Hi Guys. Thanks for the suggestions but I dont think it is preheat. The boiler fires up and the pump runs. The roomstat is turned right down and programer is set to off. The rooms get hotter and hotter. Any ideas? Thanks
Hi Guys. Hope someone can help me. I have a Vaillant combi boiler that will suddenly turn itself on even when both the room stat and programer are not calling for heat. Any ideas what might cause this? I have to turn it off at the mains electrical supply for a few minutes, then it is ok for a...