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?

Hawk Tuah · 8 Nov 2019 at 09:02

I had a minor leak (boiler pressure going down very slowly over ~ 2 months) for years and only eventually found it when I replaced out bathroom radiator to find the copper pipe was touching the floorboard, and as soon as it was disturbed it started 'peeing' out obviously.

If it's bad, maybe worth getting an inspection camera - so you can take a look for water with just a small drilled hole.

ANDARIAL · 8 Nov 2019 at 09:39

Bug One said:
I had a minor leak (boiler pressure going down very slowly over ~ 2 months) for years and only eventually found it when I replaced out bathroom radiator to find the copper pipe was touching the floorboard, and as soon as it was disturbed it started 'peeing' out obviously.

If it's bad, maybe worth getting an inspection camera - so you can take a look for water with just a small drilled hole.

Seconded
Assuming that you have a suspended ground floor?

200sols · 8 Nov 2019 at 09:49

One would hope the pipe runs to the radiators under the floors will have no joins in them so you should focus looking for leaks right under the radiators where the pipe comes up from the floor, there is probably a join under the floor there so the plastic can be switched to copper tails as they join the radiators.

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.

200sols · 8 Nov 2019 at 11:28

DarrenM343 said:
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.

Out the walls, the pipes may go up the walls instead of down beneath the floor then. Either way there will be a join in the wall to change from plastic to copper for the tails to the radiator so I would check there first for leaks.

PiKe · 8 Nov 2019 at 11:38

You could buy a cheap endocope camera that plugs into your phone and have a look yourself?

jsmoke · 8 Nov 2019 at 11:44

Ultraviolet dye?

Techno_Viking · 8 Nov 2019 at 11:46

You can also use thermal imaging to detect leaks. The camera's can be hired from Jewsons for example and you can follow pipes from the boiler.

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.

Simon42 · 8 Nov 2019 at 16:53

Techno_Viking said:
You can also use thermal imaging to detect leaks. The camera's can be hired from Jewsons for example and you can follow pipes from the boiler.

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.

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)

Simon42 · 10 Nov 2019 at 15:36

DarrenM343 said:
Did you buy one? The one's I've seen look pretty expensive.

I bought a FLIR One Pro for just under £300 (very cheap for a thermal camera, but still a fair cost in general). I needed to trace pipes buried 100 to 150mm in screed/concrete for relocating radiators and heating pipes for some building work and this saved way more than it cost. I could even tell how close pipes were to the floor above/below.

The damp meter I used was cheap and I used it wherever I saw odd joints in the pipework from the thermal image or any anomalies in the image. Obviously only good if the leak goes into other materials, but with the thermal camera, damp meter and an inspection camera for hollow walls/floors as you've used a lot can be traced/checked without much disturbance. I didn't need to find cold pipes so this worked well for me.

Once you know where all the heating pipes run then temporarily isolating areas/floors where possible may be a good approach to narrow down the search.