zigbee-herdsman-converters: Viessmann TRV ZK03840 -- motor does not act upon changed target temperature

Hey everyone,

I just got some Viessmann thermostats ZK03840 (so that I can get rid of the Eurotronic ones as that HW mess seems to never improve).

First it looks all nice, I can get the Viessmann TRV easily paired, can get/set the temperature value, but setting the value does not seem to cause the motor to e.g. open the valve. When I select a temperature on the TRV itself, it works.

The problem was described here already by @houssemsioud https://github.com/Koenkk/zigbee-herdsman-converters/issues/1242#issuecomment-726786361 yet the issue is closed without resolution (at least for me). @sjorge had some ideas how to solve this, I believe

btw. I also don’t get to see the “piHeatingDemand” or “running_state” attributes: Feb 21 18:16:58 troublemaker npm[1855]: Zigbee2MQTT:info 2021-02-21 18:16:58: MQTT publish: topic 'zigbee2mqtt/OfficeTRV2', payload '{"last_seen":"2021-02-21T17:16:58.415Z","linkquality":144,"local_temperature":21.63,"occupied_heating_setpoint":18.5,"system_mode":"heat"}'

My system:

• I’m on the latest z2m version (1.17.1-dev commit: 20def3f, zStack zStack3x0), no docker
• I have tried it with several Viessmann TRVs … all have the same fireware (01.16.0008 02.04), but two different build dates (20200525, 20200526)
• I tried the standard, no device specific config as well as the device-specific “legacy:false” setting, to no avail

Any idea / anything I could try?

cheers