Leave boiler on or not

[Sean-edwards]

Ive been told that when you switch on your heating and it gets to temp you should leave the boiler on so it just tops the heating up a bit when the temp drops instead of heating the house then switching it off. I thought this would use more energy leaving it on cause its on for longer. Anyone have any idea?

[big-all]

you will probably now get several pages off contradictory information

the only way to know is with simillar weather temperature and house use over say 5-10 days try the heating all the time
then the once or twice a day method
making sure you read the meter daily and record the outside temperature and solar gain
i personally vote for letting the house cool down in the middle as you dont need as much heat when your active

[dewaltdisney]

I have left my heating on 24/7 for quite a few years now and my bills have been consistent. However, I have cavity wall and roof space insulation, good double glazing so heat loss is reduced plus I have a condensing gas boiler. I follow the view that the house is always warm and the boiler just kicks in as needed. I adjust the thermostat down to suit at bedtime and when we go out. However, we are at home a lot so it works for us.

DWD

[Chappy]

It all depends on how good your insulation is.

[lockie]

Heating a house is one thing but keeping it warm is another subject. Ours stays very warm due to the amount of insulating i have done. Our heating goes on at 6.45- 8.15 then 12.30 - 13.00 and finally 17.00 -22.30 and its always warm with the thermostat at 19 degrees. I can get in at 2am and the lounge is nice and cozy even though the heating went off at 22.30

[Retired]

Hi,

Good question S-e and well timed for winter.

We live in a detached bungalow with double glazing and 12" thick loft insulation. We are located on a steep exposed valley side subjected to extremes of weather. I too read that it is better to leave the central heating boiler switched on so tried it; I sure became very hot as I watched the meter each day and reverted back to switching the boiler on as required; We have frost stats so are protected against freezing and only being the two of us we don't use all our rooms.

I now work on the principle if the boiler is turned off its not costing anything. At night we find an electric blanket to be luxury because the blanket heats us not the room meaning the boiler is off all night every night; it's an all night under blanket bought from Argos.

The most accurate way of testing is to do a comparison; leave the boiler on and watch the meter but then even this isn't perfectly accurate because outside temperature are constantly changing but it will give you a good idea as to costs?

If the utility bills keep rising the way they do I think it will be cheaper for us all to move over to Hawaii for six months each year; in my dreams.

Kind regards, Col.

[BillyGoat]

I hang my head in shame here, but I don't have any idea what my bills are - I've not checked in over a year. Literally not a clue.

Our heating was off for about 7 months (a broken DV valve helped.... ) and since it's been back on, it's on timed - but ONLY for the temp. It's actually on 24/7.

Our house has every external wall internally insulated, loft insulation and double glazing - it takes VERY little time to get the house up to temp and and the boiler doesn't work hard or often long. It's set to 19 during the money and evening time. The rest, it's set to 15 degrees.

We've got Hive heating control, so if we wanted too we could turn the proximity feature on, so when we leave the house, the heating is turned off automatically and on again when we are getting close home. Doubt it though.

[big-all]

i live in a mid terrace double glazed virtually no loft insulation no cavity wall insulation
heating hasnt been on since sunday and its around 18 degrees in this dining room outside is 8 degrees and raining
i have a lap top a tv led bulbs then in the open plan to the kitchen part with a fridge freezer a freezer and a cooker that gets used 2 or 3 times a week for bulk cooking but thats it

yes the rest off the house is colder but i only spend a few mins in those rooms lol

now the point i am making is i could have the heating on twice a day or continuouse but most would be wasted as firing it up as i feel the cold must be the most efficient in my case
and when i do fire it up its only usually 40 mins which is enough time to give hot water for 2 showers

[BillyGoat]

Uneven heating for a house can be as bad as no heating though.

If there is not adequite ventilation though, then people might suffer cold spots and damp - the building fabric is colder, so when heat is introduced quickly it causes issues.

I'm happy to pay for the heating to be on and not suffer any problems with my odd and sporadic use of my house.

BG

[big-all]

i make sure the whole house is aired and heated ever week or two
but it never drops below about 10 or 12 or the radiator valves will kick in

[Megaross]

I wait until my hands turn a funny colour then I flick it on for an hour or two, heating bill is super low.

[BillyGoat]

Just checked my gas and electric readings, as I realised it was a while since I last done them. Logged in (eventually) and it's been on estimated since before Jan 2014, which is as far back as it goes.

I'm paying 111.90 a month combined gas and electric. Someone is ALWAYS in and there is lots of stuff running (computers, etc) so I was expecting it to be quite bad.

Looks like I'm about 180 IN credit but final reading will come on December 12th. I'll continue to ignore it for another year now and leave the heating on 24/7 as I have been doing....

BG

[kellys_eye]

There is no difference.

The heat loss from a building remains constant. It loses heat at the same rate no matter what it's instantaneous (i.e. 'now') temperature is therefore the amount lost by switching the heating off will be the same as that needed to heat it back up. 2nd law of thermodynamics (don't ask..... google it of you MUST know but heed a 'geek warning' before you do).

The only time you 'win' is when the temperature of the building falls to a level where it cannot go any lower - at that point you reach an equilibrium that doesn't require energy to match.

So, if leaving your house for a length of time sufficient for it to fall to its minimum temperature and REMAIN THERE you will SAVE energy by not keeping the heating on.

If, however, you don't leave the house that long then it makes no difference whether you leave the heating on or off - energy consumption-wise.

SIMPLE ANALOGY

You have a barrel (house) that you fill with water (heat) from a hose connected to a tap.

The barrel has a tap on it that is open a certain amount - the dribble of water (heat) leaving the barrel represents the heat being lost from the body of the barrel (house).

To keep the house at the same temperature the tap/hose must feed the barrel with exactly the same amount of water as is being lost by the tap at the bottom. Too little going in at the top and the barrel will empty (cool) eventually. Run the tap too fast and yo overheat (overfill the barrel and waste heat).

Now imagine switching the heat off (i.e. turning the tap off) BUT instread of turning the tap off we move its hose to let the water fill a spare bucket we are keeping beside it.

The barrel (house) will gradually cool (empty) but the spare bucket will carry on filling. AT ANY TIME you could take the contents of the bucket and pour it into the barrel and bring it right back up to the 'full' level. The bucket will contain exactly the same amount of water as has been lost throught the barrels tap being left open.

[wine~o]

2nd law of thermodynamics

But doesn't Golpalott's third law contradict that ???

[kellys_eye]

Not as much as 'erindoorsalot' law does.