Heater cycles on and off frequently, with short run times, while trying to maintain temperature

Safety First: Turn off power before adjusting sensors or controls.

• Check sensor placement: Ensure pool and spa temperature sensors are installed in well-mixed water, not immediately downstream of the heater outlet.
• Verify setpoint and differential: Some controls allow adjustment of temperature differential. Increasing the differential can reduce cycling.
• Review automation programming: If connected to a pool controller, check that it is not rapidly toggling the heat demand.
• Hydraulic adjustments: Improve water mixing by adjusting return fittings or adding mixing loops if necessary.