if anyone can help with my problem it would be greatly appreciated. i have a baxi combi instant 80 he, sometimes it works, heating hw etc and sometimes it doesn't. the diognostics board shows that the problem appears to be the HW sensor. could this really be the root of the problem and how would the HW sensor allow it to work intermittently .also the water pressure in the heating system goes down pretty quickly, obviously theres a leak on the system somewhere. will one affect the other ? i ask that question as the HWsensor fault indicator can be showing even when theres over 1 bar of pressure in the system, i hope this is enough information for someone to point me in the right direction. thanks !