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False economy ?

Community Veteran
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False economy ?

Normally we switch the central heating off when retiring and have it set to come on automatically 30 minutes before we get up but it was so cold the other night so we left it on at a lower setting.
That got me wondering if it was false economy to switch it off at night as it has to heat up the house from a fairly low temperature if it's been off all night.
Does anyone know for certain what is the best thing to do and do you leave your system on all night (set at a lower temperature) ?
We have all the usual recommended insulation so that side of things is ok.
21 REPLIES
Community Veteran
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Registered: 12-08-2007

Re: False economy ?

An ex business colleague of mine always left his heating on 24/7 and said it saved him money.
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Re: False economy ?

Artmo,
Thanks for that, hope I get a few more responses from members of the forum as I will base my decision on what I should do.
With the cost of fuel these days this topic should be an important one for most people.  Smiley
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Re: False economy ?

The lower the temperature inside the house the lower the rate of heat loss. It will use less fuel to get it back up to temperature than leaving it on all night. A compromise would be to set it really low so that it's really just background heat - say 55-60oF which then wouldn't use too much overnight.
jelv (a.k.a Spoon Whittler)
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Re: False economy ?

I have just started monitoring my heating - electric - and first indications are that the initial heat up from about 4.30am takes about 2 hours and after that the energy usage drops for about 30 minutes and on for 30 minutes until it switches off at 9.00am
The reason for this check is that I am on cheap rate electricity until 7.30am and I wanted to see what was the best time to start the heating (note that the house is very well insulated so doesn't cool down too much over night and each room is individually thermostatically controlled)
In my case the night period is automatically at a lower temperature but sufficiently low that it normally never cuts in (it isn't controllable as it is a fixed set back in the thermostats)
This doesn't really answer the question but the first thing to check is how long the system takes to heat up the house to the point where the thermostat cuts it off and whether during the over night period the temperature drops so low as to cause problems.
Fundamentally having heating on all night at normal temperature is definitely not cost effective. Running it on low over night probably doesn't affect the overall cost much (if it is controlled) and could reduce the heat up time in the morning.
The quality of the insulation in the house is almost certainly the biggest factor and also whether the water pipes in a radiator system are fully lagged as keeping the hot water circulating round with individual thermostatic control on the radiators will definitely cost money the extent of which is governed by the heat loss from the pipes.
To finish - if the boiler is controlled from a master room thermostat then the loss caused by running over night at a lower temperature setting may not be important but if the boiler is only controlled via the boiler stat with individual radiator controls then it would be as the hot water would be constantly circulating
DaveyH
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Re: False economy ?

We started leaving ours on 24/7, though its set low (11C) overnight and when we're out.
Our usage hasn't changed (easy for us to monitor as we have a pre-payment meter) from when we had it set come on before we got up, and go off before we go to bed.
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Re: False economy ?

An ex work colleague of mine had his heating on 24/7/365 and claimed to have small bills.
It sounded crazy until you realise that the thermostat keeps the heating off most of the time.
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Re: False economy ?

It would have to be a well insulated house so the heat loss is low to keep the bills down. The worse the insulation the more the difference in cost if you run it overnight.
jelv (a.k.a Spoon Whittler)
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Re: False economy ?

Our heating is on 24/7 with the thermostat set at 13oC. Occasionally we have turned it up to 15oC, but even then I have the combi boiler set so that a 20oC maximum can't be exceeded by the remote thermostat. Found that this not only works out cheaper, but the house is kept at a pleasant (well for us anyway) temperature. The system also as an external thermometer so that the heating wont come on if there is only (I think) 1oC difference between inside and outside temperature.
nadger
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Re: False economy ?

Our heating is on 24/7 but is turned down slightly when we go to bed. Hot water set to run for couple of hours twice a day.
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Re: False economy ?

Quote from: jelv
It would have to be a well insulated house so the heat loss is low....

My house has double glazing, cavity wall insulation and below recommended minimum loft insulation.
Last night the living room temperature dropped from 200C to 150C.
The outside temperature dropped from -40C to -60C
Just for reference.
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Re: False economy ?

Quote from: Strat
Quote from: jelv
It would have to be a well insulated house so the heat loss is low....

My house has double glazing, cavity wall insulation and below recommended minimum loft insulation.

Get that topped up to 300mm (12 inches) if possible, payback in fuel savings is very short.
The worst 'false economy' with heating is switching it off of you go away in the winter and return to burst pipes.  Even sustained low (non-freezing) temperatures can promote dampness and be damaging to both building and contents.
Call me 'w23'
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Opinions expressed in forum posts are those of the poster, others may have different views.
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Re: False economy ?

Appreciate the advice w23 but there is so much rubbish up there that's there no room for insulation.
It is however work in progress.
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Re: False economy ?

Quote from: Strat
there is so much rubbish up there that's there no room for insulation.

Same here, but our loft is also mostly boarded on top of the insulation which should improve things, as do all the boxes full of "stuff".
In reality we don't have any significant heating on upstairs (bathroom only) and the temperature is more than adequate.
We even have windows open in our bedroom at night, though not so wide when it's -6C like last night.  Crazy
James
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Re: False economy ?

My other half has been told by her builder (who is a friend) that it's more efficient to keep her heating on at a lower level than to reheat the house.