Coleman
Runaway Heating / Sensor Calibration Drift
Spa overheats gradually (water above set temperature) without showing an overheat error.
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
Temperature sensor reading low, Stuck heater relay partially on, Poor sensor placement or contact, Control logic fault
How to Fix / Troubleshooting
Safety first: Turn off power at the GFCI breaker if water temperature exceeds safe soaking levels. Do not use the spa until resolved.
- 1. Verify temperature: Use a separate thermometer to compare actual water temperature to the displayed value.
- 2. Replace temperature sensor: If the display reads lower than actual water temperature, replace the sensor with a Coleman-compatible thermistor.
- 3. Observe heater behavior: With power restored and cover open, watch the heater indicator. If the heater continues to run after the set temperature is reached, the heater relay may be sticking.
- 4. Control board replacement: A stuck relay or logic fault requires replacement of the control board or entire control pack.
Advertisements
Repair Difficulty
Hard
4/5
Required Part
Temperature Sensor (Thermistor)
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements