Leak in ceiling, stopped by itself

[smp50]

There was a sudden and fairly strong flow of water through the ceiling (downstairs), mostly through the ceiling rose hole and a line of damp visible either side of it. After a minute or two it slowed to a drip, and then almost stopped.

There are central heating pipes in the region of the leak. The hot water tank (~2m away from the leak) and all associated local pipework is completely dry. I haven't yet taken up the floorboards at the site of the leak, but will do tomorrow.


The strangest part is that the water stopped by itself, why would a leak have stopped like that without any action being taken? All water was still "on" and the amount wasn't nearly enough to drain the CH system, say. The water was fairly clear, btw, but I'm pretty sure only CH pipes run in that region. There are no taps etc. upstairs at all.

Any insight before I pull the carpet up? Thanks,

 

[FiremanT]

Someone draining a bath or shower.?
Intermittent overflow and leaky OF pipe?
Leaking boiler condense pipe?

 

[dilalio]

What else is above that area?
What system do you have?
Discharge from boiler or uv not routed properly to outside could be another suspect.
Was it raining? Are any gutters blocked?
Was CH/DHW on?
Did anyone use a wc above?
Need more description of your property.

 

[smp50]

The boiler is downstairs, there's no tap or toilet or any other water upstairs, apart from the hot water tank and its pipework. The only pipe in that whole area is for the CH, I'm almost certain.

 

[terryplumb]

No point in trying to guess ,time to take up floor boards and investigate mate.

 

[smp50]

No point in trying to guess ,time to take up floor boards and investigate mate.

Is it possible, at least, that a "leak" can flow like that and then stop by itself? A leak as in a "hole" in a pipe or joint.

Or does this suggest it's got to be some kind of overflowy sort of thing?

 

[terryplumb]

Water pipes that are under pressure ,like hot and cold domestic and central heating pipes ,once leaking would usually continue to leak until pressure is relieved. But not beyond the bounds of possibility to leak intermittently ,but very unusual. As suggested above ,water running as a short burst and then stopping is more usually waste pipes ,overflows , pressure relief ,condensate from boilers , leaking shower/ bath seals,anything that allows limited amounts of water into waste pipework .

 

[motorbiking]

semidetached house? neighbours with a problem?

was it hot or cold water?

failed expansion tank?

 

[FiremanT]

Remember that water can track right across a house before finding an exit

 

[dilalio]

And to complicate things even more... there are hot leaks and cold leaks

 

[smp50]

Thanks for the replies, everyone. I had another look today (it's not in my own house) and am absolutely sure there are no overflow pipes in the vicinity. I did, however, find half a dozen slow drips from various joints all around the hot water cylinder (located on the first floor. The leak came through to the ground floor several metres away about about 5 joists along from where it is stationed).

The pressure was just over 2 bar, is that not too much? Do the drips suggest excessive pressure?

Especially from the bottom of that magnet/filter.


But, still, nothing that looks like it would rush with water.

 

[smp50]

Slightly different question, any tips on getting a plumber to visit? I have phoned 11 now, including four "emergency" ones and none are interested/available. No one even bothered to offer a ridiculous price! Is there a secret password I need to know, haha...?

 

[FiremanT]

Slightly different question, any tips on getting a plumber to visit? I have phoned 11 now, including four "emergency" ones and none are interested/available. No one even bothered to offer a ridiculous price! Is there a secret password I need to know, haha...?

Getting an "emergency" plumber could be an expensive mistake. No one COULD give you a "price", but ask about HOW they charge. Don't expect guarantee that the elusive leak will be found.

 

[dilalio]

My bet is a flat EV/faulty PRV and discharge dumped water internally.

 

[smp50]

UPDATE:

After pulling some floorboards up, I found... a nail through a pipe.

This was in an area I hadn't worked on since I owned the house, so it had been there for quite some time.

So there we go!