radiator leak from nut where you bleed it - advice?

wallofbeans

As I'm sure you can tell from the thread title, I'm not any kind of expert in radiators!

I've got this leak from the little bolt that you twist to let air or water out when bleeding them. They are quite old radiators. I've tried tighting the bolt more but it still leaks.

Any advice on what to do next? I thougt there might be a few other things I could try to stop it before having to call a plumber!

Thanks all!

Jonesya

You can pick-up PTFE tape from most DIY stores, it's used a thread sealer. Take out the bolt, get someone to plug the hole while doing this, wrap it with a couple of turns of PTFE and re-insert. The extra thickness of the soft PTFE tape should plug the gap and stop the leak.

Alternatively you can get silicone based leak sealants which set to plug the leak, you could apply this to the bolt thread - LS-X is a common product.

wallofbeans

Jonesya wrote: »

You can pick-up PTFE tape from most DIY stores, it's used a thread sealer. Take out the bolt, get someone to plug the hole while doing this, wrap it with a couple of turns of PTFE and re-insert. The extra thickness of the soft PTFE tape should plug the gap and stop the leak.

Alternatively you can get silicone based leak sealants which set to plug the leak, you could apply this to the bolt thread - LS-X is a common product.

Great. Thanks for advice! Not sure about the silicone sealant though.. Would that mean I couldnt undo the bolt in future, should I need to?

keystone

Jonesya wrote: »

You can pick-up PTFE tape from most DIY stores, it's used a thread sealer. Take out the bolt, get someone to plug the hole while doing this, wrap it with a couple of turns of PTFE and re-insert. The extra thickness of the soft PTFE tape should plug the gap and stop the leak.

Alternatively you can get silicone based leak sealants which set to plug the leak, you could apply this to the bolt thread - LS-X is a common product.

Its the bleed screw itself which is leaking from OPs description.

Cheers

Canucklehead

Hi,

Do you mean one of these? http://www.store2go.net/shop/psw/p/product/0909112666-Radiator+Plug+%26+Vent+Kit/

If you need to swap it then turn the valves of at each end first and let the pressure go with the vent .
The 'o' ring is usually enough to seal the joint as long as surface of the rad is clean where it meets the 'o' ring.

If the vent is just a small pin then you have a bigger problem.

GSR.

keystone

wallofbeans wrote: »

As I'm sure you can tell from the thread title, I'm not any kind of expert in radiators!

I've got this leak from the little bolt that you twist to let air or water out when bleeding them. They are quite old radiators. I've tried tighting the bolt more but it still leaks.

Any advice on what to do next? I thougt there might be a few other things I could try to stop it before having to call a plumber!

Thanks all!

Replace the whole bleed valve. Neither PTFE nor silicone are going to help here for a permanent fix. You may be able to fix this yourself without a plumber depending on how confident you are.

Cheers

Jonesya

keystone wrote: »

Replace the whole bleed valve. Neither PTFE nor silicone are going to help here for a permanent fix. You may be able to fix this yourself without a plumber depending on how confident you are.

Cheers

Not always an option - on some radiators the air-bleed valve is just a small bolt that fits into a threaded hole on the top end of the radiator. The only way you can change it is to replace the radiator.

For the OP - if you try something like LS-X it doesn't set rock solid, it sets to a firm gel so you can always undo it later, clean, re-apply and re-make as necessary.

keystone

Jonesya wrote: »

Not always an option - on some radiators the air-bleed valve is just a small bolt that fits into a threaded hole on the top end of the radiator. The only way you can change it is to replace the radiator.

Agreed but the OP hasn't specified what he/she has. Answer to CH's question would help. However the balance of probablilty is that they are more likely to have they have the replaceable type of bleed valve than the more old fashioned rad you describe. If its like that anyway its prolly time to consider replacing the rad with a modern efficient one anyway.

For the OP - if you try something like LS-X it doesn't set rock solid, it sets to a firm gel so you can always undo it later, clean, re-apply and re-make as necessary.

That IMO would be a bodge.

Cheers

wallofbeans

Jonesya wrote: »

Not always an option - on some radiators the air-bleed valve is just a small bolt that fits into a threaded hole on the top end of the radiator. The only way you can change it is to replace the radiator.

It is exactly as you say, an older radiator with just a small bolt that fits in a threaded hole. The leak is coming out of the hole.. I assume the bolt isnt fitting like it used for some reason..

Could I just replace the bolt?

Getting new rad is last resort as we are looking to move after xmas and dont want to spend on that kind of thing unless we have to.

keystone

wallofbeans wrote: »

It is exactly as you say, an older radiator with just a small bolt that fits in a threaded hole. The leak is coming out of the hole.. I assume the bolt isnt fitting like it used for some reason.

In that case I'll withdraw my previous comment.

Could I just replace the bolt?

Try the local scrappy - he's prolly gots loads of old rads sculling around and you may find one to match. Make sure its the same thread size though. If its a Myson Roundtop then the pin size IS smaller than average. In that case try ringing Myson in Newcastle and ask them to stick one in the post. Have you tried the bleed screw out of a new vent as I was assuming you had and CH linked to? Long shot but it might work.

Getting new rad is last resort as we are looking to move after xmas and dont want to spend on that kind of thing unless we have to.

In extremis go for the PTFE solution (rather than gumming the works up with LSX) then and pretend I didn't suggest it.

Cheers