Gree GUD24W2/D-D(U) - Page 35

GREE DC INVERTER HEAT PUMP CONDENSING UNIT SERVICE MANUAL
32
3.4.4 “H4” Overload protection
Error display:
ODU mainboard LED displayer
Error judgment condition and method:
When condensing pressure is higher than the protection value, system will report overload protection.
Possible reason:
■Cooling ODU heat exchanger is blocked or heat exchange is bad.
■Heating IDU heat exchanger is blocked or heat exchange is bad.
■Operating temperature is too high.
■System charging quantity is too much.
Troubleshooting
：
Outdoor heat exchanger is blocked
Indoor heat exchanger is blocked.
Ambient temperature is out of the
operation range
H
4
Overload
Too much charging quantity
.
Error still exists
?
Remove the obstacle
Remove the obstacle
Normal protection. No
need to handle it.
Release a proper amount
of refrigerant
Replace the drive board
Replace the compressor
YES
YES
YES
YES
YES
NO
NO
NO
NO