Mystery cold radiators

[Fuzdrum]

Hi, I have 5 radiators in the house. Just recently the radiators in the bathroom and the dining are cold when the ch is on. I have bled the radiators. Turning off the working radiators forces the cold ones to work. I can then turn the other radiators back on and the whole set up is working. However, the next day after the heating has been off all night, the 2 problem radiators are cold again. Don't know what to do now. The bathroom radiator is a vertical towel rail and is the only one that has a temperature controlled valve that is working correctly. Can anyone shed any light on what I can do please???

 

[JohnD]

you need to balance the radiators.

 

[Fuzdrum]

What's the easiest way to do this John?

 

[Burnerman]

Basically you turn the lockshield valves on the radiators off, and then on a bit - often one turn is quite enough.
This forces the hot water through the radiators that are struggling, as water always likes to take the easiest route around a system.....hence closing the lockshields provides a restriction.
John

 

[JohnD]

//www.diynot.com/wiki/Plumbing:faq2
I bet you haven't got pipe thermometers. You can get a reasonable approximation: the flow pipe should be "too hot to hold" and the return pipe should be "too hot to hold for long"

 

[Nige F]

But John, is that with or without PPE gloves ?