Extension kitThis Extension Kit connects your tado° Smart Thermostat to your boiler if there is no existing connection.It does it wirelessly, so there's no need to drill holes or feed wires around your home.Hot water heaterIf you have a programmer attached to your boiler to control hot water production, the Extension Kit can replace it.This way tado° can control your hot water production too.The Extension Box fits the UK standard backplate, so it's easy to attach and you can easily replace the programmer without doing any rewiring.