Hi Seco, thanks for your reply. Trying to conduct your checks I find that the system is now working perfectly. Typical. I have the M/V stripped and am trying to duplicate the fault through today. As of this moment the orange wire in the M/V is dead as the room stat has stopped calling for heat...
Help please!
My (gas) central heating system has a twin port motorised valve. When the room stat calls for heat, the C/H motorised valve opens and the boiler lights.
However, when the room stat calls to stop heat, the C/H motorised valve stays open & the boiler keeps burning.
The C/H...