SiMT041311E
Troubleshooting
Service Diagnosis
164
2.31 Heater Wire Abnormality
Error Code
PA
Method of Error
Detection
An error is identified when the outlet temperature of humidifying fan does not reach a certain
temperature within a given time after the heater is turned on.
Error Decision
Conditions
The temperature detected by the humidifying thermistor is lower than the outdoor temperature
(with the heater turned off) + 6°C, and this condition continues for 30 minutes.
Supposed
Causes
Power supply voltage is extremely low.
Breakage of heater filament
Breakage of heater harness
Abnormal temperature detected by outdoor temperature thermistor
Abnormal temperature detected by humidifying thermistor
Defective main relay
Blown thermal fuse
Defective heater control part
Troubleshooting
Check No.01
Refer to P.181
(R19689)
Caution
YES
YES
YES
Is the
power supply voltage
appropriate?
Turn off the power.
YES
NO
NO
NO
Is the heater
resistance
appropriate?
At normal temperature:
97
Ω
± 10%
[ ]
Is the thermal fuse blown?
NO
YES
Check No.01
Is a resistance of the
humidifying thermistor
appropriate?
Is the heater well cooled?
Measure the resistance
between the heater connectors.
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Modify the power supply
voltage.
Replace the heater ASSY.
Replace the heater ASSY.
Replace the thermistor.
*Refer to
PH
troubleshooting.
Replace the indoor unit
PCB (A1P).
*Main relay may be
damaged.
When the main relay
(MRM10) is damaged,
heater and rotor do not run.
Cool it down.
NO