Namron 4512758 thermostat: window_open discovered as MQTT switch with invalid device_class

What happened?

Two Namron Zigbee Thermostat 16A devices (model 4512758, firmware 1.08) fail configuration in Zigbee2MQTT.

During configure, Zigbee2MQTT tries to read:

• windowOpenCheck
• antiFrost
• windowState
• sensorMode

Both devices return:
Status 'UNSUPPORTED_ATTRIBUTE'

In addition, Zigbee2MQTT publishes an MQTT discovery message for:
switch_window_open

with:
"device_class": "window"

Home Assistant rejects this discovery message with:
expected SwitchDeviceClass or one of 'outlet', 'switch'

Both thermostats show identical behavior.
The issue is reproducible on a completely new Home Assistant installation and a new Zigbee2MQTT installation.

What did you expect to happen?

The window_open entity should be discovered without errors.

Either:

• expose window_open as a binary sensor,
• expose it without a device_class,
• or use a valid switch device_class.

Home Assistant should not reject the MQTT discovery message.

How to reproduce it (minimal and precise)

1. Pair a Namron Zigbee Thermostat 16A (model 4512758, firmware 1.08) with Zigbee2MQTT 2.13.0.
2. Allow Zigbee2MQTT to configure the device.
3. Observe the Zigbee2MQTT log:

Failed to configure ...
Status 'UNSUPPORTED_ATTRIBUTE'

for:

• windowOpenCheck
• antiFrost
• windowState
• sensorMode

4. Check Home Assistant MQTT discovery logs.
5. Observe that Zigbee2MQTT publishes:

homeassistant/switch//switch_window_open/config

with:

"device_class": "window"

6. Home Assistant rejects the discovery message with:
   expected SwitchDeviceClass or one of 'outlet', 'switch'

Zigbee2MQTT version

2.13.0

Adapter firmware version

20210708

Adapter

Coordinator: SONOFF Zigbee 3.0 USB Dongle Plus (ZBDongle-P)

Setup

Home Assistant OS

Machine:

• Intel NUC
• Intel Celeron N3160 (4 cores)
• 7850 MB RAM

OS:

• Home Assistant OS
• Linux 6.18.39-haos (x64)

Zigbee2MQTT:

• Installed as Home Assistant Add-on

Coordinator:

• Electrolama zig-a-zig-ah! (zzh!)
• CC2652RB

MQTT:

• Mosquitto Broker add-on

The issue is reproducible on a completely fresh Home Assistant installation and a fresh Zigbee2MQTT installation.

Device database.db entry

No response

Debug log

z2m: Failed to configure '0x286847fffe1c6726', attempt 3

Error: ZCL command 0x286847fffe1c6726/1 hvacThermostat.read(
["windowOpenCheck","antiFrost","windowState","sensorMode"]
) failed (Status 'UNSUPPORTED_ATTRIBUTE')

Error 'expected SwitchDeviceClass or one of 'outlet', 'switch'
for dictionary value @ data['device_class']'

when processing MQTT discovery message topic:
homeassistant/switch/0x6c5cb1fffe20acd2/switch_window_open/config

with:
"device_class": "window"

Both thermostats are Namron Zigbee Thermostat 16A
(Model 4512758, firmware 1.08).
Both devices show identical behavior.

Notes

No response

Start by locating the Namron 4512758 device definition and the code that builds its MQTT discovery payload. Reproduce with firmware 1.08 and Zigbee2MQTT 2.13.0, then inspect handling of the unsupported attributes and the window_open entity. Done means configuration no longer produces avoidable errors and Home Assistant accepts the published discovery message.