Hi All, New to the group, but expeienced in most things DIY...honest!
My problem is that central heating is not responding to the room thermostat. When the thermostat switches on (say when room temp is 18) the system keeps pumping heat to the radiators even when the room is over-hot. At first I thought the wiring or romm stat was faulty, so:
I have checked the wiring from the thermostat to the wiring junction box (that takes the wire from pump, boiler, 3 way valve and cylincer stat). The thermostat wire carries live to terminal 1when CH is on and then creates a switched live feed back to the junction box as it should.
However, the swithched live is still live for quite a while after the room has reached temerature. I have replaced the room stat with a new 2 wire Sunvic stat. It's as though the switched live wire is retaining some power in itself.
The really crazy thing is that the cable also reads live at the spare earth wire which is not connected to anything at either end!! This only happens when CH is on.
All hot water functions OK.
I have even replaced the cable and the new cable does the same, new Sunvic cylinder stat at the same time as new room stat. New Siemens RWB2E programmer, new boiler stat, new 3 way vavlwe 18 months ago...can anyone help as I have been trying to fix this for months now and all I am getting is massive gas bills.
Thanks
Paul