There is planned maintenance work on the Viessmann servers on 10/17/2022, 07:00 to 08:00 CEST. During this time there may be a limitation of API functionality. This maintenance has no effect on your Viessmann heating system. It serves to improve our servers and thus also the API.
Is there an unscheduled service breakdown going on right now?
There were a short temporary issue, but everything should be working again as expected since yesterday.