One radiator not working

26 Mar 2008
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United Kingdom
I had two upstairs radiators that were not working due to faulty valves and ane radiator in the consrvatory that got warm (not hot) at the top of the radiator but not at the bottom (odd I thought!). I have replaced the radiator valves on the upstairs radiators and these are now working fine but now the one in the conservatory is stone cold.

I have an old central heating system with a back boiler so I would assume the conservatory radiator was a later addition.

The radiator is a double convector with a thermostatic valve on the right hand side and a regular valve with drain off valve on the left. I have tried bleeding it from the bleed valve at the top but this hasn't worked (water comes out as soon as it is open - so no air).

I have also tried opening the drain valve in case there was an air lock in the pipe and this worked to a degree - the radiator started to get hot at the top but not the bottom. However once I had closed the drain valve the radiator went cold again despite the heating being switched on.

I have also taken the top of the thermostatic valve and the pin seems to move freely.

I am out of ideas as to what could be wrong with it.

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Try turning all of the rads off (shut the TRV's down), except the conservatory rad. This may force the water through a bit better and clear it out.
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The rad supply's will be pinched off another 8mm supply and not be able to supply the flow for both rads.

Conservatory fitted are great at doing it that way round here.

Try turning off other rads and turn up pump speed. might be some sludge but most likley dodgy installation.

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