One radiator not working at all

Joined
12 Nov 2013
Messages
6
Reaction score
0
Location
Cambridgeshire
Country
United Kingdom
Hi all,

My first forum post is a plea for help! Sorry about the long message, I thought it would save wasting anyone’s time if I gave as much info as I could upfront.

One downstairs radiator in the hallway stays stone cold (the whole radiator and both the pipes cold) even though all of the other rads (5 downstairs and 6 upstairs) work fine and get very hot. It’s a gravity fed system, and there is water in the fill tank. I don’t think there is a TRV on the radiator, so no stuck pins.

The valves are ATC Myson Matchmaster+ and appear to be identical at both ends of the radiator. Inconvenient, because I have no way of knowing which pipe is the inflow, and which one is the return. I also don’t know the pipe routing in the house, so I can’t figure out whether the rad is at the start or the end of the loop.

I tried to bleed the radiator, but it wasn’t what I expected: a mixture of air and water (several litres in total) bled out for well over 2 hours before I got bored and closed the bleed valve again. I can’t figure out whether there is just a lot of air in the system, or whether air is actually getting in to replace the air coming out. None of the other radiators need to be bled (just water comes out immediately) and all continued to work fine both before and after I tried to bleed the one that wasn’t working. The radiator got slightly warm when I bled it, but cooled again afterwards – I imagine because the hotter water simply replaced the lost water, rather than because flow had returned.

I can’t see any way of inspecting the valves for blockages without draining the system. I rather suspect either a severe air lock, or a physical blockage of some description. Is there an easy way to tell the difference? I’ve tried turning all the other rads off to try to clear the air…

I really don’t know what to try next… I’m reluctant to drain the system because the rest of the CH works fine, so I don’t want to mess it up completely….

Cheers,

Ian
 
Sponsored Links
Have you tried turning all the other rads off to see if this one gets hot?

Thanks Hugh. I did try this intially, but it's probably a good suggestion to try again now that I have moved the air around a bit by attempting to bleed. Any idea how long I should leave it like this for? I imagine that if it was going to clear it, then it would happen pretty soon after turning the others off.
 
My guess would be an airlock in the pipework to this rad, as it seems like it is slow to bleed (I had a similar problem until I modified the pipe run and cured the airlock)

Perhaps worth removing the rad completely and opening each valve into a bucket to see what kind of flow you get. It might be enough to shift the air. Alternatively connect a hosepipe and use mains pressure to push the air back around the system. Worked for me as a temporary cure until I redid the pipework.
 
Sponsored Links
If shutting all the others down gets the problem rad working, leave it going for a few mins for the rad to get to temp and ensure there is a good circulation through it. If, once the others are reopened, this rad gets cold again then may be a balancing issue, see FAQ's for how to balance the system.
 
Hi all,

Thanks for the comments. Good news! It now works! It was basically just an exercise in perseverence and patience, but I bled as much air as I could, and then closed off all the other rad valves, and started the CH system again.

Nothing happened the first time, but after another round of bleeding and then running the system, I started to hear some air moving around. After a couple of minutes, there was some loud gurgling (music to my ears), and the rad heated up. I left it running for an hour or so, and then turned on the other rads, turned off the pump, and then re-bled the rads.

When I got up this morning, the rads were all working fine! Happy!
 
For anyone who has a problem like this in the future, note this advice.

When bleeding the air from the rad do it with one rad valve closed and then do the same with the other valve closed.

That will encourage the pipe with the air to let the air into the rad where it can be bled out.

Had he done the bucket test ( see FAQ ) then it would have solved the problem by getting the air out of the supply pipe.

Tony
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Back
Top