Cold weather - heating on constant or timer - which is best?

[Mrs_Mcnab]

Hi

After a bit of advice please

With the cold weather we have been having, is it more efficient to have the boiler running on constant to keep the house warm or should we leave it on timer and let the house get cold overnight and then have the boiler burn like mad to warm the house up the next morning?

Thank you in advance

 

[MrTherm]

Loosing overnight all the heat that has soaked and absorbed into the building fabric during the timed day period is a waste, theoretically it would be more cost effective not to loose all that heat.

Having a night time temperature set-back facility would help to maintain some minimal level of heating but that in itself would come at a cost. For example a daily setting of about 20 degress might reduce to about 16 degrees through the night time and only requiring a morning short burst of heat to raise the temp back to 20 degrees.

Some people will not even consider low heating during the night time saying it is not healthy, it is debateable.

 

[JohnD]

theoretically it would be more cost effective not to loose all that heat.

Improved insulation reduces heat loss, but running extra heating increases heat loss (because heat loss is directly proportional to time x temperature difference inside/outside)

So it would be cheapest to let the house go cold when you are not appreciating the heat, and set the timer to warm it, say, half an hour before you get up. However if your home is not well insulated, you may find it gets uncomfortably cold overnight.

I agree with Mr Therm, a good compromise is to set the thermostat to a lower temperature overnight. The boiler will only come on if the house reaches that lower temp. For example mine is set to 16C overnight, and has only come on during a few freezing nights, because the house is well-insulated. So it uses extra fuel only on very cold nights. This is particularly handy if you have babies or elderly people in the house and don't want them to get too cold.

If you have a programmable thermostat, which will usually fit as a simple replacement for your existing wall stat, you can set different temperatures for different times of day, and days of the week, to suit your lifestyle, so the day and night temperatures will be maintained automatically.

"Best" is not the same as "cheapest" or "most comfortable," you have to decide what suits you.

 

[Mrs_Mcnab]

Thank you for your replies - very helpful

 

[OwainDIYer]

A programmable stat is the best thing since sliced bread for central heating. The house never gets cold, and if all you do in the morning is get dressed and dash out of the house it may not be necessary to blast the house with heat - which is the temptation if it's cold overnight.