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15.4.18 H99 (Indoor Freeze Prevention Protection: Cooling or Soft Dry)
Error Code will not display (no Timer LED blinking) but store in EEPROM
Malfunction Decision Conditions
•
Freeze prevention control takes place (when indoor pipe temperature is lower than 2°C)
Malfunction Caused
•
Air short circuit at indoor unit
•
Clogged indoor unit air filter
•
Dust accumulation on the indoor unit heat exchanger
•
2/3 way valve closed
•
Faulty indoor unit fan motor
•
Refrigerant shortage (refrigerant leakage)
•
Clogged expansion valve or strainer
•
Faulty indoor pipe temperature sensor
•
Faulty indoor unit PCB
Troubleshooting
When abnormality indication starts again
Is the air filter dirty?
●
Clean the air filter
Check the indoor unit air filter
Is the indoor unit heat exchanger dirty?
●
Clean the indoor unit heat exchanger
Check the dust accumulation on the indoor unit heat exchanger
Does it conform to the sensor characteristic chart?
Check the indoor pipe temperature sensor
●
Replace the indoor pipe temperature
sensor
●
Reclaim and recharge with correct amount
of refrigerant
●
Replace the indoor unit PCB
YES
NO
NO
NO
NO
YES
YES
NO
YES
Check if 2/3 way valve is closed?
●
Open the 2/3 way valve
YES
Check if inddor fan motor operates normally?
NO
Check for gas leakage. Is Oil oozing out from the 2/3 way valve?
YES
Check if expansion valve or strainer clogged (ice formed)?
●
Replace the indoor unit fan motor and/or
indoor unit PCB
YES
For safety reason and to prevent
component breakdown, always switch
off the power before remove and
connect the component.
Check the air passage
Is there any short circuit?
●
Provide sufficient air passage
YES
●
Repair the pipe flare or union nuts
●
Reclaim and recharge refrigerant
