replace the upper access panel.

LOW FIRE MANIFOLD

PRESSURE ADJUSTMENT

ON SIDE (under cap)

FIGURE 36

C−Safety or Emergency Shutdown

Turn off unit power. Close manual and main gas valves.

CAUTION

If a flexible gas connector is required or allowed by the authority that has jurisdiction, black iron pipe shall be installed at the gas valve and extend outside the furnace cabinet.

WARNING

Do not exceed 600 in−lbs (50 ft−lbs) torque when attaching the gas piping to the gas valve.

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.

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

C−Testing Gas Piping

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.

When pressure testing gas lines, the gas valve must be disconnected and isolated. Gas valves can be damaged if subjected to more than 0.5psig (14" W.C.). See figure 37.

GAS PIPING TEST PROCEDURE

MANUAL MAIN SHUT−OFF VALVE

CAP

D−Extended Period Shutdown

Turn off thermostat or set to UNOCCUPIED" mode. Close all gas valves (both internal and external to unit) to guarantee no gas leak into combustion chamber. Turn off power to unit. All access panels and covers must be in place and secured.

Page 31

GAS VALVE

FIGURE 37

When checking piping connections for gas leaks, use pre-

G61MP

ferred means. Kitchen detergents can cause harmful corrosion 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.

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

D−Testing Gas Supply Pressure

When testing supply gas pressure, connect test gauge to inlet pressure tap on the gas valve. See figures and 35 and

36. 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. See table 15 for operating pressure at unit gas connection (line).

On multiple unit installations, each unit should be checked separately, with and without units operating. Supply pressure must fall within range listed in table 15.

TABLE 15

All G61MP Units Natural LP

Line Pressure WC" 4.5 − 10.5 11.0 − 13.0

E−Check Manifold Pressure

After line pressure has been checked and adjusted, check manifold pressure. Move pressure gauge to outlet pressure tap located on unit gas valve (GV1). Checks of manifold pressure are made as verification of proper regulator adjustment. Manifold pressure for the G61MP can be measured at any time the gas valve is open and is supplying gas to the unit. See table 19 for manifold pressures.

IMPORTANT

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

The gas valve is factory set and should not require adjustment. All gas valves are factory regulated sensing atmo-

spheric pressure.

5 − After allowing unit to stabilize for 5 minutes, record

manifold pressure and compare to value given in table

19.

6 − Repeat steps 3, 4 and 5 on high heat.

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

NOTE − During this test procedure, the unit will be overfiring:

D Operate unit only long enough to obtain accurate read-

ing to prevent overheating heat exchanger.

D Attempts to clock gas meter during this procedure will

be inaccurate. Measure gas flow rate only during normal unit operation.

7 − When test is complete remove obstruction from hose

and return hose to gas valve barbed fitting.

F− Proper Gas Flow (Approximate)

Furnace should operate at least 5 minutes before checking gas flow. Determine time in seconds for two revolutions of gas through the meter. (Two revolutions assures a more accurate time.) Divide by two and compare to time in table 16 below. If manifold pressure matches table 15 and rate is incorrect, check gas orifices for proper size and restriction.

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

TABLE 16

GAS METER CLOCKING CHART

Seconds for One Revolution

G61MP

Unit

−45 82 164 205 410

−70 55 110 136 272

−90 41 82 102 204

−110 33 66 82 164

−135 27 54 68 136

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

IMPORTANT

Manifold Pressure Measurement & Adjustment

NOTE − Pressure test adapter kit (10L34) is available from Lennox to facilitate manifold pressure measurement.

1 − Connect test gauge to outlet tap on gas valve.

2 − Disconnect pressure sensing hose from gas valve. 3 − Start unit on low heat and allow 5 minutes for unit to

reach steady state.

4 − 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.

For safety, shut unit off and remove manometer as soon as an accurate reading has been obtained. Take care to replace pressure tap plug.

G− Proper Combustion

Furnace should operate minimum 15 minutes with correct manifold pressure and gas flow rate before checking combustion. See sections E− and F−. Take combustion sample beyond the flue outlet and compare to the tables below. The maximum carbon monoxide reading should not exceed 100 ppm.

Page 32

TABLE 17 High Heat

Unit CO2%

For Nat

CO2%

For L.P.

G61MP−36B−045 6.5 − 7.5 7.4 − 8.4

G61MP−36B−070 6.5 − 7.5 7.4 − 8.4

G61MP−48C−090 6.9 − 7.9 7.8 − 8.8

G61MP−60C−090 6.9 − 7.9 7.8 − 8.8

G61MP−48C−110 7.2 − 8.2 8.1 − 9.1

G61MP−60C−110 7.2 − 8.2 8.1 − 9.1

G61MP−60D−135 7.4 − 8.4 8.3 − 9.3

TABLE 18

Low Heat

Unit CO2%

For Nat

CO2%

For L.P.

G61MP−36B−045 4.8 − 5.8 5.3 − 6.3

G61MP−36B−070 4.8 − 5.8 5.3 − 6.3

G61MP−48C−090 5.1 − 6.1 5.9 − 6.9

G61MP−60C−090 5.1 − 6.1 5.9 − 6.9

G61MP−48C−110 5.3 − 6.3 6.1 − 7.1

G61MP−60C−110 5.3 − 6.3 6.1 − 7.1

G61MP−60D−135 5.7 − 6.7 6.7 − 7.7

H− High Altitude

NOTE − In Canada, certification for installations at elevations over 4500 feet (1372 m) is the jurisdiction of local authorities.

The manifold pressure may require adjustment to ensure proper operation at higher altitudes. Refer to table 19 for proper manifold pressure settings at varying altitudes and required pressure switch changes and conversion kits at varying altitudes.

The combustion air pressure switches are factory−set and require no adjustment.

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

I− Condensate pH Range

The condensate is mildly acidic and can be measured with pH indicators. The pH scale is a measurement of acidity and alkalinity. The following scale shows the relative pH of some common liquids as compared with condensate of G61MP units. The concentration of the acidity of all these fluids including the condensate is very low and harmless.

pH RANGE

0 1

Increasing

Acidity

Increasing

Alkalinity

2 3 4 5 6 7 8 9 10 11

Vinegar Wine Orange Juice Tomato Juice

Tap Water

G61 Condensate pH Range

TABLE 19

Conversion Kit Requirements and Manifold Pressures

Altitude

Kit

N/A

59M13

N/A

59M13

N/A

59M13

N/A

59M13

N/A

59M13

0−4500 ft.

(0−1372 m)

Pressure

Switch

No Change

Model

Input

Size

−045

−070

−090

−110

−135

Pressure switch is factory set. No adjustment necessary. All models use the factory installed pressure switch from 0−4500 feet (0−1370 m).

Gas

Required

Conversion

Nat

LPG

Nat

LPG

Nat

LPG

Nat

LPG

Nat

LPG

4501−7500 ft.

(1373−2286 m)

Required

Conversion

Kit

N/A

59M13

N/A

59M13

N/A

59M13

N/A

59M13

N/A

59M13

Pressure

Switch

No Change

75M22

No Change

59M93

7501−10,000

(2287−3048 m)

Required

Conversion

Kit

59M16

59M14

59M16

59M14

59M16

59M14

59M16

59M14

59M16

59M14

Pressure

Switch

No Change

56M06

56M21

No Change

56M93

Manifold Pressure at all

altitudes

Low Fire High Fire

in.

w.c.

1.7

4.9

1.7

4.9

1.7

4.9

1.7

4.9

1.7

4.9

kPa

0.42

1.22

0.42

1.22

0.42

1.22

0.42

1.22

0.42

1.22

in.

w.c.

3.5

10.0

3.5

10.0

3.5

10.0

3.5

10.0

3.5

10.0

kPa

0.87

2.5

0.87

2.5

0.87

2.5

0.87

2.5

0.87

2.5

Page 33

J−Flame Signal

A microamp DC meter is needed to check the flame signal on the ignition control. Flame (microamp) signal is an electrical current which passes from the furnace control through the sensor during unit operation. Current passes from the sensor through the flame to ground to complete a safety circuit.

To Measure Flame Signal − Ignition Control:

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38. The transducer converts microamps to volts on a 1:1 conversion. Flame signal for the SureLight control should read 0.23 or greater microamps with a lockout signal of 0.16 microamps. A digital readout meter must be used. The transducer plugs into most meters. See figure 39 for proper use of transducer.

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

transducer into the VDC and common inputs. Observe 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.

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.

FLAME SENSOR

(+) TO

IGNITION

CONTROL

SENSOR

WIRE

FIGURE 39

TRANSDUCER

(PART #78H5401)

FIGURE 38

NOTE−MUST USE DIGITAL METER

SET DIAL TO MEASURE

(+)

(−)

(−) TO

VDC

RED COLLAR

INDICATES

POSITIVE

LEAD

V−TYPICAL OPERATING CHARACTERISTICS A−Blower Operation and Adjustment

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 − Depending on the type of indoor thermostat, blower

and entire unit will be off when the system switch is in OFF position.

B−Temperature Rise

Temperature rise for G61MP 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 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 horizontal 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, increase blower speed to reduce temperature. To change blower speed taps see the Blower Speed Taps section in this manual.

C−External Static Pressure

1 − Tap locations shown in figure 40.

2 − Punch a 1/4" diameter hole

in supply and return air plenums. Insert manometer hose flush with inside edge of hole or insulation. Seal around the hose with permagum. Connect the zero end of the manometer to the discharge (supply) side of the system. On ducted systems, 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 atmosphere.

3 − With only the blower motor running and the evaporator

coil dry, observe the manometer reading. Adjust blower motor speed to deliver the air desired according to the job requirements.

4 − External static pressure drop must not be more than

0.8" W.C.

5 − Seal around the hole when the check is complete.

STATIC PRESSURE TEST

FIGURE 40

Page 34

D−Blower Speed Taps

Furnace

Blower speed tap changes are made on the SureLight control board. See figure 4. The unused tap must be secured on dummy terminals "PARK " on the SureLight board. The high heating tap is connected to the "HI HEAT " terminal and the low heating / continuous blower tap is connected to the "LO HEAT" terminal. The cooling tap is connected to the COOL" tap. To change existing heat tap, turn off power then switch out speed tap on "HI HEAT" or LO HEAT" with tap connected to "PARK ". See table 20 for blower motor tap colors for each speed.

TABLE 20

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 operation, serious injury, death, or property damage. Before servicing, disconnect all electrical power to furnace. When servicing controls, label all wires prior to disconnecting. 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:

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.

Filters

Filters should be inspected monthly. Clean or replace the filters when necessary to ensure proper furnace operation. Replacement filters must be rated for high velocity airflow. Table 21 lists recommended filter sizes.

TABLE 21

Furnace

Cabinet Size

17−1/2" 16 X 25 X 1 (1) 16 X 25 X 1 (1)

21" 16 X 25 X 1 (1) 20 X 25 X 1 (1)

24−1/2" 16 X 25 X 1 (2) 24 X 25 X 1 (1)

Exhaust and air intake pipes

Check the exhaust and air intake pipes and all connections for tightness and to make sure there is no blockage.

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__________

Winterizing 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.

Cleaning Heat Exchanger

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

Side Return Bottom Return

Filter Size

IMPORTANT

Safety glasses and surgical mask should be worn when cleaning heat exchanger and or burner 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.

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

plug from the ignitor. 6 − Disconnect wires from flame roll−out switches. 7 − Remove burner box cover and remove four burner box

screws at the vestibule panel and remove burner box.

Set burner box assembly aside. G61MP−135 only −

Remove and discard two additional shipping screws.

See figure 41.

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

procedures outlined in Burner Cleaning section.

8 − Loosen three clamps and remove flexible exhaust tee.

Page 35

G61MP−135 ONLY

Remove and discard two shipping screws.

FIGURE 41

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 necessary to cut drain pipe). Remove screws that secure 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 − Mark and disconnect all combustion air pressure tub-

ing from cold end header collector box.

13 − Mark and remove wires from pressure switches. Re-

move pressure switches. Keep tubing attached to pressure switches.

14 − Disconnect the 3-pin plug from the combustion air in-

ducer. Disconnect the two wires to the backup secondary limit, if applicable. Remove four screws which secure combustion air inducer to collector box. Remove combustion air inducer assembly. Remove ground wire from vest panel.

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 assembly to cabinet. Remove two screws from blower rail which secure bottom heat exchanger flange. Remove 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 cabinet. 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 electrical junction box. 28 − Reinstall the combustion air inducer. Reconnect the

3−pin plug to the wire harness. Reconnect the two

wires to the backup secondary limit, if applicable. 29 − Reinstall pressure switches and reconnect pressure

switch wiring. 30 − Carefully connect combustion air pressure switch

hosing from pressure switches to proper stubs on

cold end header collector box. 31 − Reinstall condensate collars on each side of the fur-

nace. Reconnect drain tubing to collector box. 32 − Reinstall condensate trap on same side as exhaust

pipe. Reconnect condensate drain line to the conden-

sate trap. 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 − Reinstall burner box cover. 41 − Reconnect wires to gas valve. 42 − Replace the blower compartment access panel. 43 − Refer to instruction on verifying gas and electrical con-

nections when re−establishing supplies. 44 − 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. 45 − Replace heating compartment access panel.

Page 36

Cleaning the Burner Assembly

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 burner box cover and remove four screws

which secure burner box assembly to vest panel. Remove burner box from the unit. G61MP−135 only − Remove and discard two additional shipping screws. See figure 41.

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 blockage 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. Reinstall the burner box cover.

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 37

VII− Wiring and Sequence of Operation

Page 38

Sequence of Operation

Sequence depends on type thermostat used. G61MP units are applicable for single stage or two stage thermostats. Both type thermostats are described below. Thermostat jumper E20 dictates which mode unit will operate in. See flow chart for more sequence detail.

SureLight Control Self Check

When there is a call for heat, the SureLight integrated control runs a self check. The control checks for S10 primary limit, S21 secondary limit (s) and S47 rollout switch normally closed contacts. The control also checks for S102 high heat and S128 low heat prove switch normally open contacts. Once self check is complete and all safety switches are operational, heat call can continue.

Two−Stage Thermostat, Two Stage Heat. Jumper E20

set at TWO".

1− SureLight control energizes combustion air inducer B6

on low heat speed. Combustion air inducer runs until S128 low heat prove switch contacts close (switch must close within 2 1/2 minutes or control goes into Watchguard Pressure Switch mode. High heat prove switch S102 may also close). A 15 second pre−purge follows once S128 closes.

2− SureLight control begins 20 second ignitor warm up

period.

3− Gas valve opens on first stage for a 4 second trial for

ignition. Ignitor stays energized during the trial or until flame sensed.

4− Flame is sensed, gas valve remains on first stage heat,

ignitor de−energizes.

5− After 45 second delay, indoor blower B3 is energized

on low heat speed.

The furnace will stay in this mode until first stage demand is satified OR a second stage heat demand is initiated.

6− Second stage heat demand initiated. A 30 second sec-

ond stage recognition period begins.

7− The combustion air inducer ramps up to high heat

speed.

8− S102 high heat prove switch closes and the gas valve

energizes second stage heat.

9− B3 indoor blower energizes on high heat speed.

Single−Stage Thermostat, Two Stage Heat. Jumper

E20 set at SINGLE"

1− SureLight control energizes combustion air inducer B6

on low heat speed. Combustion air inducer runs until S128 low heat prove switch contacts close (switch must close within 2 1/2 minutes or control goes into Watchguard Pressure Switch mode High heat prove switch S102 may also close). A 15 second pre−purge follows once S128 closes.

2− SureLight control begins 20 second ignitor warm up

period.

3− Gas valve opens on first stage for a 4 second trial for

ignition. Ignitor stays energized during the trial or until flame sensed.

4− Flame is sensed, gas valve remains on first stage heat,

ignitor de−energizes.

5− After 45 second delay, indoor blower B3 is energized

on low heat speed.

6− A 10 minute (factory set) or 15 minute (field set) second

stage heat delay period begins.

7− After the delay the combustion air inducer ramps up to

high heat speed.

8− S102 high heat prove switch closes and the gas valve

energizes second stage heat.

9− B3 indoor blower energizes on high heat speed.

Page 39

HEATING SEQUENCE OF OPERATION

NORMAL AND ABNORMAL HEATING MODE

POWER ON

CONTROL SELF−CHECK OKAY?

GAS VALVE OFF. COMBUSTION AIR INDUCER OFF. INDOOR BLOWER OFF. CHECK FOR BROKEN IGNITOR OR OPEN IGNITER CIRCUIT.

DS1 AND DS2 ALTERNATING FAST FLASH.

GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.

INDOOR BLOWER OFF. (RESET CONTROL BY

TURNING MAIN POWER OFF.) DS1 ON, DS2 ON

POLARITY OKAY?

YES

IS THERE A

PROPER GROUND?

YES

IS VOLTAGE

ABOVE 75 VOLTS?

YES

BURNER OFF?

(CONTINUOUS FLAME CHECK)

YES

NORMAL OPERATION:

DS 1 −− SIMULTANEOUS SLOW FLASH DS 2 −− SIMULTANEOUS SLOW FLASH

THERMOSTAT CALLS FOR HEAT:

DS 1 −− SIMULTANEOUS FAST FLASH DS 2 −− SIMULTANEOUS FAST FLASH

YES

PRIMARY AND SECONDARY LIMIT

SWITCHES CLOSED?

YES

ROLLOUT SWITCH CLOSED?

YES

FIRST (LOW) STAGE PRESSURE

SWITCHES OPEN?

YES

SECOND (HIGH) STAGE PRESSURE

SWITCHES OPEN?

SIGNAL HOLDS UNTIL UNIT IS PROPERLY GROUNDED.

DS1 AND DS2 ALTERNATING FAST FLASH.

SIGNAL HOLDS UNTIL VOLTAGE RISES ABOVE 75 VOLTS.

DS1 AND DS2 ALTERNATING FAST FLASH.

GAS VALVE OFF. COMBUSTION AIR INDUCER ON.

INDOOR BLOWER ON HEATING SPEED.

INDOOR BLOWER ON. HAS PRIMARY OR

SECONDARY LIMIT RESET WITHIN 3 MINUTES?

60−MINUTE LIMIT WATCHGUARD MODE.

GAS VALVE OFF, COMBUSTION AIR INDUCER

OFF, INDOOR BLOWER OFF WITH DELAY.

DS1 AND DS2 ALTERNATING SLOW FLASH.

GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.

HAS MANUAL ROLLOUT SWITCH(ES) BEEN

RESET (CLOSED) WITHIN 3 MINUTES?

GAS VALVE OFF. COMBUSTION AIR INDUCER OFF. INDOOR BLOWER OFF. CONTROL REMAINS UNTIL

PRESSURE SWITCH IS DETECTED OPEN.

POLARITY REVERSED.

DS1 −− FAST FLASH

DS2 −− SLOW FLASH

DS1 SLOW FLASH, DS2 OFF.

COMBUSTION AIR INDUCER OFF.

DS1 SLOW FLASH, DS2 ON.

DS1 OFF, DS2 SLOW FLASH.

YES

TWO−STAGE OR SINGLE−STAGE THERMOSTAT

CALL FOR HEAT

COMBUSTION AIR INDUCER ON LOW SPEED.

DS1 AND DS2 SIMULTANEOUS FAST FLASH

CONTINUED ON NEXT PAGE

COMBUSTION AIR INDUCER OFF.

GAS VALVE OFF.

INDOOR BLOWER OFF.

CONTROL WILL NOT ATTEMPT SECOND−STAGE

OPERATION DURING THIS HEAT DEMAND.

FIRST−STAGE OPERATION WILL BE ATTEMPTED.

DS1 OFF, DS2 FAST FLASH.

Page 40

HEATING SEQUENCE OF OPERATION

CONTINUED

FIRST−STAGE (LOW FIRE) PRESSURE

SWITCH CLOSED WITHIN 2.5 MINUTES?

YES

15−SECOND COMBUSTION AIR INDUCER

PRE−PURGE INITIATED BY CLOSED FIRST−STAGE

PRESSURE SWITCH (or 15 SECOND

INTER−PURGE PERIOD.)

DS1 AND DS2 SIMULTANEOUS FAST FLASH.

IGNITOR WARM−UP (20 SECONDS)

DS1 AND DS2 SIMULTANEOUS FAST FLASH

IS VOLTAGE ABOVE 75 VOLTS?

YES

IS THERE A PROPER GROUND?

IS IGNITOR INTACT AND CONNECTED?

YES

THERMOSTAT CALLS FOR HEAT

DS1 AND DS2 SIMULTANEOUS FAST FLASH

(Refer to box A on previous page)

GAS VALVE OFF. COMBUSTION AIR INDUCER

OFF. INDOOR BLOWER OFF. UNIT WILL RETRY

AFTER 5−MINUTE WAIT PERIOD.

DS1 OFF, DS2 SLOW FLASH.

COMBUSTION AIR INDUCER OFF, IGNITER OFF.

SIGNAL HOLDS UNTIL VOLTAGE RISES ABOVE 75 VOLTS.

DS1 AND DS2 ALTERNATING FAST FLASH.

COMBUSTION AIR INDUCER OFF, IGNITER OFF.

SIGNAL HOLDS UNTIL UNIT IS PROPERLY GROUNDED.

DS1 AND DS2 ALTERNATING FAST FLASH.

COMBUSTION AIR INDUCER OFF, IGNITOR OFF.

SIGNAL HOLDS UNTIL IGNITOR IS REPLACED

OR RECONNECTED.

DS1 AND DS2 ALTERNATING FAST FLASH.

AT END OF IGNITOR 20 SECOND WARM UP

PERIOD, 4−SECOND TRIAL FOR IGNITION.

GAS VALVE OPENS, IGNITOR ENERGIZED DURING

4−SECOND TRIAL UNTIL FLAME SENSED.

DS1 AND DS2 SIMULTANEOUS FAST FLASH.

YES

4−SECOND FLAME STABILIZATION PERIOD.

DS1 AND DS2 SIMULTANEOUS FAST FLASH.

FLAME RECTIFICATION CURRENT CHECK

CAN FLAME BE PROVEN WITHIN 4

SECONDS AFTER GAS VALVE OPENS?

(u0.16 microamps)

FLAME PRESENT?

YES

CONTINUED ON NEXT PAGE

GAS VALVE OFF. COMBUSTION AIR

HAS CONTROL RESET IGNITION SEQUENCE

INDUCER ON. INDOOR BLOWER OFF.

DS1 SLOW FLASH, DS2 FAST FLASHN.

HAS CONTROL FAILED TO SENSE

FLAME FOR FIVE CONSECUTIVE TRIES

DURING A SINGLE HEAT DEMAND?

YES

WATCHGUARD MODE. GAS VALVE OFF,

COMBUSTION AIR INDUCER OFF.

INDOOR BLOWER OFF.

DS1 AND DS2 ALTERNATING SLOW FLASH.

IS 60−MINUTE RESET PERIOD COMPLETE?

YES

FOUR (4) TIMES?

DS1 SLOW FLASH, DS2 FAST FLASH.

YES

Page 41

CONTINUED

FLAME SIGNAL ABOVE

(u0.22 microamps)

YES

HEATING SEQUENCE OF OPERATION

THERMOSTAT CALLS FOR HEAT.

DS1 AND DS2 SIMULTANEOUS FAST FLASH.

YES

DS1 SLOW FLASH, DS2 FAST FLASH.

LOW FLAME SIGNAL

(Does not affect control operation)

SEE BOX A.

SINGLE−STAGE THERMOSTAT MODE

(E20 SET AT SINGLE")

YES

START SECOND−STAGE RECOGNITION

ON DELAY (10 OR 15 MINUTES).

DS1 AND DS2 SIMULTANEOUS FAST FLASH.

FIRST−STAGE (LOW FIRE)

PRESSURE SWITCHES CLOSED?

YES

FIRST−STAGE HEAT DEMAND SATISFIED?

DS1 AND DS2 SIMULTANEOUS SLOW FLASH.

GAS VALVE OFF, COMBUSTION AIR INDUCER

OFF FOLLOWING POST PURGE.

INDOOR BLOWER OFF WITH DELAY

DS1 AND DS2 SIMULTANEOUS SLOW FLASH

SECOND−STAGE HEAT DEMAND.

SECOND−STAGE HEAT DEMAND REQUIRED?

DS1 AND DS2 SIMUTANEOUS SLOW FLASH.

SECOND STAGE PRESSURE SWITCHES CLOSED?

ABNORMAL FLASH CODE.

NOTE − IF SECOND−STAGE PRESSURE SWITCHES

WERE ORIGINALLY FOUND CLOSED,

ABNORMAL CODE WILL FLASH.

SECOND−STAGE 30−SECOND DELAY ON BEGINS.

DS1 AND DS2 SIMULTANEOUS FAST FLASH

SECOND−STRAGE COMBUSTION AIR INDUCER

ON. SECOND−STAGE GAS VALVE ON. HIGH

HEAT INDOOR BLOWER SPEED ON.

DS1 AND DS2 SIMULTANEOUS FAST FLASH.

SECOND−STAGE PRESSURE SWITCHES CLOSED

IN LESS THAN TEN (10) SECONDS?

DS1 AND DS2 SIMULTANEOUS FAST FLASH.

YES

CONTINUED ON NEXT PAGE

TWO STAGE THERMOSTAT MODE

(E20 SET AT TWO")

YES

45−SECOND INDOOR BLOWER ON DELAY BEGINS.

DS1 AND DS2 SIMULTANEOUS FAST FLASH.

YES

PRIMARY, SECONDARY, ROLLOUT AND BACKUP

SECONDARY LIMIT SWITCHES CLOSED?

GAS VALVE OFF, COMBUSTION AIR INDUCER OFF, INDOOR BLOWER ON. DS1 SLOW FLASH, DS2 ON.

HAS PRIMARY, SECONDARY, ROLLOUT OR BACKUP

SECONDARY LIMIT SWITCH CLOSED WITHIN 3 MINUTES?

(Indoor blower on low speed during 3−minute period)

LIMIT SWITCH WATCHGUARD MODE.

GAS VALVE OFF, COMBUSTION AIR INDUCER OFF,

DS1 AND DS2 ALTERNATING SLOW FLASH.

IS 60−MINUTE RESET PERIOD COMPLETE?

GAS VALVE OFF. COMBUSTION AIR INDUCER ON.

INDOOR BLOWER OFF AFTER DELAY.

SECOND−STAGE PRESSURE SWITCHES CLOSED

AT BEGINNING OF HEAT DEMAND?

DS1 AND DS2 SIMULTANEOUS SLOW FLASH.

RETURNS TO FIRST−STAGE HEAT MODE WHICH

CONTINUES UNTIL SECOND−STAGE PRESSURE

SWITCHES CAN BE PROVEN or HEAT DEMAND IS

SATISFIED. FIVE (5) MINUTE WAIT PERIOD

INITIATED BEFORE RETRY. WERE 5 ATTEMPTS

DS1 AND DS2 SIMULTANEOUS SLOW FLASH.

YES

INDOOR BLOWER OFF WITH DELAY.

DS1 OFF, DS 2 SLOW FLASH.

DS1 OFF, DS2 SLOW FLASH.

SECOND STAGE HEAT DEMAND

MADE FOR SECOND−STAGE HEAT?

YES

NORMAL OPERATION.

YES

Page 42

CONTINUED

HEATING SEQUENCE OF OPERATION

SEE BOX A

NORMAL OPERATION

DS1 AND DS2 SIMULTANEOUS SLOW FLASH.

ARE PRIMARY, SECONDARY, ROLLOUT AND

BACKUP SECONDARY LIMIT SWITCHES CLOSED?

YES

FIRST−STAGE (LOW FIRE) HEAT

PRESSURE SWITCHES CLOSED?

SECOND−STAGE (HIGH FIRE) HEAT

PRESSURE SWITCHES CLOSED?

YES

DS1 AND DS2 SIMULTANEOUS FAST FLASH.

HEAT DEMAND SATISFIED?

YES

THERMOSTAT CALLS FOR HEAT

DS 1 AND DS 2 SIMULTANEOUS FAST FLASH

GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.

HAS PRIMARY, SECONDARY, ROLLOUT OR BACKUP

SECONDARY LIMIT SWITCH CLOSED WITHIN 3 MINUTES?

LIMIT SWITCH WATCHGUARD MODE. GAS VALVE

BLOWER OFF WITH DELAY. IS 60−MINUTE RESET PERIOD COMPLETE? DS SLOW FLASH, DS2 ON.

GAS VALVE OFF, COMBUSTION AIR INDUCER OFF

DS1 SLOW FLASH, DS2 ON.

OFF. COMBUSTION AIR INDUCER OFF. INDOOR

AFTER 15 SECOND POST PURGE, INDOOR

RETURN TO FIRST−STAGE HEAT MODE.

FIRST−STAGE CONTINUES UNTIL SECOND− STAGE PRESSURE SWITCHES CAN BE PROVEN or HEAT DEMAND IS SATISFIED. A FIVE (5)

MINUTE WAIT PERIOD IS INITIATED BEFORE

RETRY. WERE 5 ATTEMPTS MADE FOR

FIRST−STAGE HEAT DEMAND SATISFIED?

SEE BOX B

INDOOR BLOWER ON.

BLOWER OFF AFTER DELAY.

DS1 OFF, DS2 FAST FLASH.

RETURN TO HEAT DEMAND?

SECOND−STAGE HEAT?

SEE BOX C

YES

SINGLE−STAGE THERMOSTAT MODE

(E20 SET AT SINGLE")

YES

HEAT DEMAND SATISFIED?

DS1 AND DS2

SIMULTANEOUS FAST FLASH.

YES

GAS VALVE OFF, COMBUSTION AIR

INDUCER OFF AFTER POST PURGE

PERIOD, INDOOR BLOWER OFF AF-

TER SELECTED DELAY.

DS1 AND DS2

SIMULTANEOUS FAST FLASH

DEMAND FOR HEAT SATISFIED.

POWER ON STAND BY.

DS1 AND DS2

SIMULTANEOUS SLOW FLASH

TWO STAGE THERMOSTAT MODE?

(E20 SET AT TWO")

YES

FIRST AND SECOND STAGE HEAT

DEMAND SATISFIED SIMULTANEOUSLY.

DS1 & DS2 SIMULTANEOUS FAST FLASH.

YES

GAS VALVE, COMBUSTION AIR INDUCER

AND INDOOR BLOWER RETURN TO FIRST−

DS1 AND DS2 SIMULTANEOUS FAST FLASH.

FIRST STAGE HEAT DEMAND SATISFIED?

GAS VALVE OFF. COMBUSTION AIR INDUCER

OFF AFTER 5−SECOND POST−PURGE PERIOD.

INDOOR BLOWER OFF. DELAY INITIATED.

DS1 & DS2 SIMULTANEOUS FAST FLASH.

SECOND STAGE HEAT

DEMAND SASTISFIED?

DS1 AND DS2

SIMULTANEOUS FAST FLASH.

YES

STAGE OPERATION.

YES

Page 43

COOLING SEQUENCE OF OPERATION

POWER ON

SIGNAL IMPROPER

GROUND AT DS.

SIGNAL HOLDS

UNTIL UNIT IS

PROPERLY

GROUNDED.

THERMOSTAT CALLS FOR FIRST−STAGE COOL.

INDOOR BLOWER ENERGIZED ON FIRST STAGE

COOL SPEED AFTER 2 SECOND DELAY.

FIRST−STAGE DEMAND FOR COOL SATISFIED?

THERMOSTAT CALLS FOR SECOND−STAGE COOL.

IS POLARITY REVERSED?

COMPRESSOR AND CONDENSER FAN

IS THERE

PROPER GROUND?

ENERGIZED.

YES

IS VOLTAGE

ABOVE 75 VOLTS?

YES

SIGNAL POLARITY REVERSED.

DS1 FAST FLASH, DS2 SLOW FLASH.

COMPRESSOR AND CONDENSER FAN DE−ENERGIZED.

LOW VOLTAGE SIGNAL AT DS HOLDS

UNTIL VOLTAGE RISES ABOVE 75 VOLTS.

INDOOR BLOWER DE−ENERGIZED.

INDOOR BLOWER RAMPS UP TO SECOND−STAGE COOL SPEED.

SECOND−STAGE DEMAND FOR COOL SATISFIED?

YES

UNIT RETURNS TO FIRST STAGE COOL

Page 44

CONTINUOUS LOW SPEED FAN SEQUENCE OF OPERATION

MANUAL FAN SELECTION MADE AT THERMOSTAT.

AFTER 2 SECOND DELAY, INDOOR BLOWER IS

ENERGIZED ON CONTINUOUS FAN SPEED

(LOW HEAT / LOW COOL).

YES YES

YES

COMPRESSOR IS ENERGIZED AND INDOOR

BLOWER CONTINUES TO OPERATE IN LOW

COOL SPEED.

THERMOSTAT CALLS FOR FIRST−STAGE HEAT.THERMOSTAT CALLS FOR FIRST STAGE COOL.

YES

BURNERS IGNITE AND INDOOR BLOWER

CONTINUES TO OPERATE IN CONTINUOUS

LOW (LOW HEAT / LOW COOL) MODE.

YES

FIRST−STAGE COOL DEMAND SATISFIED?

SECOND STAGE COOL DEMAND

INDOOR BLOWER RAMPS TO SECOND

STAGE COOL SPEED

SECOND STAGE COOL DEMAND SATISFIED?

YES

INDOOR BLOWER RAMPS DOWN TO FIRST STAGE

COOL SPEED.

NOTE − Continuous low speed fan and cooling low speed are equal to the low heat fan speed.

FIRST−STAGE HEAT DEMAND SATISFIED.

THERMOSTAT CALLS FOR SECOND−STAGE HEAT.

YES

INDOOR BLOWER SWITCHES TO HIGH HEAT SPEED

AFTER 30−SECOND RECOGNITION PERIOD.

YES

SECOND−STAGE HEAT DEMAND SATISFIED.

YES

INDOOR BLOWER RAMPS DOWN TO LOW

HEAT SPEED.

YES

Page 45

VIII− Field Wiring Applications and Jumper Settings

Field Wiring Applications

Jumper Settings (See figure 4)

Thermostat

1 Heat / 1 Cool

NOTE − Use dip switch 3 to set second−stage heat ON delay. ON−10 minutes. OFF−15 minutes.

E20

SINGLE Leave Installed

W915

Y1 to Y2

T’STAT

Wiring Connections

CONTROL

TERM. STRIP

OUTDOOR

UNIT

HSXB15

(LSOM)

1 Heat / 2 Cool

SINGLE Clip

NOTE − Use dip switch 3 to set second−stage heat ON delay. ON−10 minutes. OFF−15 minutes.

2 Heat / 2 Cool TWO Clip

T’STAT

CONTROL

TERM. STRIP

CONTROL

TERM. STRIP

OUTDOOR

UNIT

HSXA19

(LSOM)

OUTDOOR

UNIT

HSXA19

(LSOM)

2 Heat / 1 Cool TWO Leave Installed

Page 46

T’STAT

CONTROL

TERM. STRIP

OUTDOOR

UNIT

HSXB15

(LSOM)

Thermostat

FM21 Heat Pump / 1 Cool

Field Wiring Applications (Continued)

Jumper Settings (See figure 4)

E20

W915

Y1 to Y2

SINGLE Leave Installed

Wiring Connections

*Disconnect existing furnace transformer and replace with 75VA, 24V transformer if defrost option to be used.

75VA, 24V

TRANSFORMER*

NOTE − Wiring connections to outdoor unit and thermostat made at FM21 control board per FM21 instructions.

CONTROL

TERM. STRIP

FM21

NOTE − Cut Y1/Y2 jumper for two−stage cooling.

Page 47

IX−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 connections.

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

9 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, replace 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 9−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.

− On initial power up the combustion

air inducer does not energize.

− Diagnostic lights flash normal power

on operation.

LED#1−Slow Flash LED#2−Slow Flash

1.4

1.4.1

Open combustion air inducer motor circuit.

1.4.2

Failed combustion air inducer motor.

Page 48

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

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

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

LED#2 Alternating Fast Flash

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

6−Pin connector is improperly

attached 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 6−pin connector for proper installation. Correctly insert connector into control.

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 between 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, secondary or backup secon-

dary (if equipped ) limit open.

2.1.2

Miswiring of furnace or improper

connections 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 continuous fan demand.

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

− Diagnostic lights flash the pressure switch failure code.

LED#1−Off, LED#2−Slow Flash

2.2.1

Miswiring of furnace or improper

connections 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. Replace if defective.

Page 49

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

switch failure code 2.5 minutes after

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

connections to combustion air induc-

2.3.1

ACTION 1 − Check for correct wiring and loose

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

er.

− Diagnostic lights flash the pressure

switch failure code 2.5 minutes after heating demand.

ACTION 1 − If there is 120V to combustion air inducer and it does not operate, replace combustion 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

Miswiring of furnace or improper

connections 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

calibration.

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 condensate. 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. Remove 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 50

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

4.1.1

Check that gas is being supplied to

the unit.

4.1.2

Miswiring of gas valve or loose-

connections at multi−pin control amp

plugs or valve.

4.1.3

Defective gas valve or ignition

control.

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

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 demand 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.

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

PREMATURELY

Condition Possible Cause Corrective Action/Comments

ACTION 1 − Check for restricted intake and ex-

haust 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 condensate lines.

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

ACTION 1 − Check that sensor is properly located and that the sense wire is properly attached 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 below 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.

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

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.

Page 51

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

connection.

5.3.3

Air leakage at the connections

between the primary heat exchanger,

secondary heat exchanger, and

combustion air blower.

5.3.4

Insufficient flow through the heat

exchanger caused by a sooted or

restricted heat exchanger.

5.3.5

Burners are not properly located in

the burner box.

5.4.1

Recirculation of flue gases. This

condition causes rough ignitions and

operation. Problem is characterized

by nuisance flame failures.

ACTION 1 − Check that the manifold pressure matches value listed on nameplate. See installation instructions for proper procedure. ACTION 2 − Verify that the installed orifice size match the size listed on the nameplate or installation instructions. ACTION 3 − Check gas valve sensing hose to insure 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. ACTION 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 manual.

ACTION 2 − Check for proper combustion.

ACTION 1 − Check that the burners are firing into

the center of the heat exchanger openings. Correct the location of the burners if necessary.

ACTION 1 − Check for proper flow of exhaust gases away from intake vent. Remove any obstacles 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 52

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

PROBLEM 6: CONTROL SIGNALS LOW FLAME SENSE DURING HEATING MODE

code

Condition Possible Cause Corrective Action/Comments

6.0

− Unit operates correctly but the diagnostic lights flash low flame sense

Sensor rod is improperly located on

6.1.1

the burner.

ACTION 1 − Check the sensor rod for proper location 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 PAPER 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

connections at control or indoor blow-

120V is not being supplied to the

indoor air blower or blower motor fail-

7.1.1

er 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 53

SERVICE NOTES

Page 54

Lennox G61MP User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

SPECIFICATIONS

BLOWER DATA