Problem with one radiator but can't see what to adjust

[LeonN]

Hi,

Central heating looks to be ok on 6 of the 7 radiators in my house (2 floors). Heat flows as expected.

But there is a problem with the radiator in the front bedroom, which remains cold (top and bottom of radiator). I've bled it several times and now water comes out straight away so don't think that's the problem.

I looked at some videos which mentioned a thermostatic radiator valve and also a 'lockshield' - so I was hoping that was the problem here.
But looking at the radiator - on both sides I see this (after removing the cap (screwed in) - pictures below.

I can't see anything obvious to adjust. But other than bleeding the radiator, I can't see what else to check/change.

Now I do note the two pipes to the radiator are cold, but what is odd is that all the other radiators in the house are perfectly hot.
Boiler/Pump seems fine as well.
Radiator not been on since about March.

Any help would be welcome.
thanks
Leon

 

[SimonG]

Get a spanner and open the two valves slightly.

Righty tighty, lefty loosey

 

[Rob Foster]

So no work has been carried out on this rad at all. Yes no
Was it turned off at some point when you last used the heating system yes no
You get water when you bleed the rad yes no not air
Please answer here and we can get in with solving your problem directly ...Rob Foster aka centralheatking

 

[Harvest Fields]

Get a spanner and open the two valves slightly.

Righty tighty, lefty loosey

From the spindle in the centre not the nut holding it all together.

 

[LeonN]

Thank you very much Simon/Rob and Harvest. Rob in answer to your questions,

• no, nothing has been done on the radiator since march (when it was working fine)

• when i bleed the radiator, water comes out straight away

Let me try loosening the valves as suggested and I will update.
thanks
Leon

 

[LeonN]

ok - so an update.
Thanks for your help so far all of you.

Two radiators have this problem (of no heat). Both are upstairs but there are 3 radiators working fine upstairs.
So on both of the faulty radiators I managed to open the valve on one side only. I tried doing the same on the other side of each radiator but it would not move at all). Its not clear from the above pictures but on the 'valves' on one side, there is an extra bolt attached, as if its not supposed to move.
Now doing the 'righty tighty and lefty loosey' on each radiator (one side only) I managed to turn it a few times. But this didn't make things better
I thought it may be an imbalance in the central heating, as some radiators are working fine (and are in fact super hot).
First I thought that:

• If I move the valve completely to the right (tighty righty) then I end up making the radiator cooler, because I'm preventing sufficient flow to it.
• If I move the valve completely to the left (loosey lefty) then I end up having a hot radiator but prevent the other radiators from getting enough heat.

So I selected a super hot radiator, and thought first to move the valve to the right, then was going to move it left a bit at a time. But even moving it to the right didn't cool it down, so thats not correct.

Have I turned the valves too much ? (for both the working and non working radiators). It didn't change anything in each case.

 

[Ben-gee]

You need to open the valves on both sides of the radiator to get flow. If you have only done one side the radiator will remain cold. Address this before looking elsewhere .

 

[LeonN]

ok -thanks very much for clarifying.

 

[LeonN]

Opening the valves on both sides on both 'faulty' radiators did absolutely nothing. It may be my imagination but the whole central heating system seems a bit more noisy now. Lots of clanking and clunking.
Its very odd - on the radiators which don't work - even when all the valves are open TO THE LEFT, there is no heat in the radiator. I can't even feel any heat in either of the pipes leading to each radiator.
The radiator valves were in horrible shape, a couple of them got bent out of shape when I tried to turn them with a spanner. Would it help at all to install some new TRV valves ? Do I really really need to drain all the water out of the system before installing these valves ?
But I would be more optimistic if there was any heat in the pipes at all. This is really frustrating, I've tried different pump speeds - any advice on what else to check ?

 

[Harvest Fields]

If you are going to that length get an engineer in to give you a price

 

[LeonN]

I did try balancing the radiators, and a couple of the (working) ones are now a little cooler - but still working. The 'dead' ones though remain ice-cold.

 

[Harvest Fields]

As above mate. Time to get a pro out me thinks.

 

[LeonN]

If you are going to that length get an engineer in to give you a price

Sure - but ideally i'd just like to get those two radiators working again. It can't be the pump as thats new, boiler must be ok as other radiators are fine, both 'faulty' radiators have been bled several times, and this evening i totally opened both valves i.e. twisted them as far to the left as possible, but it did nothing.

I just noted what a hassle it was to twist the valves and figured new TRVs would be easier in future, but honestly Im more concerned about getting those two rads working.

 

[LeonN]

As above mate. Time to get a pro out me thinks.

ok thanks

 

[Best]

I am fairly certain that those radiator valves are the old Peglers Belmont type.
They have two O rings on the spindle inside each (which are replaceable without turning water off).
Turning the valves on or off can cause them to leak if they haven’t been turned for a long time - like the LS valve.
The nut below the spindle is not a packing nut, but just a lock nut preventing the works coming out.
New valves needed.

 

[Harvest Fields]

Was that clockwise or anti-clockwise as you look down on them?

 

[LeonN]

I am fairly certain that those radiator valves are the old Peglers Belmont type.
They have two O rings on the spindle inside each (which are replaceable without turning water off).
Turning the valves on or off can cause them to leak if they haven’t been turned for a long time - like the LS valve.
The nut below the spindle is not a packing nut, but just a lock nut preventing the works coming out.
New valves needed.

thanks for your help. In which case I'll get a replacement valve and have a go at changing it. I can see there are some kits where I can freeze the pipe and not have to drain the water out of the heating system.
One thing which does puzzle me however. If most of the other radiators are working and it was just the valves, then wouldn't the pipes to the (broken) radiators be hot i.e. the water was coming through them - it was just being stopped at the valve.
I had another go this evening, trying to balance the working radiators out, and as expected - both the 'in' and 'out' pipes of the working radiators were hot to the touch once the heating was on.
But in the two rooms where the radiators don't work - the pipes 'to' the radiator are completely cold (as well as the 'from' ones of course).
I did look in the loft (where the large pipes are) and couldn't see any obvious leaks.
But wouldn't the pipes to the faulty radiators at least be hot i.e. water was getting to them ?

thanks

 

[LeonN]

Was that clockwise or anti-clockwise as you look down on them?

As I look down on the valves - Im trying to bring them all to the right (righty-tighty) to get the radiators 'cool' then generally bring them to the left (lefty-loosey) to get them heated up. I've tried this loads of times on the faulty radiators but I've noted this evening the pipes leading to these faulty radiators don['t get warm - even when i set my pump to maximum.

 

[New Gas Engineer]

Pipes might be cold due to hot water not flowing through the rad because of a faulty lockshield??

Maybe.
Possibly.

 

[LeonN]

Pipes might be cold due to hot water not flowing through the rad because of a faulty lockshield??

Maybe.
Possibly.

Possibly - but if you mean hot water not flowing through the rad because of a faulty lockshield - then the flow pipe (i.e. going out from the radiator would be cold surely ?)

 

[Harvest Fields]

Better off just getting a pro in mate.

 

[Best]

Pipes to a rad that is turned off will only get hot if the circuit pipes that they are connected to are close by and/or level or rising towards the radiator

 

[JCplumb]

Providing that they have worked at some point it's likely to be one of two things. Faulty/closed valve or blockage/air lock.
You need to close the valves and remove a rad, then open each valve into a bucket.
Doing this tests each valve and will also allow you to determine if there's a blockage. Often with a blockage or air lock - opening a valve into a bucket will give you a trickle and a splutter and then the blockage will clear.
If you're on a combi you need to keep the pressure topped up when doing this, you could go up to about 2.5 bar if it's stubborn, just make sure you go back down to 1 bar afterwards.
A radiator can bleed normally if only one of the 2 connecting pipes is blocked or only one valve is closed or faulty so the fact that you can bleed the rad isn't really useful.
Google how to remove a radiator, it's not as difficult as you might think, couple of towels and trays and you're away.
I would advise you to get a plumber in, but you've been advised that already and seem to be willing to try to fix the issue yourself.
Your system sounds like it will need balancing after, there are threads on this forum that go into detail about balancing.

 

[LeonN]

Thanks very much to you all for your help.