Failure Display on Outdoor Unit PCB: ● ● ● ●
Check combustion blower motor.
➀Measure AC voltage at blower motor connector (CN05) (under heating operation, during combustion).
Normal
PUR – PUR AC 30 – 115 V
*Use a circuit tester (set to AC range).
In case of abnormality ➞ Replace outdoor unit PCB.
➁Disconnect combustion blower motor connector, and measure resistance at connector.
Normal
PUR – PUR 10 – 30 Ω
* Use a circuit tester (set to Ω range).
In case of abnormality ➞ Replace combustion blower motor.
12-6-8. ON/OFF Valve Failure
Failure Display on Outdoor Unit PCB: ● ● ● ●
Check ON/OFF valve coil (CN06).
➀Measure AC voltage at the ON/OFF valve coil connector (under heating operation, during combustion).
Normal
BLK – BLK AC 104 – 126 V
*Use a circuit tester (set to AC range).
In case of abnormality ➞ Replace outdoor unit PCB.
➁Disconnect ON/OFF valve connector and measure resistance at connector.
Normal
BLK – BLK 300 – 500 Ω
* Use a circuit tester (set to Ω range).
In case of abnormality ➞ Replace ON/OFF valve coil.
12-6-9. Reversing Valve Failure
Failure Display on Outdoor Unit PCB: ● ● ● ●
Check reversing valve coil.
➀Measure AC voltage at reversing valve coil connector (CN03) (under heating operation, during combustion).
Normal
BLK – BLK AC 104 – 125 V
*Use a circuit tester (set to AC range).
In case of abnormality ➞ Replace outdoor unit PCB.
➁Disconnect reversing valve coil connector and measure resistance at connector.
Normal
BLK – BLK 300 – 500 Ω
* Use a circuit tester (set to Ω range).
In case of abnormality ➞ Replace reversing valve coil.
Caution: Reversing valve failure can be displayed when there is a shortage of refrigerant. Therefore if the above check shows normal, check the amount of refrigerant.
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