Please help! 1 cold radiator

[SGraham99]

I have 1 cold radiator that is furthest away from the combi boiler. I have balanced the radiator so that the lockshield valve is all the way open, however no hot water coming through the TRV.

When all the other radiators are off it barely gets warm. I thought it might have been an airlock so left it on its own.

It backs on to another radiator on the other side of the wall which is hotish.

Next plan is to take it off and clean it through however has anyone got any other tips?

Thanks in advance

 

[cross thread]

Have you checked the pin under the thermostat head is free ?

 

[SGraham99]

Have you checked the pin under the thermostat head is free ?

Yeah gone through and made sure that the pins a moving up and down. The pipe feeding the TRV isn’t getting hot when all the radiators are on.

 

[Jurassicspark]

I have 1 cold radiator that is furthest away from the combi boiler. I have balanced the radiator so that the lockshield valve is all the way open, however no hot water coming through the TRV.

You might have not balanced it correctly. When you say, the radiator heats up when turning the other off suggests it's not balanced properly. Turn the others down a bit more.

 

[JohnD]

When all the other radiators are off it gets warm.

You need to balance your radiators.

I have balanced the radiator so that the lockshield valve is all the way open

This is not done by opening the lockshield on the cold one.

It is done by partially closing the hot ones.

 

[SGraham99]

You might have not balanced it correctly. When you say, the radiator heats up when turning the other off suggests it's not balanced properly. Turn the others down a bit more.

Will give it a try with all the lockshields at a quarter turn thanks. Slightly changed my post as it was barely getting warm with all the other radiators

 

[SGraham99]

You need to balance your radiators.



This is not done by opening the lockshield on the cold one.

It is done by partially closing the hot ones.

Yeah I went through and closed all the lockshield valves and then opened in quarter turns from nearest to furthest (nearest 1 quarter open, 2nd nearest 2 quarter ect.). The one not getting hot is the furthest away so I left that fully open

Would you suggest a different way?

 

[Stuckinarut]

I have 1 cold radiator that is furthest away from the combi boiler. I have balanced the radiator so that the lockshield valve is all the way open, however no hot water coming through the TRV.

When all the other radiators are off it barely gets warm. I thought it might have been an airlock so left it on its own.

It backs on to another radiator on the other side of the wall which is hotish.

Next plan is to take it off and clean it through however has anyone got any other tips?

Thanks in advance

Ok, is this a new radiator added, a new problem, or what?

 

[terryplumb]

Close both valves on the problem rad. If system is sealed / pressurised ensure pressure is 1.5 bar . Then open its bleed valve ,have a towel to hand ,let water run out until it stops running. Open the TRV and see if water starts ,and continues , to flow out . If it doesn't the TRV is faulty or the pipework to it is blocked.
If water does flow out well,close the TRV and open the lockshield and repeat the test to see if water flows.

 

[JohnD]

Yeah I went through and closed all the lockshield valves and then opened in quarter turns from nearest to furthest (nearest 1 quarter open, 2nd nearest 2 quarter ect.). The one not getting hot is the furthest away so I left that fully open

Would you suggest a different way?

Try them all, at a quarter

You are looking at at opening that, half an hour after starting the heating from cold, has the inlet pipe on every radiator "too hot to hold" and the outlet pipe between warm and "too hot to hold for long." Any radiator hotter than that is stealing flow from the others.

Almost all the adjustment is in the first half turn or so from fully closed.

After that, use the TRVs to bring each room to your preferred temperature. Often around "3."

 

[SGraham99]

Close both valves on the problem rad. If system is sealed / pressurised ensure pressure is 1.5 bar . Then open its bleed valve ,have a towel to hand ,let water run out until it stops running. Open the TRV and see if water starts ,and continues , to flow out . If it doesn't the TRV is faulty or the pipework to it is blocked.
If water does flow out well,close the TRV and open the lockshield and repeat the test to see if water flows.

Thanks will try this, however whoever installed the rad put 2 blank valves on the radiator rather than 1 bleed valve which is making it hard to bleed without making a mess haha

 

[SGraham99]

Try them all, at a quarter

You are looking at at opening that, half an hour after starting the heating from cold, has the inlet pipe on every radiator "too hot to hold" and the outlet pipe between warm and "too hot to hold for long." Any radiator hotter than that is stealing flow from the others.

Almost all the adjustment is in the first half turn or so from fully closed.

After that, use the TRVs to bring each room to your preferred temperature. Often around "3."

Turned a very hot radiator off and now the pipe feeding the cold rad is too hot to hold but actual rad is barely warm.

Set all the other lock shields to a quarter turn and see if this works.

Thanks for the help

 

[SGraham99]

Ok, is this a new radiator added, a new problem, or what?

All existing and been cold for nearly a year now

 

[Stuckinarut]

Can you post a photo of the problematic radiator with both valves showing?

 

[SGraham99]

Can you post a photo of the problematic radiator with both valves showing?