Cold radiator - new TRV needed?

[somnerd13]

Just a bit of background to get started..

Rewind about 5 years and suddenly on one cold winter, I realise that the radiator in my bedroom isn't heating up. After freezing my *******s off for a few days I decide to try and fix it. Not really having a clue about plumbing all I could think of was bleeding the radiator, however no matter how long I bled the radiator for - nothing came out. Bugger, I have no idea what to do now. Anyway, a few weeks later it is no longer my problem as my parents and I swap bedrooms, and they never ever have the radiator on anyway so it's not a bother to them. End of issue... or is it?

About 6 weeks ago, after having lived away from home for 2 years, my girlfriend and I temporarily move into my parents house whilst we wait for the purchase on our new place to go through. We move into the room with the broken radiator, I switch the heating on to get the room warm and guess what - it still hasn't been fixed!! Now having a bit of extra knowledge about plumbing, I narrow the problem down to a lack of pressure in the central heating system. The other upstairs radiators only get lukewarm and the pressure turns out to be about 0.75bar. I fill the system (close loop) to about 1.5bar - all of the other radiators work fine now, except for ours, still...

Now what baffles me is that there is actually water in the radiator - and it's full. I have no idea why the radiator isn't warming up, and I can only think that the TRV has failed and a new one is required.. Does this sound right, or could it be another problem?

 

[Slugbabydotcom]

TRV probably is stuck in the off position. Its not an easy task trying to unjam them when this happens. Tapping gently with hammer sometimes helps. Grabbing the pin and pulling on it is a lot risky in most cases.

When you say that there was nothing coming out when you tried to bleed air then this could mean that the valve at the other end is not opened either.

Other possibilities are that one or more of the pipes leading to the rad are blocked with air or debris or perhaps they are not plumbed in correctly.

I would take the rad off and try to get some water from each rad valve to see if you can locate the blockage or cause.

Before you do that try turning off every other rad in the house. That way all the energy from the pump will be forcing around this circuit and could possibly clear a blockage.