Energy myth-busting: Is it cheaper to have heating on all day? 4 December 2012 at 7:43PM edited 30 November -1 at 1:00AM in Energy 1.1K replies 161.7K views

macman

elcid1 wrote: »

I am away for 2 weeks over Christmas and been advised to leave my new Vaillant condensing combi on permanently but with the room stat in my hall set to 10. My frugal mind says leave heating set to come on 8a.m. to 10a.m. early morning and say 11p.m. to 1a.m. at night. My house was flooded 2 years ago due to old system having storage tank in the loft and I was away at Christmas for 2 weeks having left heating set as above, but it was not enough to protect pipe above loft insulation. New boiler now so that cannot happen again but which setting is advised. Plumbers all say leave permanently on but 10deg.on room stat.

Combi = no loft tank, so nothing up there to freeze. All new boilers have a frost 'stat anyway, which should kick in at around 10C-consult the manual.

amiehall

You want the boiler to kick in whenever the temperature in your home is low enough for there to be a risk of your pipes freezing no matter what the time of day. This is clearly most likely to be at night.

wiggers

Interesting that the 'Myth Buster' just seems to express a general opinion. No qualifications are given for the type of structure, type of heating system, occupancy patterns nor any evidence of controlled tests to prove what they are saying is at all accurate. Also, drying clothes takes the same amount of energy to evaporate the water regardless of whether you are using a tumble drier or your central heating system. (Assuming it is too cold to hang outside.) More important to make sure the spin cycle removes as much water as possible before you start drying. As other posters have pointed out, if you don't have trickle vents on your double glazing then hanging to dry indoors will cause condensations problems, which will also make the house feel colder when the heating comes back on. All the water that has condensed back onto the walls will have to be evaporated again.

Herongull

howee wrote: »

But it's not running all the time that's the reason my bills are low £56 per mth (4 bed detached 10yr old), the heating only kicks in if its needed, I was in on Sunday and the heating never kicked in. The same applies at night it does not kick in unless its bitterly cold outside. The digital stats are fantastic as the temp only has to vary by .5 degs before it cuts in which means you don't get variations in temp like you do with an old mercury switch type.

Of course if you prefer to go cold before the heating comes back "only another hour throw me a blanket" then that's fine but not for me.

Sounds like there is something wrong with your meter. The gas company will end up chasing you for the arrears.

My house warms up really quickly when I turn the heating.

Improve your insulation if you have a problem with rate of heating or perhaps your boiler isn't up to scratch?

Wasting energy as you do is not environmentally friendly:(

Herongull

hansonaj wrote: »

"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!:)

This implies you have very poor insulation, so the heatloss when the heating is on is very high:eek:

You probably just had a mild year when you did the comparison.

Herongull

lisa701 wrote: »

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.

It is not a "theory"! It is a myth.

Your "test" just happened to involve a week of milder weather.

Herongull

The logic is really simple, so can't understand why anyone even thinks of doing unscientific "tests".

Heat loss to outside = money (and energy) wasted. Anyone disagree with this?

Heat loss is minimised when:

1/ insulation is good. Anyone disagree with this?

2/ The difference between inside and outside temperatures is less. (Greater heat loss on cold nights. Greater heat loss if you heat the house to higher temperatures). Anyone disagree with this?

Therefore if you only heat the house when you need the heating on (ie when you are home and awake), you greatly reduce the heat loss.

Always have the heating off after you go to bed, because warm house and cold nights = very high heat loss. Keep the heating turned low in bedrooms when it is on, and get yourself a lovely John Lewis 13.5 tog down duvet:j

hansonaj

So there is evidence , gas usage a bill costs that show the myth is actually a reality.

From what hmbeez states the science would definitely imply it is only a myth for certain types of houses.

Would have thought the energy saving trust should know these details.....

hansonaj

Herongull wrote: »

This implies you have very poor insulation, so the heatloss when the heating is on is very high:eek:

You probably just had a mild year when you did the comparison.

Yes poor insulation....but it is 100 year old house and there is only so much that can be done...

From my recollection last year was not a cold winter and comparable to the year before......

I would say this is just not an easy one size fits all myth to bust.

macman

The myth can only be a reality if your house is 100% insulated-which it can't be. If it was, you'd only ever need to heat it the once!