Nest thermostat. Cheapest I can find.
By stacking B & Q codes i got a nest + stand delivered for £194. This is only £6 more than cheapest ever amazon deal.
use code CLUB1H011 for £20 off
use the 5% discount code today. it comes on the bottom right corner and it generates a code for you.
some reason the 10% discount code EMAIL4759 is not working for me now but i have just used it. use that instead of £20 off one if it works