Hi Hugh. Looks like end of line. Yes, it's a matter of whom now. BG or one of the lads from Corgi (like to give pepes with own business chance).Would have expected system to shut down once roomstat reaches set temperature, something isn't right. Without being on site it is difficult to guess any further, it needs someone on site now to test and diagnose whilst looking at your system.
Will def let everyone know what is causing trouble though. God bless and thanx. Ellen.