This morning, I woke to find my Vaillant boiler wouldn't start up. A red light is flashing where normally a green one flashes.

On the display screen it keeps moving between F22, O.1bar and 0.2bar.

I assume that this is Fault 22 but am not sure what that means. I was hoping that bleeding the radiators might help. But having done that today, I have found no change.

Any advice would be most welcome as my landlady doesn't like spending money on us, and I am rather hoping to avoid the confrontation of having to get someone in.

Chris, January 2010

f22 means low water problem top up pressure to 1 bar

adam, January 2010

F 22 is pointing to dry fire
this means there is very little water in the system this can have underlying causes like a water leak some where.
system needs refilling via the filler loop under the boiler back up to 1.5 bar pressure cold, bled the air from the all the rads .recheck the pressure and top back up to 1.5 mark turn off BOTH of the filler loop taps.

no joy contact the land lord .

wirecutterman, January 2010