How long to give a leak to self seal?

[David Costelloe]

I've just converted to unvented. I was warned the extra pressure might expose weaknesses in some of the (60 year old) joints and fittings - so two new float valves and new tap were needed as a direct result of the change.

And, we now have a small drip (drop every two seconds), presumably from a compression fitting that drips down down a boxed in riser to the ground floor. To deal with it will mean breaking into tiles etc.

The drip seems to be getting better not worse

What chance it will self seal? Is that rare/unheard of. We are in a very hard water area, but we use a water softener. I have a vague recollection that there is a second kind of water hardness that is not removed by a water softener.

If there is a chance, how long should I give it before getting an axe to the covering?

 

[HERTS P&D]

Get the axe out and access the pipe work, it will only get worse.

Andy

 

[Madrab]

Never an option to think a water system will self seal. As suggested, get it repaired before it gets worse

That being said, the system should really have been pressure tested before the unvented was commissioned as there would always be the possibility that there may be leaks on a long term gravity system and any potential remedial repairs etc should have been written into the quote. I don't get it why installers think it's OK to do a half assed job and then leave customers to deal with the aftermath and the extra cost.

It's not difficult to pressure test a system overnight even without a test pump

 

[Lower]

Has anyone tried to nip up the compression fitting? Its unlikely to self seal.

If nipping up the compression fitting doesn't fix the drip, sometimes backing the nut right off, loosening the joint and then tightening it back up again can make it seal.

 

[David Costelloe]

there may be leaks on a long term gravity system

To be fair to the contractor, I was forewarned that there might be leaks and addressing them would be charged at an hourly rate. It would have been sensible to quote to replace all the low pressure fittings though.

Anyway, I took the risk, open-eyed, and it is only this one annoying drip that we are left with finding and fixing. And it seems to be stopping (no regular drips), though I'll follow advice and get if fixed.

 

[David Costelloe]

For what its worth, I managed to get an endoscope camera to locate the leak - fiddley but got there in the end. It's on a 60 year old soldered joint on a disused hot water feed to a basin removed 30 years ago when we last did the bathroom. We're "lucky" with the location - it is within a tiled boxed vertical riser (? - column) that provides water services to each floor, but it is behind a cistern, so the access damage will be easy to cover. Just have to hope those rusty screw holding the cistern to boxed column come lose easily and that the cistern does not break in the removal process.

 

[HERTS P&D]

Post pictures of the rusty screws.

Andy

 

[David Costelloe]

Not the screws yet, but this is what I found. Link is to the video
https://1drv.ms/v/s!AjgnfywOCDzorrtsFuJhhMteV2YxJw?e=q10ikB

 

[David Costelloe]

Rather pleased with finding this leak. Is it old? Or does verdigris form quickly

 

[David Costelloe]

Leak addressed.

The old vent for the gravity system was also part of the hot water supply system and the leaky joint was from work I had done 30 years ago. It was under perhaps 2 or 3 feet of head until it became part of the unvented system (ie the open end was capped off).

Rather than risk breaking the toilet cistern and cutting into the tiles, we figured a way of making it obsolete by various changes to pipework under the floor - the same floorboards that were last up in 1991.