Honeywell Y9420H Sundial RF2 Pack 2

Fitted quite a few of these. Pricey, but my control system of choice. Reliable, and encoded so it automatically sorts itself after a power cut. And you can temporarily override the time settings simply by changing the thermostat temperature.

If you try to download info from the Honeywell website to check on what you might want to buy you'll come up against messages saying "you are not authorised to download this information". If you email them they are surprised to learn of any problems but they can't seem to sort it out