ok thanks.... if it isn't a DIY thing, I'll leave well alone
The pressure relief valves can't be tested by twisting them? ....albeit not really a 'test'as such.
Hi all... hoping I get a prize for the clearest explanation of a problem :)
In short, the overflow outside is a constant poor and it leads up to the pipe you see coming out of the airing cupboard floor and into the black overflow viewer (...a Tundish?)
The overflow is constantly running and...