Working out gas loss

Afternoon everyone.

Without going into to much detail, we have had a small gas leak in our place since we bought it, small enough we could not smell it, but large enough that when I had my first annual inspection it all had to be shut off until they found the leak as was above legal maximum.

We’re debating what to do with this but I’m trying to figure out how much we actually lost. I’ve found some calculators but honestly may as well be Japanese to me.

Any rocket scientist on here able to help?

I know the size of the pipe and rough distance from the meter (if that has any play) thanks in advance.

So it just so happens that I’m adding to my skills with a Gas Safe qualification. Today is the end of the first section of my training.

So if you have a leak above the allowed drop you need to get it fixed before reconnecting, as your Gas man says.

Could I ask what the purpose of knowing the volume lost is? I suspect even if you know the total installation volume many other factors will prevent an absolute loss figure, such as having appliances on can lower the pressure in the pipe.

Lol, is there anything you don’t do?

So, we bought a new build, they replaced our electric cooker (before we moved in), turns out they knocked the pipe feeding the hob and gas has been escaping ever since.

I’ve complaint to my energy supplier a number of times as our bills seemed high when we’ve not really been using it.

So, first point is to see if that is a factor, or big enough factor in why out bills have been high

Secondly, were trying to establish the health implications in all this as well.

Thirdly should we choose to pursue the house builder it would help.

As it stands I’ve had to pay for a gas check twice as the first one could not certificate it due to the gas loss.

If it can be proved (and I’m not doubting you for a moment) that the replacement cooker caused the damage before you moved in then it’s pretty clear to me that the house builder gave you possession of a house in ‘immediate danger’. Potentially an ID situation that is reportable to the HSE. That is to say a gas leak is an explosion waiting to happen. That no explosion happened is beside the matter.

Having fitted many kitchens as part of my work I can tell you that the hob gas pipework should be out of the way of the oven so that it cannot be damaged. If the replacement oven was somehow larger than the original then the fitter should reasonably have measured it and had the pipework adjusted rather than just ramming it in!

In my recent training (and I hope I’ve got this right), I’ve learnt that natural gas will rise and carbon monoxide will fall. Carbon monoxide is a killer but you haven’t described that as your problem. Natural gas will rise and possibly escape through open windows and doors…or it might not and could become sufficiently concentrated to be an explosion risk.

Seems to me that the builder should accept that they have created a dangerous situation, cover the costs of testing and repair and make a contribution towards your gas costs. Getting an admission of liability might not be easy. One thing is for sure, they won’t want the HSE involved so I would mention this in any correspondence.

I think you’ll have trouble calculating the quantity of gas lost. The accurate way of doing it is also a very dangerous way which requires you to turn on the gas to the leaking pipe and measure the gas used at the meter over a period of time. I can’t overstate how dangerous this is and must not be attempted.

Your Gas Safe man could write a statement and provide pics of the damage to show how a careless cooker I installation has created a danger.

Hope this helps.

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It’s all been corrected, had to be as guy one turned it all off and I had to get Transco out to confirm before anyone would go near it

The guys that fitted it took pictures to prove it was not their work but they also showed me

In terms of loss, first guy was saying 4.6mbar over 2 mins while Transco said 3.5mbar.

Therefore, even if we took the lower reading I think it would be safe to say it was a reasonable amount.

Noted on the HSE, think I’ll go to the developer see what they say/offer and drop in HSE see if that shifts them.

You’ll get a rough idea of the loss once it’s fixed and you get your next couple of gas bills. If they are significantly cheaper after the fix it should be obvious.