If error codes P0, P4, PC 00 or PC 04 appear on your indoor unit, it indicates a compressor driver error / IMP malfunction or IGBT over-strong protection.
During the initial start-up and system commissioning:
1. Ensure the vacuuming process is completed correctly and the copper piping is void of
humidity and any air particles.
2. Ensure there are no copper pipe kinks, as they will cause restrictions that will not allow the
refrigerant to flow properly starving the compressor.
3. Inspect the wiring and connection between the outdoor fan motor and the outdoor control
board.
4. Inspect the wiring and connection between the compressor and the outdoor control board.
5. Ensure that the valves to release the refrigerant are fully open (counter-clockwise until
resistance; please ensure not to force past the point of resistance).
If the system has already been commissioned:
1. Inspect the wiring and connection between the outdoor fan motor and the outdoor control
board.
2. Inspect the wiring and connection between the compressor and the outdoor control board.
3. Inspect the outdoor fan motor and unit ventilation and ensure that the coils are clear of any
debris or congestion. If the fan motor does not run, please refer to the EC 07 / F5 error
code. If the fan motor is faulty, replace the fan motor.
4. Check if the unit has sufficient refrigerant by comparing refrigerant pressures compared to
the outdoor ambient temperature.
5. Check the compressor’s three winding by testing the resistance values, they should all be
uniform. If the resistance values are not uniform the compressor should be replaced.
6. Check the compressor’s three winding by testing for continuity to ground. If any of the
windings are shorting to ground the compressor should be replaced.
7. If the tests completed above pass but the issue persists, please replace the outdoor control
board.
This process helps systematically identify and resolve issues related to the compressor and its
associated components, starting with simple wiring checks and progressing to more complex
component replacements if necessary.
To order a replacement part or to get further assistance in diagnosing your unit, please contact one of our support representatives by submitting a ticket using the link below.
*Please note these procedures must be performed by a certified HVAC contractor.
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