We did it! The binding will be included in the next milestone. A huge thank you to @STSC @opus @cweitkamp and @sven1234 for your support. The binding wouldn’t have gotten this far without you.
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That’s great. Thank you very much for all the time you spent into the development. 
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Every hour I get the following error message:
API IOException: Unable to execute GET: java.util.concurrent.ExecutionException: org.eclipse.jetty.client.HttpResponseException: HTTP protocol violation: Authentication challenge without WWW-Authenticate header
Do I need to change some settings?
@Oliver2 I tested it on my system and couldn’t reproduce the error. Which version do you have installed?
Good point. I didn’t realised there is a newer version available. With the latest binding release these errors are gone.
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Hi @rogrun,
I finally migrated to your new add-on. Unfortunately some Channels for power consumption seem to deliver no values to the Items. Power consumption heating is working, Power consumption water and total are not working. Just tested values for today. Might be the same for yesterday, and so on.
Maybe my power consumption for water is too low to be displayed.
Can you help? Thank you in advance.
Hi @cweitkamp yes this is possible. Can you please send me the API response (in TRACE mode) via PM.
I’d like to analyse the original values from the API
Hi @rogrun,
i have similar problems with Power channels like @cweitkamp.
Things i discovered in the past 2 weeks during the development if a widget for semanticHome:
Power consumption items dhw-, heating- and total- this-month aren’t aren’t from december but from november.
Analog last-month are from oktober so at least the naming of the channels is misleading.
I have no clue who is responsible the binding or viessmann for delivering this data.
From my insight up till now this seem to be like that for all power consumption channels.
So having no data for this-month that i am able to represent in a chart i tried to build the data for the aktual month with a rule emptiing an additional item at first of month and than adding every day at 00:01 the data from yesterday to those items.
The problem that arose is the most of the time all day channels don’t update as they should.
To illustrate i added power consumption dhw yesterdays as chart for the past month so you can see that the data the channel provides isn’t usable.
Last week i migrated my installation from the old style with bridge to the new account style.
After migration at least the channel heating.dhw.scaldProtection (Verbrühungsschutz) isn’t available anymore although the viessmann developer portal still list this data-point.
If i can help with logs to get this sorted out just tell me what i shall provide.
Thanks for this otherwise great binding.
Edit:
Could be helpful to know what kind of device 
Heatpump Vitocal 250A
Hi @Sysiphus These four channels contains the RAW data in an array from viessmann API
For example:
The first value (0.72) is the current consumption for today und the next (0.754) for yesterday and so on..
On my system, the values match those in the ViCare app. I think there is something wrong with the provided data from the viessmann API.
For further analysis please send me your log in TRACE mode via PM. I need the complete API Response wich starts here:
I will take a look at your log and search for the cause.
Hiya,
after upgrade to openHAB 5.1.0 i installed the latest Viessmann binding, finding that everything was redesigned. OK, configured everything and it worked fine for half a day. Now the case is:
Redirect URL is actually like this:
When i call it, i get:
So i seem to do the right thing. Am i overlooking something?
Here’s the log:
2026-01-30 14:27:25.704 [INFO ] [enhab.core.model.script.Thing Status] - processing viessmann:gateway:e808e31db7:7637415015668201 / INITIALIZING
2026-01-30 14:27:25.706 [DEBUG] [rnal.handler.ViessmannGatewayHandler] - Initialize Viessmann Gateway
2026-01-30 14:27:25.707 [TRACE] [rnal.handler.ViessmannGatewayHandler] - Loading Device List from Viessmann Gateway
2026-01-30 14:27:25.708 [TRACE] [.viessmann.internal.api.ViessmannApi] - API: GET Request URL is ‘https://api.viessmann-climatesolutions.com/iot/v2/equipment/installations/264832/gateways/76374xxx68201/devices’
2026-01-30 14:27:25.709 [WARN ] [.viessmann.internal.api.ViessmannApi] - API AuthException: Unable to execute GET: Can not set auth header because access token is null
2026-01-30 14:27:25.709 [DEBUG] [viessmann.internal.api.ViessmannAuth] - ViessmannAuth: State is NEED_AUTH: Executing step: ‘authorize’
2026-01-30 14:27:25.709 [TRACE] [viessmann.internal.api.ViessmannAuth] - ViessmannAuth: Getting authorize URL=https://iam.viessmann-climatesolutions.com/idp/v3/authorize?response_type=code&client_id=78bxxxxxxxxx0e&code_challenge=S_SqxxxxxxxxxorIhDjI&redirect_uri=http://localhost:8080/viessmann/authcode/&scope=IoT%20User%20offline_access&code_challenge_method=S256
2026-01-30 14:27:25.806 [DEBUG] [viessmann.internal.api.ViessmannAuth] - Response body: {“error”:“invalid_request”, “error_description”:“Invalid redirection URI.”}
2026-01-30 14:27:25.806 [DEBUG] [viessmann.internal.api.ViessmannAuth] - BAD REQUEST(400) response received: {“error”:“invalid_request”, “error_description”:“Invalid redirection URI.”}
2026-01-30 14:27:25.806 [TRACE] [viessmann.internal.api.ViessmannAuth] - ViessmannAuth: Auth response: {“error”:“invalid_request”, “error_description”:“Invalid redirection URI.”}
2026-01-30 14:27:25.806 [WARN ] [viessmann.internal.api.ViessmannAuth] - ViessmannAuth: Login failed. Invalid redirection URI.
So obviously the redirect URI isn’t used. But why?
What am i missing?
Thanks so much for helping
Anne
Have you tried with the redirect URI that is mentioned as must be:… Including the slash at the end?
Which ciessmann binding did you use before. There were two. Vicare and Viessmann.
Before i had Vicare, now Viessmann. Adding the Slash didn’t help, unfortunately.
Viessmann works differently, there is no need for the browser and the URI with Fritzbox… is wrong, as the error message points out.
Basically you are setting up a new binding and your old channels will not work because they belong to the vicare binding.
OK, changing the URI helped…i don’t understand how, but anyway, i don’t care 
Have many thanks, greatly appreciated!
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Hey guys. A new version is out now.
@Sysiphus thx for your log.
@rogrun - since the binding is now official, perhaps this should now be changed from “stable” to “beta” since it seems to have changed purpose? I guess the official binding is now considered “stable”? Currently both versions will show up side-by-side on the Add-on Store with the only difference being “openHAB” badge for the official version.
@laursen Good point. I changed it.