One radiator is not getting hot unless I turn down all the others, wait for it to get hot and then turn the rest back on. At which point it operates normally and doesn't grow cold.
Can anyone help with advice as to what's happening?
Bleed it man
Regards
Mick
Bleed them all of air, when cold then hot, then check water pressure and fill only when system is COLD. you only need enough water to heat the highest radiator, you may have enough, even to much now.
If it can get hot when the others are turned off then it doesn't need bleeding.
Sounds more like an issue of balancing to me - all the other rads are taking all the flow and the dodgy one is suffering. A balanced flow to all the rads on the circuit is achieved by fiddling around with the lockshield valves to restrict the flow to those rads which would otherwise hog it. The lockshield valve is the one that you don't usually touch, it's probably covered by a removable plastic cap. You could try to solve the problem by opening up the lockshield valve on the cold rad. If that alone doesn't work then slightly close the lockshield valves of a couple of the rads nearby. That should force more of the flow through the cold one. However, random tinkering might throw other rads off-balance, so count the number of quarter turns you make so you can restore things to the status quo ante if necessary.
To do it properly is a bit more time consuming - see the FAQ at
As another guide to a simple fix. Start from cold and dash around to see which gets warm the quickest. Make this the 1st target for throttling back the lockshield. I would personally close it fully then open it half a turn and do the cold start again.
sounds like symptoms of system out of balance.
I wrote a piece for the FAQ on balancing .... not sure if it is still there since it went web based.
If not send me a PM and I'll email you a copy.
The water is taking the easiest path round the circuit - and that radiator is obviously too difficult.
You sort it by making the existing path relatively more difficult and forcing the flow into that rad.
This is called balancing the system - see FAQ for details.
sounds like trvs and no balance doing what you would expect. Rads nearest the boiler hogging the flow till they shut down.
Thanks everyone, I will attempt to balance the system then!
PS thanks for pointing me to the FAQ it'll help with some other stuff too.
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