Well it's fixed I think
I opened up my spare motorised valve, looked at the circuit diagram and my own theory and hey there is the switch. It latches in and out when the thermostat tells it to and it is this that is controlling the boiler and pump. I then took off the switch on the immersion...
Thanks for the replies so far - I am going to swap the motorised valve (I have a used spare) but was I correct in my thoughts - is there a secondary circuit that has to be completed in the zone valve when it is open / shut position that also switches the pump/boiler on/off respectively ? That...
Ok I have trawled most of the posts on this subject and they all suggest one thing - sludged up system. But I am not convinced as there are some weird things happening to my system
It is an ideal w2000 boiler with 2 position motorised valves for CH and HW.
The pump is a Grundfoss Selectric...