Heater displays F06 and will not operate; may occur intermittently.

Safety first: Turn off power at the breaker before accessing the control compartment.

• Locate outlet sensor: On Thermeau heaters, the outlet water temperature sensor is typically threaded into the outlet header or attached with a clip. Consult the unit’s diagram for exact location.
• Inspect wiring: Check the sensor’s two-wire harness for cuts, abrasions, or signs of rodent damage. Ensure the connector is fully seated on the control board.
• Check for corrosion: Look for corrosion on the sensor terminals or connector pins. Clean lightly with electrical contact cleaner and reconnect.
• Compare temperature reading: If the display shows an obviously incorrect water temperature (e.g., 0°C or 99°C when pool is moderate), the sensor is likely faulty and should be replaced with a genuine Thermeau thermistor.
• Reset and test: After replacement, restore power and verify that the displayed water temperature is reasonable and that F06 does not reappear.