Find my leak

[Jameswren]

I have a leak but can't find where it is and run out of ideas where to look and how to check.

I have a pressurised system with an orange, football sized pressure vessel and a dial on it - the dial drops gradually over a few days. I've left the heating off this week and the pressure has dropped to zero.

I have:
*A town house
*10 radiators
*Replaced 7 radiators and some of the pipe work
*A Glowworm boiler
*No visible damp areas on walls, floors, ceilings
*No wet areas on joints to radiators
*Very hot water from taps to all outlets

I appreciate this may be a bit of a project but would really appreciate some help!

 

[Whitespirit66]

Have you checked the copper pipe to outside from the PRV?

Re-pressurise, turn ch on, and see if it's dripping outside.

Tie a plastic bag over end of the pipe outside, and see if it collects water from system over a few days.

 

[gas_man_gaz]

have you checked the pressure relief valve isn't leaking? if it is then the expansion vessel needs checking

 

[Jameswren]

To Whitespirit66 - what's the PRV? And where will I find the copper pipe? I assume you mean from the boiler.

To gas_man_gaz - there's a small black thing underneath my orange football thing (looks like the valve cap on my tyres). Is that what you mean? That's dry.

 

[Jameswren]

Forgot to mention, all rads are full of air generally and I bleed them very often - assume that's a given if the pressure is dropping though.

 

[Jameswren]

I don't have a copper outlet from the boiler but do have a grey, plastic, flexi type pipe feeding into a white plastic pipe going directly to my sink waste pipe. I've taken that off and some water came out.

 

[Phill Peck]

What model is your boiler?

Is there a red ball in your airing cupboard?

 

[Jameswren]

It's a GlowWorm felxicom 15hx

Yes, have a red ball near my cylinder.

 

[Phill Peck]

The red ball is your expansion vessel this tells us that your prv is not in your boiler

Some where near that red ball there should be your pressure gauge and prv (pressure relief valve) it is brass and has a red plastic head. From this there will be a copper pipe that should go outside somewhere.
If you can find where this goes depressurise and find out if it drips out of this pipe.

If your house is a new build then this pipe work may just appear outside at low level, possibly with a small cage over it

 

[Jameswren]

Untitled

• Jameswren
• 25 Apr 2013
• 1

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[Jameswren]

//media.diynot.com/178000_177205_60531_45773369_thumb.jpg

 

[Phill Peck]

Ok behind the gauge is the prv it has a black plastic head the pipe seems to go up maybe into the loft? This is not ideal but a separate issue you need to trace this pipe and see where it goes it should terminate outside somewhere

 

[Jameswren]

Pass - no idea where that will go to and it'll be very high level. I'll try and trace it to the loft for an idea but it's a three storey property.

 

[Jameswren]

Almost certainly it will be somewhere I cannot get to without ladders that I don't have.

Assuming this is the problem, is there any issue leaving it without fixing anything? I'm not concerned about having to top-up the pressure every few days as long as it isn't damaging pipework/my boiler etc.

 

[Phill Peck]

It is not good to be adding water every couple of days this will increase the corrosion rate in your system

Have a look in the FAQs about re pressurising expansion vessel

Other wise your gonna have to get someone out, the long term effects of having to regularly top up will be more expensive than sorting this fault.