Possible Causes

1. Incorrect insertion position of the temperature sensor.

2. Dry burning of the water tank due to insufficient water.

3. Resistance drift of the water tank temperature sensor.

4. Adhesion of the electric heating relay.

5. Damage to the sampling circuit of the main control board.

Solutions

1. Check the correctness of the sensor socket position.

2. Verify if the water tank is filled with water.

3. Check whether the sensor resistance matches the actual temperature.

4. Power off the appliance and check if the relay is short-circuited.

5. Replace the main control board.