Sometimes, after the power connection is lost, the ViCare Climate Sensor must be restarted. The following procedure should be followed:
Step 1. Remove the batteries.
Step 2. Attach the batteries again and then reset the device.
Step 3. After all of the above steps are done, return to the original settings and reconnect the device to the application.
If mentioned actions did not help, you should contact your Viessmann installer partner.