John Stumbles wrote:

Let me stick my neck out here Mary and hazard a couple of guesses:
(1) that you're the sort of people who put on a jumper rather
than the central heating when it gets chilly, and
(2) that your boiler and hot water cylinder are pretty ancient and
prodigiously chuck heat into the house and out the flue for ages while
heating the water in the cylinder.


Quite presumptuous, aren't you!