Gas usage calculations and how to manage heating

[Graphista]

I know loads are posting similarly so apologies but I really need help.

I put my heating on about 4 weeks ago, took a reading then and one today. I've used an online calculator for usage price and it's scared the crap outta me! Thankfully I've a buffer of credit with my energy company but I still want to keep costs down while not being too cold and keeping the flat in order (rented, already had an email from landlord re heating needs to be on to avoid frozen pipes etc)

With some trial and error I've worked out during the day 17°c on thermostat is about right for me. But I've not been changing it at night and tbh sometimes I'm getting too warm anyway which is of course daft and wasteful.

How do I work out what to have thermostat at? If turning down for night how?

And can someone help me work out my costs as I'm not sure the online calculator was accurate and I'm not even sure what kind of meter I have for calculations (I can post a pic if needed)

I'm terrible at this sort of maths and find it all incredibly confusing.

Can anyone please help?

For your costs, give us your meter readings and your rate per kwh.
Your gas meter will either measure in m³ or ft³ - it should say which on the meter.

Bear in mind the recent cold snap - I was using about 2x as much gas a day for heating compared with today.

Yes, it's recently been very cold for quite an extensive period, so any form of heating will have been just about as expensive as it could possibly get and you'll likely be paying over 3 times more per unit than you were last winter.

Plus, if you pay by monthly DD, it hides somewhat the variation in cost between summer and winter. Which is a good and a bad thing. Easier for budgeting but, as you have discovered, rather terrifying if you notice how much a month's heating actually costs.

1st reading 7433.25
2nd reading 7549.92

M3 on meter pic

Unit rate 10.277p per kWh (is this correct for cap?)
Standing charge 27.22p per day

It was FREEZING here last week and the cold makes my physical disability worse. So I really can't just suck it up. I've hot water bottles and warm clothes I wear layers bed socks etc but it really was getting too cold to not have it on at all. But I'm also not made of money!

Just want to get the balance right between not freezing and not ending up skint!

I'm away a few days over Xmas need to leave heating on as per landlord instructions to avoid frozen pipes etc but at what thermostat setting is needed?

It's my first winter in this flat too so I don't know what previous costs were.

1252kwh/£128.65 usage plus 28 days standing charge of £7.77 - i make it £136.22

Not sure about the thermostat while youre away - hopefully other posters will fill in there!

Just for context I've had mine on 18 overnight and usually 21 most of tulhe day (COPD) and found that turning it off for a bit then on again actually cost me the same or more.
My usage over the last 4 weeks has been
21/11-28/11: 275kwh
29/11-4/12: 360kwh
5/12-11/12: 360kwh
12/12-18/12: 495kwh
19/12-21/12: 131kwh

It shows you on your bill how to convert between m3 and kWh. On mine it says

m3 x 1.023 x 38.1/3.6 = kWh the 1.023 and 38.1 can vary slightly, but not hugely I don't think.

So you have 116.6 x 1.023 x 38.1/3.6 = 1263 units x .10277 = about £130 plus your standing charge of just under a tenner a month, so say around £140/150 for a month's heating in the worst time of year.

That's not too bad really - there will be people in larger properties paying £500+ over the past few weeks.

Our Hive unit uses 7 C for frost setting, but I'm sure you'd have to have the heating off for days for it to get that cold, or have really terrible insulation. Our heating kicks in overnight if it drops below 15 C and it didn't come on last week as far as I know.

If you have smart meters I'd really recommend using the Loop app to track and cost your usage - loop.homes/

That's roughly what the online calculator made it. I'm £400 in credit with energy company at the moment paying £80 per month each for gas & electric direct debit I really don't want to have to increase that.

Bill says for equation -

Gas units used x calorific value (39.6) x volume correction (1.02264) divided by 3.6

Which may as well be in Klingon for me!

No smart meter as yet need to talk to landlord about this.

If it helps, your property epc certificate should say how much energy it should take annually to properly heat your home

www.gov.uk/find-energy-certificate for England and Wales, for Scotland it's www.scottishepcregister.org.uk/

You should expect heating over the colder months to use about 80% of your annual gas consumption.

And yep that conversion formula's right - it's just a way of converting the volume of gas used from square metres into kwh.

And yep that conversion formula's right - it's just a way of converting the volume of gas used from square metres into kwh.

Ok I've managed to download a pdf of my epc what am I looking for? It was done in 2018 before energy prices went nuts!

I don't understand why meters don't just say exactly what you've used in KWH as that's what everything is worked in

I'm in England, not sure about the Scottish site, but my certificate just shows online rather than a pdf. There's a link at the top that says "Estimated energy use and potential savings" and it takes me to this bit near the bottom of the page

@Graphista if you multiply what you've used in units by 11.25 you will get your kwh of gas. Then Multiply by your price per kwh.

7549 - 7433 = 116 x 11.25 = 1305kwh
1305kwh x 10.277p = £134.11
28 days @ 27.22p = £7.62
Total = £141.73

My heating is off overnight
If going away I'd leave it somewhere around 12-15⁰C I think

Old meters like mine times units by 32 to get khw

newer meters times units by 11.25 to get khw

then times khw by 10p or whatever your rate is

add on sc

then vat of 5%

And @Graphista heating on 11/12 at night unless really cold /want it to come on

OP, we used the same amount in the first ten days of Dec as we did for the whole of November, and obviously last week would have been heavy usage. Now it's warmer, we've just got it set to come on am and teatime.

Regarding heating while you're away, you could either set it at 14/15c so if it gets really cold it'll kick in occasionally which will hopefully help with pipes. If not, we leave ours set for an hour am and pm around 17c.

Thanks for all the replies, I shall turn it down at night to around 15 I think and same for when I'm away and hope that's not too expensive or too cold. Such a minefield these days isn't it?

1 metric unit is 11.187kwh so £1.20 ish.
When it’s above freezing my thermostat gets set to 14° and rarely kicks in overnight, last week I set it at 16° and it was coming on around 3-4am from 18° at 10pm.
I was using 4 units a day last week, 5 if we ran a bath, it’s back to 2 / 2.5 units this week. I’m in pretty much all day currently.

Mine is set at 12 at night / when away. When I’m away I also make sure to leave all the doors open (including cupboards) so there aren’t colder spots.