I think this is a simple problem to solve. I have one rad upstairs and one downstairs that are stone cold - not even warm at the valves. They used to work when I moved in but have not worked since I drained the system to fix a leaky rad valve. I have drained the system dosed with sludge remover refilled bled rads and drained and refilled and bled rads again but still no joy. I have balanced all the other rads to allow more flow for the faulty ones - no joy. After it refills the faulty rads get a little warm in one corner but soon get cold again. I start bleeding rads from upstairs first this is right isn't it? I have even fitted a new pump. The only thing I have not done is remove the rad valves and check for blockage. If they were blocked would the pipe work before the valve be hot? Another problem which I am sure is related, is the header tank is filling with hot water from the expansion pipe. This gets worse if I turn the pump on full. The boiler stat is turned down low and works fine. From what I have learned it looks like the pump may be in the wrong place. It looks as if it is fitted in the pipe that comes down from the header tank (top up pipe? not the mains feed) and its under the cross over pipe (between the expansion pipe and the top up pipe). Of course I may be wrong. Not a plumber as you can tell. The system was fitten in early 80's.
Hope you can help. These two rads are driving me up the wall.
Regards Peter.
Hope you can help. These two rads are driving me up the wall.
Regards Peter.