New Radiator fitted

[Big Ron]

to a very weak (cracked plasterboard) stud wall held together with tiles!

Just re-filled the system with inhibitor and got a very small leak where the valve fits into the radiator (Which I tightened as much as I dared). Not yet fired it up. Can I expect the leak to slowly seal itself with deposits or is it a drain and remove job? I thought the leak might actually get worse when the rad is hot, but I don't want to risk taking off the rad again as the wall is suspect and I might get cracked tiles.

Do small leaks seal themselves in time? I could tie a rag to the valve and let the water evaporate - it's not enough to drip...

Ron

[Andy Hall]

You might be lucky, you might not. Given the situation, perhaps leaving it a week with a container underneath and seeing what happens would be reasonable. You don't say whether the radiator is upstairs or down, but at any rate you could drain much of the water into containers and salvage a reasonable proportion. For a repair, more PTFE tape or some PTFE sealing liquid on the threads.

[Roger Mills]

Does PTFE sealing liquid work the same way as Loctite? If so, can you later undo things on which it's been used?

[Mike Clarke]

[snip]

I had one like that after replacing a few valves with TRVs. Initially I had some leaks but following advice to a post I made here I managed to get them all to seal nicely except one. I tied a bit of rag round the pipe to evaporate the drips until I had time to go to Screwfix for some Fernox leak sealer. It stopped dripping on its own accord shortly after getting the sealer and before I got round to adding it to the system.

[Andy Hall]

No it doesn't really. It hardens to a rubbery compound and the items can still be easily undone. The feel is very similar to that of loosening joints made with PTFE tape.

[Andy Champ]

Ron,

can't you turn both the valves off, and remake the joint with some PTFE in it? You'll only lose a rad's worth of coolant that way.

Andy

[Big Ron]

That makes sound sense, Andy, but without draining down at least partially (upstairs rad) I'd get a rad full of coolant all over my new bathroom floor. How would you go about catching it as you release the valve seating from the rad? I'd imagine it could be very messy.

Ron

[TheScullster]

"Big Ron" wrote

Plenty of towels round the base of the feed pipe and under the joint. Scrap bit of lino (8-10" long) with long slot in one end lodged around the feed pipe under the valve and positioned to catch discharge from the joint. Bottom edge of lino strip in suitable shallow bowl. Close both rad valves and carefully crack joint between valve and rad. Open joint enough to get strong trickle flow, slacken bleed nipple in rad top. Allow rad to drain, emptying bowl as required. Remove rad very carefully and tip remaining contents into bowl (plenty of towels to ensure black sludge doesn't stain anything important).

HTH

Phil

[Roger Mills]

Ta!

What are the relative merits of liquid vs tape in terms of:

• ease of use

• effectiveness in creating leak-proof joints

• ability to get a tight joint at a desired orientation (e.g. outside tap)?

[Roger Mills]

I fund that the foil dishes of the type used for takeway food are very good for catching and/or directing the water into a bowl 'cos you can bend them to fit round the pipe one end and with a spout the other end.

The alternative is to pump air in through the bleed screw and expel the water up into the F&E tank. I made a device for doing this, using a schrader valve from an old car tyre and other bits and bobs - piccy at

[Ed Sirett]

The resin wins in all aspects. It does not fray as it comes of the reel. you can use it where tape is not best practice [1] e.g. on olives. For the latter pipe sealing cord e.g. loctite 55 ( very similar to dental floss ) is very good even allowing you to undo the joint slightly and still seal.

[1] OK I accept that some people like to use tape on olives and I don't want to start a pointless 'my way best cos it is' holy war.

[Andy Hall]

On threads that are relatively coarse like radiators and outside taps it's a bit easier and more predictable.

Too much PTFE tape and it rides out of the thread and leaves not enough in there to seal. Not enough and there's not enough (IYSWIM)