So this prompted some studying on my part. I managed to work out by timing the on off cycle of the Boiler and a few other numbers, that our heating bill is about £3.12 per day.
I also found out Mrs Kryton (who complains the Kitched is cold, and that there are cold spots on the house) has been fiddling with the TRV’s, leaving the Rad next to her end of the sofa on full.
Having wandered around the house re-setting the TRV’s to approx the same as our bedroom (which with the baby monitor was showing 20), AND setting the Thermostat down a degree (20 at night, 22 daytime) we’ve woken to a much more even temperature around the house.
The whole exercise is probably a bit geeky, but we may see some savings…