You'll need a Wireless Receiver or Extension Kit if:
a) you want to control hot water by replacing an existing programmer or controller that is wired to your system
b) you don't have a thermostat in your heating system or are replacing a wireless thermostat.
In the above instances, the Wireless Receiver is wired directly to your boiler to act as a command receiver for the Wireless Temperature Sensor which is placed in the area being heated.
The Wireless Receiver is only available as part of a Starter Kit and functions in conjunction with a Wireless Temperature Sensor. Only one Wireless Receiver can be installed per account.
The Extension Kit performs a similar function to the Wireless Receiver and can be used in the same instances mentioned above. The Extension Kit is wired directly to your boiler to act as a command receiver for the Smart Thermostat.
The Extension Kit can be bought in conjunction with a Starter Kit - Wired Smart Thermostat V3+, or as an add-on for a setup that already has a Smart Thermostat. Only one Extension Kit can be installed per account.
All home setups must start with the purchase of a Starter Kit. This includes the relevant heating control devices and an Internet Bridge, which is required for controlling tado° remotely via app. Read more about the available Starter Kits here