plumber with experience and equipment to find leak under solid floor

Irish Steve

Yeah, the title sums it up, a friend in Kilbride has a leak in under floor pipework, Oil fired traditional system, Qualpex type plastic pipes are buried in screed, and there's a leak somewhere, but finding it is going to need someone with experience and the right equipment to do it, he doesn't want to have to dig up the entire ground floor to find it.

He's away on a regular basis with work, so asked me to start the ball rolling, given the heating season is about to kick in.

So, I have the happy task of getting his heating working properly again, which means finding the leak and fixing it.

Any of you guys out there got the experience and the gear to do this without tearing up all the pipe runs?

Thanks

Steve

Dtp1979

Irish Steve wrote: »

Yeah, the title sums it up, a friend in Kilbride has a leak in under floor pipework, Oil fired traditional system, Qualpex type plastic pipes are buried in screed, and there's a leak somewhere, but finding it is going to need someone with experience and the right equipment to do it, he doesn't want to have to dig up the entire ground floor to find it.

He's away on a regular basis with work, so asked me to start the ball rolling, given the heating season is about to kick in.

So, I have the happy task of getting his heating working properly again, which means finding the leak and fixing it.

Any of you guys out there got the experience and the gear to do this without tearing up all the pipe runs?

Thanks

Steve

Get your hands on a good IR camera

shane0007

First off, drain system. Isolate the downstairs circuit from all other circuits, including the boiler. Remove any air vents & cap. With a compressor, fill the system with air to 3 bar. Leave stand for at least 30 minutes.
This will confirm that the leak is definitely down stairs.
Then go around all obvious pipe routes, listening for air hissing from anywhere. Pay particular attention to pipework below radiators. There is normally a fitting under ground on the flow & return radiator pipework & are the normal location for leaks.

Failing that you will require equipment such as thermal image camera, sonic listening device or gas seeking equipment.

Irish Steve

Dtp1979

The IR camera may indeed have to come into play, I suspect this is going to be a bit of a pig to find, the ground floor system is quite large.

Shane0007 thanks for the pointers, that ties in with the sort of route I was thinking of, there are fittings in a number of places where I'd not normally expect fittings, partly because of the layout, and to make things worse, I have my suspicions that the pipes were not lagged or protected in any way, so even a stone in the screed may have caused problems,

will report back on this, another route may be a specialist that was recommended by a local plumbers merchant, he apparently specialises in under floor leak work, and has all the specialist tools for tracing the problems,

Steve

shane0007

The qualpex shouldn't be an issue with concrete surrounding it not insulated, other than efficiency reasons & very bad practice. The issue will be concrete touching brass fittings or copper piping, therefore there should not really be fittings in unusual locations other than below rads & tees from the primaries to the rads.

IMO you should 100% make sure the leak is actually in the ground floor circuit, as you may look a bit foolish bouncing across a floor with a kango only to find it was a leaking AAV!!!

Irish Steve

Shane,

Yeah, with you on the caveat. we know there's a leak somewhere, and on the basis that there are no damp patches on the ceilings or upstairs floors, that kind of limits the possible areas of problem. That said, I'm going to make sure that the hot cylinder is out of the loop as well, a leak from the coil into the main body of the cylinder is not impossible, as the header tank is above the storage tank$$. To coin an old phrase, I'm ruling nothing out, and everything in, and fortunately, we have access to a good compressor and regulator valve, so we can pressurise things and listen for noise without the compressor hammering away in the background.


The plan is to isolate all the circuits, which won't be too bad, as there is a manifold system that they all fan out from, might mean some muscle to get it apart, but yeah, I intend to be 110% sure of the area of the leak before we do any digging. I am hoping we might be able to close the valves on the rads as well, and then pressurise the flow and return so that we can determine which line is the problem.

You may rest assured that I am not going to get caught by a bad AAV, or a bad motorised valve body, I've seen that before, and will admit to being surprised at how much water can leak out of a small valve body when the O ring gets badly worn.


Appreciate the input,

Steve

shane0007

If the system is manifolded, you can test each loop individually. If you find the culprit just blank the manifold connections to that rad until you decide the best route to take onward from that.

Irish Steve

Shane,

Unfortunately, the rads are not independently fed by a full manifold system, that would have been too easy, there's a manifold that has the feeds to each area and the hot water coming off in 22mm, and there are separate pumps for each area, but after that they then are "normal" loops that have all the usual suspect joints on them as radiators are Tee'd out. I suspect it relates to a possible planned upgrade to include a back boiler as well as the oil boiler, but that's another (hairy) story for another time <g>.

Cheers

Steve

shane0007

Sorry, I could be mistaking. I thought we were talking about a leak in the heating system to the rads.

Irish Steve

Shane,

As far as I know, one of the feeds to the rads on the ground floor, mostly under screed, is leaking. It's an abomination of a system, there's a non standard 2" copper manifold system that has 3 pumps hanging off it, on the supply side, one for the hot water, one for the upstairs loop, and one for the lower floor loop, the roof tank and expansion run from the manifolds as well, there's a second 2" manifold that brings all the loop returns together, and has the tank feed etc on it.
There are also spare connections on the manifold that are ( I think) intended to bring in a feed from a back boiler.

The loops are supposed to be controlled by MV's, but they never got fitted, so at present, there are ball lever valves to control the zones, and the pumps are switched manually (Yeah!)

One thing is certain. Finding and fixing it will not be fun!

Cheers

Steve

Irish Steve

An update.

Had to go at this before Christmas, and had a local plumber in with me who has all the specialist leak finding equipment, and quite quickly, we pinned it down to an area about the size of a dining room table, not far from a radiator.

That's where the fun started, we decided to try and isolate it a bit tighter, as I didn't want to hack out too much floor, so we took an air vent out with the section isolated, and pressurised it to try and get some noises.

Worked too darn well, not sure quite how, but the leak closed up and couldn't be found or heard. PAIN.

So with nothing to look for or find, we packed everything up, refilled and bled the system, and went on our merry way.

Within a week, it was leaking again, and as the owner was home again, I decided to have another look at it, on the basis that if difficult decisions about hacking up floors were needed, I didn't have to make them,

So, we started following the pipe from the radiator with a small hammer drill.

Wasn't long before it was clear that we were heading in the right direction, the screed was coming up very wet, so we continued along the line. That was when I was glad I had a wet & Dry vacuum with me, a couple of inches later, we had a small fountain erupting out of the floor, about 2 inches high, and it didn't take long for the hole we had to start filling up with water. Cue vacuum cleaner. Carried on excavating, and found that, as suspected, a joint had blown, not just a little, the pipe was completely out of the fitting. Fix meant finding the next joint on the line after the blown fitting, and removing it from the fitting, and then putting a new slightly longer piece of pipe into replace the one that had been removed, the blown piece was a good 5 cm too short to fit correctly into the fittings.

Not much fun, the pipe system is an old plastic push fit, Acorn, the early version that has clamp rings that won't come off the pipe, so if repairs have to be done, a new piece of pipe and parts from the fittings have to be used.

End result was success, the heating system now doesn't leak, though we did end up changing a few other fittings that were weeping slightly, I just hope that we don't get any more issues, I'm not convinced about the quality of the Acorn system, the issue seems to be that the O rings go hard and out of shape, and thermal expansion and contraction over time then allows them to weep slightly.

So, that's the story of the leak, thanks to everyone that provided assistance either in thread or via PM, it made sorting this problem out somewhat easier to deal with

Cheers

Steve