Fix a leaking compression joint without draining the CH?

[HalfEatenFlapjack]

I recently removed an internal wall, and also replaced a radiator in the new (downstairs) room. To do this I removed the pipes, cutting them close to the junction under the upstairs floorboards, and installing two isolation valves, so that I can continue to use the central heating during the demolition/plastering/decorating, then when I’m ready to install the new rad, simply attach the new pipes to the isolation valves, and fill the new rad without having to drain the system again.

However, one of the (Compression fit) isolation valves is leaking. Not badly – a pad of tissue paper is sufficient to contain the occasional drip. I’ve applied some leak-sealant adhesive – twice – with no success. Is there any other way I can seal the leak, without draining the system, removing the valve and starting again? My CH is a pig to bleed, and I really want to avoid draining it.

Thanks!

 

[JohnD]

is it a sealed system, with a pressure gauge on the boiler, or an open vented system, with a feed and expansion tank in the loft?

 

[kjacko]

Is there enough accessible pipe to use a freezing kit on it?

 

[dhutch]

Is it the valve thats leaking, or the fitting to the pipe.
- If its the valve thats passing but the join is ok (cheap valves often arnt great long term) just cap it off on the outlet, unless its leaking out of the spindle.

Failing that, and presuming you have tried tightening it another flat, I would just fid it proberbly.

Infact what I would actaully do assuing there is space is run the lot off the end and start again. Either with new olive/valve, a push fit valve, or a push fit cap.

If its a presurised system, just let the presure off, and do it quickly, or otherwise, just do it quickly, not a lot will come out, and its not hard to represurise/bleed most systems. Assuming you get all ready to go, the time to actaully go from one to the other (cutting the end off to geting something back over the pipe) is fractions of a second. Thats what ive been doing when making changes to my mess of plumbing that came with the house.


Daniel

 

[HalfEatenFlapjack]

is it a sealed system, with a pressure gauge on the boiler, or an open vented system, with a feed and expansion tank in the loft?

It's an open vented system.

Is there enough accessible pipe to use a freezing kit on it?

Possibly. It's plastic pipe though. Can you freeze plastic pipe?

Is it the valve thats leaking, or the fitting to the pipe.

The compression fitting onto the pipe - the 'upstream' end of the isolation valve.

I'd be reluctant to just whip it off and stick a new one on with water in the system. There's not enough room to get a container underneath, and it's above the plasterboard ceiling of my newly plastered and painted room!

 

[dcawkwell]

Just drain it down.
Why is this such a problem for people I do it all the time.
Takes 30 minutes with a hose pipe.

 

[JohnD]

It's an open vented system.

then you can "bung" the vent pipe and the F&E pipe in the loft, this will prevent more than a small amount of water coming out as it will create a vacuum. try opening the drain cock once bunged to reassure yourself.

you can get conical rubber bungs off the plumbing shelf.

it really does work.

 

[45yearsagasman]

Bung it if at all possible. Saves time and saves dumping all your inhibitor down the drain. Just a thought.

 

[gas112]

Did you use an insert into the plastic pipe before putting compression fitting on

 

[CBF]

Did you use an insert into the plastic pipe before putting compression fitting on

I'm already guessing the answer to that one

 

[Kris1985]

Did you use an insert into the plastic pipe before putting compression fitting on

I'm already guessing the answer to that one

was my first thought after seeing that plastic pipe was used.