HVACopediaKinghome · Heat pump
F6 Frequency limit for overload / ODU tube sensor fault
What the control is telling you
On the wall units F6 means the compressor speed is limited because of overload or high temperature. On Ultranixx units F6 is the outdoor tube temperature sensor fault.
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; Kinghome Ultranixx cold-climate KU36UHO and KU60UHO outdoor units with KU..UH2I and KD..UHI air handlers
Likely causes
- Overload or high temperature (wall units)
- Sensor open/shorted or poor plug contact (Ultranixx)
Test and repair steps
- Clean coils and check airflow and charge (wall units).
- Check the tube sensor plug and resistance (Ultranixx).
- Replace the sensor or board as indicated.
Models that show this code
27 models in Kinghome KM HT1DI, Kinghome KM HF1DI, Kinghome Ultranixx Eco, Kinghome Ultranixx
Other codes on the same units
- F2 Sensor fault (indoor coil or outdoor condenser)
- F3 Outdoor ambient temperature sensor fault
- F4 Sensor fault (outdoor condenser or discharge)
- F5 Outdoor discharge temperature sensor fault
- F8 Frequency reduced - overcurrent
- F9 Frequency reduced - high discharge temperature
- H3 Compressor overload protection
- H4 Overload protection (high condensing pressure)
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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; Kinghome Ultranixx cold-climate KU36/60UHO service manual GC202306, 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.