Central heating & Gas fire - best economy?

martyp

Hi all
Can anyone advise on what the comparison of gas usage is between a gas fire in the living room and putting central heating on (combi boiler).
To save on the amount of gas used at the moment, I have the gas fire on in the living room and stay in that room with the doors closed. If I go elsewhere in the house it's noticeably colder (down as low as 14C). Just before going to bed I'll switch the central heating on for about 30 minutes to give the house a quick warm up. The central heating doesn't usually get turned on unless I'm doing things in other rooms.
I even wash my hands under a cold tap and try and use hot water as little as possible.
Am I actually saving money doing it this way by only using the central heating for a brief period each day? I'm not sure how much more energy is used with central heating or if it's bad to only put it on for a short time rather than for a few hours?

dooby

I'd try it different ways and do a meter reading at the same time everyday/every few days after each test to see how many unit things you are using.

I'm currently keeping an eye on my gas and electric readings and it's quite interesting i'm finding.

MarkyMarkD

I would expect that martyp is actually spending a similar amount by operating as suggested, but having a less comfortable house.

When I last looked at the figures, the surprising fact is that individual gas fires are very inefficient compared to a central heating system with radiators.

If you were not turning the heating on for 30 minutes anyway, I'd suggest that you were maybe saving some money - not that much, but some - but having a lot less comfort. But doing a combination is almost definitely more expensive than simply using the heating all the time.

If you have rooms you don't use much, turn the radiators in those rooms down. And use the central heating!

(It depends how good your central heating boiler is, and conversely how bad your gas fire is. The only reliable method is to do one day one way, and one day the other way, and read the meter each time.)

martyp

Thanks dooby, I currently take readings about once a week and put them into a spreadsheet. The graphs really show a big difference between winter and summer usage. Electric seems to go up noticably as well in winter although I don't use any electric heating. I can only guess it's the electric shower needing to work harder to heat the water and also the water pump for the central heating? Christmas lights too...

martyp

Thanks MarkyMarkD, I really wasn't sure how the two methods compared. I'll turn the radiator off in the spare room I think as I don't go in there much. It's still nice on a cold morning to go down and sit in front of the gas fire for a bit to warm up quickly.
I'll see how things go using the central heating more.
How is central heating with regards to long or short periods of usage? I mean does it peak on the amount of gas used when it's switched on and then reduce as it stays on for a while, just to maintain the heat? I'm wondering if it has to work a lot harder if only on for say 30 minutes compared to 3 hours?

MarkyMarkD

Yes, as you say, your CH will use a lot more gas when first switched on in a cold house than it will once a "steady state" is reached.

But it's still cheaper to use it only when you need it, rather than to leave it on 24/7.

What I was getting at was that your 30 minutes before bed is costing you quite a lot per minute. It would be more efficient to have that 30 minute boost at the start of the evening, then just a little cost to "top up" through the rest of the evening and not bother with the gas fire IMHO.

talulahbeige_2

martyp wrote: »

. Electric seems to go up noticably as well in winter although I don't use any electric heating. I can only guess it's the electric shower needing to work harder to heat the water and also the water pump for the central heating? Christmas lights too...

Remember that your household lights are on a lot more in winter too due to dark nights