Energy myth-busting: Is it cheaper to have heating on all day? 4 December 2012 at 6:43PM edited 30 November -1 at 12:00AM in Energy 1.1K replies 159.5K views

hansonaj

"Should I leave the heating on low all day, or turn the thermostat up and down?"

A heating engineer told me this once and I also thought it must be rubbish and a myth.

Yet I disagree with this myth being busted....and agree with those who say it is true.

Why ?

Because I installed a thermostat in my house and over the year I used less gas than previous years , as calculated by the meeting reading i take monthly

......AND we actually had a warm house.

Living in a large old house and having tje heating on a timer morning and night just meant years off cold. By the time the house had heated back up in the evening it was time to go to bed.

So for me the boiler running full on twice a day for 3-4 hours (yes it can take that long to heat up the house in winter), versus once for 3-4 hours in the morning andthen as needed seems to make sense to me. And my figures agree.

Maybenit is down to the age of the house, the insulation (I can mot have cavity wall insulation) etc. Rather than a blank myth or no myth!:)

hubb

2010 wrote: »

If it`s on it uses energy, if it`s off it don`t.

Exactly. I only turn our heating on here and there when we are home in the evening (I work from home in the day but choose not to have it on as the small studio bedroom's electronic gear tends to produce heat in itself) We have a coal fire lit in the room where we sit at night. The heating, if really cold, gets a few bursts here and there but the coal fire keeps the room warm enough. The kitchen has no rads so it's always freezing (tried to get a few plumbers to put one in but that's another story)

Our heating bill for a 2 bed Victorian semi (just the two of us) is around £760 a year (before the new prices). I bet if our heating was on all the time it would be a lot lot more and we don't have thermostats on the rads (again, for want of getting a reliable plumber who will come back and do the job)

sheffield_lad

oldskoo1 wrote: »

I'm really struggling to believe your house looses no heat at 20c for an entire night when the outside temperature was around -1 to 2c depending on where you live.

I live in an 8 year old 5 bed and my bills are £130 a month in gas at the moment. It seems to loose 0.5c per hour or 2 at the coldest. And at 7c outside it will hold a temperature for several hours.

It seems the low point where heat drop off rapidly decreases for my house is 13.5c in the hall or around 15c downstairs and 16c upstairs. It could stick here for 24hours.

But at 20c surely it's loosing heat every hour? Meaning your boiler is constantly topping up.

I infact run my heating from 6am to 11pm regardless of the day, but no need to have it on overnight.

I turned the stat down last night to 18 degrees and the tepm when I goot up was also 18 deg so if the stat had been set to 20 last night the heating would have kicked in. Its took the boiler 35mins to bring the temp back to 20d. What I am going to do is look how many units I use on the meter over the next 2 nights one running it at 20 all night and one running at 15 (it does not fall below this), and turning up to 20 in the morning.

Bill wise the £56 per month is gas only divided by 12mths so summer and winter use. I am surprised at what you are using as your property will be better insulated and you will have a far better boiler than my F rated balanced flue ideal classic.

nande2000

I suspect this myth comes from contrallabilty and human nature rather than the laws of physics.

What I mean is if you come in from work to an unheated house then the temptation is to over compensate and overheat the house.

Somewhere inbetween on all day and on demand is where the most efficient point is, depending on the thermal mass of your house.

Norman_Castle

Heating engineers install and maintain heating systems. They have opinions, but are not energy use experts.

lisa701

I decided to test the theory about it being cheaper to have the heating on all day. My hubby thought I was mad checking the meter and temperature of each room every day morning & evening.

After a week of it being on timer, and a week of it being on constant I found I used much less gas with the heating on constant. House was a lot more pleasant to be in too.

fagen

During the bad winter of 2010/2011 I decided to experiment and leave the central heating on full time. I had read a few articles by Jeff Randall in the Daily Telegraph saying it worked.

I have individual thermostats and have a policy of closing doors. I was dreading my bill but it was amazing to see that in consumption and price I paid no more than the previous winter. The great advantage too was that I was never cold especially in the morning.

With this system you notice the boiler just kicks in every now and again.

PS Last year I was away quite a bit so can't judge as system turned down and on timer.

notanewuser

hubb wrote: »

Exactly. I only turn our heating on here and there when we are home in the evening (I work from home in the day but choose not to have it on as the small studio bedroom's electronic gear tends to produce heat in itself) We have a coal fire lit in the room where we sit at night. The heating, if really cold, gets a few bursts here and there but the coal fire keeps the room warm enough. The kitchen has no rads so it's always freezing (tried to get a few plumbers to put one in but that's another story)

Our heating bill for a 2 bed Victorian semi (just the two of us) is around £760 a year (before the new prices). I bet if our heating was on all the time it would be a lot lot more and we don't have thermostats on the rads (again, for want of getting a reliable plumber who will come back and do the job)

My bill for last year was £820 - 4 bed detached, 10 years old. That was with the heating on constant.

Previous year, with rads in unused rooms off and heating on a timer - £950.

Hmbeez

If your home is or brick-and-block construction, and is well insulated, it has high thermal mass and will take hours to heat up, but will stay warmish for some time. If it has an inner timber frame, you are only heating up plasterboard, therefore it has low thermal mass, and will heat up / cool down quickly.

For high thermal mass, you should have a step-down or programmable room thermostat, costing about £15, and set it low for night time and when you are at work, and high for when you are in (you can override it for other occasions). This is the best comfort/cost compromise.

For low thermal mass, have the system off whenever possible - it will quickly heat up. A step-down stat is still useful.

If your house is high thermal mass and poorly insulated, it will cost you lots whatever you do. If feasible, improve it!

hubb

Victorian single brick and no cavity wall is what ? Again, not on at all v on all the time doesn't add up to being cheaper on account of using zero energy.