Unusually high gas usage of 43000kwh per year

theoretica

How large is the house in square m floorspace?  Detached or terraced?  How many floors? 

theoretica

markin said:

Underfloor is only efficient its its used correctly, that usually means on always on at very low flow temps of around 35c vs using it as a big rad for 2hrs morning and 3hrs evening at 55c

Can one boiler efficiently run underfloor at one flow temperature and radiators at a higher one?

InvertedVee

giles007 said:

About 6 years ago we moved into a modest sized 5 bed house, my wife and 2 teenagers. We had some work done on half of the house a couple of years ago which made it more insulated than when we first moved in. I have always thought our gas bills were high, but put that down to us having an AGA oven, but when prices started to rise last year the bills became astronomical so I started investigating.

We are currently with Shell Energy who took over from First Utility a couple of years back.

Our annual usage for gas is averaging about 43000Kwh

I looked up on the web, on the ofgem website, about average consumptions based on the size of your house and although i understand it is only an "average", the figure they give is 17000Kwh

www.ofgem.gov.uk/information-consumers/energy-advice-households/average-gas-and-electricity-use-explained

Like I said earlier I thought that it might be the AGA, so just before Christmas last year I turned the AGA completely off. The usage only went down by about 10%, month on month.

So does anyone have any ideas as to how I might be using so much gas? Over twice the average for a 5 bed house, and i would say we are not overly above average gas users.

We have had a new and very efficient boiler for a couple of years which has its regular servicing, we don't smell gas anywhere so don't think its an obvious leak

I did a test a while back when I knew the heating was off. I turned on the hot water, saw the gas meter needle tuning, then turned off the hot water, and the needle stopped.  So its not like the meter might be faulty in that it runs all the time. I am thinking that maybe the meter is faulty in that it runs too fast when gas flows through it?

We don't run the heating very high, we have efficient underfloor heating in much of the downstairs. We don't have an unusual amount of showers or baths either.

Just FYI we have an imperial meter and have had it since we moved in 6 years ago

many thanks in advance

Giles

Welcome to the forum Giles. This place has a good track record of helping people spot where the issues are.

I'd just begin by saying it's not impossible that a gas-heated house with low levels of insulation will use 45000kWh/year. Until 4 years ago I lived in a large 5-bed house with similar consumption. I got through 52573kWh one year. And no AGA.

Qyburn

theoretica said:

Can one boiler efficiently run underfloor at one flow temperature and radiators at a higher one?

A sub zone can be run at a lower temperature using a mixing valve. The installations I dealt with in large buildings had a separate pump as well.

wild666

giles007 said:

About 6 years ago we moved into a modest sized 5 bed house, my wife and 2 teenagers. We had some work done on half of the house a couple of years ago which made it more insulated than when we first moved in. I have always thought our gas bills were high, but put that down to us having an AGA oven, but when prices started to rise last year the bills became astronomical so I started investigating.

We are currently with Shell Energy who took over from First Utility a couple of years back.

Our annual usage for gas is averaging about 43000Kwh

I looked up on the web, on the ofgem website, about average consumptions based on the size of your house and although i understand it is only an "average", the figure they give is 17000Kwh

www.ofgem.gov.uk/information-consumers/energy-advice-households/average-gas-and-electricity-use-explained

Like I said earlier I thought that it might be the AGA, so just before Christmas last year I turned the AGA completely off. The usage only went down by about 10%, month on month.

So does anyone have any ideas as to how I might be using so much gas? Over twice the average for a 5 bed house, and i would say we are not overly above average gas users.

We have had a new and very efficient boiler for a couple of years which has its regular servicing, we don't smell gas anywhere so don't think its an obvious leak

I did a test a while back when I knew the heating was off. I turned on the hot water, saw the gas meter needle tuning, then turned off the hot water, and the needle stopped.  So its not like the meter might be faulty in that it runs all the time. I am thinking that maybe the meter is faulty in that it runs too fast when gas flows through it?

We don't run the heating very high, we have efficient underfloor heating in much of the downstairs. We don't have an unusual amount of showers or baths either.

Just FYI we have an imperial meter and have had it since we moved in 6 years ago

many thanks in advance

Giles

Have you tried lowering the temperature that the heated water flows through the radiators and lowering the thermostat temperature? I have the water temperature set at 40 degrees and the thermostat set at 16 degrees, this is ideal for me but might not be the same for you. If you can lower the water temperature flowing through the radiators by say 5 degrees per week and turning down the thermostat by 1 degrees per week until you have a temperature you are comfortable with. It could mean the radiators are constantly on in cold weather but the amount of gas used will be considerably less than if the water temp. flowing through the radiators is at 60 degrees or higher. My daily usage in kWh in cold weather is 31kWh for 8 hours of heating with the temperatures I have set, though it could be more for your home.

giles007

Thanks again for your replies, I will try to reply to you all in this one post

Meter



bills are being calculated as follows




Usage 

So I have checked back over the last 6 years or so and have more information as to what has been used.
2016/17 and 2017/18 we were with First Utility and I don't have access to the online account any more as they were taken over by Shell Energy, however I was sent yearly summaries on email so I have listed that usage below. The situation is further complicated as from Dec 2018 to Sept 2020 we were away in the USA on a work placement and rented the property out to tenants (I don't know their usage), then when we came back, we had issues with a transfer of the tenant's gas supplier, British Gas, to Shell Energy (a whole other complicated saga) for a few months and then we started a building project which meant that the gas was off for 5 months or so prior to Aug 2021, so between Sept 2020 and Aug 2021 the readings are patchy/estimated at best.

Anyway I have the following usage 

04/08/2016 - 03/08/2017 First Utility 51825 kWh

17/08/2017 - 16/08/2018 First Utility 51113 kWh

Aug 2018 to Dec 2018 no data as no access to First Utility online account anymore

Dec 2019 to Sept 2020 house occupied by tenants, no gas usage data available

Sept 2020 to Aug 2021 patchy data as transferring supplier and gas was turned off during building work

Sept 2021 to Present - Usage based on customer reads submitted to Shell Energy (usage coloured into yearly for clarity)



So turning the AGA off mid December 2022 has not really made a huge dent if you compare the Winter month usages 21/22 and 22/23. Jan thru March this year is still very high usage


Boiler
The building work we had done replaced an old Mexican boiler with a new all singing all dancing Glow Worm

House Energy Rating
on moving into the property in 2016 the house's energy efficiency rating was D (average according to ONS) - we have not had it re measured since the building work but cant believe it would be worse as the loft was insulated as was half of the house as walls were replaced / insulated

House square footage
2700 sq/ft

Heating and Schedules
We have a couple of UFH zones downstairs and they are set to 21 degrees from 6am to 11pm, then they are set to 17 degrees overnight
The rest of the house is controlled by 1 thermostat which is set to
20 degrees 6am to 9am
16 degrees 9am to 3pm
20 degrees 3pm to 11pm
16 degrees 11pm to 6am

Under Floor Heating
Installed over half of the downstairs. Its a separate manifold with water temperature set at 40c


So from what I can see we have an average efficiency rated home. Have always had very high gas usage, house improvement work has reduced usage (51000kWh to 43000kWh), turning off the AGA reduced usage a bit more (approx 10%) - But we are still burning gas for England



many thanks in advance for any further assistance you guys can give me

[Deleted User]

Your meter is nearly 40 years old. Has your supplier not suggested that it needs replacing? Given your consumption, I would be asking the supplier for an independent meter check undertaken by SGS. Your meter would be removed and sealed and sent to SGS for laboratory flow testing. You will only pay for the meter change if the meter is found to be within limits.

theoretica

giles007 said:

House square footage
2700 sq/ft

Heating and Schedules
We have a couple of UFH zones downstairs and they are set to 21 degrees from 6am to 11pm, then they are set to 17 degrees overnight
The rest of the house is controlled by 1 thermostat which is set to
20 degrees 6am to 9am
16 degrees 9am to 3pm
20 degrees 3pm to 11pm
16 degrees 11pm to 6am

So first thought is that your house is more than 4 times the size of my flat - and you are using about 8 times the energy. 

Second thought is that all the temperatures and times you have set are hotter/longer than I have.  Overnight - basically off for me (7 degrees I think but it never comes on).  Daytime in weekdays - right down as I may be out and override it if I am in and cold.  Do you turn the heating off if you are all out for the day?

If you don't feel cold now and then, especially when not following your normal routine, then you are almost certainly heating when you don't need to.

The Aga would have been turning gas into heat - so in winter, depending on your thermostat set up, it might have reduced other use and not ended up with more total heat.  But being on in summer, when the heating would have been off I expect it would have made a difference to usage.

Third thought - your summer use is also high - do you turn your heating right off?  Is that just hot water?  Hot water + Aga?

Fourth thought - where is the one thermostat that controls the rest of the house (is it in the hottest place?) and do you actively use TRVs?  If the thermostat calls for heating the radiators in a different room could be on max pumping out heat to well above the thermostat setting.  What temperatures are the rooms actually getting to at different times of day?  Is your boiler actually being switched off by the thermostat?

giles007

[Deleted User] said:

Your meter is nearly 40 years old. Has your supplier not suggested that it needs replacing? Given your consumption, I would be asking the supplier for an independent meter check undertaken by SGS. Your meter would be removed and sealed and sent to SGS for laboratory flow testing. You will only pay for the meter change if the meter is found to be within limits.

Thanks Dolor - Would a new gas meter have to be a smart meter? we are concerned (rightly or wrongly) about EMF radiation

giles007

theoretica said:

giles007 said:

House square footage
2700 sq/ft

Heating and Schedules
We have a couple of UFH zones downstairs and they are set to 21 degrees from 6am to 11pm, then they are set to 17 degrees overnight
The rest of the house is controlled by 1 thermostat which is set to
20 degrees 6am to 9am
16 degrees 9am to 3pm
20 degrees 3pm to 11pm
16 degrees 11pm to 6am

So first thought is that your house is more than 4 times the size of my flat - and you are using about 8 times the energy. 

Second thought is that all the temperatures and times you have set are hotter/longer than I have.  Overnight - basically off for me (7 degrees I think but it never comes on).  Daytime in weekdays - right down as I may be out and override it if I am in and cold.  Do you turn the heating off if you are all out for the day?

If you don't feel cold now and then, especially when not following your normal routine, then you are almost certainly heating when you don't need to.

The Aga would have been turning gas into heat - so in winter, depending on your thermostat set up, it might have reduced other use and not ended up with more total heat.  But being on in summer, when the heating would have been off I expect it would have made a difference to usage.

Third thought - your summer use is also high - do you turn your heating right off?  Is that just hot water?  Hot water + Aga?

Fourth thought - where is the one thermostat that controls the rest of the house (is it in the hottest place?) and do you actively use TRVs?  If the thermostat calls for heating the radiators in a different room could be on max pumping out heat to well above the thermostat setting.  What temperatures are the rooms actually getting to at different times of day?  Is your boiler actually being switched off by the thermostat?

Thanks theoretica

I don't think our settings are that drastic - we have played with them in the past - up down a degree, on / off for shorter hours etc, but all to no real discernable avail.

We have always turned the AGA off in the summer months, as yes it does heat as well as cook
Whilst the AGA was on though, the underfloor heating didn't ever kick in as the temperature was always adequate from just the AGA.

Yes it would have been just hot water in the Summer

Oddly the upstairs temp is controlled by a thermostat downstairs (odd historical house configuration) and it gets affected by the downstairs heat - we often complain its too cold upstairs.

I cant see any reason we would be pumping out heat and not be readily aware that we are