Any thoughts on how to lower the temperature on Vaillant Combi boiler. With the hot water set on is lowest temperature its still very hot. The temperature valvue is at 40 degrees.
Just had a new bathroom fitted and now the boiler won't fully light. Its a Valiant and always extremely reliable. Pilot lights but then goes out. I
Is this a pressure issue or air in the system? If so, how do I re-set pressure / get air out of the system?
(not calling back the Cowboy plumber...