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Gas advice, tut tut tut
Advice?
No. its an instruction.
If you have gas leak, turn the gas off.
Boiler using excessive gas after service
- Thread starter ed1178
- Start date
Advice?
No. its an instruction.
If you have gas leak, turn the gas off.
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Unless a leak this big is outdoors I'm sure he'd have smelled it by now.
It might be un-burnt gas venting out via the flue.
Gas valve passing gas but no ignition.
( Yes I realise that in theory this cannot happen, the controller ( PCB ) would not allow it to happen. But PCBs and gas valves can go faulty )
But it seems the boiler is still working. If it passed gas for a while and then ignited there'd be a bang!
In any case if he divides his figures by 2 (see #23) I doubt he has a problem. Between 11 Nov and 11 Jan I used 488 m3, about 5500 kWh, very similar to OP's usage.
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My old tariff before the firm went belly up had the gas at 2.11 pence per kwh, multiply this by 5500 and it is not too extreme.
Sorry, that was a typo, the 5500 kWh was since December 12th. The actual bill landed today, closer to 5600 kWh since my confirmed and accurate reading on 12th December, 183 kWh per day according to bulb. It’s usually closer to 50 kWh per day in the cooler months, perhaps a bit higher when really cold. But not over three times higher.
I suppose my question is, is it possible for boilers to burn more gas than they should for a given output? Is it burning so hard that excess heat is being pumped out of the flue (more so than normal) can a 15kw boiler burn twice a much if the gas valve is set wrong?
OK
Not sure, maybe the experts can comment. I'd just say the gas pressure at the burner is (most likely) adjustable, and it's possible the service guy increased it. That would increase the gas flow, but you would expect the heat into the water to increase also, so little effect on daily consumption. And I'd be surprised if it made the difference you're seeing.
It's definitely worth getting the service engineer back in for a chat, at least.
I would suggest no, it cannot happen without it being very obvious - made very obvious by the amount of unecessary heat escaping out of the flue when the boiler is running.
There was an earlier mention of Smart Meters and the IHD showing the actual meter reading and I thought our IHD did NOT show the actual reading only consumption and cost etc.. They are of Secure manufacture - if the readings are there - then I cannot find them, anyone else found them?
Anyway, to the point.
Despite my Smart Meters being unSmart for several years/ suppliers now, they do still provide accurate instantaineous consumption. So I decided to see just what my Ecofit Pure 418 consumes at full chat. 418 is a an 18kw Vaillant gas boiler. It peaked at 17.94Kw, minimum 17.53kw without any modulating.
I wonder if the OP has Smart Meters and could use the IHD (In Home Display) to check his boiler?
Anyway, to the point.
Despite my Smart Meters being unSmart for several years/ suppliers now, they do still provide accurate instantaineous consumption. So I decided to see just what my Ecofit Pure 418 consumes at full chat. 418 is a an 18kw Vaillant gas boiler. It peaked at 17.94Kw, minimum 17.53kw without any modulating.
I wonder if the OP has Smart Meters and could use the IHD (In Home Display) to check his boiler?
An older boiler like this has the power input set by varying the gas supply pressure to the burner. The installer or servicer checks and if needed resets the pressure on the gas valve. The gas supply pressure from the meter is about 21 mbar and a typical burner pressure about 5 to 12 mbar so little scope for very wide misadjustment.
If the burner pressure is too high and if all the burner is lit then the additional heat is transferred into the system water so the additional power is not lost.
The one potential way for the gas not to be burnt is if part of the burner is not ignited fully. But that is unlikely as unburnt gas usually quickly lights if there is a flame nearby. That is about all the servicer could check and is very unlikely.
If the burner pressure is too high and if all the burner is lit then the additional heat is transferred into the system water so the additional power is not lost.
The one potential way for the gas not to be burnt is if part of the burner is not ignited fully. But that is unlikely as unburnt gas usually quickly lights if there is a flame nearby. That is about all the servicer could check and is very unlikely.
what is the gas meter going to show you?
If a burner burns successfully @ 5 bar and also @ 12 bar would it be using a little over twice as much gas?! Could the servicer have increased the pressure to the boiler? I'm by no means a gas/boiler expert just trying to understand.
No, flow varies as square root of pressure drop, so at 12 mb, approx 1.5 x flow at 5mb.
Note mb, not bar
As a registered gas installer I know how to check for gas leaks and that is not done by looking at the meter. If the meter registered a gas leak, it would be quite large needing evacuation
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