F.75 — No pressure rise detected when pump turns on

What does F.75 mean?

The boiler has detected that there was no increase in water pressure when the pump turned on. This indicates an issue with the pump, the water pressure sensor, or air in the heating system.

• Water pressure sensor defective.
• Pump defective.
• Air in the heating system or quick bleeder defective.
• Too little water in appliance; check adjustable bypass; connect external expansion vessel to return.

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 problem persists, contact a qualified service technician to inspect the pump and pressure sensor.