"Dave Baker" wrote in message
...

8

However with a reasonably well insulated house the net extra cost is very
low. If we assume in cold weather an 18 degree C difference between inside
and outside when the heat is on, 16 hours of heat on during the day and 8
with it off overnight and a 4 degree total drop in temp of the house
overnight (i.e. an average of 2 degrees) the net extra cost of keeping the
heating on all the time is only about 4%. That's less than you'd save just
turning the thermostat temperature down by 1 degree.


Sorry but that does not make sense.
If its off for 8 hours out of 24 you will save nearly one third.
You may save more as it usually colder at night and will use more energy
than in the day.
It will take slightly more energy to raise the temp back to the norm in the
morning but it shouldn't take much.