Great. I have same problem with gloworm betacom 4 . Pressure regulator at the meter faulty. Called gas supplier they come and changed it and works fine.
This was in no way helpful. People need to know how to fix the issue. I had an engineer come out and “fix” it but then it stopped working the next day. Vaillant should be banned from making boilers if this issue is so common
We had a Vaillant boiler installed a few months ago and I've already had the error F22 show up several times and now the error F28 is showing up and we are left with no heating or hot water. What a joke...