Heater shows E41 and will not fire in pool mode

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.

Possible Causes

Failed pool temperature sensor, Loose sensor connector, Incorrect pool/spa sensor configuration

Safety First: Disconnect power before servicing.

Check pool mode: Confirm the heater is in POOL mode and that any automation system is calling for pool heat.
Inspect pool sensor: Locate the pool temperature sensor in the pool return line. Check for cuts, abrasions, or water intrusion at the sensor head.
Measure resistance: Compare sensor resistance to Rheem's pool sensor chart. Replace if readings are abnormal.
Verify wiring at board: Ensure the pool sensor is connected to the correct terminals and that there are no loose or corroded pins.

Medium 3/5

Pool Temperature Sensor

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