GEAppliances AZ75E09DAC, Technical Service Manual

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Resistance Heater Troubleshooting
Note: Normal heat is provided by heat pump operation when outdoor temperature is above 25 °F.
The number of heaters that operate is dependant on the Power Supply Kit used.
• Tandem - 1 heater
• Perpendicular - 2 heaters
• Large Tandem - 3 heaters
Place dip switch in I2R lockout.
Do heaters come on?
YES
Check heater resistance at
heater connector.
265 VAC
BK to R =28
BK to W = 20
230/208 VAC
BK to R = 21
BK to W = 16
Resistance OK?
NO
Replace heater.
Check for 5 VDC
between CN2 pin
3 to CN2 pin 10.
5 VDC present?
NO
Replace main
board.
Place thermostat in heat mode. Set
thermostat to setting 5 ˚F above room
temperature.
Do heaters come on?
YES
Replace
thermostat.
Monitor heater
operation.
Do heaters short
cycle?
NO
Check for 24 VAC at main board
terminal strip (CN5) between
terminal 14 (white) and terminal
15 (common).
Is 24 VAC present?
Replace faulty
thermal protector.
YES
Normal operation
NO
YES
NO
Check for
continuity through
both thermal
protectors.
Continuity?
YES
Replace faulty
protector.
NO
NO
With thermostat
calling for heat,
check for line voltage
between RY102
(orange wire/brown
wire) and RY103
(black wire).
Line voltage present?
YES
Check for open wire between RY103 and
heaters. Check for open wire between RY102
and power cord connector. Check for open wire
between power cord connector and heaters.
YES
NO
Check for 5 VDC
between CN2 pin
2 to CN2 pin 10.
5 VDC present?
YES YES
NO
Does the indoor
fan come on?
YES
Go to Dead Unit
trouble shooting.
NO
Replace main
board.
Replace main
board.
Replace driver
board.
Check resistance
at heater.
Resistance OK?
NO
Repair faulty
wiring.
YES