Air Lock?

[BUNTINGR]

Hello! I was wondering if somebody could help me? I have a cold radiator in a downstairs room which I have tried bleeding and letting water out from the top valve, radiator gets hot gradually but as soon as I stop it goes cold. The pipe to the left hand side of radiator gets hot after bleeding but the pipe from the TRV right hand side is stone cold and never gets hot.

Do I have an air lock if so what do I do? I am a complete novice!

Thank you

 

[Blasphemous]

If you're able to bleed from the bleed nipple as you seem to be saying you are and the system is hot at one side of the rad and cold at the other, its more likely to be sludge in the system causing a blockage. Without seeing the problem, my bet would be you need the system flushed.

Click on 'Find an Expert' on the Blue Header at the top of this page to help point you towards someone in your area who can quote.

 

[TicklyT]

Could it be the TRV has jammed closed?

You could unscrew the TRV head and see if the plunger underneath moves freely.

 

[dotto]

Hello! I was wondering if somebody could help me? I have a cold radiator in a downstairs room which I have tried bleeding and letting water out from the top valve, radiator gets hot gradually but as soon as I stop it goes cold. The pipe to the left hand side of radiator gets hot after bleeding but the pipe from the TRV right hand side is stone cold and never gets hot.

Do I have an air lock if so what do I do? I am a complete novice!

Thank you

You say that the pipe to the left gets hot (flow) and the pipe on the oppsite side (return) with TRV...........I thought that you would fit TRVs on the flow and not on return pipes. If my statement is correct ( i am only a novice), the TRV on the return is pushed down onto the valve seat preventing any flow of water in the radiator( rad cold). By bleeding the rad, you create a path for the flow of water that's why the rad gets hot and as soon as you shut the bleeding valve you stop the path for the flow of water again, so rad gets cold again. Having said that, if that rad was working well previously, then it might be sludge.

 

[sime10]

On modern Trv's they are bi directional which means flow or return.

Try turning off the others that are working and you should get nice and hot on that rad


If it is an old one take the TRV head of and push that little spindle in and out