Heimann smoke sensor keeps getting unavailble - intended or not?

I recently acquired two Heimann smoke sensors (exactly speaking, Trust ZSDR850, but they seem to be the same and are recognized as “Heimann” without any type number).

The first time I got them connected they were

  • visible in the Deconz VNC app with connectivity lines to their parent node
  • visible in Phoscon web app and not greyed out, but nevertheless from the very first moment on in the details described as “not available”, only the manufacturer Heimann was visible.
  • in Homeassistant the smoke detectors are visible with additional entities for “battery”, “lowbat”, “tampered”, and “test mode”.

After a restart of Phoscon about 12h ago the situation is as follows:

  • one smoke detector is not greyed out in Phoscon and still has a connectivity line in Deconz
  • another smoke detector is greyed out in Phoscon and has no connectivity line in Deconz
  • in Homeassistant most of the entities are unavailable, after a few hours only the “battery” and the “test mode” entity of the first smoke detector had reappeared

When starting a test alarm with the completely greyed out smoke detector, the situation is as follows:

  • the smoke detector is no longer greyed out in Phoscon (but still has no connectivity line in Deconz) - update - now that I again look into Phoscon, there is a line
  • in Homeassistant its entities for “battery” and “test mode” have reappeared, but nothing else

I’m a bit unsure if this behaviour is as intended or erraneous. E.g. I have some Ikea switches which also won’t reappear in Phoscon after a restart as long as they have not been operated once, but they work nevertheless. For smoke sensors I’d like to be a bit more sure that they work as expected…

I have similar experience I think is due to the fact that they are battery operated and they do not update too often (mine is days as you see from the rest API result.
But if I generate smoke the sensor wakes up and report right away and they activate as smoke detected in Home assistant. In order to clear the smoke alarm (after smoke has cleared) you need to press the button on the smoke alarm and then it will clear the state in home assistant right away.

Does this match with your experience?

"154": {
    "config": {
        "battery": 100,
        "enrolled": 0,
        "on": true,
        "pending": [],
        "reachable": false
    "ep": 1,
    "etag": "A Number here :)",
    "lastannounced": "2022-09-24T08:06:02Z",
    "lastseen": "2022-10-09T17:59Z",
    "manufacturername": "Heiman",
    "modelid": "SmokeSensor-EF-3.0",
    "name": "Attic Smoke Sensor",
    "state": {
        "fire": false,
        "lastupdated": "2022-10-03T20:45:00.665",
        "lowbattery": false,
        "tampered": false
    "swversion": "2019.8.29",
    "type": "ZHAFire",
    "uniqueid": "The Mac Address"

I also suspect some power saving operation mode, but as this is not discernible from malfunction it is a bit irritating. Right now the fire alarms are back as device in Homeassistant, but all other entities but “test_mode” and “battery” are missing. I don’t even have an entity which I could read for a current alarm?!?

Where did you get the output from?

Until now I only tried the test button for the alarm. This did not really change anything other then making the entities re-appear in Homeassistant. I would have expected the “test_mode” entity to be triggered in this case, but this was not the case.

I suggest reset and re-pair. Also are you using the latest deconz plug in and I suggest updating to the latest firmware.

That output is from the rest API. I have enabled the external rest API access in Deconz add on on port 40850 and then followed the instructions from Getting Started - deCONZ REST-API using PostMan and you get all sensor data from homeassistant.local:40850/api/yourkey/sensors using get command (there is a sample there for lights)