Keeping heating on 24 hours to save energy

saveallmymoney

Cardew wrote: »

Boilers modulate their output. It could run 20% more of the time at low output and be cheaper, or 20% less at a higher output and be more expensive.

Not my boiler, its not condensing either.

I have extensive monitoring (IT and home automation geek).

I'm not saying its cheaper to run it all the time, just surprising how close it is so i can forsee that in some very limited circumstances for some people it might end up cheaper.

matelodave

Lurker21 wrote: »

My boiler serves the central heating and hot water.

A couple of years ago I turned the boiler temperature down as suggested above. But for some reason the pump kept running all the time.

It turned out the thermostat on the hot water cylinder was set higher than the boiler temperature, so the pump kept trying in vain to get the cylinder up to temperature.

There is always a danger that the boiler or radiators can't produce enough heat to operate the thermostats and so runs continuously - that's what happens if you've got undersized boilers, radiators or the thermostat set incorrectly or located in the wrong place. It can also happen if you turn the boiler temperature down too low

Robwiz

Heat lost from your home is proportional to the temperature difference between outside and inside. It's coldest over night so there's little point in heating unoccupied rooms when the fabric losses are at their highest.

The only justification for running a setback temperature (say 14-16º) is when using low grade heat from an air source heat pump that would struggle to close the temperature difference quickly.

MillicentBystander

JJ_Egan wrote: »

You should really think about that as they are not comparisons .

A car has a purpose of movement not of being warm.


CH has a purpose of warming not moving .

And maybe you should also think about it .;) They are not massively different in the sense that houses and cars both consume more fuel when started from cold but no-one in their right mind would leave a car's engine running 24/7. Geddit?

C_Mababejive

Its really simple. Heating on> meter turns>££££

Halle71

I am pretty sure that in our draughty, Edwardian, end of terrace which is left empty for 10 hours at a time and only half occupied when we are there, it would be significantly more expensive to heat 24 hours a day. But in my parents house that is 3 years old, insulated to current building regs and has an efficient heating system it would be cheaper to keep it on all the time, especially because they rarely leave for more than 3-4 hours.

teabelly

One other strategy if you have a boiler timer with the mechanical pins is to set it to come on for 15 mins (or whatever the pin time is) every 90 mins or so and shorten the blocks in the morning and evening as the temperature hasn't fallen back so far. I found it quite good in the colder weather. House seemed warmer and the gas usage wasn't noticeably more. No thermostat, TRVs on the radiators and a normal non condensing boiler.

It's another strategy for comparison which is in between leaving it on and turning it off.

matelodave

The only way is to try it for a couple of weeks as normal and another with it on all day keeping a careful daily record of the meter readings (and ideally the outside temperature) to see if there is any appreciable difference in both your consumption and comfort.

You could try a programmable thermostat to turn the heating down three or four degrees, rather than fully off during the periods you don't want full heat. That would prevent the place from getting stone cold and would give you more control.

A wireless one can be shifted around to find the best place for it and it will allow you to programme several different temperatures at different times of the day and even on different days of the week.

These work well (http://www.amazon.co.uk/Salus-RT500RF-Programmable-Frequency-Thermostat/dp/B003ERP1LE ) aren't expensive and a reasonably competent DIYer should be able to install it. The receiver unit is installed next to the boiler to make cabling easy and the thermostat unit can be anywhere you like - ideally in one of the living rooms rather than the hall.

Pincher

I have no ON/OFF setting for my programmer.
There are only two possible states: ECO(=OFF) and COMFORT(=ON).


In winter, the house may fall down to 14 degrees (but more like 15~16) during the day if no heat is applied. If I set ECO to 12 degrees, the boiler will not come on.


Even at ECO=16, and COMFORT=18, my consumption is nothing extravagant.


As the boiler has to heat the hot water cylinder in the summer, the system is still on 24/7. Obviously you just set COMFORT AND ECO to 12.


So, you can tell the Kiwi (bird brain) that the central heating IS ON 24/7, but set the ECO to 14 degrees, and everyone is satisfied.

macman

Halle71 wrote: »

I am pretty sure that in our draughty, Edwardian, end of terrace which is left empty for 10 hours at a time and only half occupied when we are there, it would be significantly more expensive to heat 24 hours a day. But in my parents house that is 3 years old, insulated to current building regs and has an efficient heating system it would be cheaper to keep it on all the time, especially because they rarely leave for more than 3-4 hours.

No it wouldn't. If their modern house was 100% insulated (impossible) and never lost any of the heat produced, then it would cost NO MORE to leave the heating on 24/7. Never less. Basic thermodynamics.
PS: any comparison over, say, two weekly periods is entirely flawed, because for that to work, the ambient temperatures would need to be the same across the two test periods, which they will not be.
As usual on this topic, people confuse comfort with economy. Post 16 sums it up, really.