Underfloor Heating Leak in finished house.

davidod1

Hi Folks,

Could anybody please give some advice on tracing a leak in an underfloor heating system.

The house was built about a year ago by direct labour which means there is no one to throw blame at and be sure that it would stick.

The leak is in one loop that covers at least in part an area of the entrance hall. This area is tiled and some darkening or staining is evident in the tile grouting in one section. We did get a man with a thermal detection system who pointed to an area that this was the source of the leak but when some tiles in this area were lifted and the floor dug up there was no sign of the leak.

It would be possible to keep going along in this fashion until the whole floor was dug up but this would be extremely destructive and expensive not to mention traumatic. It is stressful enough even as we stand at the moment.

I am hoping that someone might know of a system that would be so thermally accurate that it could show with certainty the source of the leak.

Any other advice would be very welcome.

Many thanks,

Dave

mickquinn05

As far as I know HSS hire thermal imaging equipment, worth a shot..
http://www.hss.com/g/25910/Infra-Red-Camera.html

davidod1

Thanks Mick. Do you know if the quality of the results will be dependant on the quality of the operator?

anthonyos

have you isolated the loop and pressure tested it to confirm its the sourse of the problem

davidod1

Yes to both of those.

anthonyos

how big of an area is it?

davidod1

Don't know how big the loop is, but the only evidence of the leak is in the hall area - within about 10' X 3'.

mickquinn05

this seems to be made for the job http://www.inlec.com/environmental-testing-equipment/leak-detection-equipment-c220/under-floor-leak-detection-kit-xmic-listening-system-thermal-imaging-camera-p379

tinofapples

Would you not follow the installer ? I've had a couple of leaks at the manifold in my house and have gotten the price of replacing skirting outta my plumber. The last leak we had I claimed of the house insurance and I believe they have since followed him, to what extent I don't know however.

davidod1

It looks good equipment OK.

Two points though. I don't think they will hire to Ireland, they only show the UK. And second I really would prefer to have a skilled operator with the best equipment and most suitable equipment to do the job.

In order to minimise the destruction machine and operator need to be top class.

mickquinn05

O right taught you just wanted to hire the equipment, a lot of people have this equipment for BER certification and so on, here is one crowd that dose it anyway http://www.gff.ie/leak.html

davidod1

Thanks tinofapples. He pressure tested the whole system before finished off the job and there was no evidence of a leak at that stage. He advised the guy who did the initial thermal test but as I said earlier his results proved not to be accurate. I think we are on our own in this.

FOLKS - I'll be gone for 45 minutes so I won't be able to give an immediate reply to any questions.

anthonyos

a pressure test is only as good as the man carrying it out i,m afraid

wing52

Is there any chance you could eliminate any thing which was fixed to the floor after the screed/floor was laid?

Generally,if a circuit passes a pressure test and fails afterwards

It indicates a screw/fixing of some sort or pipe failure from being flattened or crushed.

A moisture meter could be useful in narrowing down the area around the leak.

Hope that helps.

davidod1

That's what we seem to have found out - the hard way.

At this stage now we just wan't to get it sorted and I think that means getting the right person with the right equipment to tell us with certainty where to dig. That's where I was hoping someone may have a couple of pointers.

JohnnieK

I'll get the number of a guy I've used before and he has been spot on to date. I'll PM it to you tomorrow.

deandean

Find the loop thats leaking, at the manifold, by pressure testing each loop.
Disconnect the leaking loop.
Live with the colder patch on the floor.
Not ideal i know but if you can't chase anyone...

davidod1

This is a photo of the hall where the problem is. To the left is the area of discolouration, near the entrance to the kitchen. To the right of the stairs is the area where we were told is the source area, and hence dug up. No signs of a leak there.

Believe me deandean we may end up doing that. Problem is that we did think that by digging up the area to the right that it would be solved.

Outkast_IRE

I will post something that i had to do for a customer once before when he was let down by his own plumber.

I isolated the loop with the leak.
drained that look as best i could with an air compressor.
Hooked up an aircompressor to the loop with a leak and blanked the other end so pessurising it with air.

Brought it up to 3 bar, ensured there was nobody else in the house and just listened, the compressed air was making a high pitched sound where it was escaping so i was able to listen and track it to a rough area.

This worked for me in a particular situation, im just putting it out there as a potential help, if you have easy access to an air compressor and the appropriate fittings.

Personally i know people say water travels etc etc etc, but generally if theres discolouration i would be looking at digging up that patch first to at least see whats going on to cause the discoloration , often times if the leak isnt in that exact spot you can see the direction the water may be running from.

shane0007

Sonic listener would also determine the location before breaking the floor.

davidod1

What you're saying Outkast_IRE about the discolouration sounds plausible, and it's where I would have thought to start digging. It was just that the guy with the electronics was so definite.

I'll look in to the feasibility of trying that pressure test idea. It might be possible to do it. Thanks for that.

davidod1

shane0007 wrote: »

Sonic listener would also determine the location before breaking the floor.

Are you talking about a specific device or using an air compressor pressure and then listening?

shane0007

davidod1 wrote: »

Are you talking about a specific device or using an air compressor pressure and then listening?

Yes, specifically a sonic listening device. It basically tunes into the frequency of the sound of the water leaking from the pipe, making most other sounds inaudible. By using this device, you can pin point exactly where the leak is.

There is another system also that uses gas. The circuit is isolated. A gas is pumped into the circuit. A sniffer is used to pick up the point of exit of the gas.

A friend of mine has all 3 devices, the third being a thermal image camera.

Outkast_IRE

shane0007 wrote: »

Yes, specifically a sonic listening device. It basically tunes into the frequency of the sound of the water leaking from the pipe, making most other sounds inaudible. By using this device, you can pin point exactly where the leak is.

There is another system also that uses gas. The circuit is isolated. A gas is pumped into the circuit. A sniffer is used to pick up the point of exit of the gas.

A friend of mine has all 3 devices, the third being a thermal image camera.

But wouldnt the gas just find the easiest escape route ? which may not be straight up ?

shane0007

The specific gravity of the gas is lighter than air therefore it will always want to travel up. Flooring materials are porous and will allow the gas to pass through them. The sensor will pick up on the gas and is sensitive enough to give a varying reading in that it can give a audible reading, higher when influenced by higher levels of gas, i.e. closer to the leak.

deandean

+1 on the sonic listening device i forgot i have seen these used twice and in more difficult environment (outdoors and 300 to 600 mm deep. I saw one steel pipe pressurised to 1 bar with air; the oother was the incoming water pipe to a house. In both cases the guys sprayed an X on the ground and the leaks were located to within inches. Sorry i don't have a contact. Lovely hall david, jeez you would have a heavy heart taking a kango to that floor.

davidod1

Thanks all for the advice folks. Like you say 'deandean' it was with a heavy heart that the Kango was taken to the floor - in two places; neither of which were right.

shane0007

davidod1 wrote: »

Thanks all for the advice folks. Like you say 'deandean' it was with a heavy heart that the Kango was taken to the floor - in two places; neither of which were right.

If there is a leak then sonic device would have pinpointed the location without breaking the floor!

DGOBS

I know of one lad who used to pressure test in the dead of night, and crawl around the floor with the stethoscope in the hope of 'hearing' the hiss of the leak (assume it would have to be a reasonable size leak) but he 'claims' to have had a lot of success!

If it's a small leak, would a leak sealer like oxypic not be worth a try?

davidod1

Looks like there is good news. We have found 2 leaks and a water pressure test seems to be holding up - at the moment.

If there are any further indications of a leak I think the sonic test with air seems to be way to go.

Thanks to all who helped, it is very much appreciated.

Dave

deandean

That's great to hear.

BTW where were the leaks - what caused them?

davidod1

The two leaks that were found were to the right of the stairway and just under the wall. At the moment the pressure test is still holding.

The assessment given by the plumber who installed the system is that the pipes were damaged by ice forming in the pipes during the building process.

He says that the damage was most likely caused after the initial pressure test was completed. Who knows; maybe that is what happened.

Thanks again to all who contributed.

Dave

deandean

Aha. Does this timeline fit:

• Slab poured and house blockwork up but house not yet closed in (i.e. windows and doors not installed);
• Plumber installed pipework and pressure tested AOK;
• One of those two cold winters came along and froze the ball$ out of everything
• Leak found later, after the heating system was pressurised

?

anthonyos

deandean wrote: »

Aha. Does this timeline fit:

• Slab poured and house blockwork up but house not yet closed in (i.e. windows and doors not installed);
• Plumber installed pipework and pressure tested AOK;
• One of those two cold winters came along and froze the ball$ out of everything
• Leak found later, after the heating system was pressurised

?

me eye and foe ice in the pipe i think you need to get the boxing gloves out

JohnnieK

anthonyos wrote: »

me eye and foe ice in the pipe i think you need to get the boxing gloves out

I've come across this before to be honest.

davidod1

Yeah - if there are no more leaks I think we'll be very glad to see the end of it. We're not going to able to prove anything one way or the other anyway.

BTW the timeline does fit and the frost was heavy. Whether there should have been water in the pipes is another question. We're not going to go there though.

Thanks again to all who contributed.

Dave