The Thermo Link ORIGINAL communicates with the Thermo Hub via Zigbee. If the Thermo Link appears as unreachable in the Home + Control app and the Thermo Hub is reachable, the cause is usually a lost Zigbee connection between the Thermostat and the Thermo Hub.

When a Thermo Link loses connection, the network icon on the physical product display turns red, and an alert is displayed in the app.

💡Products associated with the Thermo Hub (Thermostat ORIGINAL, Radiator Valve ORIGINAL, Thermo Link ORIGINAL, or Zigbee repeater) will continue to work in fallback mode even if the Thermo Hub is unavailable.

1. Check that the Thermo Hub is powered on and connected to the internet. You can do that from the Settings of the mobile application:
   Settings > Manage my home > [Thermo Hub's room] > [Thermo Hub's name] > Identify.
   If the Thermo Hub is working as expected, its LED will blink blue for 5 seconds. 

2. Check the distance between the Thermo Link and the Thermo Hub. The Zigbee radio signal can be weakened by thick walls, metal structures, or interference from other wireless devices. Try to relocate the Thermo Hub to reduce the distance between the latter and the Thermo Link.

   For optimal radio transmission, do not place the Thermo Hub or the Thermo Link:

• Within 50 cm of other electrical equipment (even non‑radio devices)

• Behind or inside the boiler frame

• Too close to each other (less than 10 cm)

• Behind a TV

• Near an aquarium

• In or on metal objects

• Inside a closed cabinet

• Close to multiple electric wires or cables

Check Thermo Link's connectivity

1. Check that the Thermo Link is powered on reliably. Press the button on the Thermo Link. The LED must be solid blue when the boiler is ON. If the LED stays OFF, cut the power to the house and check the Thermo Link’s wiring and power connection.

2. If the Thermo Link is powered on but still unreachable, cut the power and re-activate it. On reboot, the product will try to join its associated gateway.

⚠️Do not perform a factory reset unless instructed to do so. A factory reset will remove the Thermostat from your home and require a full reinstallation.

If the Thermo Hub is too far from your Thermo Link ORIGINAL, or if walls and metal structures weaken the Zigbee signal, you can add a Netatmo Zigbee repeater to extend the network.

Install the repeater between the Thermo Hub and the Thermo Link ORIGINAL, in an area where it can receive a stable signal from the Thermo Hub. Once the repeater is properly installed, reboot the Thermo Link ORIGINAL to force a reconnection. Cut the power and reactivate it. You can add several repeaters in your home as long as the number of mains-powered devices (Thermo Link and Netatmo Zigbee repeaters) does not exceed 8.

Updated September 29, 2026 12:12