Isolating Radiators

[DavidGee]

i seem to have a leaking radiator pipe which is embedded in a concrete floor on the ground floor of the house.

As the central heating system is pressurized to save tracing the pipework and then removing the concrete around the pipe s(the ground floor of the house is quite large and could easily take a few days to remove the concrete around the piping plus all the associated damage to the flooring) would it be possible to drain the system, fit isolating valves on the radiators refill the system and open up the radiators one at a time in the order they run from the boilder

When the pressure between two radiators falls as shown the pressure guage it should indicate that the leak is between that pipe run.

(The upper floor has already been isolated and the pressure does not drop / no air in the radiators indicating the leak is on the ground floor)

Does anyone know if this is a practical way forward

Thank you

D

 

[LPC]

Surely you need to isolate the pipe runs themselves rather than the radiators (which would be fairly difficult)? How fast does the pressure drop to 0? If it's a significant leak there should be a wet patch in the concrete somewhere.

If i'm installing a pressurised system where there are pipes running through concrete I always put a caveat that if the pressure drops and a leak cannot be traced then the only solution is a repipe of the downstairs rads with drops from above.

Or you can always hire/borrow a thermal imaging camera, get the system really hot and try and 'see' the leak through the concrete.

EDIT: I should add, you have checked if the PRV is letting by haven't you? Don't want to go digging up your house without checking that first!

 

[Killy Bing]

Wont work my friend, youll be checking a single radiator and the entire run of pipework in the house.

get an engineer to confirm its actually a leak then go from there

 

[DavidGee]

Many thanks for the information, I was hoping to use each radiator as a barrier to isolate the run of pipe between them, it seems though that it is not going to work

A engineer has confirmed that there is a leak, I was just trying to come up with a way to avoid breaking up the ground concrete.

Thanks again for your response

David

 

[lame plumber]

plus the fact all your rads should have isolating valves on them already, and in case you havent picked up yet, your pipe work should be a flow and return system from which the rads are teed off so the mains runs have no isolators on them bar those on the boiler and you suold isolate those first to ensure its not the boiler thats leaking.

 

[kris]

Hi david just remember the pressure reading is on the whole system not between 2 radiators unless youve isloated an area already with iso valves which like already mentioned alot of these isolation vales are one direction and put on the wrong way will give you more headaches,
9 times out of ten you never need to isolate an upstairs as youd know if you had a leak come time youd see evidence in the cielings,
BEWARE::: care should be taken as isolating a pressurised system is only ok if u know what you are doing

 

[kris]

Hi david just remember the pressure reading is on the whole system not between 2 radiators unless youve isloated an area already with iso valves which like already mentioned alot of these isolation vales are one direction and put on the wrong way will give you more headaches,
9 times out of ten you never need to isolate an upstairs as youd know if you had a leak come time youd see evidence in the cielings,
BEWARE::: care should be taken as isolating a pressurised system is only ok if u know what you are doing

when the boiler / heating is switched on sorry

 

[DavidGee]

Thanks for the feedback ... it's appreciated.

I was under the impression that he only valves on the radiators which were adjustable were the temperature control valves and they would not always fully stop the water thus the need to fit proper isolating valves.

With regard to the flow and return I was really just trying to apply pressure to different sections of the pipe to find where the pressure dropped thus giving me a rough area where the leak could be but clearly this is not practical

Thanks for the information, it really is appreciated.

 

[DavidGee]

Thank you for the advice - it's appricated

Yes, the one direction issue on the valves occurred to me once I had posted the query but I am starting to run out of practical ideas as to how to find the leak

I take your point with regard ceilings being damaged on upstairs leaks but this one is strange as the system has been topped up a few times over the past week and there is no sign of any water damage / damp - I can only assume that the carpet underlay / concrete are acting as a sponge but I have bought myself a moisture to see if that picks up anything when I roll the carpets back ... I know it's a long shot but you never know your luck

Thanks again.

David

 

[DavidGee]

Many thanks for the information it's really appreciated.

I am trying essentially pressurize the pipework between radiators so that and seeing if the pressure between two radiators drops, if it does this gives me a rough idea where the leak could be. To do this I figured the radiators would have to be isolated to stop water running through them.

The pressure drops very quickly it goes from about 1.25 Bar to zero in a few hours, it's strange as the system has been topped up a few times over the past week and there is still no signs of any water damage or moisture on the floors / walls.

With regard to your comment re: repiping with drops from above, does this negate the need to find the leak or does it involve the refitting of external piping round the skirting boards? - It would be great if you could let me know

Many thanks re: the tip on the thermal camera - I will see if i can hire one and give it a go.

I think that the PRV valve is OK the downstairs heating has been isolated but the central heating on upstairs - the pressure is steady and there is no signs of problem with the boiler / or valves.

Thanks again for your help

David

 

[Killy Bing]

Many thanks for the information it's really appreciated.

I am trying essentially pressurize the pipework between radiators so that and seeing if the pressure between two radiators drops, if it does this gives me a rough idea where the leak could be. To do this I figured the radiators would have to be isolated to stop water running through them.

David

Fools errand, take it from someone whos had to find leaks on systems with 50+ rads
Doesn't work like that, your zoned pipework all interconnects unless you valve off sections which is completely impractical in your case.

thermal imaging camera, boil the system and look for a heat bloom around the pipework.

Where are you based?

 

[Ermintrude]

Yep KB I was going to suggest camera!

 

[kris]

Ive always fancied treating myself to a testo camera but not sure i could justify the big price tag on the 880-2, which is £3999, i know there are cheaper ones,

 

[Ermintrude]

Hire one from survey suppliers .

 

[DavidGee]

Thanks for the tip re: the thermal camera ... I think it is a great way forward.

The house is based in a small village outside near Clacton on Sea

Thanks again for your advice

David

 

[DavidGee]

Thanks for the suggestion - seems a lot better than trying to guess where the leak might be...

David

 

[PhoenixServices]

You could also drain the system cut off the upstairs and get a company in to pump it with a special gas. Then they use a sniffer to try and find it. That's how I've done it before.

 

[DavidGee]

Many thanks for the suggestion - have you found that this has worked well.

David

 

[Killy Bing]

You could look at it a different way, i would find a pipe run and chop up the concrete too it, if its bare copper and un protected you can practicly guarantee none of it is.

so you have the option of hiring a camera, finding the leak, chopping the concrete up, repairing it and waiting for the next to appear.

or you could say sod it, have pipework dropped from upstairs and abandon all of the downstairs pipework and be done away with the risk.
if you're intending to stay in the house that is.

 

[DavidGee]

Thanks,

For the second option, would this this involve running new external pipe work along the skirting board downstairs or somehow using the existing pipe work within the concrete (or a combination of both)

Many thanks for the help

David

 

[happyflyer]

i seem to have a leaking radiator pipe which is embedded in a concrete floor on the ground floor of the house.

As the central heating system is pressurized to save tracing the pipework and then removing the concrete around the pipe s(the ground floor of the house is quite large and could easily take a few days to remove the concrete around the piping plus all the associated damage to the flooring) would it be possible to drain the system, fit isolating valves on the radiators refill the system and open up the radiators one at a time in the order they run from the boilder

When the pressure between two radiators falls as shown the pressure guage it should indicate that the leak is between that pipe run.

(The upper floor has already been isolated and the pressure does not drop / no air in the radiators indicating the leak is on the ground floor)

Does anyone know if this is a practical way forward

Thank you

D

David,

You are a very lucky lad, that these guys understand what you mean, I have been in the trade all my life and I have not got a clue what you mean by your question, why don't you draw out what you mean, scan it and post it. Thermal imaging camera sounds great, but it won't always show up the problem, I have one, where do you live, copper pipe should never be buried in concrete that,s really why its leaking, can't you just leave the pipe in the floor and re-pipe the GF radiators on the surface.

 

[happyflyer]

You could also drain the system cut off the upstairs and get a company in to pump it with a special gas. Then they use a sniffer to try and find it. That's how I've done it before.

Never heard of that one before, what gas did they use, was it expensive, what happens if the gas follows the gap between the concrete and the pipe for a few yards, it becomes a big dig like Time Team, trench 1 and trench 2, still sounds interesting.

 

[Worcester]

Never heard of that one before, what gas did they use, was it expensive, what happens if the gas follows the gap between the concrete and the pipe for a few yards, it becomes a big dig like Time Team, trench 1 and trench 2, still sounds interesting.

So will the leaking water, where the gas goes, the water goes and vice versa.

 

[stevetheplumber]

unless its a massive house its probably more cost effective to cut some chases and relay the pipe workeven if you do find where the leak is and fix it you could be doing it all again next yearive always found when you dig it up for repair its an install fault thats caused it to leak no lagging or flux all over the pipework and as fast as you find one bit the next will pop

 

[tolly]

The gas being talked about is a mixture of nitrogen and hydrogen, 95% nitrogen, 5% hydrogen. I do a bit of work for an insurance company that gets me in to help out on this method. Works well, they reckon its accurate to within one square meter. The gas will permeate through most flooring and substrates like concrete, screed, tiles and wood etc but it wont go through plastic. Expensive mind, £550/day