Central Heating Leak under Timber Floors - Next step?

tyler71

Had the downstairs heating switched on briefly last week and noticed that the header tank in the attic was running empty. Did a few tests to check out and it looks very like we have a bad leak in the downstairs heating section, although there is no trace of leakage anywhere. We've solid timber floors throughout most of the ground floor with plastic underlay, so it's probably under that and running into the foundations.
Called a plumber out to have a look and he was also of that opinion. It's a bit of a concern of ours that we have to take up a lot of wooden flooring to find it - at the moment don't know what the piping routing is at all underneath, and I was wondering if anyone else had had similar issues. I'd like a bit of advice both in how easy is it to take up and replace solid timber flooring and also is there any good leak detector devices out there that might help narrow down the source of the leak (the plumber didn't have a great opinion of the contract leak detector guys)

Billy Bunting

Thermal imaging camera would find it if you can hire one, failing that the original plumber would have a better idea of where he laid the pipes.

steloide

You might also try a Moisture Content Meter. That should indicate where the most moisture is.
How was the leak caused????

AckwelFoley

How quick is the header tank emptying?

If its is significant, ie as fast as it is filling or close to it, it is possibly good news as a leak that bad is probably not comming from under the floor from a rad pipe as i dont think a half inch pipe in concrete will empty a tank quicker than the pressure from the mains can fill it

I would - if i were you start at the boiler and work your way to the house. i got called out to a house in the exact situation. I found the leak underground to the inch of where it was.

A commonly suspect spot is where the pipes from the boiler come into the house, ie normally just under the path. These pipes are commonly not buried deep enought just at the point of entry and open to the elements despite being under concrete..

If the leak is significant and under the floor in the sittingroom, regardless of timber floor etc, there will be tell tale signs, check for dampness on the walls etc, but to be honest i suspect the leak is outside - of course all this is on the assumption you actually have a boiler outside!

But regardless, if you have plastic underlay (which ive never come across) the walls should show some signs - or behind the skirting

tyler71

The header tank is emptying as fast as it fills. I thought (and hoped) it was the boiler outside as well but for the life of me can't see anything and at the rate it's emptying I really should be able to. I shut off all the radiators downstairs and after that was able to heat the hot water circuit (separate circuits for upstairs, downstairs and water) without any drop in the water level, which is why I'm thinking it's on the supply to the downstairs rads.
Been searching all over the house for any signs of moisture but can't see anything, don't know how sensitive the moisture meters have to be to pick this up, I thought that the floorboards would start warping if they were getting damp anyway.
Is the thermal imaging much good? Just a bit worried about trying it because the leak seems to be so big that even if I got the water good and hot beforehand you wouldn't have much time to get a good look before the water ran cold again.
Going to ring the original plumber tomorrow to get an idea of the pipe run - pipes are normally ran through the doorways, aren't they?

AckwelFoley

Hmm,

I can tell you for certain it is a popped fitting, Ask the plumber some details such as if the pipes are in the screed or in the subfloor.

It 2 zones so, upstairs and down?

Did you turn off the upstairs and see if any of the rads heated?

Perhpas try turning off the upstairs zone completely.. then turn off all the rads downstaits at the valve, then turn on your heating and open the valve on the first rad on the circult, if you get some heat there its showing you have water going in, then turn it off and do the same with the second, if there is some heat there you know you have water getting to it, if not you know the leak is on the feed to that rad. May not work but its a suggestion. You would need to know the order of the loop of course, but generally starts closest to the source

minty247

are the pipe joints soldered or is it plastic push on fittings?????. I had a leak on a boiler housing and i used a radweld on it. It may be worth a shot. It works on copper or plastic. Pour a bottle in at either the boiler safety valve or funnell it in at a rad. good luck

AckwelFoley

minty247 wrote: »

are the pipe joints soldered or is it plastic push on fittings?????. I had a leak on a boiler housing and i used a radweld on it. It may be worth a shot. It works on copper or plastic. Pour a bottle in at either the boiler safety valve or funnell it in at a rad. good luck

When the header tank is emtying as fast as its getting filled that stuff wont work. That leaksealer is handy is you have a small seeping or a slow drip in a system but not for this amount of loss

tyler71

Tried putting the heat on briefly and got heat in the rad which should be first in the loop (it's closest to the boiler),nothing on any of the others. The problem is I don't really know how the loop runs, so I don't know what's next in the line. This is why I was asking are the lines usually run through the door openings as then the next in the loop would be the kitchen.
Not sure what material the lines are - the lines coming into the rads are copper but upstairs it's the same but then they switch to plastic - going to phone the original plumber today to try to get some answers.

Plumberboy

Ive been in this situation and one solution instead of taking up the solid floors is let the pipes become obsolete...You can trace the pipes back to the hallway or wherever, cut them there and run new pipes in, it might mean a bit of boxing but for the most part they could be hidden behind skirtings ect.....Many a time ive been nearly sure i was so close to a leak when in fact i was 10, 15 ft away so maybe thats the best solution

tyler71

That's an interesting idea. So you'd chase the pipework in the wall behind the skirting? Talking to a guy about the floors, he said there's no way you'd get the old boards down again without damage so you'd have to put in new boards and hope they match - which I'm not keen on. Also with that plan all your pipework would be accessible - Im worried we could go through a lot of hassle to find one leak and then get the same thing with another joint in a few years.

antiskeptic

You said you shut off the downstairs rads and the leak stopped. I'm assuming you shut the d/s zone control valve too? That would indeed indicate a feed side leak on the d/s zone.


The thermal imagine would be problematic if you were trying to run things at full bore. You could however, take the motor off the motorized zone valve and crank the valve open a little by hand. That way your attic feed should be able to keep up with the leak without dumping tonnes of water God-knows-where. You'd have to be running things a while in order for the locally raised temperature to register at the surface so that the thermal imagine can 'see' it.

Alternatively (and somewhat Heath Robinson). Hire a small air compressor and connect it up (with a long piece of hose, leaving the noisy air compressor outside) to one of the feed points at a rad. shut off the other rads. Borrow a foetal heart monitor from a mother who has it all (:)) or obtain some similarily sensitive mircrophone and go listen for the leak.

Have someone keep an eye on the compressor to cut it out if the pressure rises above say 2 Bar.

Carpenter

If you know exactly where the leak is (lucky) it is possible to take up 1 board with a router and replace it because I did it not so long ago but let me tell you it is a very slow process

tyler71

Yeah, definitely got that impression on having a quick go at moving a floorboard that it's a far from easy process - they've been down eight years. Pinpointing the leak is the thing that would really help make a call on the way forward - I might be able to borrow a compressor and an ultrasonic leak detector from the maintenance guys at work, but Im starting to move out of my comfort zone zone and am getting worried about really screwing things up worse than now.
Was talking to a floorboards guy today and he recommended contacting an independent assessor who can look at the situation and talk to the insurance company about getting them involved and about the best way to go - my main fear is that I'll be going back and forth between getting a plumber in and then a carpenter and then the plumber again and that it will drag on for a long time with the house in a mess for a long time, would really like to get a team in that could work together and sort it out.

tyler71

Just thought I'd give a (nearly) final update on this in case anyone else finds themselves in a similar situation. Got a guy in with a listening device to find the leak - he pinpointed two possible areas. Got him back with the original plumber to start breaking ground - six holes later no joy. Luckily most of these were in tiled areas and we have spare tiles so relatively easily fixable.
The plumber called a guy he knew with a humidity meter and it picked up two areas of high humidity - and finally the second area was where we found the leak - joint completely popped and water gushing out and down through a break in the plastic.
Had to take up a few floorboards to get there but not too many and he was very neat - used a very fine rotary blade to cut the tongue from one board and gently prised it up and got the rest of them out from there.
So now leak is fixed - I have eight holes in the house to fill and patch up and might need to get a carpenter to make a proper job of the floorboards but the major job is done. Since this happened I've heard of a lot more people who've had this plex piping popping, so something to watch out for. Cheers to everyone who posted advice, I've learnt a lot over the last few weeks.

Wyldwood

In a similar situation now. 30 year old house, tank in attic emptying at an alarming rate, plumber declared there's a leak under the floor somewhere. He suggested bringing a guy with a listening device to trace leak but, reading this thread, OP doesn't seem to have had success with that so I'm not sure that's the way to go now.
Problem is the floors are concrete topped with wooden floor on battens & tiled kitchen. I'm now wondering if it would be easier/cheaper to get the downstairs rads replumbed, if this could be done in a concealed way, rather than take up bits of the wooden floor & dig up the concrete, that sounds a serious mess.
Tyler71 did you investigate the possibility of redoing the piping or did you just go with the dig? Don't know whether to get insurance involved.

tyler71

Sounds like a very similar situation. We did think about completely replumbing, but it's very invasive and in the end it all comes down to the relative cost of everything - so we decided to try to find the leak first. In fairness to the guy with the listening device, he charged us next to nothing because he didn't find the leak and he was on a difficult one anyway because the piping runs weren't where the plumber thought he'd ran them .
We talked to an independent insurance assessor and the insurance only covers up to about 750EU for this type of 'access' situation where there's no apparent damage. Our overall cost (not counting repair work, most of which I hope to do myself) ended up less than that, not sure if we'll try to claim yet or not.
The main thing is to find the location of the leak without causing too much damage. Do you know how your piping is ran? - because this will narrow it down a lot, most likely to the joints and take-offs to the rads. If you don't and your house is 30 years old the runs might be in copper and you might be able to use a metal detector to trace the run.
Other guys here probably have more experience, but I'd recommend firstly using a humidity meter - apparently the wooden floors mask the readings but will still pick it up and it should read through tiles. Listening device is still probably worth a shot next, and then the final but expensive option is to get in the guys who pump helium into the pipes and then use a helium detector to pick up the leak - they're about 450EU for the first three hours and 100EU per hour afterwards so as I said, probably your last option. Look for any unusual signs, our plumber picked ours up first becuase there was an unusual dark mark on the floorboard over the leak, apparently also there's usually 'salting' on the wall over the leak, caused by residue from the water.
We were lucky to have a plumber quite skilled with floorboards (would heartily recommend him if you're round Cork) - if you're not that sure about your guy then the best thing is to find the leak first and then get a carpenter in along with the plumber and let them at it.
Best of luck, all I can say to you is what my father said to me, if it's going to happen the middle of summer isn't the worse time for it.

Wyldwood

Tyler71 thank you very much for such a helpful reply. Unfortunately we've no idea where the pipes are, 2nd hand house. There is no sign of damp anywhere so it's impossible to tell where the leak is. My problem is the raised wood floor over the concrete will make it hard to find. A metal detector sounds like a good idea.
I'm in Cork so it would be great if you could PM me the name of your plumber in case the guy I got doesn't come up trumps.

Wyldwood

Thanks for the info Tyler71, hopefully we'll be sorted soon.