Central heating query

[tigwig]

Not sure which section to put this in really but I am just wondering is it more economical to have the heating on at a set temperature throughout the day (say around 18-20) to keep the house warm or to only have it on when I am in. This means turning it on and off several times and obviously the house getting really cold after a few hours then having to have the thermostat higher.

[tezestwing]

Hi I think you will find quite a varied response to this one not forgetting the going to bed one
I personally prefer to keep the boiler on at all times and use the room stat to control the general heating when going past it about 18/20c cold days occupied 10c when out 10/15c at bedtime but also use the TRVs for the finer bedroom temp and north facing windows hth Tez

[tezestwing]

BTW condensing boilers work most efficient when they are full on hth

[Iggle Piggle]

I have a digital thermostat that varies the temperature at set times through the day/night. I have this set to 17 degrees from 12pm to 6.30am then 21 degrees in the day. I think there are about 6 settings on mine and it cost about 28 quid.

[Hymie]

I blame the countries physics teachers for so many questions similar to this being asked – and so many offering the wrong answer.

It is most economic to have the heating off at times that you are not in the house. This may require a sudden boost of energy when you return - but how do I know this will be less than that used to maintain the house temperature (or even a slightly reduced temperature), while you are out?

The simple answer is that with the heating off, the internal house temperature will cool, once cool (and even during cooling) the loss of heat energy (through the walls/ceiling) will slow due to a reduced thermal gradient (across the walls/ceiling) – eventually dropping to zero, when the room and outside temperature reach equilibrium. With the room temperature maintained at 18-20ºC, the thermal gradient will be much higher, with a constant (higher) heat energy loss.

I know people who have their immersion heater (used only for bath water) on 24/7. Believing it to be more efficient than turning it on only when they want a bath. Although I suppose one advantage is that they don’t have to wait an hour for the water to heat up.

[scotman]

Like most questions of this nature it depends.
Mostly it depends on the quality of insulation in the house, the better this is the less heat is lost and the difference between the options diminishes. Also depends on the 'value' you place on not having to wait for things to happen.

[buildersmate]

Very well explained Hymie. I don't have the patience with this one any more.