Panasonic CS-HZ9RKE-1, Service Manual

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17.4.18 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
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
Caution
For safety reason and to prevent
component breakdown, always switch
off the power before remove and
connect the component.