Radiator cold at bottom

N9eav

I have a double core radiator that's always cold at the bottom, to be honest it is'nt that hot at the top either.
I think it's probably knackered
It's the furtherest away from the manifold (micro bore) and so the exit valve is wide open.(?)
I have tried shutting all the other radiators off and blasting this one through with the pump on full...
It's been bled.

Perhaps plumb1 or other plumbers, heating engineers out there can confirm the rad needs replacing (tis quite old) or a solution...
???
cheers ???

theGrinch

have you bled the radiator to make sure it isnt just air?

andrew

It sounds like its blocked with sludge, you need to lock the valves off and remove the rad for a good wash out.

nicknak123

Hello..I had a problem with a radiator which needed bleeding often, fitted a self bleeding radiator valve (available @B&Q) - was easy to do too & sorted my problem.

heatherw_01

I have the same problem, but I don't think it is to do with bleeding as that is when it is cold at the top

plumb1_2

It could be a couple of things
1,as someone else has said blocked with sludge,take off and blash through with hose pipe.
2,you said its microbore,depends on the size 8mm or 10mm.A a 10mm pipe will only carry about 5000btu,so the radiator could be to large for the supply pipe,and will never get hot only warm.
You will have to repipe in 15mm

Having said the above why is it blocked with sludge.
I will recomend cleaning the whole system,with a chemical cleaner as well.

N9eav

Thanks for the above. I have tried most of them in the past. The rad. does get hot at the top, so it's getting water, but it tends to be cold at the bottom.

Can radiators corrode so that they don't function properly anymore? I don't want to buy an £80 rad if I get the same problem...