H1
Ruud
Defrost Sensor Fault / Coil Temperature Sensor Error
Ruud air conditioner (heat pump) displays H1; unit may stay in defrost too long or not defrost properly.
Advertisements
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Advertisements
Possible Causes
Open or shorted defrost thermistor, Sensor not properly attached to outdoor coil, Damaged sensor wiring, Defective defrost control board
How to Fix / Troubleshooting
Safety first: Disconnect power at the outdoor disconnect before working on sensors or boards.
- Step 1 – Locate defrost sensor: Find the thermistor clipped to the outdoor coil tubing, usually near the bottom of the coil.
- Step 2 – Check attachment: Ensure the sensor is firmly clipped and making good contact with the copper tube. Reattach if loose.
- Step 3 – Inspect wiring: Follow the sensor wires back to the defrost board. Repair any damaged insulation or broken conductors.
- Step 4 – Measure resistance: Disconnect the sensor and test with a multimeter. Compare to Ruud’s temperature/resistance chart. Replace if out of range.
- Step 5 – Replace defrost board if needed: If a new sensor does not resolve H1, the defrost board may be faulty and should be replaced.
Advertisements
Repair Difficulty
Medium
3/5
Required Part
Defrost Thermistor
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements