F22On Vaillant boilers, fault code F.22 means: Water pressure too low. Usually yes, once you have fixed the simple cause below (for example topping up the pressure) and reset the boiler.
Can I keep using the boiler?
Usually yes, once you have fixed the simple cause below (for example topping up the pressure) and reset the boiler.
Common causes
- Water leak in the heating system or pressure not topped up
- Faulty pressure relief valve or expansion vessel
How to fix it
- Top up the pressure to about 1–1.5 bar with the filling loop or tap (see your manual)
- Check radiators, valves and pipes for leaks; if the pressure keeps dropping, call an engineer
- Press the boiler's reset button once and wait for it to restart
Frequently asked questions
What does Vaillant error F.22 mean?
On Vaillant boilers, fault code F.22 means: Water pressure too low.
How do I fix Vaillant error F.22?
Start with these steps: Top up the pressure to about 1–1.5 bar with the filling loop or tap (see your manual); Check radiators, valves and pipes for leaks; if the pressure keeps dropping, call an engineer; Press the boiler's reset button once and wait for it to restart.
Is it safe to use the boiler with fault F.22?
Severity: Low. Usually yes, once you have fixed the simple cause below (for example topping up the pressure) and reset the boiler.