Thanks for that the cold water feed is definitely ok.
There were two radiators that were cool in the centre at the bottom I took them off and flushed them out.
Your right they were full of crud the system is back up and running.
There is no hot water running in the cold water tank from the...
Prof : plumb
I checked the vent pipe dimensions they are ok
Turned the pump down to speed 1 (was on 2)
Then I wondered about what you said on the possible cold feed pipe block
The supply to the tank is only a few inches from the pump isolation valve
So I bailed out the tank to see if there...
:?: I have a Potterton Netaheat central heating boiler which just runs the heating system.
The water tank in the loft that feeds the system is getting hot,
I now notice that hot water is running into the tank from what i beleve to be the vent pipe.
The system appears to be working ok apart...