The LED on the front of your Extension Kit tells you what state your Extension Kit is in.  

Slow pulsing/breathing

The Extension Kit is operating normally.


The Extension Kit is not supplied with power.

This is usually because your Extension Kit is wired incorrectly. Please double-check the wiring instructions in the online installation assistant. 

Rapid blinking 

The Extension Kit is pairing.

The Extension Kit is wired and powered, but is not paired yet. 

Please find the instructions to pair the Extension Kit with the Internet Bridge here.
If the Extension Kit is not running on the latest firmware, you may see other blinking patterns on the device. Once the firmware has updated(this is an automatic process), the states should match those mentioned above.

More information:
How can I control my heating system when the radio link between the Smart Thermostat and the Extension Kit is lost?

Did this answer your question?