I tweaked the temperatures and times of my programmable thermostat a couple of months ago, turned the heating down by a degree at various times of day, and decided I don't need to heat the water twice a day at weekends, so that's mornings-only all week now.
Gas consumption has been a solid 7kWh/day over summer, so 50p/day for water alone, a few years ago that 50p included the standing charge, now it's on top. My boiler is of the dinosaur variety, and I quite like it that way, would have replaced it years ago if I didn't.
Anyway, I was woken a little early today by the boiler coming on for heating (stat comes on when it decides in order to reach set temp by set time) it was only 1.9°C below the required temp, so it was only on for half an hour, so that's 10kWh today.
I must try to get the Pi running the software that graphed the heating controls, sure that python versions have changed since then ...