F22 error on Vaillant Ecotec Plus Boiler

[claire_reese]

Hi all,

I have a Vaillant Ecotec Plus 418 boiler (standard boiler, not combi), but as of this morning my heating and hot water has stopped working, and I get the error message F22.

I believe this means the pressure is low and I've looked online, and it suggest I must use valves under the boiler to repressurise. However, my boiler/pipes do not have these valves (as far as I can see).

I've included 4 photos. Photo 1 is the boiler panel, photo 2 is the underneath of the boiler, and photos 3 and 4 are in the airing cupboad.

Can anyone help or suggest anything? Thank you!

 

[Last Plumber]

I'm not sure what a PCB is?

Sorry.
Printed Circuit Board inside Boiler.