Chart over group with items and sub-groups not showing sub-groups


Can someone give me a hint how a chart over a group item will also display sub-groups?
I am trying to aggregate room temperature values in rooms with multiple sensors, but no value is shown in the chart at all for this rooms. I am aware of the constraint that “all members of this group will be persisted, but not the group itself”. But does this also mean sub-groups are not persisted, even when they use aggregate functions? How can I make sure that this happens?

Thank you for your support!

I am using following structure:

Group                         Heizung                   "Heizung"                          <heating>
Group                         IstTemperatur             "Temperatur"                       <temperature>
Group:Number:AVG              IstTemperaturZimmer       "Temperatur Zimmer [%.1f°C]"       <temperature>   (IstTemperatur, Heizung)
Group:Number:AVG              IstTemperaturZimmerEG     "Temperatur EG [%.1f°C]"           <temperature>   (IstTemperaturZimmer)
Group:Number:AVG              IstTemperaturEGWohnen     "Temperatur EG Wohnen [%.1f°C]"    <temperature>   (IstTemperaturZimmerEG)
Group:Number:AVG              IstTemperaturEGFlur       "Temperatur EG Flur [%.1f°C]"      <temperature>   (IstTemperaturZimmerEG)
Number IstTemperaturEGBadHeizungNone            "EG Bad [%.1f°C]"          <temperature> (IstTemperaturZimmerEG) { channel="knx:device:IPIF:OTHER:IstTemperaturEGBadHeizungNone" }
Number IstTemperaturEGBroHeizungNone            "EG Büro [%.1f°C]"         <temperature> (IstTemperaturZimmerEG) { channel="knx:device:IPIF:OTHER:IstTemperaturEGBroHeizungNone" }
Number IstTemperaturEGEingangHeizungNone        "EG Flur Eingang [%.1f°C]" <temperature> (IstTemperaturEGFlur)   { channel="knx:device:IPIF:OTHER:IstTemperaturEGEingangHeizungNone" }
Number IstTemperaturEGFlurHeizungNone           "EG Flur Mitte [%.1f°C]"   <temperature> (IstTemperaturEGFlur)   { channel="knx:device:IPIF:OTHER:IstTemperaturEGFlurHeizungNone" }
Number IstTemperaturEGWohnenHeizungTre          "EG Wohnen Tür [%.1f°C]"   <temperature> (IstTemperaturEGWohnen) { channel="knx:device:IPIF:OTHER:IstTemperaturEGWohnenHeizungTre" }
Number IstTemperaturEGWohnenHeizungWintergarten "EG Wohnen WG [%.1f°C]"    <temperature> (IstTemperaturEGWohnen) { channel="knx:device:IPIF:OTHER:IstTemperaturEGWohnenHeizungWintergarten" }

While EG Bad and Büro (which are items, not groups) are shown in the chart over group IstTemperaturZimmerEG, the sub-groups IstTemperaturEGWohnen and IstTemperaturEGFlur do not appear. Everything inside IstTemperatur and Heizung is getting persisted to rrd4j:

Items {
        PersistRRD4J* : strategy = everyChange, everyMinute

Sitemap entry:
Chart item=IstTemperaturZimmerEG period=D refresh=180000 service="rrd4j"


  • Platform information:
    • Hardware: Synology DS716+
    • OS: DSM 6.2.2-24922 Update 4 with Docker 18.09.0-0506
    • Java Runtime Environment: The one within openhab/openhab:2.5.0-amd64-debian
    • openHAB version: 2.5 (openhab/openhab:2.5.0-amd64-debian)

Adding the group item to the persistence config file did the job! :slightly_smiling_face:

Items {
        PersistRRD4J* : strategy = everyChange, everyMinute