Major leak in central heating system

[dongle99]

3 bedroom terrace house. Central heating system about 25 years old except for one additional radiator in extension about 10 years old.

Yesterday my central heating system system just emptied itself completely in about 30 minutes. Fortunately the boiler stopped by using its safety valves etc. There is no water showing anywhere and trying to fill up the header tank again fails as the water just runs out continuously.

The piping downstairs is buried in the concrete flooring.

I have called our plumber who is as mystified as I am and is coming tomorrow to look at the piping for the extension as a first move but this does entail taking up concrete floor in places.

Anyone had experience of this sort of problem. Any advice would be welcome.

 

[moony]

pipes in concrete floors are prone to leaks, pin pricks etc.....

but to be honest it needs someone to look at it - our advice in work is to always have the pipes in concrete replaced if going onto a pressurised system as we have had quite a lot of problems so the problems could relate to your unpressurised system especially after a long time, 25 years is a long time so the concrete would be my first port of call, once all obvious places had been checked and no visible signs of leaks.

good luck with it. i would suggest at least think about replacing the pipes under the concrete.

 

[dongle99]

pipes in concrete floors are prone to leaks, pin pricks etc.....

but to be honest it needs someone to look at it - our advice in work is to always have the pipes in concrete replaced if going onto a pressurised system as we have had quite a lot of problems so the problems could relate to your unpressurised system especially after a long time, 25 years is a long time so the concrete would be my first port of call, once all obvious places had been checked and no visible signs of leaks.

good luck with it. i would suggest at least think about replacing the pipes under the concrete.

Thanks you for your very helpful reply. It looks like a whole replacement job for the concreted pipes

The plumber was talking about two methods.

1. Digging up the concrete and replacing with new pipes
2. Dropping pipes from the upstairs circuit to supply the downstairs radiators.

The latter method would seem to be the least disruptive but there would be pipes showing in the corner of each room which has a radiator. Are there any other disadvantages doing it this way I wonder.

 

[tucker]

Most of my downstairs radiators were supplied by pipes running down the corners of the wall and along the skirting on 10mm pipes.

Dissadvantages - I found the runs were too long on 10mm pipe and the radiators were therefore a long way from the main flow and return. Looks a mess and not very discreet.

I've changed several by feeding them via plastic 10mm pipe behind the plasterboard, by taking out a 100mm chanel straight down to the back of the rad. You can hardly see the pipes as a result.

More work as it needs patching and making good with skimming, but if you are having to do significant work already, then I'd find it's worth a bit more for a tidy job.

 

[justlead1]

Hi. Have a look around the outside of the property property at low. It was quite common to fit drain off cocks on the outside, may well have frozen and burst. Good Luck

 

[moony]

Most of my downstairs radiators were supplied by pipes running down the corners of the wall and along the skirting on 10mm pipes.

Dissadvantages - I found the runs were too long on 10mm pipe and the radiators were therefore a long way from the main flow and return. Looks a mess and not very discreet.

I've changed several by feeding them via plastic 10mm pipe behind the plasterboard, by taking out a 100mm chanel straight down to the back of the rad. You can hardly see the pipes as a result.

More work as it needs patching and making good with skimming, but if you are having to do significant work already, then I'd find it's worth a bit more for a tidy job.

yeah this is the way a lot of new builds are being done around here cant really see the pipes, like you say more patching work. using back plates that sparks use for sockets to bring the pipes out of the wall.

 

[dongle99]

In our small property. If we were to drop pipes from upstairs in the corner of a room any horizontal pipes to each radiator are quite short i.e. not more than 4ft and mostly a lot less for the near radiator valve plus the width of the radiator for the further valve. The down pipes would mostly be hidden by modifiable cupboards, book cases and coat hangers so they should not be too obtrusive.
This would look to be our best choice and would keep redecorating down to a minimum and any suspect buried pipe would be isolated. Unless anyone knows of any plumbing principals that I haven't thought of ?????

P.S All the walls for hanging pipes and radiators on are external brick walls so sending behind plasterboard is not an option.

Have had a look round the outside but all the stopcocks are indoors.

 

[mark.brazenor@b]

I would drop pipe down from upstairs. You can easily box these in so they are not on show.

 

[David_D]

Had the same problem in my mothers house last year. Its a Dormer bungalow. All pipes down stairs were underneath a concrete floor. the house is only seven years old so this should not have happened. Id say the system was never pressure tested from the first place. Anyway it was a disaster right from the start. I actually work on refrigeration and ac myself but I was drafted in cause no one would take on the job cause the pipes were under the floor. The first thing I did was get a bloke in with a thermal imaging camera to firstly trace the pipes as I had no idea what way they ran and secondly to see if he could notice any particular hot spots when the water leaked. Initilly we thought we found it with his camera but when I lifted the floor in that area the leak was not there. To cut a long story short I had to take up the hole route of the pipes changing bits of qual plex and fittings as I went. Eventually the last place there was to check I found 2 leaks on one qualpex elbow and a one qualpex T peice. I changed the fittings pressure tested the system. refilled the system left the floors up for a few days to be on the safe side and then filled them back in with concrete. It was the worst job I have ever had to do so good luck if you choose to go down the same route.

 

[Renewable M]

It's one of those where you can't have everything...... simple repair, less cost but pipes down the walls, or, nice neat and nothing on show but the upheaval.

The only thing I'd say is: you have to live with the pipes down the walls for ever..... the upheaval is very short term!

All the best with it.

 

[dongle99]

OK thank you for your advice. I will post in and tell you what we decide to do. What ever it is our plumber cannot start for three weeks. Hoping for a heat wave.