E15
SunHeater Temperature Sensor Calibration / Range Error

Heater displays E15; temperature reading on display is obviously wrong (very high or very low)

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

Incorrect sensor type installed, Damaged thermistor cable, Control board calibration fault, Sensor shorted to ground

How to Fix / Troubleshooting

Safety: Turn off power before disconnecting sensors.

  • Compare displayed vs actual temperature: Use a reliable pool thermometer to measure actual water temperature at the heater inlet. If the SunHeater display is off by more than 10°F, suspect a sensor or board issue.
  • Verify sensor part number: Confirm that the installed Water Temperature Sensor matches the SunHeater part number. Using a generic or wrong-value thermistor can cause E15.
  • Inspect cable routing: Ensure the sensor cable is not run alongside high-voltage wires, which can induce noise. Reroute if necessary.
  • Check for shorts: Disconnect the sensor and measure resistance between each lead and ground. Any continuity indicates a short; replace the cable or sensor.
  • Control board replacement: If a correct, tested sensor still results in E15, the main control board's analog input may be faulty and require replacement.
Advertisements

Repair Difficulty

Medium 3/5

Required Part

Water Temperature Sensor
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements