Soldering central heting pipes live?

[G-Force]

Hi All,

Please help!

On one of my central heating pipes, the elbow joint has a tiny leak which I would like to fix. I cleaned the paint of the surrounding areas and cleaned it all well down to the copper but I cannot get solder to plug it. Tried fluxing it well but to no avail.

As I heat the pipe I can see small amounts of water vaporising thru the hole.

Just to mention that this whole system is in use now and that I have no way of isolating just that area!

Of course it's not switched on when I am trying to solder.

How can I plug this leak please?

Any info appreciated!

[Tim Jenkins]

You'll never solder it with water still in the pipe I'm afraid.

You could try a pipe freezing kit maybe and re-do the entire joint or you drain the system down and re-do the joint.

Tim.

[The Natural Philosopher]

You HAVE to empty the pipe of water to sloder successfully.

There are freeze sprays which will freeze the water in the pipe either side, but still it takes a LOT of heat to evaporate the water inside.

You cannot really do what you are trying to do.

One possible boidge is to wrap the whole thing in PTFE tape, and then bandage it up. Thuis will mostly stop it dripping.

If yu can dry the outside of the pipe enough, car body filler soaked bandage wrapped around it will sometimes work if it is lowsih pressure.

The real answer is to drain the CH and do the job properly tho.

[Andrew Gabriel]

Also, you'll almost certainly have to take the joint right apart and clean up the pipework (get a new elbow, don't bother trying to clean the old one). It very likely didn't solder first time properly because the pipework was not cleaned up well enough in the first place, and you are very unlikely to be able to rectify that without disassembly and cleaning again. You don't have to clean all the shiny solder off the pipe ends, but where copper shows (the ring of solder will be incomplete, hence the leak), you do have to clean that back to bright shiny copper with steel wool.

[Set Square]

As others have said, you haven't got a cat in hell's chance of re-soldering it with water in the pipe.

Many years ago, I fixed one or two small leaks in my heating system by using something called Bars Leaks (or somesuch) which was marketed for fixing radiator leaks in cars. It was brown crumbly stuff (a bit like gravy granules) which you put in the header tank so that it got circulated round the system. When it encountered a leak - and came into contact with air - it reacted in some way in order to bung up the leak.

Don't know whether it's still available - but the cure was still going strong when I sold the house about 8 years later.

[PoP]

As others have said, you'd have to remove the water from the pipe in order to do this job.

However one other option you might have is to freeze the pipe both sides of the joint, then replace the joint with a compression fitting rather than solder. If it is a straight-thru fitting then you could chop a bit of the length off the pipe and use a compression repair fitting like this:

it's an elbow or tee then you might have a bit more work to do to replace it as you'd have to clean the pipe ends properly before adding the compression olive - I'm not sure it would be a good idea to put the olive over a previously soldered section (perhaps someone else could comment on that? Doesn't sound like a brilliant idea to me).

PoP

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[Stuart]

I wouldnt even think of using that ( Bars Leaks ) . Do it the proper way,drain the system down , remove the old fitting,clean up the pipe ends and refit a new elbow , soldering it properly . Stuart

[Jonathan Curtis]

Whilst it's advisable to take the joint apart, I have had success by leaving it intact and smearing around the pipe just before the joint with flux, when hot enough dab your solder in some flux and offer it up to the joint. Of course the system was drained first though!I would have thought there isn't much wrong with this method until you want the solder to defy gravity.

Jon

[mike ring]

"G-Force" wrote in news:3ff80ab8$0$15355$ [e-mail]:

No chance without shutting down; assuming you don't want to do that, would a bodge with a jubilee clip and rubber or pvc or summat hold it.

a sort of tape fix, they also make internal sealers, yoou might want to check them out

mike r

[OldScrawn]

Hasn't anyone else used the two part epoxy putty that's sold for plumbing repairs? It will stick to wet surfaces and is sufficiently stiff to cope with small leaks at modest pressure. Depending on the geometry, you can always back it up with a bit of thin sheet ally (coke can) and jubilee clips.

[Rick Dipper]

You have to remove all the water from the pipe.

If you don't want to drain down, you may be able to freeze the pipe, cut out the join and add in a new piece and joins.

Rick

[Rick Hughes]

.

Er no.... you cannot solder with water in the pipe, either drain it down, or use a freeze kit and isolate a section.

If you don't want to do this, if the hole is small then a leak sealer poured into the system may do the job ... I had a pinhole in the middle of a rad, it fixed this and the system run for 10 years with no further leak.

What you MUST do if you want to do this is (assuming you have a header tank) turn off the supply to the header tank ball valve. (turn off boiler first) Drain off at least twice the contents of the header tank - via a downstairs drain c*ck on one of the rad feeds. Empty in a bottle of leak sealer (Fernox LS-1 for example)

turn the water back on and this will allow the sealer to mix in the system.

Remember to bleed the rads afterwards - as this will probably induce some air.

If you have a sealed system you will have to depressurise, drain off a bucket full or so of water, use add the sealer ... how depends on system, you may have to rig up an injector to squirt it in.

Rick

[Abdullah Eyles]

They say: "The leak is now repaired, and in less than 10 minutes the self-vulcanising tape will have formed a unique, durable seal that will last until you have time to make a more permanent repair."

So you can't escape from the inevitable.... just postpone it!