HVACopediaKinghome · Heat pump
H3 Compressor overload protection
What the control is telling you
The compressor overload input is open; on Ultranixx units the board saw it open for 3 s.
Applies to: Kinghome KM09HT1DI, KM12HT1DI, KM18HT1DI, KM24HT1DI wall mini-splits; Kinghome KM09HF1DI to KM24HF1DI wall mini-splits (Gree GFH..DA/DB); Kinghome Ultranixx Eco KD24UHO to KD60UHO outdoor units with KD..UHI air handlers
Likely causes
- Overload terminal loose or open
- Faulty outdoor board
Test and repair steps
- Check the overload terminal; it should be closed (under 1 ohm on the wall units).
- Refer to overload checks in the manual.
- Replace the board if needed.
Models that show this code
21 models in Kinghome KM HT1DI, Kinghome KM HF1DI, Kinghome Ultranixx Eco
Other codes on the same units
- F5 Outdoor discharge temperature sensor fault
- F6 Frequency limit for overload / ODU tube sensor fault
- F8 Frequency reduced - overcurrent
- F9 Frequency reduced - high discharge temperature
- H4 Overload protection (high condensing pressure)
- H5 IPM module protection
- H6 Fan motor feedback fault (indoor or outdoor)
- H7 Compressor out-of-step
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Source: Kinghome KM09-12-18-24HT1DI service manual, sec. 9.1 error code list; Kinghome KM09-24HF1DI service manual, sec. 11.1 error code list; Kinghome Ultranixx Eco KD24-60UHO service manual, sec. 3.3-3.4. Summarized in our own words; check the original manual for your model.
Homeowner looking at this code? See what it means for you and when to call a technician.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.