British Gas are offering an exclusive 20% cashback on all Hive products for existing British Gas customers. I know this isn't the cheapest that it has ever been but I can't find it cheaper anywhere else at the moment with the installation included.
What’s Hive Active Heating™?
It's a smart thermostat that lets you control your heating and hot water from your smartphone, tablet or laptop
So whether you’re at work, on the bus or in the pub, the Hive App lets you change the temperature of your home in just a few taps.
Hive Active Heating™ works with your existing heating system and there's no need to change your energy supplier. If you have a separate hot water tank, you can control your hot water too.