Lambda Heat Pump in OpenHab

Development Add-ons
81

Here is the new version:
https://drive.google.com/file/d/1ka0Kr5cKx3obRT3_JZ_bEletTS4cr3_i/view?usp=sharing

Please test it. I do not have a solar component. Can somebody test the solar part, especially the last two channels:

solar-maximum-buffer-temperature
solar-buffer-changeover-temperature

It wasn’t a problem with the function codes but with the registers in the pollers used to access the registers >=50 and their representation in the yml-files which are reponsible for the connection to the user interface.

There are several channels which in my heatpump do not provide meaningful values:

Heatpump Energy source outlet temperature
Heatpump Volume flow energy source
Requested Password
..
Heatpump requested difference between T-Flow and T-Return

Buffer Actual Modbus Temperature
Buffer Request Type
Buffer Request Flow Line Temperature
Buffer Request Return Line Temperature
Request Heat Sink Temperature
Buffer Request Heating Capacity

Heating circuit Return Line Temperature
..
Heating circuit Operating Mode

82

I just did a quick test using one of the test rules above and for me the new version doesn’t make a difference. Did anyone else try?

83

I’ll be able to give the solar part a test next week

84

@Beluga:
var double Boiler_MT_Neu = 44.0
lambdaboiler_maximumboilertemperature.sendCommand(Boiler_MT_Neu)
logInfo(“Lambda_Testskript”, “Maximum Temperature neu : " + String.format(”%.1f", ((lambdaboiler_maximumboilertemperature.state) as Number).floatValue) +“°C”)

in my logs shows:

2025-11-03 12:22:33.786 [INFO ] [.core.model.script.Lambda_Testskript] - Maximum Temperature neu : 43.0°C

2025-11-03 12:22:33.786 [INFO ] [penhab.event.ItemStatePredictedEvent] - Item ‘lambdaboiler_maximumboilertemperature’ predicted to become 44.0

2025-11-03 12:22:33.788 [INFO ] [openhab.event.ItemStateUpdatedEvent ] - Item ‘lambdaboiler_maximumboilertemperature’ updated to 44 °C

2025-11-03 12:22:33.789 [INFO ] [openhab.event.ItemStateChangedEvent ] - Item ‘lambdaboiler_maximumboilertemperature’ changed from 43 °C to 44 °C

and the UI of the lambda shows: Solltemp: 44.0 °C

{Seems that the logInfo is faster than the reaction of openhab to the sendCommand.}

  • Did you stop and restart OpenHab after copying the jar into the addons directory?
  • Does the value of your Item connected to the Maximum Boiler Temperature channel change when you change Solltemp. in the UI of your Lambda?
  • Are you on 5.1.0 or on an older version of OpenHab?
  • Go to the Userinterface of Openhab - Things - Lambda Boiler - Channels. Does it show two different groups Boiler Group and Boiler Reg50 Group, the first group with four channels, the last with one channel: Maximum Boiler Temperature
85

Just wondering, is openHab 5.1 required? I’m still on 5.0.2.

86

No, I was on 5.0.1 too, so it should work…

But for versions 4. and older I would have to compile a jar for Java 17.

I did an upgrade to 5.0.2 - Maximum Boiler Temperature changes values on my system…

87

I just deleted the jar (all associated things went grey, so it was the right one), downloaded again and restarted. Unfortunately, same as before. To answer your questions:

  1. Stop and restart → yes
  2. Change in Lambda UI leads to change in Openhab → No
  3. Version → 5.0.2
  4. Channel groups → just one group with five items

Your last question probably points to the solution. I just added a new boiler thing and this one indeed has a Reg50 channel group.

Busy with other stuff at the moment, but guess I will return with some good news in the evening. :wink:

88

OK…
The developement circle of the binding in OH requires me to supply textual definitions of the things and items. So I use the conf directory to supply these to my installation. So the restart of OH creates new things. If you use the UI only (which I prefer too) you have to delete the old thing and add a new thing (and probably have to connect your existing items its channels - which is annoying;).

89

I now deleted the old boiler thing and added the new one. Except for the maximum boiler temp item all existing items were linked automatically. Oh, and it’s working now! Changes via the Lambda UI are now reflected in the item and changing the item-state in Openhab leads to a change in the Lambda UI :partying_face:

Thanks!

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