High yearly gas estimates - explanation?

why_so_serious4

Dear Money Savers!

I was hoping that someone could help me understand why my yearly gas estimates are so high, and subsequently, our monthly usage (and cost). I live in a three bed basement flat in an old four storey (basement incl.) Georgian building in Bristol.

The estimated usages for the year are:
Gas - 24167 kWh
Elec - 4163 kWh

Previous years' usage has been:
Gas:
Dec'15 - Dec'16: 18058 kWh
Dec'16 - Dec'17: 22709 kWh
Elec:
Dec'15 - Dec'16: 3832 kWh
Dec'16 - Dec'17: 4072 kWh

What has me concerned is that when I look at quoted figures for the average gas and electric bills for a large house (4/5 bedrooms) they are at 19000 kWh and 4900 kWh respectively. Annoyingly, there is no representation of the standard deviation in the figures quoted so it's difficult to understand if our estimates/usage are within normal range, but something tells me our gas usage shouldn't be 5000 kWh greater than the average large house when we are a small three bedroom flat.

Some further details:

• We've replaced our boiler in the last year. The old one was pushing 15 years of service and we were probably lucky if it was operating at 50% efficiency. We've replaced it with an Ideal Logic+ Combi boiler that is probably in the region of 90-99% efficiency. So why hasn't this decreased our gas usage?
• The flat is not well insulated given the age of the building and the doors and windows probably let out a fair bit of heat.
• The thermostat is currently programmed to 21.5C for 1h20m in the morning and 21.5C for 3h30m in the evening on weekdays, and 21.5C for 1h30m in the morning and 21C for 3h in the evening on weekends. The remaining time it is programmed to maintain an ambient temperature of 18C in the flat.
• We probably have a thermostat schedule running for 5/6 months of the year, throughout the rest of the year it is likely to be off.
• We have a gas cooker.

I don't feel as if our heating programme is that liberal, perhaps I am wrong. Could anyone help explain why our gas usage is coming in so high, and why it seems to be increasing despite a much more efficient boiler being installed? Or is high gas usage just something that we have to get used to if we want to heat a basement flat in an old Georgian building?

dogshome

Hmmm - In an old Georgian building conversion, chances are that the occupier in the flat above you is complaining of being too warm and opening the windows in Winter.
Not a lot you can do about that, apart from insulating all the ceilings


However, how many people in residence ?
The leccy bill seems high.

System

Welcome to the forum. It is unlikely that your old boiler was as inefficient as you think. What size of boiler in kWs did you have before and what is the output of your present boiler? I suspect that it has a higher output than your old boiler.

Your ‘problem’ is your usage pattern. Modern condensing boilers are efficient because once a property is up to temperature the boiler output falls. Some modern boilers modulate down from, say, 24kWs to 4kWs. This will not happen if the boiler is trying to get a house up to temperature of 21.5C in 1hr 20mins: the boiler will be running at max output, and doing the same later on in the day - particularly, if your flat is not particularly well insulated.

Bigphil1474

Hengus, the OP said 'The remaining time it is programmed to maintain an ambient temperature of 18C in the flat'. So even when the programme kicks in, it's only heating from 18 to 21.


Op, I think that may be your problem. Presumably it is off at night? If you are saying it is constantly set to maintain minimum 18c 24 hours a day except for 5h a day, that's a lot. My annual gas usage is around 12,500kWh in a 3 bed mid terrace, we have the heating at around 19c for an hour in the morning and a couple of hours in the evening, the rest of the time it's off and it's an extra jumper time. Given most of your gas usage is in the winter, yours will be running all the time possibly from early October to April time. Unless I'm reading your message wrong. I'd suggest you have it set to keep ambient above 5C except when the programme kicks in. There are lots of discussions about keeping heating on all the time vs off/on and which is cheaper, but aiming for 18c all the time is having the heating on IMO. If you need it at least 18c during the day, then your gas use is going to be high surely, and your figures sound about right.

why_so_serious4

Thanks all. There are just three of us living here.

Perhaps we are more liberal on the OP than I thought. I'm currently at home during the day and already have to stay pretty wrapped up even maintaining the 18C.

The max output for our boiler now is 30kW. ]. Sorry but I'm not sure on the specs for the old one.

I think I'll put our max temp down on the programme and see what difference we see.