Finding leak in central heating system

DarrenM343 · 8 Nov 2019 at 08:01

The house had a issue back in 2015 and my heating guy managed to use leak sealer to seal the leak. It's back again. Has anyone tried using a company to detect leaks successfully? I've read recently about specialist companies using air or gas and using sound detection devices to listen for the leak. Wondering if anyone has used this and how successful was it?

The house is a relatively new build, a private one, and all the heating pipework (plastic) is in the walls/under tongue and groove floorboards. We've pretty sure it's on the ground floor as there's never been any damp patches spotted on the ground floor ceiling or any walls. Lifting(cutting out) the floorboards or parts of them which the room partititions are probably built on top of will be pretty painful and time consuming.
Anyone else tracked down a leak? How did you do it?

DarrenM343 · 8 Nov 2019 at 11:22

Yep, the ground floor is suspended. Using an inspection camera sounds a good idea. The pipes come straight out of the walls and into the rads but I assume it'll be easy to see the pipes/connections below.There will be insulation under there I assume but using a camera is at least something to try first.

DarrenM343 · 8 Nov 2019 at 11:50

Checked out the rads, it's plastic straight to radiators.
My suspicion is that it might be very close to the boiler, which is located in the utility room. There's a copper pipe (outlet) going from boiler straight down into the floorboard. That's probably a good place to start. There's a rad in the utility room then one in the next room (dining room), then into the living room where there are two and then downstairs toilet and hallway and I assume they're linked together in that order. The odd room is the kitchen which doesn't have rad.
What we thinking happened back in 2015 was that the pressure went too high due to a blockage to expansion vessel which seemed to have caused it to spring a leak somewhere. There's a blow off valve but seemed to have blown off inside the house before the pressure was high enough to activate the valve.

Thanks for all info btw.

DarrenM343 · 10 Nov 2019 at 10:04

Simon42 said:
This.

I have a small FLIR thermal and it enabled complete tracing of heating pipes (which was my original purpose). However in conjunction with a cheap damp detector it confirmed increased moisture where I saw an odd image from the thermal camera and found a leak I didn't even know I had.

There are other methods of detection of pipes and leaks but I was surprised how well this worked for all heating pipes even deep in screed/concrete.

Did you buy one? The one's I've seen look pretty expensive.
My plumber is having another look this week and depending on how that goes I'll probably rent an FLIR i7 next weekend.
I have managed to find one leak already using a flexi camera (boroscope?) as someone mentioned in this thread. House had a problem with a leak when using the shower enclosure. It's been resealed around the tray as water was penetrating even though the seal looked in good condition, but have found this under the white boxing. I think water is going through where the enclosure meets the wall/tray. Might be more than one issue but I peeled off some of the sealant outside the shower where the tiles are and was damp behind there. It's a bit difficult to tell as there's some staining on the wall outside a little higher up but at the moment I'm assuming it's finding a way through at the bottom where I suspect there's a section of tile underneath not sealed.
I've picked up a damp meter too and will have a prod of the wall around the shower/boxing later (need a 9V battery first!).
Pic one is under the triangular section of the wood boxing, as can be seen in the second picture taken from inside the shower. It's only a small space (pic makes it seem larger)