Central heating leak

[Arthurgreen]

I have a leak under my floor but having had 9 plumber visits this year no one has found it.
it seams it’s a small leak that must happen when pipes cool and contract.
I was wondering if there was a dye I could put in so I can trace where it has dried up.
I presume it’s dried before plumbers can find it.
I can get under floor and crawl around.

 

[SimonG]

How do you know you have a leak under the floor if nobody can find it?

 

[Arthurgreen]

How do you know you have a leak under the floor if nobody can find it?

Lol cos the pipes go from boiler down through the floor .it’s a bungalow .no pipes in walls.

 

[WC1]

Your water board will have a list of approved contractors. Among them will be leak detection experts but if 9 guys independently failed to find it I'd say there's something else going on.

 

[Arthurgreen]

Your water board will have a list of approved contractors. Among them will be leak detection experts but if 9 guys independently failed to find it I'd say there's something else going on.

My question is if it’s ok to use a dye to trace leak.

 

[ShaunCorbs]

If all your pipes are in the concrete time for a repipe

 

[Arthurgreen]

If all your pipes are in the concrete time for a repipe

Where did this concrete come from?

 

[WC1]

My question is if it’s ok to use a dye to trace leak.

If there was a simple diy solution then it's likely that the leak would have been found by now.

 

[ShaunCorbs]

Where did this concrete come from?

If it’s suspended open a hatch/make and get someone under there looking as it could damage more stuff

 

[Arthurgreen]

If it’s suspended open a hatch/make and get someone under there looking as it could damage more stuff

Please if you can’t answer my question , just ignore the post.ty

 

[SimonG]

Lol cos the pipes go from boiler down through the floor .it’s a bungalow .no pipes in walls.

So it's a combi boiler that's losing pressure?

And all the radiator valves have been checked for weeps?
And the pressure relief discharge has been checked?
And the boilers been isolated to check that it's the system and not the boiler?

 

[Ben-gee]

What system do you have?
Get someone under the floor and just increase the pressure beyond normal use - they’ll find the leak then!

 

[Arthurgreen]

So it's a combi boiler that's losing pressure?

And all the radiator valves have been checked for weeps?
And the pressure relief discharge has been checked?
And the boilers been isolated to check that it's the system and not the boiler?

All checked,new boiler 6 weeks ago and new valves on all radiator,leak definitely under wooden floor boards with 2ft space to crawl about.
bungalow with 8 rooms ,a lot of pipes and joints.

 

[Ben-gee]

What’s the problem then? Just get under there with a torch and some blue paper - if there’s a leak you’ll find it.....getting boring.

 

[Arthurgreen]

What’s the problem then? Just get under there with a torch and some blue paper - if there’s a leak you’ll find it...getting boring.

You sound like the 9 plumbers who have tried that.
I just wish you could answer my question with a simple yes it could work or no it will damage your boiler. This is more like a politicians forum(they don’t answer questions either)

 

[PETE 123]

Could try some drain dye added into heating system floresent type or uv leak detection kit

 

[Arthurgreen]

Could try some drain dye added into heating system floresent type or uv leak detection kit

Thank you Pete I presume that it won’t damage boiler? Or you wouldn’t have said try it?
it’s a big job for a 73 year old diy,er crawling on my belly under floor ,about a 100 ft round trip,taking all foam pipe insulation off and gaffer taping back on.
if I miss leak I’d have to do it a couple of times. (It’s 8 rooms)
I just thought with fluorescent dye I won’t miss leak and if it’s dried up at least I’d see we’re it had leaked.
Regards

 

[ShaunCorbs]

Cap flow and returns boiler side pressure test system to 4 bar will show the leak as it will be spraying out

 

[Brambles]

Arthur,

If you think you have an under floor leak call in a leak detection specialist. Leaks under suspended floors generally do not dry out to the same level as the surrounding ground, so are easily detected from above.

If you want to go down the dye route, use a dye detectable with UV light - but you will need at least a litre for a 250 litre volume system - but it is not cheap, circa £95 / litre.

If you are crawling around under the floor with a UV torch, remember that mice and rat urine glows under UV, so don’t get misled.

Shaun’s proposal is quicker, cheaper and neat - but at 4bar you may well develop a new leak too.

If you are looking for a cheap, risky (but can be a very effective solution) for a system with an old non condensing boiler - dose the system with 1 litre of Halfords Professional Radiator Leak Sealer - circa £15, but you will need a magnetic filter / dosing point to add it to your system - it is thixotropic and the consistency of thick red custard. It seals most holes, including narrow bore heat exchangers.

Don’t use it on a modern or condensing boiler

Fluorescent dye is most unlikely to damage your system or boiler et al

 

[Arthurgreen]

Arthur,

If you think you have an under floor leak call in a leak detection specialist. Leaks under suspended floors generally do not dry out to the same level as the surrounding ground, so are easily detected from above.

If you want to go down the dye route, use a dye detectable with UV light - but you will need at least a litre for a 250 litre volume system - but it is not cheap, circa £95 / litre.

If you are crawling around under the floor with a UV torch, remember that mice and rat urine glows under UV, so don’t get misled.

Shaun’s proposal is quicker, cheaper and neat - but at 4bar you may well develop a new leak too.

If you are looking for a cheap, risky (but can be a very effective solution) for a system with an old non condensing boiler - dose the system with 1 litre of Halfords Professional Radiator Leak Sealer - circa £15, but you will need a magnetic filter / dosing point to add it to your system - it is thixotropic and the consistency of thick red custard. It seals most holes, including narrow bore heat exchangers.

Don’t use it on a modern or condensing boiler

Fluorescent dye is most unlikely to damage your system or boiler et al

Thanks for all your advice .very helpful.
when new boiler was fitted 6 weeks ago a magnetic filter was fitted and leak sealer added,so that bits covered
thanks again.