Radiator not warming up.

[Nath1985]

Hi. I have an unusual (I think) issue with one of my radiators.
Since I moved into this property 18 months ago the radiator in the kitchen (next to the boiler) hasn't worked and I have only recently attempted to sort the problem.
The pipes coming to and coming from the rad are not getting hot either.
I have tried everything I can think of to no avail.
So far I have.
Taken off the rad, took it outside and flushed it through with a hose.
Replaced the TRV with a new one.
Replaced the lockshield valve with a new one.
Turned off every other rad at theockshield and turned the heating on in an attempt to flush the system.
The thing that makes it unusual is that when I undo the TRV at the tail or the pipe, even a little bit the pipe starts getting hot as does the radiator. As soon as I nip it back up it goes cold again. It does this with the old and new TRV.
Any help would be greatly appreciated. Thanks in advance.

 

[Harry Bloomfield]

Take the TRV head off, under which you will see a pin. The pin should be able to be pushed down a mm or so, if you use the side of a pair of pliers or even a coin to apply the pressure. If it doesn't move, it's stuck - grip it with a pair of pliers and try to move it up. Do it carefully, so as not to pull it all the way out.

 

[Nath1985]

Hi Harry. I forgot to mention I tried that also.
There is a brand new TRV on there now and the issue persists. Thanks

 

[terryplumb]

It's either piped incorrectly ,or there is a blockage on the return as it sounds like the TRV is fitted to the flow. There is no water flowing through the radiator into the return.

 

[Harry Bloomfield]

Turn all radiators off, apart from that one, see if you get some flow then.

 

[terryplumb]

Turn all radiators off, apart from that one, see if you get some flow then.

He tried that Harry ,by closing all their lockshields.

 

[Johntheo5]

Shut both the TRV and the LSV, open the rad vent until water stops venting, open vent fully, open the LSV, does the rad vent/bleed water at a good rate, if not return blocked, maybe repeat with TRV. If both venting maybe rad connected like a one pipe system.