Central heating leak - frustrating!

[gavcradd]

Hi, thanks in advance for any suggestions with this. I'm stumped and my regular plumber keeps putting me off.

We have a leak in the airing cupboard upstairs (contains the water storage tank, water pump and pipework) - enough to make a damp patch on the living room ceiling, but not enough to be dripping. However, it only happens about once every couple of months or so. Of course, as soon as I notice the damp patch I go and look, but all that I can see is damp carpet around the airing cupboard door.

This has been happening for about 6 months and I'm no nearer to solving it. I put towels and sponges in various places to try to see where it was coming from, and it's definitely down the left hand side with the pump on, and the pipework slightly above the pump is getting wet. However, if the pump is faulty, why does it happen so infrequently?

Any ideas on things to do/check? Should I just replace the pump? I'm scratching my head!

 

[JohnD]

tie kitchen roll round all the joints and pipes. It will show where it has got wet.

Is there a tank in the loft? maybe the water is coming from there.

It could also be an overflow that only occurs on days when you have not been using water and the level has had time to rise.

 

[gavcradd]

Kitchen roll - good idea, will do that. Thanks!

Definitely not from the loft as there are towels, etc on a shelf above the water tank in the airing cupboard and they're bone dry.

Not sure about the overflow idea, the kids were both bathed last night and the shower was used, but it could well be something building up - it happens every couple of months, perhaps 3 time since the summer.

 

[leakydave]

Do a bit of investigation work yourself. See if the leak coincides with baths, showers, no baths or showers, cold or wet weather etc.

It can be time consuming as a plumber to try and make intermittent leaks happen... see if you can spot it as it happens and record relevant info for your plumber to get to the bottom of it.

Twice I have been called to 'leaks' that were the result of roof defects or blocked gutters that caused water to drip through ceilings or dampen walls in very heavy rain.

 

[bathjobby]

leakydave is spot on, water can travel a long way along joists, pipes etc before 'showing' itself. My best used method in the past for trying to identify the source of such a leak as this is talcum powder, with a puff ball i.e. can blow a fine cloud out rather than shaking it from the can.
Blowing the powder around the affected area will show where it is already wet, or if it is all dry at the time, will leave streak marks to show where it is coming from when is happens again. Good Luck.