28mm gas leak

[novicegas]

Hi Guys,

Half way through an install, conventional to combi, have re run gas from meter to combi in 28mm. Pressure tested it half way through house and there is a .17mbar drop, permissable. finish the pipe to the meter and there is now a 1.1mbar drop. Initial ttest drop was .10 which means I've increased it to 1.1mbar. Have capped the meter tonight so can go back tomorrow. Have tested the meter connections at meter and boiler and all joints, with both leak spray and a battery operated leak detector. Have no idea where the leak is. I know the permissable drop for new pipe work is below .25 but have no idea what to do about the other .75mbar. Help, what would you guys do?


Many thanks

 

[novicegas]

And absolutely no smell of gas at all through the property when I was testing it.

 

[Rickster123]

Did you test it when pipe work was still hot?

 

[SilentMike]

you using a digital manometer?

 

[galaxy_plumbing]

try to purge and test then, had similar problem before when air was in the pipework.

 

[julesverne]

check your manometer tubing if its old and worn/small splits

 

[Resolute]

If you've tested with a recently soldered joint then that maybe the cause. Try a TT first thing and see what the result is.

 

[AWheating]

chuck the digital gauge in the van and use a water gauge, purge the pipework and retest. It is probably air/temp stab. cant see any reason to use an over sensitive digital guage for a tightness test.

 

[dave1]

chuck the digital gauge in the van and use a water gauge, purge the pipework and retest. It is probably air/temp stab. cant see any reason to use an over sensitive digital guage for a tightness test.

I agree

 

[REDSAW]

i would cap and test the meter to start.

 

[Pssst]

Me too..

 

[Resolute]

So what was it?

 

[stevetheplumber]

id cap and air test the pipework if i had any leak on new work that i couldnt find not sure if anythings changed but i was always told no drop on pipework

 

[novicegas]

Hi guys, Thanks for all your responses, all very helpful and much appreciated. After much worry over the night following morning I retested and the drop was now 2mbar, oops. Used my gas leak detector and found that near a number of joints where i tapped onto the old supply that goes to the hob the detector went mental, couldnt decipher which one so resoldered them all and hey presto no drop. Remember hearing a clunk when I was soldering downstream of the join to the old pipework so thinking it must have twisted out when working nearby. A sound I need to remember. Ttested three times to be sure, twice with digital and once with water. Breathed a sigh of relief then completed the install. Cheers once again.

 

[AWheating]

glad you got it sorted out mate.