by: Helge, published: Sep 8, 2025, in

Factory Reset a Zehnder ComfoClime Unit

This article describes how to perform a factory reset on the Zehnder ComfoClime 24/36 Arduino board. It find it necessary to document the steps as the description in the installation manual is incorrect.

Performing a Factory Reset on the ComfoClime Arduino Board

  • Press and hold the restore button.
  • Press the reset button once.
  • Continue to hold the restore button until the green LED to the right of the rotary switch starts blinking.
  • Release the restore button.
  • The Ardiuno board is reset to the factory settings.

Source

I obtained the information about the correct procedure from Zehnder’s technical support. They were unaware of the incorrect description in the manual.

Re-Provisioning After the Factory Reset

As the ComfoClime loses all settings (including the WiFi connection) during the factory reset it needs to be re-provisioned. This is easiest to do with the ComfoClime app via Bluetooth. A few tips:

  • Connect your phone to the WiFi network you want the ComfoClime to join.
  • The phone needs to be very close to the ComfoClime’s Arduino board for the Bluetooth connection to succeed.

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