F.22 — Dry fire (too little water or pump issue)

What does F.22 mean?

The boiler has detected too little water within the appliance, or there's an issue with the water pressure sensor, pump, or its connection. This is a critical safety fault.

• Too little water in the appliance.
• Water pressure sensor defective.
• Cable to pump or water sensor defective.
• Pump blocked or defective, or pump output too low.

Click steps to track your progress.

1. 1

   Check the system pressure on your boiler's gauge. If it's low, refill the system to the recommended pressure.

2. 2

   Vent radiators to release any trapped air in the heating system.

3. 3

   If the pressure is correct and the fault persists, contact a qualified service technician to inspect the pump and sensors.