Heater display is on but shows no temperature or only dashes; heater does not fire.

Safety first: Turn off power before unplugging or testing sensors.

Step-by-step checks:

• Inspect sensor connection: Locate the water temperature sensor plug on the control board and ensure it is fully seated.
• Check cable integrity: Follow the cable from the sensor to the board, looking for cuts, abrasions, or pinch points.
• Test resistance: Disconnect the sensor and measure its resistance. An open circuit (infinite resistance) indicates a broken sensor.
• Replace sensor: If faulty, replace with an OEM Pahlen sensor of the same type and rating.

When to stop: If a new sensor does not restore temperature reading, the control board input may be defective and should be checked by a technician.