How best to run central heating this winter?

darknite

darknite

darknite

Associate
Joined
9 Jan 2010
Posts
1,379
Location
Norfolk
Ok i've been talking to everyone about this issue the last few weeks. Different views from a lot of people. BUT this year I bought a new Bloor Home. With it was a nice full guide on do's and don'ts in a new build house. Example don't lay boards in the loft. . . didn't know that one. Again BUT they gave a suggest use guide for the central heating. In it they suggest keeping the heating on all the time, setting it to 18 or 19c at times you are not at home, and 20 - 21c for times you are at home. They claim it is more energy efficient this way, and the system does not have to work so hard heating the house from say 16c to 21c.

Google searching this issue, majority of people say TURN IT OFF when you don't need it, IE not home. This goes against the builders advice.

Currently I have the system come on at 5am, warm up to 20c, keep at 20c until 8am. Then drop to 16c until 4:45pm then heat up to 20.5c until 10pm.

What do you guys think is best? What do you currently do? Always on? On only when needed? Different temp rads upstairs to down?

I have been wondering about keeping the heating on all night, 20 - 21c while we're at home and awake, then maybe lowering that to 19c ish while sleeping?

Be interesting to see what you all do! New build homes and older.

For extra information my current home is a 4 double bed detached house, with an EPC rating of B 83. My current electric and gas bill combined is £56 per month.
 
Last edited:
There's no way that keeping it on during the day is more efficient than just having it on when you need it. It's a total myth.

Imagine a pan of water - would it use more energy to boil it once in the morning and again in the evening, letting it go cold in the middle, or keep it warm during the whole day?

It takes, what, 30 minutes to heat a modern house from cold? Not a lot of energy wasted there.
 
I think it really depends on how energy efficient your property is.

I rented a room in a newish house a few years back that would never seem to go below 18 degrees even with the heating off in the middle of winter, so we set the target temp to 19 degrees and it barely ever needed to come on.

My parents house on the other hand seems to bleed heat and I would agree that never turning it off would be better to prevent things getting too cold. Unfortunately my parents are tightwads and only have the heating on for 1 hour in the morning and 1 hour in the evening and for the rest of the time the house is freezing. They then wonder why the have a problem with damp in the house!
 
New build? Should be thermally efficient and thus you can heat the house quickly and it will stay warm.

Doesn't work in our house though! Old house, and even with effort still leaks heat rapidly, so we have heat when needed but never off for long periods because if the house gets proper cold it takes a lot to get it warm again.
 
My house is pretty well insulated, I always turn the heating off when I go out. It takes about 15 minutes before the living room is warm if I set it to manual, but when I'm in, Auto is set for 18 degrees. Don't understand how people can handle having their heating at 23*C or so :eek:

Energy bills are nice and low.
 
Put it on when it's cold and turn it off when it's hot, I haven't used mine yet this year.

I love cold weather, warm just makes me tired and achy.
 
This morning was about 1 or 2c outside. The house took about 40 - 45 minutes to warm up. From around 17.5c to 20.5c. Though I am unable to close most of my doors down stairs at present due to boxes and items waiting for collection etc. That makes a big difference.
 
I don't bother with heating in the morning as a bit of a chill does no harm if you're getting ready to head out the door anyway. If the temperature drops sharply, then it would come on around 6:30 so the edged is taken off for when I get up around 7:30.

In the evening it kicks in about 5pm as I get home at 6pm. It goes off at 9pm and thereafter if I am chilly, I wear a jumper. There is no sense burning gas till I go to bed.
 
We barely use the central heating, if its cold enough to need heating the gas fire goes on on the living room. Its very rare we need the whole house heating.

We do have the central heating on in the evening but its set so that it heats the water up for things like baths and washing up, then at 9pm it starts pumping the warmed water around the radiators. This way the heated water doesn't go wasted.
 
I personally would want to set it so its around 18c - 20c when home so would only go on when temperature goes under that. When not at home it doesnt matter and it should keep warm enough till you get home.
We used to live with my partners parents and they never had the heating on other than a while in the morning and evening. I was freezing all the time and the heat didnt really keep in that well anyways.
Now we live in a small flat and all the other flats keeps us pretty warm. I have heating on maybe 1h every 2 days unless its really cold day and it keeps quite warm here.
 
cheesyboy said:
There's no way that keeping it on during the day is more efficient than just having it on when you need it. It's a total myth.

Imagine a pan of water - would it use more energy to boil it once in the morning and again in the evening, letting it go cold in the middle, or keep it warm during the whole day?

It takes, what, 30 minutes to heat a modern house from cold? Not a lot of energy wasted there.
Click to expand...
my boiler is temp controlled so during the dat i set it to 12c.

house never goes that cold for the boiler to come on
 
darknite said:
setting it to 18 or 19c at times you are not at home, and 20 - 21c for times you are at home.
Click to expand...
That's what we do. Timer controlled for 6:30am-9:30pm and then 18C on the thermostat if we're out and 20C if we're in. That said my walls have been recently done and I insulated the loft to hell and back, so the boiler doesn't fire up that often.

That's not for efficiency reasons, it's just we don't like coming into a house that's under 18C :p
 
This is the theory behind the "keeping your heating on all the time" theory...

If you turn your heating on only when you're cold, it takes a long time to heat the house up because you're attempting to go from cold air to warm air, which takes a high input of energy. This means that your boiler has to work very hard for a short period of time (say 4 hours for an evening) to make your house warm.

If, however, your heating is at a low temperature all day, the delta T (temp. difference) between the cold air that you have in your house, and the warm air that you want is much lower. This means that when you turn the up higher the air in the house (as well as your radiators) takes much less energy to heat up.

OK, there's an argument to say that both instances require an input of energy. Evidence shows that the latter situation uses less energy, and provides greater comfort.

If you're willing to spend a little money, weather compensation is certainly the way forward as it reads the temperature outside the house and compensates inside accordingly.

If you want to go even further into it, you could try lowering the speed of the pump in your house (if you have a variable speed pump) and then having a flow temperature from the boiler at 70C. This lower temperature (normally flow at 80-85C in the UK) means that firstly, less energy is required to reach your set point temperature. Secondly, if your water is flowing at a slower speed through your central heating system, there will be a much greater period of time for the energy to transfer from the water into the room. Your return temperature to aim for, then, would be about 40C. Normally in the UK systems flow at 80C and return at 60C. That means that there has only been 20C worth of energy used (essentially), which is very inefficient. There is absolutely no need to run at such a high flow temperature. To put it into context, throughout Denmark they run at 50C flow and 20C return!

In turn, this can produce a huge amount of saving.

Source: I work for a company called SAV Systems who are attempting to lead a heating revolution in the UK. We have brought many consultancies over to our way of thinking, which basically encourages less waste in central heating systems. We try and run everything by Danish methodologies, which are highly energy efficient compared to that of the UK, and most of the world.
 
The control box on my wall is technically always on. it wont let the house go below 16c. Then I can set up to 4 times per day when I want it warmer. There is a page in the house guide about this helps prevent damp issues etc etc. I do however turn of the heating on the boiler over the summer and just leave hot water on.

I think i'm going to try keeping the house warmer over night. Wont let it go under 18.5c maybe, 19? Then allow it to drop to 16c during the day when the house is empty. Will see what my bill changes too!

Plan 4:45pm - 10pm 20.5c, then 10pm til 5am 18.5c, then 5am - 8am 20.5c, then 8am - 4:45pm 16c. It takes that long for my lot to actually leave the house! All leave for work at different times.

Worth a shot!
 
Basic thermodynamics say that heating on all day uses more energy than it only being on when you 'need' it

Especially in a old house which loses heat very quickly
 
Simon said:
Basic thermodynamics say that heating on all day uses more energy than it only being on when you 'need' it

Especially in a old house which loses heat very quickly
Click to expand...

Why do you think that? If it's on low ie radiators are tepid, that's not necessarily true. You are attempting change a much greater delta T if you have the heating on just when you need it, which requires a lot of energy.

Out of interest, are you in HVAC? If so, I have a very interesting guide for you to read.
 
I currently run our heating at 20.5c during the day 05:30 to 22:00 with a set back of 16c overnight.

We recently replaced our heating system and went with over sized radiators in combination with weather compensation to keep a low flow/return temperature even today where it was -1 this morning the radiators were ticking over with a flow temp of 53c.

A modern boiler only condenses when the return temperature is under 56c so due to the old design of systems that initially had non condensing boilers they ran at 70-75c with a flow/return differential of 11c rather than a modern condensing boilers 20c. If you run a modern boiler at 75c in these systems without either rebalancing the radiators and/or oversize them the boiler will never go into condensing mode which can give you an additional 10% in efficiency.

Taking into account the milder winter our system is saving around 30% compared to our old system, actual gas usage is down 49%.
 
You must log in or register to reply here.
Back
Top Bottom