Apologies if this has already been posted but cannot find any the same.
I am having a problem with my central heating. Firstly I thought it was the boiler but it fires up when the timer is set for the hot water tank on a morning. When I switch the CH on on the control box nothing happens. The pump works fine when the HW is running so its not the pump. The thermostat is on as if to start the CH. This is a system with a header tank. The 3 way valve doesn't operate when i turn on the CH. Could it be a stuck valve or broken motor? Can I manually override this valve? If you would like more information please ask. Any help would be greatly appreciated.