Setting desiredflowtemperature Vaillant boiler - homeassistant & Mqqt

[peterelvidge]

Thanks for creating what seems to be an incredibly flexible integration! I had bee trying to achieve similar with my Valiant before giving up as its far to slow to be useful..

I have been experimenting.. setup is:

• Valliant ecoTec Boiler (detected as product 0010020405) – with nothing other than the boiler and ebusd on the ebus line.

• Ebus shield on raspberry pi running ebusd 24.1.24.1

• Using vaillant/bai.308523.inc – copied locally so I can change things like poll priorities

• Using MQQT and Home assistant.

• This is the config I am starting ebusd ( etc/default/ebusd)
  EBUSD_OPTS="-d ens:/dev/ttyAMA0 --latency=50 --pollinterval=1 --configpath=/etc/ebusd --mqtthost=192.168.1.45 --mqttport=1883 --mqttuser=mqqt-user --mqttpass=whatever --mqttjson --mqttint=/etc/ebusd/mqtt-hassio.cfg"

• Using standard mqqt-Hassio.cfg with only change to allow writes (filter-direction = r|u|^w)

In my application I would like to get status information into home assistant and be able to set the desiredflowtemperature.

The fields I am trying to read are:
FlowTemp, ReturnTemp, Flame, Statenumber, Currneterror and FlowTempdesired.
The things I am interested in I have put as r1 in the config file to try to get frequent updates.
FlowTemp and Returntemp worked first time and I am able to get an update about every 10-15 seconds which is ideal..

I have come up against a few challenges:

FlowTempDesired – I can read it in homeassistant fine, when I change the flow temp manually on the boiler control panel this updates – but if I change the type to w;r1 while home assistant sees it as writable, and I can see the set happen in mqqt explorer it does not actually update the boiler. I get the same behaviour if I try to write to this via ebusctl:

root@raspberrypi:/etc/ebusd# ebusctl
localhost: write -c bai flowtempdesired 65
65.00

localhost: read -c bai flowtempdesired
70.00

Should this work this way and FlowTempDesired be a writable field – should I be updating some other field instead?

Flame & Currenterror – I see these published to MQQT.. and I can get into homeassistnt if I setup the MQQT manually.. but it’s not autoconfigured, not a big deal, just interested to understand why, if a good reason and if / how I can change this?

Statenumber – this actually seems to be a very useful field as a quick overview of what the boiler is up to – and would be good to drive an icon etc. on HomeAssistant.. just wondering if anyone has already figured out what all of the numbers map to..

[JonesGW-MGD]

Hi Peter,

I've not needed to do this myself as I have weather comp, but the accepted wisdom on this forum and its 'twin' for the configuration files is instead of manipulating flowtempdesired, you instead emulate a controller by setting a setmode command. Or more specifically, you create a setmodeoverride command and add to your config file. This is probably a good starting point:

john30/ebusd-configuration#170

Otherwise search both forums for setmodeoverride or replacing my controller

(If you have an existing controller (which you suggest you do not), you need to repeatedly send this command otherwise the controller will override it periodically - like in a matter of minutes. I also believe you need to do this even if you don't have a controller, as the boiler will override it too) but a HA automation can easily do this.

On the flame and currenterror. I believe mine auto-config'ed. I suspect if you've only changed the filter-direction, you also need to avoid the default filters. You can do this with the --mqttvar=filter-name= parameter

(btw I have a fairly recent Valliant - ecoTec IQ Exclusive 835 combi and I find d.40 and d.41 (flow and return) are reasonably inaccurate - perhaps due to proximity inside the boiler - I put a separate ESP32 with a couple of DS18b20 temp probes on the flow and return pipes close to the boiler and feed that into HA via MQTT and I think they give me a more accurate picture - but at the end of the day the internal sensors are probably good enough for relative measures.)

Gareth