The boiler made a whining sound and fault 22 came up saying pressure very low. How do I top up the water pressure please as it doesn't tell me in the instruction book, just to ask the installer how to do it or contact Vaillant for technical support at 50p per minute. As I don't have a man to help me, would appreciate some advice. Thanks.

Angie, May 2007

Angie (and anyone else happening upon this site) -

I also had the F.22 error on my Vaillant ecoTEC combi boiler. I looked underneath and found two valves. I turned one, then the other, but nothing happened.

Happily, on another HowToMendIt thread, someone said to open the left valve, then the right one *while the left valve was still open*. (Left and right are per one being underneath the boiler with one's head to the wall.)

That was the answer to my problem. Now, if I could only answer the problem of my boiler installer's mobile phone number being no longer available 7 months after installation ...

Shazzbot, July 2011

Locate/identify the mains cold water supply pipe to the boiler. There should be a branch in this pipe close to the boiler, terminated with a valve. There should additionally be a branch in the central heating flow pipe with a 15mm non return valve connected to to it.

These would be connected to each other by a removable flexible hose. Recharging the system pressure is effected by opening the valve in the mains water supply pipe until the correct pressure is shown.

tamperman, June 2007