Dripping copper pipe nut connection

Any

Hi,

We are having massive problems with our bathroom, which will be ripped out as a part of larger house design in 5 months time, so we are constantly patching something up until then. Long story.

Following larger leak from the shower, we took the ceiling down in hallway below and repaired the leak.

As part of repairs, we discovered little drip coming from the nut which is on the copper pipe coming to our towel rail in the bathroom above. I believe this is pipe coming from our combi boiler direct to the rail (I am looking at the pipe from below-where the ceiling would have been would we have pne!!).

Originaly my OH had wrapped PTFE tape around it and tightened it up. This helped. He had done it while everything was on, so did not undo the nut or anything.
This week we had the heating on, and it started again (at least we think this is connected). It's difficult to tighten it any more, what is the best way to repair it properly?
It is dripping at about 2 drops a minute now, so must be tiny, but needs repairing.

Thank you for help

flashg67

sounds like a compression fitting. PTFE might work, but really needs the nut undoing. If you're quick, you shouldn't lose too much water.
If it still leaks, it's likely the joint needs replacing, or at least a new compression olive fitting (they get crushed as part of tightening the nut, which creates the seal) which is best done by draining the system (I'm not a plumber but have changed these fittings myself after speaking to a plumber for advice!).

Any

So you think loosen up the nut, quickly wrap new PTFE around it and tighten up again?

If it is olive, we'll need to call the plumber I assume, as draining combi boiler system needs to be done professionaly?

Jonesya

This stuff is pretty good - if you can undo the nut and get a good thick smear of this around it - it's like a soft silicone

http://www.screwfix.com/p/fernox-ls-x-leak-sealer-50ml/23614

Lorian

It's not possible to use the ptfe tape properly without undoing the nut....

Any

Jonesya wrote: »

This stuff is pretty good - if you can undo the nut and get a good thick smear of this around it - it's like a soft silicone

http://www.screwfix.com/p/fernox-ls-x-leak-sealer-50ml/23614

This has fantastic reviews, definitely worth a try.
Thanks!

thescouselander

As above you need to take the nut off for PTFE to work - I'd suggest the following:

1) Back the nut off all the way and push it back until you can see the olive
2) Wrap PTFE around the olive - 3 or 4 turns should do it. You might need to pull the pipe back a bit so you can cover the whole olive.
3) Tighten the nut


Now the problem is if you just undo the nut water is going to go everywhere. There are two ways to stop this depending on what sort of system you have:

Gravity Fed System:

If there is an isolation valve from the heating header tank use that otherwise buy some bungs and block the pipe coming from the header tank and the expansion pipe (dont forget to remove them afterwards).

Pressurised system

Hopefully there will be some isolation valves for the heating feed and return at the boiler - if so shut these off and there should be minimal water leakage. If not probably best to de-pressurise the system by draining water off - probably at a drain point somewhere downstairs.. Again don't forget to put everything back as it was afterwards.

Any

Thanks.
As I said it is a combi boiler.
I cannot see an isolation valve unfortunately, wouldn't draining the water need to be done by professional then?
I thought it is not allowed to touch the boiler unles you are gas registered...
Or am I taking this too seriously.

This is a new house to us, we used to have tank in the old house so this is all new to us!

Grenage

Gas registered for working on the innards of a boiler, or involving the gas pipes.

Mucking around with PTFE and the like while it's all done up is just making things complicated. Generally you'd find the lowest radiator in the place, and hopefully it will have a drain point. Put some hose on it and lead it to a drain, then open the valve; open the bleed valve on a radiator upstairs after 5 minutes to speed it up.

Take the old nut and olive off, clean it up with a towel and some wire wool. New olive, no PTFE, smear of jointing compound if you really want. Do the nut up hand tight, then an extra half turn with a spanner.

Refill and hopefully no drips; it's a time to add some inhibitor, too!

keith969

It's often difficult to get old olives off, as they compress onto the pipe.

If the pipe has some play in it, you can cut it off at the olive and fit a new one. If not... the method I have used works if you're very careful. Get a junior hacksaw blade and gently saw a slanting cut in the olive, taking great care not to so much as mark the pipe. Before the olive is cut through, using a flat blade screwdriver, turn it in the cut so the remaining material breaks and the olive can be freed.

Dont't forget if you use ptfe tape to wind it in the direction of screwing the nut up, if you see what I mean.

thescouselander

As above just drain the system down then. I don't agree with using jointing compound though. In my limited experience the pressure and heat of the system just causes it to ooze out of the joint and then the leak reappears.

Also a roll of PTFE will cost pennies vs a few quid for jointing compound and since you already have a roll of PTFE you might as well make use of it.