F.73 — Water pressure sensor signal too low

What does F.73 mean?

The water pressure sensor is sending a signal that is too low, indicating a problem with the sensor itself or its wiring.

• Interruption or short circuit of the water pressure sensor.
• Interruption or short circuit to ground in the supply line to the water pressure sensor.
• Water pressure sensor itself is defective.

Click steps to track your progress.

1. 1

   Press the fault clearance key on the boiler to reset it.

2. 2

   Visually inspect any accessible wiring connected to the water pressure sensor for damage.

3. 3

   If the fault persists, contact Vaillant Service Solutions, as this indicates a sensor or wiring issue.