Leaking radiator - advice needed.

Dinarius

This wall radiator has a tiny leak. I think it may only leak when radiator is cold, though not sure.

The leak is from the nut(?) at the top, and it drips onto the valve below, causing some rust.

Can I simply use a spanner and give it a little tighten?

Is the rust an issue?

Thanks.

D.

DublinDilbert

Turn off both sides and see if you can get the nut loose, might be hard to shift as it’s rusted. Looks like the nut isn’t sealing, possibly due to lack of a seal. A few wraps of ptfe should seal that up.

Dinarius

Thanks.

D.

Dinarius

I have closed the thermostat valve completely.

I have also closed the other valve, on the other side, completely by also turning clockwise.

I then loosened the problem nut at the top of the radiator.

Three one litre jugs of water later, it was still draining. So, I retightened it.

The heating had been off for a couple of hours, at least.

How much water should it expel before I can remove the nut completely?

Thanks.

D.

Callan

I've had this problem with a few radiators in my house.
You're only noticing the leak when the rad is cold, as the water is evaporating when the rad is on.

I'd try tightening the nut slightly first. This worked for a couple of rads in my case.
If that doesn't work.

Turn the rad off on both sides.
Bleed the radiator until no water comes out. This will release pressure.
Loosen the nut and remove, there will most likely still be enough pressure in the rad for some air/water to rush out.
I sanded of the rust where the nut goes. It looks better now, and makes it easier to monitor.
Replace the nut
I'd replace the nut with a new one instead of using PTFE on the old one. https://www.screwfix.ie/p/radiator-vent-blanking-plug-nickel-2-pack/40972?_requestid=48385
Some plumber suppliers will sell them individually for a couple of euro.
If you have a sealed system, you may need to topup the water in the system.

Callan

Dinarius wrote: »

I have closed the thermostat valve completely.

I have also closed the other valve, on the other side, completely by also turning clockwise.

I then loosened the problem nut at the top of the radiator.

Three one litre jugs of water later, it was still draining. So, I retightened it.

The heating had been off for a couple of hours, at least.

How much water should it expel before I can remove the nut completely?

Thanks.

D.

From the pictures it looks like you have a lockshield valve. Did you take the cap off and use pliers to turn it off?

Dinarius

Here are pics of the two bottom valves.

Yes, I removed the cap and used a pliers to turn it off - clockwise, so that it was fully retracted.

The rust you see next to it is caused by the problem nut at the top of the radiator dripping down onto it.

As I say, I didn't expect so much water to emerge.

Thanks.

D.

Callan

I'm not a plumber, I wouldn't expect that amount of water either though. I used the bleed valve to drain it until it stopped, wasn't more than a mug full.

The valves must not be closed fully.

Dinarius

Callan wrote: »

I'm not a plumber, I wouldn't expect that amount of water either though. I used the bleed valve to drain it until it stopped, wasn't more than a mug full.

The valves must not be closed fully.

The valve I closed with the pliers is definitely closed fully.


But, maybe the spring valve behind the thermostat is not being fully closed by turning the thermostat to zero. :rolleyes:


Thanks.

D.

John.G

You can't do anymore with the TRV end valve, only hope that the rubber seal is holding.
The lockshield (pliers) end sometimes needs opening (1/4 turn) and closing a few times to make it seat/seal properly, I generally use a 6" adjustable spanner and have to give it a good nip up to stop any leakage.

Dinarius

Thanks.

Have tried it twice now and still no joy.

I am definitely closing the lockshield valve, so I can only assume that there is a problem with it not closing fully, or with the TRV end not doing its closing job.

Leaking (well, seepage to be honest) is only happening when cold.

Will get someone to look at it next week.

D.

Wearb

Dinarius wrote: »

Here are pics of the two bottom valves.

Yes, I removed the cap and used a pliers to turn it off - clockwise, so that it was fully retracted.

The rust you see next to it is caused by the problem nut at the top of the radiator dripping down onto it.

As I say, I didn't expect so much water to emerge.

Thanks.

D.

If the spindle is moving up and down when turned, it's not operating the valve properly.

Dinarius

Wearb wrote: »

If the spindle is moving up and down when turned, it's not operating the valve properly.

Thanks.


Spindle is clearly moving inwards on the lockshield valve when I turn it clockwise. And it reaches a point where I can feel it's at the end.


D.

DublinDilbert

Yea one of your valves is letting by slightly. I would shout both valves off, loosen the nut off one or so turns (don't go mad) wrap the exposed threads/end of nut with some PTFE (careful which direction you go) and then tighten it back up. This has got me out of trouble lots of times even on waste fittings / u-bends.

I remember seeing an old school neighbor who was a plumber do this using a piece of wool on a leaking bleed nipple thread. The same piece of wool is still there today.

If you don't have PTFE any hardware place will have it, some shops even sell if they have display with hardware bits. You could also try putting a few turns of dental floss on the thread, again go anti-clockwise so it gets forced into the thread when tightening.

BTW if you have a sealed system you might want to top it up when cold to replace the water you drained.

Dinarius

Thanks.

Will try some PTFE.

When you say "...direction you go", I presume you mean applying the tape so that it wound the opposite way to the direction the nut is screwed tight?

Thanks.

D.

DublinDilbert

Dinarius wrote: »

Thanks.

Will try some PTFE.

When you say "...direction you go", I presume you mean applying the tape so that it wound the opposite way to the direction the nut is screwed tight?

Thanks.

D.

Correct yes. Give it a few wraps, it can't do any harm anyway.

Even if some gets trapped between the nut/end of the radiator it will probably form a seal (although long-long term this might not be the best, but should stop a drip).