The Switch controls the boiler, turning the heating on and off according to the heating mode. 

Control button

When the control button ('A' on page 2 of the PDF guide) is lit green, Cosy is actively controlling your heating and you can use the Cosy Display and App. You can revert to your old heating controls at any point by switching it off.


Link status

The link status indicator ('B' on page 2 of the PDF guide) shows the wireless connection between the Hub and the Switch. 

• Green = connected.
• Amber = not connected. Try moving the Hub closer to the Switch.
• Red = the Switch is not paired with the Hub.
• A flashing red light means the Switch is attempting to pair with the Hub.