Plumbing Question

Upstairs radiator not working - all others are ok - valve on one end therm controller on other - took a spanner to valve and ensured open - still will not come on - what could the problem be?

8 Answers

Best Answer


On the thermostatic valve undo the ring which holds it onto the radiator, either by undoing the little screw or by unscrewing the retaining ring itself. Pull the valve off
and you will reveal a little silver plunger like a pencil lead about 1cm in size. Push this
plunger into the valve a few times to free it. The plunger getting stuck is often the problem. Then put the valve back together again. You should be able to feel the warm water coming into the rad as you waggle the plunger in.



Answered 7th Dec 2011

photofinish contracts

Member since 6 Oct 2011

hi,there,s one way of finding out the problem,have central heating on and turn all working radiators off ..just leave the offending radiator on..failing that the trv valve is stuck in the off position,usually if you can remove the thermostatic top,no water will leak out..and just tap the spindle in the centre of the valve and off it goes..put the top back on..

Answered 7th Dec 2011


Member since 4 Nov 2008

Try taking the thermostatic head off and tapping the pin underneath. It is a very common problem that these pins stick. Have the heating on and keep tapping it firmly, but not too hard and you should find the rad getting hot.
Hope this helps.

Answered 7th Dec 2011


Member since 3 Nov 2010

Pin stuck on thermostatic valve?

Answered 7th Dec 2011

Paul Caton Gas Services

Member since 23 Mar 2010

you could have an air lock. Turn all other rads off and this should shift air lock.

Answered 7th Dec 2011

RD Services Ltd

Member since 29 Nov 2010

get a bleed valve key and open the bleed nipple at the top of the rad at one end,and let the air out .

Answered 7th Dec 2011

crest installations and maintenance services

Member since 25 Oct 2011


Is the radiator old? been in the property for years? could be a build up of sludge in heating circuit or a balancing issue turn the flow into other rads down a bit to allow circulation to extend up to the problem rad.

I would first try to bleed top problem rad,
Then i would shut a couple of rads off down stairs for the time being and check the problem rad to see if it improves regarding heat performance.
Allow a few hours to see if the heated water gets through to the upstairs rad.

I have seen this many times and it is just a patience thing in getting the heating system balanced.

If not get the system power flushed.

Try shutting off 2 lower floor rads first as this will allow distribution to by pass the bottom rads and deliver to rest of circuit reaching top rad.


Concept building services

Answered 7th Dec 2011

Concept building services

Member since 1 Jan 2008

Someties thermostatic valves jam shut call someone to free it off

Answered 7th Dec 2011

sovereign plumbing and heating

Member since 23 Nov 2011

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