Heating pipe: Leak in concrete floor.

[Shed Steve]

My C.H system is open-vented type. A pipe-run in the concrete ground floor is leaking slightly, the floor surface is wet. From tying-up the ball-valve and measuring the drop in water level over two days, I worked out it has lost about 8 litres in 48 hours. Is there a possibility, that Fernox leak-sealer may seal this? I have not used it before. Any advice would be much appreciated, thank-you.

 

[dilalio]

You can try, but there are no guarantees I'm afraid! Sometimes it works, sometimes not.

Could you not just dig up the screed and repair said pipe? It may be that it wasn't taped up to protect it from lime in the cement, in which case, the whole run might need doing.

 

[flameport]

Is there a possibility, that Fernox leak-sealer may seal this?

It may seal for a certain amount of time. Perhaps a week, a month or maybe longer. The only certainty is that it will fail again.

The only real solution is to dig out the leaking pipe and repair/replace.

 

[FiremanT]

Some years ago I dug up a floor that was constantly damp in two corners. Elbows in noth coeners had never been soldered!

 

[Gas2Air]

I know of a certain company, with the same fault, whom suggested to the customer to do away with the FE tank and have a sealed system put in. She had a spanking new 30kw Greenstar combi, on a 6 rad system in a bungalow, 1 bath and sink, no shower, and was told to just keep using the external fill loop if pressure dropped. Can you guess who they were? £3,700 she was charged.

 

[footprints]

As said sometimes it does, sometimes not, I put some in a system as a temp fix for someone with a similar problem, still fine 4 years on!

 

[Shed Steve]

Thank-you all for your replies, most useful. House was built '64, so pipes been in floor some time....I shall try sealer, hopefully get me through to next year. Then look into replacing ground floor rads., with new drops from pipe-runs in first floor, which may need up-sizing. One thing leads to another!

 

[simond]

I give your chances at around 1%, if the screed has eaten the copper it will be as rotten as a pear. The leak sealer stuff relies on it being exposed in air to solidify and because it is encased in (wet) concrete this is unlikely.

 

[Nige F]

1964 - the best you'd get for lagging the pipes then would be a bit of hair felt simond is probably right. Piped from above will be there forever and you won't waste heat warming a concrete floor. Also you could re position the rads to suit better.

 

[footprints]

Give it a try anyway nothing to loose Try the concentrate directly into a rad so you don't waste chemical in the tank and are less likely to flush out any "helpful" sediment draining and refilling.

 

[Shed Steve]

Update.....the sealer worked for about a week! So broke-out the concrete floor, and wrapped the leaky joint in PTFE tape, and surprisingly it held! Eventually last month got round to replacing the downstairs heating pipes with drops from pipes in first floor. Lot of furniture shifting, lifting carpets and prying-up floorboards, then a long days' work from my plumber, all sorted now. I trust that heating pipes are no longer laid in concrete floors??

 

[oilboffin]

Ha ha ha oh yes they are sometimes correctly and sometimes not,nothing changes.Bob

 

[dilalio]

Some years ago I dug up a floor that was constantly damp in two corners. Elbows in noth coeners had never been soldered!

I call them "no blows"

 

[AGAS]

So broke-out the concrete floor, and wrapped the leaky joint in PTFE tape

are you saying there was a compression fitting in the floor ?

 

[Shed Steve]

AGAS, it was a repair done seven years ago, soldered joint leaking slightly, probably as we could not clean the old pipe properly underneath, and may have been corrosion present. I am surprised to learn that pipes are still sometimes buried in concrete floors, should be a law against it !