Radiator brainache

LE_Bore

A new radiator was hanging around in our house while some building work was being done. At some point, it got dented. Probably from me bashing my bonce on it in frustration at it not getting hung. 

Plumber cones in, a trusted chap who has been straight as a die thus far. I ask about the dent and he says he can hang it back to front so the dent doesn't show.  But it has an internal valve with marked in and out connections, says I. Don't fret, he reckons, it will just take 10 mins longer to heat up. 

He hangs the rad, runs the system. It takes maybe 5 mins longer to heat up. But it gets plenty hot. Now, a couple of months later, it's no longer getting hot. In fact it barely gets warm. I have bled it, turned the boiler up to stun, turned down the other rads, etc.  Still no go. Any ideas please, lovely people?

Thanks for reading.

WIAWSNB

Is this a column rad? These are directional, as I found to my cost (actually, I knew it was, but still got my new F and Rs pipes the wrong way around, and had to swap them back at the tees...)
I just don't know if having it reversed will only give the slower heating symptoms your plumber claims, but since your plumber seems clued up, and it did initially work ok, then he would appear to have been correct.
So, what's gone awry? No idea. Could it possibility be that the rubber bung inside was dislodged by it being the wrong way around - ie, pushed by the reverse flow? I don't know, but surely highly unlikely - it must surely be a secure fit?
Or, the fault is with the rad valves. What type are they - is one a TRV? If so, make please - or a photo. Some are one-direction.
Or, the cause is further afield - say an airlock in the pipe. Is your system vented (wee F&E tank) or unvented?

Make and type of rad? Worth a chat with the manufacturer - ask what is the worst that can happen if reverse flowed.

Were new pipes run to this rad? Are they easy to get to? Could they be swapped around if needed?
Another possibility is that your other rads are pinching too much flow, so this one is starved - ie the system needs balancing. You say it still doesn't heat up if other rads are shut off, but have you also tried opening this rad's valves up more? If you tweak them, try and note their starting points so you can return there afterwards.
Do you know the difference between 'control' (eg TRV) and 'lockshield' valves? 

HHarry

If it did work and now doesn’t I’d start with an airlock.

Can you turn the other radiator valves off to try and force the water flow through this one?

LE_Bore

Thank you for your replies. Sorry for the delay in mine.  I have tried turning off the other radiators but didn't get more than a slightly pathetic warming in the culprit. I bled the rad, but the only 'blood' was water -- not so much as a hiss of air. 

It is a column radiator, but a horizontal one though the columns are still upright. Pics of the external valves are here. I suspect the problem is an anti backflow valve inside. But if so, how did the plumber get it to heat up in the first place? Could turn it round and hope for the best, but it is definitely dented on the side I can't currently see.

Thanks again.

nofoollikeold

1. It won't be an "anti-backflow" device, but have a baffle fitted to direct the water.  
2. If it has worked in the past it seems unlikely it has been connected the wrong way round.
3. It is possible the TRV is faulty. Try the following:
3.1 Turn the dial to max.  
3.2 Take the head off (unscrew the knurled chrome plated ring just below the grey body).  No water will come out.
3.3 With a flat metal object psh the head of the pin down.  If it is stuck and doesn't move, try turning it round gently with pliers.  Don't pull it up, they can sometime come out and you will have a leak.

WIAWSNB

As nflo says.
Also have a close look at both sides of the chrome body of that TRV, and see if there are any arrows embossed on it.

bjorn_toby_wilde

That looks like a Flomasta valve. I think they’re all bi-directional so that should rule that out

WIAWSNB

LE_Bore said:

 

Any luck with the rad?
If not, see your top pic above? That's the 'lockshield' valve. Get a spanner or wrench, and turn that spindle one turn anticlockwise. Note the starting position, so you can return it there afterwards. 
Does the rad heat up now?
If not, then unscrew the 'head', which is the whole grey part. You do this by unscrewing the chrome ring at its bottom.
Remove the head, and use summat solid - even a teaspoon under yer thumb - the firmly press the exposed pin downwards. It should move down a good few mm under spring resistance, and pop back up instantly when released. Does it?

LE_Bore

Thank you. Got to be honest here… very reluctant to do anything with this on a Sunday. Brand new carpet and wallpaper in the room! If I mess it up, won't be able to get help today. Tomorrow, builder is here finishing a job so can get help... or blame him!!! Like I'd dare.

Tomorrow then. But very grateful for your help and knowhow. Will report back ASAP.

WIAWSNB

LE_Bore said:

Thank you. Got to be honest here… very reluctant to do anything with this on a Sunday. Brand new carpet and wallpaper in the room! If I mess it up, won't be able to get help today. Tomorrow, builder is here finishing a job so can get help... or blame him!!! Like I'd dare.

Tomorrow then. But very grateful for your help and knowhow. Will report back ASAP.

Totally understand. 

The suggestions re the valves wouldn't have had any unpleasant consequences such as leaks - it's all 'dry' stuff. 

However, if the installer is coming back, the right thing to do is to ask him - it'll almost certainly have a very simple answer, and he'll probably rather no-one was fiddling with it beforehand

Please let us know what the cause was. 

LE_Bore

It's not the installer, sadly. But maybe I should have got the builder to fit it.

Will get back to you with any progress. Or even news of a fix!

Thanks again.