F.22 / Flashing pressure value - Heating system water pressure too low

What does F.22 mean?

The boiler display shows the fault message F.22, or the current pressure value flashes. This indicates that the water pressure in the heating system has fallen too low. If the pressure drops below 0.5 bar, the boiler will switch off.

• Insufficient water in the heating system.
• A water leak within the heating system.

Click steps to track your progress.

1. 1

   Purge the lowest radiator until water flows out of its valve without bubbles.

2. 2

   Purge all other radiators in the system until water flows out without bubbles, then close all purging valves.

3. 3

   Slowly open the stop valve on the filling line and the cold water valve to allow water into the heating system.

4. 4

   Monitor the digital display and the analogue pressure gauge, filling until the pressure is in the middle of the grey area (between 1.0 and 2.0 bar when cold).

5. 5

   Close the stop valve on the filling line and the cold water valve once the correct pressure is reached.

6. 6

   Check all connections and the entire heating system thoroughly for any leaks.