When I filled the boiler the Ch return valve in the boiler was turned to off, I thought this might effect it!The auto air vent at the top of the boiler was rusted up and when I attempted to turn it the top snapped off. Anyway I drained some water out and refilled and it now works fine I presume...
I changed the divertor valve this morning to rectify the problem of intermittent no DHW , the CH was working fine( the valve was failing to operate the micro switches each time)I now have the problem of no DHW or CH. What happens is that on demand, Ch or DHW, the pump runs and then the fans...