Heater cycles on and off frequently without maintaining a steady run

Safety: Normal checks can be done with the heater running; avoid hot surfaces.

• Check flow and filter: Ensure the pool pump is running at adequate speed and the filter is clean. Restricted flow can cause high limit trips and short cycles.
• Verify sensor placement: Make sure the Water Temperature Sensor is not installed too close to the heater outlet where it can see artificially high temperatures.
• Adjust thermostat differential (if available): Some SunHeater controls allow adjusting the temperature differential. Increasing the differential can reduce cycling.
• Use a pool cover: Reducing heat loss can help the heater run longer, more efficient cycles.