Hello Guys,
Wondering if anyone can help me. And before anyone asks, I am fully ACS qualified and fully Gas Safe Registered.
Was called to a job a couple of days ago just for a routine landlord safety check and during the let by and tightness test I found a very small but continuous leak on an installation. The leak itself took longer than the permitted four minutes and there was no smell of gas with the leak actually taking about 10 minutes to fall from 20.77mb to 16mb with the incremental drops at about 0.02mb.
Now, my initial test was at the meter. I then disconnected the free standing cooker from the supply and isolated the boiler (Ariston Microgenus 24HE ) and run the test again with pretty much similar if not exacts to those listed above.
Now here where it gets strange. I used my electronic manometer at the meter test point whilst having a second electronic manometer, in the form of my flue gas analyser connected to the test point of the boilers gas valve. Beneath the boiler, about 60cm there was an isolation valve which I had in the off position at the same time the gas meter ecv was also off. I pressurised the system via the meter ecv up to the boilers isolation valve and monitored the monometer at the boiler test point and there was no change in the pressure reading telling me that at least the boiler isolation was not letting by at all and no gas was entering the boiler however, the gauge at the meter was still showing this minute drop in pressure which led me to conclude that the pipe work between the ecv and the isolation valve under the boiler may have been at fault.
Just to add, I did also check the bayonet connection after disconnecting the cooker using LDF and there didn't appear to be any problems.
I de-pressurised the system, reattached the gauges to the meter and boiler test points with the isolation valve under the boiler being in the off position. Pressurised the system fully, again the gauge at the meter showing a very small but continuous drop with the second gauge showing zero pressure. I opened the boilers isolation valve pressurising the 60cm pipe work between the iso valve and the boiler to 20mb, shut it off. Again there was a small but continuous drop with the increments being in the hundreds of units with the time between each significant drop being quite lengthy.
It is possible that the iso valve under the boiler is the culprit but i did check this with the aid of LDF and couldn't see any activity so was wondering if the leak was at the boilers gas valve with perhaps the low gas, pilot solenoid not being fully closed off accounting for the small leakage but this might be a misinterpretation as the gauge at the meter was still showing a slow but continuous pressure drop simultaneously ! Another thing I did notice that at intervals, the speed of the drop did increase but again this only registered in the hundreds of units.
Could it be the gas valve solenoid, the pipe work or both.
Save to say, I did isolate the supply completely and issued a advice notice and label indicating an immediately dangerous situation and the landlord called Transco.
Anyone had any similar experiences or can offer advice on my experience ?
Cheers in advance
Wondering if anyone can help me. And before anyone asks, I am fully ACS qualified and fully Gas Safe Registered.
Was called to a job a couple of days ago just for a routine landlord safety check and during the let by and tightness test I found a very small but continuous leak on an installation. The leak itself took longer than the permitted four minutes and there was no smell of gas with the leak actually taking about 10 minutes to fall from 20.77mb to 16mb with the incremental drops at about 0.02mb.
Now, my initial test was at the meter. I then disconnected the free standing cooker from the supply and isolated the boiler (Ariston Microgenus 24HE ) and run the test again with pretty much similar if not exacts to those listed above.
Now here where it gets strange. I used my electronic manometer at the meter test point whilst having a second electronic manometer, in the form of my flue gas analyser connected to the test point of the boilers gas valve. Beneath the boiler, about 60cm there was an isolation valve which I had in the off position at the same time the gas meter ecv was also off. I pressurised the system via the meter ecv up to the boilers isolation valve and monitored the monometer at the boiler test point and there was no change in the pressure reading telling me that at least the boiler isolation was not letting by at all and no gas was entering the boiler however, the gauge at the meter was still showing this minute drop in pressure which led me to conclude that the pipe work between the ecv and the isolation valve under the boiler may have been at fault.
Just to add, I did also check the bayonet connection after disconnecting the cooker using LDF and there didn't appear to be any problems.
I de-pressurised the system, reattached the gauges to the meter and boiler test points with the isolation valve under the boiler being in the off position. Pressurised the system fully, again the gauge at the meter showing a very small but continuous drop with the second gauge showing zero pressure. I opened the boilers isolation valve pressurising the 60cm pipe work between the iso valve and the boiler to 20mb, shut it off. Again there was a small but continuous drop with the increments being in the hundreds of units with the time between each significant drop being quite lengthy.
It is possible that the iso valve under the boiler is the culprit but i did check this with the aid of LDF and couldn't see any activity so was wondering if the leak was at the boilers gas valve with perhaps the low gas, pilot solenoid not being fully closed off accounting for the small leakage but this might be a misinterpretation as the gauge at the meter was still showing a slow but continuous pressure drop simultaneously ! Another thing I did notice that at intervals, the speed of the drop did increase but again this only registered in the hundreds of units.
Could it be the gas valve solenoid, the pipe work or both.
Save to say, I did isolate the supply completely and issued a advice notice and label indicating an immediately dangerous situation and the landlord called Transco.
Anyone had any similar experiences or can offer advice on my experience ?
Cheers in advance
