How to find leak in pressurised CH system?is it possible?

[fluff29]

hi guys
We had new boiler & rads installed last year & moved from a gravity fed to pressurised system boiler. There has been a leak since fitting (15mm pipe work not replaced as in good condition with no sludge etc). Losing about 0.5 bar every 2-3 weeks. A tube of sealant was put in at the time & we don't want to add another one incase it clogs up valves, etc.

-Should we pay for the plumber to try to find the leak? A colleague mentioned getting them to put the pressure up to 3bar to hear the leak. Would this work?
-Should we just leave the leak until it becomes a bigger problem?

In your experience, is it going to be an issue to try and trace the leak? We are happy to pay for the plumber to trace the leak but we have no idea how to do this and the plumber's only offer was to add more sealant.

It would be good to get the thoughts from plumbers/engineers fitting systems on a daily basis.

Thanks
Fluff

 

[oilboffin]

Put up the pressure and keep going round and look for leaks,you're right don't put leak sealer in as it'll bung it all up it's just a trying game.Bob

 

[Madrab]

Get some blue roll, have the system cold and crank it up to 2.5bar. Wipe all the valve connections, joins, bleed screws pipework you can get to etc. Being blue roll it will go dark when it finds even the smallest drop of water.

 

[TicTac]

Then you'll need to start lifting the floorboard.

 

[fluff29]

Thank you all. Will we hear the leak if the pressure is at 2.5 bar? The issue is that we have sheets of chipboard that are nailed down so we don't want to search every length of pipe checking for the leak.

If we take this route of turning up the pressure:
-will it create more leaks other than the current one we have?
-will we definately find it?

Also, what are the consequences that we just leave the leak and keep topping up? I'm thinking possibly:
-will eventually move to a bigger leak.
-we will have to put fernox in more regularly as we keep losing water.
-will we continue to get air locks due to always having to top up.

Is there any issues with turning the boiler up to 2.5 bar when cold? Is there a pressure valve of some sorts?

Sorry for the questions but I will need to relay this to a plumber to get him fix it for us.

Thanks again
Fluff

 

[fluff29]

Then you'll need to start lifting the floorboard.

This is the bit we don't want to tackle. Plus we have an unknown of where the pipes run

Get some blue roll, have the system cold and crank it up to 2.5bar. Wipe all the valve connections, joins, bleed screws pipework you can get to etc. Being blue roll it will go dark when it finds even the smallest drop of water.

Good tip on the blue roll. I normally check with white kitchen roll.

 

[TicTac]

Maybe you need to find a water diviner.

 

[fluff29]

Haha, it might come to that. I have to get my new carpets down soon so we really need to either try to find the leak or just keep topping up the boiler and deal with a bigger leak in future. Unfortunately for what we paid for the boiler and rads I anticipated have a fully working system that was leak free.

 

[TicTac]

It's not uncommon to find leaks when you convert from a gravity fed to a pressurised system, but to my mind, they should both have been soldered to the same standard. If you keep topping up, then you'll need to keep adding inhibitor, but you'll also risk having water somewhere it shouldn't be, and that may cause long term damage.

 

[HERTS P&D]

I bet the leak is on the ground floor as if it was on the first floor then it would of be made apparent by now.

Andy

 

[dilalio]

This is the bit we don't want to tackle. Plus we have an unknown of where the pipes run

That won’t really stop the leak from being in those places

It’s better/cheaper for you to spend time trying to find it than it will be, using a tradesman!

Also check that the PRV isn’t passing or any AAVs inside or outside the boiler.

There are leak detection services you can call in.

As said, pressurise to 2.5/2.8 bar when cold and don’t run boiler. PRV is set to open at 3 bar so should hold and “may” help you find the leak(s). Stethoscope or upturned drinking glass/screwdriver may also assist.

 

[Madrab]

0.5 bar over 2-3 weeks then it's probably a weep and not anything more serious so chances are you wouldn't hear anything but it may make the weep more obvious

Your installer should/could have tested (1.5 times working pressure) the system as part of the conversion and if not then caveated the work before it was done stating that it may leak.

If the install is less than a year old and there's a guarantee and no caveat then you may have recourse with the installer to have it put right.

 

[John D v2.0]

Add some fart spray to the system and wait for the smell to come out somewhere? I've heard any kind of perfume would work.
Ps not a serious suggestion

 

[fluff29]

That won’t really stop the leak from being in those places

It’s better/cheaper for you to spend time trying to find it than it will be, using a tradesman!

Also check that the PRV isn’t passing or any AAVs inside or outside the boiler.

There are leak detection services you can call in.

As said, pressurise to 2.5/2.8 bar when cold and don’t run boiler. PRV is set to open at 3 bar so should hold and “may” help you find the leak(s). Stethoscope or upturned drinking glass/screwdriver may also assist.

Thanks. I will maybe need to come back with some questions on managing this safely in a bit.

0.5 bar over 2-3 weeks then it's probably a weep and not anything more serious so chances are you wouldn't hear anything but it may make the weep more obvious

Your installer should/could have tested (1.5 times working pressure) the system as part of the conversion and if not then caveated the work before it was done stating that it may leak.

If the install is less than a year old and there's a guarantee and no caveat then you may have recourse with the installer to have it put right.

Thanks madrab

The system was fitted in September 2017 with a one year guarantee. We got a Worcester wall mounted system boiler, with motorised valves, controls for HW and separate programmable star for heating. Plus 11 rads and a heated towel rail. The existing 15mm pipe work & HWST were kept. New 15mm plastic pipe was used for rads that changed in size. We were losing pressure when initially installed but stabilised after a couple of days, installer returned put in sealer for any small weeps and we paid the balance. I thought a leak woukd have been evident immediately when out under pressure, how wrong was I.

Do we have any redress as it is probably the old pipe work that is leaking?

Also, should the pressure test have shown up the small weep? Any advice on this part woukd be appreciated.

The installer only offered to put another can of sealer in. I'm not sure what the response woukd be about trying to find the leak but we will need to have a chat with him.

Thanks again

 

[terryplumb]

Is your hot water cylinder pressurised or gravity fed from a cold water tank ( usually in loft ) ? How did you establish that you have a leak on the system pipework/ rads ,as opposed to the boiler ? Does any water come out of the pressure relief pipework ? This question was asked earlier but I don't think you responded.