Bottom of radiator cool

[mroberts]

radiator at the top of the house is cool at the bottom and warm at the top. The pipe where the water goes into the radiator it v hot, the pipe where it comes out is cool. I have replaced the valve where the water exits the rad. Any ideas? a blockage perhaps?

Thanks

Mark

 

[ChrisR]

If exit pipe is cool, see "balancing" in For Ref section.
Once that's fixed if lower edge won't get hot ever, it's sludge.