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17

STEP

ACTION

YES

NO

GO TO

27.

Disconnect jumper wire across R and W/W1 thermostat terminals and replace secondary
voltage fuse.

28

28.

Disconnect BLUE wire to gas valve GV and jumper R and W/W1 thermostat terminals.

29

29.

Does status code 34 flash? If not, status code 24 should occur when BLUE wire is ener-
gized.

33

30

30.

Turn power off and disconnect PL1 from variable speed furnace control.

31

31.

Do you have continuity between the BLUE wire and chassis ground?

32

3

32.

The BLUE wire to gas valve GV is shorting to ground. Replace or repair it.

11

33.

Replace gas valve GV.

4

34.

Turn power off and disconnect PL1 from variable speed furnace control.

35

35.

Do you have continuity between the GRAY wire connected to the high heat pressure
switch HPS and chassis ground?

36

3

36.

You have a short circuit in the high heat pressure switch circuit.

11

37.

Reconnect the pressure tube from the pressure switch assembly back to the collector box.

38

38.

Does status code 24 begin flashing when the high heat pressure switch HPS is energized?

39

56

39.

Disconnect jumper wire across R, W/W1, and W2 thermostat terminals and replace second-
ary voltage fuse.

40

40.

Disconnect BROWN wire to gas valve GV and jumper R, W/W1, and W2 thermostat ter-
minals.

41

41.

Does status code 24 begin flashing when the high heat pressure switch HPS is energized?

42

33

42.

Turn power off and disconnect PL1 from variable speed furnace control.

43

43.

Do you have continuity between the BROWN wire and chassis ground?

44

3

44.

The BROWN wire to high heat pressure switch HPS and gas valve GV is shorting to
ground. Replace or repair it.

11

45.

Disconnect jumper wire across R, W/W1, and W2 thermostat terminals and wait until
blower stops.

46

46.

Jumper R, G, and Y/Y2 thermostat terminals.

47

47.

Does status code 24 begin flashing when G and Y/Y2 are energized?

3

48

48.

Reconnect User Interface ABCD connector (if used) or all thermostat leads (if used) to the
variable speed furnace control. Do not reconnect the humidifier lead to HUM terminal.

Operate the furnace in heating and cooling mode from thermostat.

49

49.

Does status code 24 occur during heating cycle?

50

51

50.

You have a defective thermostat or a short circuit in the wiring between thermostat and
furnace. If the furnace is twinned, also check the twinning kit relay TKR.

11

51.

Does status code 24 occur during cooling cycle?

52

53

52.

You have a defective thermostat or a short circuit in the wiring between thermostat and
outdoor unit, or a short circuit in the outdoor unit contactor or reversing valve(heat pump

only).

11

53.

Does problem usually occur in cooling mode?

54

55

54.

Check outdoor unit contactor. Failure to pull in can cause excessive current draw on low--
voltage circuit. This can be an intermittent problem.

11

55.

Reconnect humidifier and check for excessive current draw when the blower turns ON. If
current draw is excessive check wiring to humidifier solenoid, diode bridge(if used), and

humidifier solenoid.

11

56.

Continue to observe the furnace operation for 10 minutes.

57

57.

Does status code 24 flash after the blower comes on?

58

59

58.

The insulation is loose and has shorted against the limit switch(es).

11

59.

Check for loose or torn insulation because it can cause intermittent occurrences of status
code 24.

45

Summary of Contents for PG9UAA

Page 1: ...be performed by trained service personnel When working on heating equipment observe precautions in literature on tags and on labels attached to or shipped with the unit and other safety precautions th...

Page 2: ...the switch Correct inadequate combustion air supply component failure before resetting the switch CAUTION Before operating the furnace check each manual reset switch for continuity If necessary press...

Page 3: ...eat pressure switch HPS closes When the high heat pressure switch HPS closes the high heat gas valve solenoid GV HI is energized and the inducer motor RPM is noted by the furnace control CPU The RPM i...

Page 4: ...If the furnace control CPU switches from low cooling to high cooling the furnace control CPU will energize the air conditioning relay ACR When the air conditioning relay ACR is energized the R to Y1 a...

Page 5: ...ll continue operating for an additional 5 seconds if no other function requires blower motor BLWM operation a Continuous Blower Speed Selection from Thermostat To select different continuous blower ai...

Page 6: ...Flame is proved while gas valve is de energized Inducer will run until fault is cleared Check for Leaky gas valve Stuck open gas valve 23 PRESSURE SWITCH DID NOT OPEN Check for Obstructed pressure tu...

Page 7: ...ration or the inducer RPM signal was lost for 5 seconds during operation Check for Proper vent sizing Restricted combustion air supply Failed inducer motor Improper motor wiring 43 LOW HEAT PRESSURE S...

Page 8: ...re erased after 72 hours or can be manually erased by putting setup switch SW1 1 in the ON position and jumpering R W W1 and Y Y2 simultaneously until status code 11 is flashed 9 10 9 Go to page numbe...

Page 9: ...ly in only one of the twinned units 9 16 9 Are the fuses breakers or manual disconnects to the problem unit correctly set 11 10 10 Fix problem 5 11 Are the Auxiliary Limit switches properly set 12 10...

Page 10: ...airflow when the G thermostat lead is disconnected and a call to dehumidify is active 12 13 12 Replace the variable speed furnace control 7 13 Reconnect the G thermostat lead or jumper and observe op...

Page 11: ...HI solenoid in gas valve GV has failed or the furnace is extremely underfired STEP ACTION YES NO GO TO 1 Remove the blower access panel Disconnect the R thermostat lead from the furnace con trol board...

Page 12: ...in Index for the CLEANUP AND STARTUP INSTRUC TIONS INDEX 5 Is setup switch SW1 6 in the ON position 6 7 6 Put setup switch SW1 6 in the OFF position 4 7 Jiggle setup switches SW1 1 and SW1 6 back and...

Page 13: ...S 8 26 Power to the furnace was probably interrupted or line voltage was too low during a call for heat This is normal operation Go to the page number indicated in Index for the CLEANUP AND STARTUP IN...

Page 14: ...code indicates the furnace failed to ignite gas and or prove flame in 4 attempts The variable speed furnace control will auto reset in 3 hours If the inducer motor is not running during lockout refer...

Page 15: ...oving sensor electrode FSE 8 5 Does status code 22 stop flashing 6 7 6 Clean flame sensor with fine steel wool Inspect burner box assembly and remove any carbon deposits near the flame sensor opening...

Page 16: ...t PL1 from variable speed furnace control 9 9 Do you have continuity between either RED wire connected to the limit circuit and chassis ground 10 3 10 You have a short circuit in the limit switch circ...

Page 17: ...ure switch HPS and gas valve GV is shorting to ground Replace or repair it 11 45 Disconnect jumper wire across R W W1 and W2 thermostat terminals and wait until blower stops 46 46 Jumper R G and Y Y2...

Page 18: ...chematic for the correct part number If absolutely necessary you can install two resistors into the PL4 connection on the control board R1 goes across the middle 2 pins and R2 goes across the outer 2...

Page 19: ...lay is completed the variable speed will stop displaying status code 31 STEP ACTION YES NO GO TO 1 Turn power off remove blower access panel and disconnect the R thermostat lead from the furnace contr...

Page 20: ...the high heat pressure switch HPS 12 Status Code 32 LOW HEAT PRESSURE SWITCH DID NOT CLOSE OR REOPENED This status code can occur as a result of the low heat pressure switch LPS not making or the low...

Page 21: ...l across heat exchangers when fault occurs 25 26 25 Replace the pressure switch assembly 8 26 Is inducer motor rotating in direction indicated on the inducer housing 28 27 27 Replace inducer motor or...

Page 22: ...have continuity across limit switch LS 19 16 16 Wait for unit to cool then recheck for continuity across limit switch LS 17 17 Do you have continuity across limit switch LS 19 18 18 Replace limit swit...

Page 23: ...low 210 deg F 18 56 56 The problem may be related to poor air distribution or excessive pressure drop across filter Check filter and return air grilles for blockage Add turning vanes more supply openi...

Page 24: ...ed component 15 15 Fix problem 8 16 Put setup switch SW1 6 in the OFF position and jumper the R and W W1 thermostat ter minals 17 17 Is 24 vac across BLUE and GREEN YELLOW wire to gas valve GV 21 18 1...

Page 25: ...sure within 4 seconds after the gas valve is energized Flame sensor location Air leakage around igniter bracket 8 48 Furnace will not operate or ignite on low heat Check the following Flame sensor loc...

Page 26: ...te The voltage should be very stable and should not fluctuate more than 02 vdc If the voltage fluctuates get a different volt meter before going on to the following steps Note Since the variable speed...

Page 27: ...rol module from motor portion of blower motor DO NOT PULL ON WIRES GRIP PLUG ONLY 42 42 When blower control module is completely detached from blower motor verify with stand ard ohmmeter that the resi...

Page 28: ...29 Disconnect collector box tube to pressure switch assembly 30 30 Turn power on and jumper the R and W W1 thermostat terminals 31 31 Does status code 42 flash within 20 seconds after a call for heat...

Page 29: ...ressure switch HPS makes 45 49 Status Code 43 LOW HEAT PRESSURE SWITCH OPEN WHILE HIGH HEAT PRESSURE SWITCH IS CLOSED This status code can occur as a result of the low heat pressure switch LPS not mak...

Page 30: ...rol 8 19 Replace the low heat pressure switch or the pressure switch assembly 8 Status Code 45 CONTROL CIRCUITRY LOCKOUT This status code indicates the variable speed furnace control detected one of t...

Page 31: ...ONNECTOR SW1 SETUP SWITCHES AND BLOWER OFF DELAY STATUS AND COMM LED LIGHTS 3 AMP FUSE TRANSFORMER 24 VAC CONNECTIONS PL3 ECM BLOWER HARNESS CONNECTOR PL1 LOW VOLTAGE MAIN HARNESS CONNECTOR EAC 1 TERM...

Page 32: ...32 A09683 Fig 2 Wiring Diagram PG9UAA...

Page 33: ...en delivers requested airflow CFM as defined by serial commands received from the variable speed furnace control The ECM blower motor is configured via the variable speed furnace control to react to c...

Page 34: ...LOW HEAT PRESSURE SWITCH Make Point Break Point Make Point Break Point 60 000 1 81 in W C max 1 63 in W C 0 05 0 86 in W C max 0 71 in W C 0 05 80 000 0 91 in W C max 0 76 in W C 0 05 100 000 0 95 in...

Page 35: ...0 20 in w c Supply ESP before Coil 0 40 in w c Total ESP 0 60 in w c Example 2 Return ESP before Filter 0 10 in w c Filter Static Pressure Drop 2000 cfm 0 10 in w c Supply ESP after Coil 0 20 in w c...

Page 36: ...ill work within the voltage range of 102 to 132 VAC Hence there is no voltage regulation circuits on the furnace control board A new Silicon Nitride igniter has a normal resistance range of 40 to 70 o...

Page 37: ...rnace will do on a cold start coming out of night setback coming on in low heat and coming on in high heat EXAMPLE 1 Furnace ran for 16 minutes in low heat and 5 minutes in high heat during previous c...

Page 38: ...f time as calculated by the following LH run time 5600 HL 122 Unit will initiate the next cycle in Low Heat for a maximum of 16 minutes before initiating High Heat if the call for heat still exists Un...

Page 39: ...oduct theory and skills programs is available using popular video based formats and materials All include video and or slides plus companion book Classroom Service Training plus hands on the products...

Page 40: ...s D 7310 W Morris St D Indianapolis IN 46231 Printed in U S A Edition Date 10 10 Manufacturer reserves the right to change at any time specifications and designs without notice and without obligations...

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