testing for leaks without turning water on...

[Puddephatt]

Hi there wonder if anyone can give me any suggestions. Ive just bought an old vacant house with an old boiler, (Ideal Mexico), the house has been vacant for some time and the mains water and electricity is currently off. There is signs of an old large leak (plaster boards have come off in 2 places) before I turn on water and electrics I want to check the system to see if the leak has been fixed, at the moment it looks like it leaked and was either turned off or fixed. I seem to remember that plumbers use a portable air pressure gauge when testing a new system, can I do this and if so How, any suggestions would be really appreciated from a keen amateur. Cheers

 

[Mbear]

Personally I'd fill the system and see what happens. But put basins/buckets below where u suspect the leak/s to be. If the house hasn't been decorated yet then u don't have too much to lose? As for pressure testing, I can't think of anything that allows you to do that. I've certainly never used anything remotely alike to what u describe. Maybe you seen plumbers testing gas pipework with a u-gauge and thought it was for the heating circuit? Also the boiler u describe would most likely be fitted to an open system, therefore you'd have to bung the cold feed and open vent to even allow you to do such a thing otherwise the pressurised air would just escape. Best bet if your not too sure is to get sum1 in to give the joints a once over,refill it and re-commision the whole system

 

[wnjswozo]

get a plumber in,after this winter your more likely to have a few bursts,so he will be able to fix/advice whilst heres there,you know it makes sense,rodney

 

[moony]

pressure test kits are for sale in screwfix both wet and dry kits....

without seeing your house its hard to say how you would do it.

but generally you open one end and cap off all other open ends and add either water or air to a certain pressure (1.5 times the working pressure normally) and leave for a hour and check for any drops in pressure.

obviously a wet kit would produce leaks - a dry kit would be better for you.

a dry kit its difficult to see where the leak is- using ldf is an idea but it may be buried.

good luck

 

[craig2050]

Turn it on whats a bit of water

 

[steadyon]

I'd be a bit careful of air testing to 1.5 times working pressure. Guessing at working pressure of 2 to 3 bar suggests an air pressure of 3 to 4.5 bar. Air compresses and thus stores up latent energy. If something goes all of a sudden that energy is released and you can get a pretty fierce and dangerous blast. It is possible to blow poorly made joints apart with air, and you can get fittings flying through the air. Make sure no one else is around and wear PPE.

I'd do both air and water tests, assuming loose ends can be capped off:

First, air to 0.5 or 1bar for a couple of hours and see if pressure drops. If it does, try and find the leaking air (not easy), make good and repeat.

Secondly, when no air leak, water pressure test at 2bar, repairing any leaks.

Finally go up to 3 or 1.5 time working pressure with water.

Perhaps a bit over the top, but if it'll stand that it should be OK in normal use and you can be confident its OK.

 

[Blackcatgas]

Personally I'd fill the system and see what happens. But put basins/buckets below where u suspect the leak/s to be. If the house hasn't been decorated yet then u don't have too much to lose? As for pressure testing, I can't think of anything that allows you to do that. I've certainly never used anything remotely alike to what u describe. Maybe you seen plumbers testing gas pipework with a u-gauge and thought it was for the heating circuit? Also the boiler u describe would most likely be fitted to an open system, therefore you'd have to bung the cold feed and open vent to even allow you to do such a thing otherwise the pressurised air would just escape. Best bet if your not too sure is to get sum1 in to give the joints a once over,refill it and re-commision the whole system

Agree + 1

 

[Bernie2]

Yes would agree with that. 3 bar is blow off point. So even if the system normally worked at 2 bar, making the 1.5 times test pressure 3 bar, it should never rise beyond 3 bar anyway on a normal system.

The problem with air tests is that it shows its leaking but it doesn't tell you where. You can get coloured gas of course or use a gas that shows up on a scope.