OK, some more testing done... The valve (which I think is 2 way rather than 3) appears to be working as it should. It looks like the pump is to blame - but not because it isn't working... it just won't come on when the CH is switched on. It works perfectly when you turn on the HW, pumping the...
I have a E tech s 240 boiler that was installed in my 3 year old flat.The boiler is connected to a Salus EP100 programmer. It's a tank in tank, electric, unvented thermal store system, as far as I can gather from reading stuff online.
We can only get the boiler and it's built in tank to heat...