I've just drained my system to fit a new radiator. Water has stopped coming out of the drain valve but the header tank is still full. I opened all the air valves on the radiators and nothing is coming out of any of them so I am assuming that the radiators are empty.

Mark, September 2008

have u got any zone valves fitted if so try manually opening them

Mark, September 2008

you have a blocked cold feed.

hi-spec plumbing & heating (essex), September 2008