Radiator problems

[easylife]

Hi,
I have a problem of one of my downstairs rads not getting warm
The problem started a few days ago when the rad only got lukewarm but the incoming feed was very hot,(previously fine for years) i bled the rad to check for air locks but this had no effect
Today when the central heating kicked in, the in coming hot water pipe was cold so all the other rads were turned off to try to force the hot water to just this rad but this has had no effect
My first thought was that the rad must be blocked by sludge but surely the pipe would still get hot, so i think it must be something else, problem being that i have run out of ideas so your ideas would be much appreciated
Cheers Alan

[The Builder]

a blockage in the pipework is very unlikely, unless you have that 'orrible little 6mm microbore..............more likely an airlock in the system. Turn up your room stat to get the pump running, then bleed that rad again..............long shot, I'm afraid.............but difficult without seeing the layout of the system...................

[easylife]

thanks for your help, i will try your suggestion as any help is welcome

[gucciman]

i find it very strange that the inlet pipework was hot the one day but then not the next day, if the rad had remained cold but the inlet pipe hot then i would have suspected a faulty thermostatic radiator valve (TRV) if you have one that is.

if it does have a trv then try taking the trv head off and see if the rad then gets warm.

its unlikely that air is the cause of the problem as the air in a system naturally rises to the upstairs rads. you could try re-bleeding the system but make sure the system is turned off when you do it and i would vent the rad that is playing up and all of the upstairs ones.

[easylife]

Gucciman
i think it has a tvr (variable heat control on the outlet?) which i will remove and then test
docspock all the other rads up and down stairs are working fine so why would you suspect the pump

[alavahalf]

Had the same problem when we decided to turn the heating on after the summer...2 radiators not getting very warm even though I had removed the top of thre TRV's
I asked a heating engineer what it might be...He said'' The TRV is possibly stuck down due to it not being used over the summer....hit the side of the valve before you condem it...if it does'nt free off..replace it.''
Gave it a belt with a screwdriver and it's worked fine ever since...!
Worth a try..?

[easylife]

alavahalf,
thanks for the reply, i will give your suggestion a go, you never know
Cheers

[gucciman]

if the trv is on the return (outlet as you said) then it needs to be a reversible flow trv.

and if removing the head of the trv doesn't help then it could be the body of the valve itself. has already said by alvahalf try gently rapping the side of the valve with a spanner and also work the little pin up and down and try some wd40 on it.

[easylife]

Hi all,
problem solved,
as mentioned by gucciman and alavahalf the TRV was sticking down so a few sharp taps with a spanner and the nipple popped up
just like to thank all who took the time to answer
many thanks Alan