Central heating leak

oleras

I hope someone can help me with this one........about 2 months ago i heard the header tank in the attic for the central heating system filling, i.e. system needed to be topped up, i checked the ballcock, fine. checked the hot water cylinder to make sure the coil was not damaged, fine...was not leaking back to the storage tank in the attic ( its a bunglow by the way). Called the plumber and he said it has to be a leak in the system, split pipe or loose joint, we used a type of rad-weld to try and seal it but to no effect ! the leak obviously had become worse, header tank could not stay filled, more was going out of it then the mains could get into it ! im sure all this seems easy to fault find but there was no evidence of water in the house, nothing, no damp patches. next step was to dig outside, between the boiler house and the house....opened it all up as far as the house, bone dry...no leak in a pipe or a joint.
Now here is where my trouble is.... next step is open the floor inside the house, only thing is it is mostly ceramic tile and wooden floor....only way that will come up is with a kango and circular saw !! dont want to go down that road... what i really need is a way of knowing what room it is before i take up the tiles or wood.... murphys law and that it will be in the last room i open up !! i tried to get a fiber optic camera that could look through the pipes , but i was told they are only good for sewage and the like, 4inch pipe. does anybody know a way to find it, electronic ear? camera? anything........this is really starting to get on my nuts !! any help will be appreciated, im in the limerick area for the record........and sorry for the long post...lol

oleras

rooferPete

Hi oleras,

What you are describing is very strange, by that I mean the leak is so bad it will not allow the header tank to fill up and yet there is no sign of dampnes inside or outside the house.

You have mentioned a wooden floor, if this is a "Real" timber floor with joists, tossle walls and and a sub floor there should be vents in the plinth outside the house.

Taking the vent out may be the way of getting a view under the floors and a general idea of the location of the leak, I know a small pinhole type leak in a concrete floor will show dampness on the floor in a fairly short time.

The amount of water you describe would flood a house very fast so the leak must have an easy exit.

You could try hiring out a leak seeker or try locally to see if there is someone with a thermal imaging camera, my first place to look would be around the outside of the house for the vents.

.

tapest

rooferPete wrote:

Hi oleras,

What you are describing is very strange, by that I mean the leak is so bad it will not allow the header tank to fill up and yet there is no sign of dampnes inside or outside the house.

You have mentioned a wooden floor, if this is a "Real" timber floor with joists, tossle walls and and a sub floor there should be vents in the plinth outside the house.

Taking the vent out may be the way of getting a view under the floors and a general idea of the location of the leak, I know a small pinhole type leak in a concrete floor will show dampness on the floor in a fairly short time.

The amount of water you describe would flood a house very fast so the leak must have an easy exit.

You could try hiring out a leak seeker or try locally to see if there is someone with a thermal imaging camera, my first place to look would be around the outside of the house for the vents.

.

Hi R/P and oleras

Is this a possibility ?
As is the case in old houses, he may have a big / deep sub floor, with clay underneath...and if there's good drainage...he has effectivly a "french drain"
t

oleras

thanks for the replies folks...... some more facts, house is about 30 years old, all flooring is concrete, the wooden floors are floating semi solid, so one would asume it would be coming up the walls by now !! what we also tried was putting a main supply on the pipe that drains the system along with the header tank and it still would not slow down, took 2 full mains into the system and still not a sign of anything..... at the moment the supply to the heating is turned off, to be honest its imposible to sleep with the tank constantly filling overhead me ! but it has been on for a week at a time and nothing..... when you say a leak seaker is that some sort of electronic ear and where could i find one ? thanks so much once again for the replies !

oleras

rooferPete

Hi tapest,

I was thinking along similar lines myself, the amount of water being lost is frightening to say the least.

Oleras,

Is there any chance the valve in the boiler house is allowing the water to escape ? I am presuming the water was turned off when the test was done.

The only way I can think of the amount of water you describe not being seen is if the floor was originally a pre-cast slab placed on top of the rising walls, that would allow under the floor to act like a tank.

Almost the same as tapest described and it would have the water draining away at such a low level that your garden wouldn't appear like a swamp.

The leak seaker is an electronic tool similar to a moisture meter but more heavy duty, however I'm not sure it would work in your situation.

I think the best options you have are a thermal imaging survey or a pressure test carried out by your plumber.

.

Dilbert75

Parents had a similar problem a few years ago - the joints in their C/H system were brazed and several broke in different places. One was under the kitchen floor (all floors in the bungalow are concrete) and they only found it with one of those listening thingies - we got it by the old-fashioned Irish method. We gave a few quid to a plumber in the Council to come out one evening and do the job. Found it quickly enough - dug up the floor and there was a waterfall underneath the floor, helping the filling to neatly subside under the floor.

That said, are you 100% sure that there's no pressure relief / drain valve stuck open?

oleras

all the valves were checked and look ok, the idea of a french drain scenario seems about right.... last year we put on a conservatory with a rad that was tapped into the system and i have a feeling the builder did not put down any plastic sheeting under the cement, even though he said he did ..... the reason i questioned it was because there was no excess to trim around the floor....and for the last few months, since it was tiled we have about 10 woodlice dead on the floor each morning, if it was sealed from the outside where would the woodlice come from? so the posability that the water is going straight to ground seems plausible, because it would have showed in the house if there was a break in the pipe.does anybody know if i would have any comeback against the company that installed the conservatory and done the groundwork if it turns out to be there ? it was my plumber that installed the pipework and rad and it was leakchecked before the concrete was poured on top of the pipes (qualpex).but are there any regulations that insist a water barier should be installed between the ground and the cement ? thanks so much for the replies folks.... i appreciate it !!

tapest

oleras wrote:

all the valves were checked and look ok, the idea of a french drain scenario seems about right.... last year we put on a conservatory with a rad that was tapped into the system and i have a feeling the builder did not put down any plastic sheeting under the cement, even though he said he did ..... the reason i questioned it was because there was no excess to trim around the floor....and for the last few months, since it was tiled we have about 10 woodlice dead on the floor each morning, if it was sealed from the outside where would the woodlice come from? so the posability that the water is going straight to ground seems plausible, because it would have showed in the house if there was a break in the pipe.does anybody know if i would have any comeback against the company that installed the conservatory and done the groundwork if it turns out to be there ? it was my plumber that installed the pipework and rad and it was leakchecked before the concrete was poured on top of the pipes (qualpex).but are there any regulations that insist a water barier should be installed between the ground and the cement ? thanks so much for the replies folks.... i appreciate it !!

That's one for RooferPete....ya see I do know my limitations. Not sure if qualpex must be lagged if in rather than under concrete floor.
If you know where the plumber made his connections for the extra rad, blank it off at that point and see if problem persists
t