one cold radiator

[rich29]

removed radiator flushed out and replaced 2 new valves. After refilling the system and bleeding six buckets of water out of radiator, radiator warms up but immediately goes cold again. Inlet valve is warm during this procedure but outlet valve is stone cold. This is a microbore system that has had sludge remover treatment in it, I suspect that their may still be sludge in the piping. Can anyone please advise how to remove sludge

 

[oilman]

You'll have to pressureise the pipe, either with a pump or with the mains. Be careful if you use the mains, full pressure on your system could strain things.

 

[rich29]

how would I pressurize the pipe with the mains please

 

[oilman]

Hmmm,....stick a hosepipe up it?

 

[rich29]

thanks! i'll give it a go.

 

[alisquires]

We have one cold radiator.

We've closed all other rads off, messed with the pin in the thermo, even changed the thermo. Bled the rads, drained the system, took it off the wall and flushed it out. It worked until the heating went off and now won't heat back up. Any ideas?

Do you think there is sludge in the system and we need to clean it, or is the boiler not powerful, the rad is about 9-10ft long? Please help it's freezing