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17.5.26 Indoor Freeze-up Protection (H99)
Malfunction Decision Conditions:
During anti-freezing control in cooling operation, when the indoor refrigerant liquid temperature < 0°C.
Malfunction Caused:
1 Faulty water pump.
2 Insufficient water flow rate in system.
3 Water leak in system.
4 2 way valve partially closed.
5 Clogged expansion valve or strainer.
6 Refrigerant shortage (refrigerant leakage).
7 Faulty indoor refrigerant liquid temperature sensor.
8 Faulty indoor unit PCB (main).
Troubleshooting:
For safety reason and to prevent component breakdown,
always switch off the power before remove and connect the component.
Check the system water pump.
Check for clogged
expansion valve or strainer.
Is the expansion valve or
strainer clogged (ice formed)?
Check refrigerant amount.
Is the additional refrigerant
amount filled correctly?
Does it conform to the sensor
characteristic chart?
Check the indoor refrigerant
liquid temperature sensor.
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Is the water pump working?
Check the system water
flow rate.
Check the system water passage.
Is there any water leakage?
Check the 2 way valve.
Is the 2 way valve partially
closed?
Is the water pump speed
adjusted according to system
hydraulic external static pressure?
No
No
No
No
No
No
No
Replace the faulty water
pump.
Readjust the water
pump speed.
Reclaim and recharge with
correct amount of refrigerant.
Replace the indoor unit PCB
(main).
Replace the indoor refrigerant
liquid temperature sensor.
Fix the system water
leakage.
Open the 2 way valve.
- Replace the expansion
valve and/or strainer
- Reclaim and recharge
refrigerant
Caution