Gas leaking up into flue

21 Mar 2007
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United Kingdom
Hi, we had our gas meter changed over a week ago and before commencing the engineer did a drop test which showed 10 bar drop so he called his gaffer who said it was ok to install the meter but to cap it.

There are only two items using gas in the house the boiler and hob which are both in the kitchen. There was a fire but the previous tenants had it removed and capped so they could plaster the hole and have a wall tv mounted.

I called a gas plumber and he came and isolated the hob by its valve and then tested, still dropping so did the same with boiler still dropping.

Anyway the cause was a leak somewhere in the pipes in walls behind kitchen units after checking for leaks on exposed joints and pipes.

There was no smell of gas at any time I should add.

The guy was an emergency call out guy with high rates so I got someone else in to fit a new supply to hob and boiler after cutting a hole in the wall where meter backs in to kitchen. Anyway he finished and drop tested and all was fine. He then turned on hob and boiler and when boiler fired up you can smell gas coming out of boiler. His gas leak detector was going crazy up near the flue.

Now he can isolate the gas valve to the boiler and no drop but turning on the valve causes another drop so the boiler is definately leaking up into the flue.

I am going to call the guy who does our annual services and looks after it to come out but does anyone have an idea what might be leaking? The boiler worked fine but gas was getting in to the flue

The boiler is an ideal logic combi 30 about 5 years old.
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Its fixed. The guy who installed the new pipes found a failed fibre washer in one of the gas connections in boiler which might have been disturbed when they were routing new supply to boiler and connecting the new pipe work up.
As matter of nosiness, did you ask your "regular" guy to do any of the work?
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As matter of nosiness, did you ask your "regular" guy to do any of the work?

I rang him when we were told by the national energy supplier's subcontracted engineer who capped supply. He was busy hence why I called out an emergency gas guy which was a very high price per hour.

He couldnt find anything obvious. I called a leak detection specialist for gas whose fees were huge just for finding it and he told me it might be easier to get a new supply fitted hence what I did.

They did a great job of sorting things and I wasnt prepared to rip half the house to bits.
Am I right in thinking the only fibre washer is on the inlet?

I might get some cards printed:

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