Hier habe ich Dir das mal kurz zusammengebaut:
[
{
"id": "334b6af8.fbb0fe",
"type": "tab",
"label": "Heizung ID:8",
"disabled": false,
"info": ""
},
{
"id": "d2797b0d.7a895",
"type": "comment",
"z": "334b6af8.fbb0fe",
"name": "ID 888 Betriebsart",
"info": "",
"x": 130,
"y": 80,
"wires": []
},
{
"id": "ebba093c.69fb5",
"type": "ioBroker in",
"z": "334b6af8.fbb0fe",
"name": "Betriebsart",
"topic": "viessmannapi.0.heating.circuits.0.operating.modes.active.value",
"payloadType": "value",
"onlyack": "",
"func": "all",
"gap": "",
"fireOnStart": "false",
"x": 100,
"y": 120,
"wires": [
[
"6dfe4ebb.be0848"
]
]
},
{
"id": "6dfe4ebb.be0848",
"type": "change",
"z": "334b6af8.fbb0fe",
"name": "",
"rules": [
{
"t": "change",
"p": "payload",
"pt": "msg",
"from": "standby",
"fromt": "str",
"to": "Aus",
"tot": "str"
},
{
"t": "change",
"p": "payload",
"pt": "msg",
"from": "dhwAndHeating",
"fromt": "str",
"to": "Hzg & Warmwasser",
"tot": "str"
},
{
"t": "change",
"p": "payload",
"pt": "msg",
"from": "dhw",
"fromt": "str",
"to": "Nur Warmwasser",
"tot": "str"
},
{
"t": "change",
"p": "payload",
"pt": "msg",
"from": "forcedReduced",
"fromt": "str",
"to": "Dauernd reduziert",
"tot": "str"
},
{
"t": "change",
"p": "payload",
"pt": "msg",
"from": "forcedNormal",
"fromt": "str",
"to": "Dauernd Tagbetrieb",
"tot": "str"
}
],
"action": "",
"property": "",
"from": "",
"to": "",
"reg": false,
"x": 300,
"y": 120,
"wires": [
[
"dc1218df.dfd688"
]
]
},
{
"id": "dc1218df.dfd688",
"type": "function",
"z": "334b6af8.fbb0fe",
"name": "",
"func": "var modus = msg.payload;\n\nreturn {\n payload: {\"attribute\": {\"id\": 888, \"value\": 0, \"data\": modus}}\n}",
"outputs": 1,
"noerr": 0,
"initialize": "",
"finalize": "",
"x": 530,
"y": 120,
"wires": [
[
"797aa90.ceb89d8"
]
]
},
{
"id": "797aa90.ceb89d8",
"type": "homeeDevice",
"z": "334b6af8.fbb0fe",
"virtual-homee": "",
"name": "Viessmann-Therme",
"nodeId": "8",
"showNodeId": false,
"profile": "3028",
"icon": "nodeicon_heatingsystem",
"attributes": [
{
"instance": 0,
"minimum": 0,
"maximum": 0,
"current_value": 0,
"target_value": 0,
"last_value": 0,
"unit": "text",
"step_value": 1,
"editable": 0,
"state": 1,
"last_changed": 1573711842,
"changed_by": 1,
"changed_by_id": 0,
"based_on": 1,
"data": "",
"id": 888,
"type": 216,
"node_id": 8
}
],
"statusTemplate": "",
"x": 830,
"y": 120,
"wires": [
[]
]
}
]
Ich hatte das hier schonmal beschrieben:
Es funktioniert auf jeden Fall mit den Attribut types 44 (Firmware), 45 (Software) und 216 (Programm).
Als Dankeschön für die Vorarbeit darfst Du gerne @stfnhmplr einen Kaffee ausgeben. 
