BAI00 SW0709: No writeable messages / template mismatch (Glow‑worm Ultimate3 30c)

[northernwolfhound]

Good day all,

We moved in over a year ago and subsequently found that the boiler had no thermostat, only the basic control panel on the front with operating modes [Heating + hot water, Heating only, Hot water only, None].

I recently found the time to spin up home assistance and started to integrate some climate sensors etc around the house. Then I had the bright idea that maybe I could use HA as a thermostat substitute. So now I have spent the past few weeks, and far too many hours trying to make that happen.

I've managed to get the below entities quite easily just by spinning everything up, although "scan config 05: ERR: read timeout" appears to be a common log (I believe common on Vaillant boilers), as are a number of "native unit of measurement 'None' which is not a valid unit for the device class" (I believe a config mismatch). The one thing that has utterly eluded me however is the ability to write instructions to the boiler, and therefore action as any form of control.

Is anyone able/willing to help me get something up and running?

Hopefully below is enough information for someone to help me get further. Thank you in advance.

TL;DR:

• Glow‑worm Ultimate3 30c (Vaillant BAI00 SW0709)
• Reading works via ebusd
• Writing does not work
• Need help enabling write commands (e.g., hc1, flowtempdesired, heating mode)
• Using HA + ebusd addon + MQTT discovery

Looking for:

• Correct template set for Glow‑worm Ultimate3 / BAI00 SW0709
• Confirmation whether this firmware supports write commands
• Whether a Vaillant controller (VR33/VR65/etc.) is required to unlock writes

Happy to provide additional logs or run further ebusctl commands if needed.

Diagnostic commands:

ebusctl info
ebusctl find -f write
ebusctl read -f bai FlowTempDesired
ebusctl write -f bai FlowTempDesired 50

Results:
- find -f write → ERR: element not found
- write FlowTempDesired → ERR: element not found

This suggests my BAI00 SW0709 firmware exposes no writeable messages with the current templates.

Additional test:

ebusctl read -f bai
→ ERR: element not found

This confirms that the current template set does not match my BAI00 SW0709 firmware.
ebusd can read some values (via partial matches) but has no complete message definitions for the bai circuit, and therefore exposes no writeable commands.

Additional Diagnostics:

ebusctl info verbose

Result:
- Templates load ("vaillant/bai.308523.inc", "vaillant/08.bai.csv")
- No matched message definitions shown in verbose output

This indicates that the templates load successfully but do not match my BAI00 SW0709 firmware.

Template source:

Using the default templates from https://ebus.github.io/ebusd-configuration/

Boiler:

    Make:   glow-worm    
    Model:  glow-worm ultimate3 30c [https://www.glow-worm.co.uk/homeowner/products/ultimate-combi-boilers-1473.html]
    Equivalent: Vaillant ecoTEC pro 30kW combi
    Thermostat: None [No additionally installed thermostats or sensors]

Burner Control Unit:

    MF=Vaillant
    ID=BAI00
    SW=0709
    HW=1303
    Scan.08 Id = 21;22;17;0010021404;1300;507703;N2
    address 00: master #1
    address 03: master #11
    address 08: BAI00

eBUS Adapter:

    eBUS Device:	ebus adapter stick c6 [https://www.elecrow.com/ebus-adapter-stick-c6.html]
    ebusd device string: "ens:192.168.1.204:9999" or "mdns:58e6c5e4a50c" since ebusd 24.1
    Chip ID:	58e6c5e4a50c, ESP32-C6, rev 2
    Hostname:   glowworm-boiler
    PCB:	Stick 3.44.0
    Build:	20260330
    Flash:	4194304
    IDF:	v5.5.3-245-ga9de5ec5b9-dirty
    Reset reason:	software
    eBUS/Host r/w:	2340594/102204, 228504/4108959

Host System:

    Device:    Wyse 5070 Pentium Silver

Home Assistant:

    Home Assistant OS
    Core 2026.4.2
    Supervisor 2026.04.0
    Operating System 17.2
    Frontend 20260325.7

Home Assistant App (addon):

eBUSd:

    Version 26.1.8
    Hostname 2ad9b828-ebusd
    ebusd flags:
        --foreground
        --updatecheck=off
        --mqtthost=core-mosquitto
        --mqttport=1883
        --mqttuser=<redacted>
        --mqttpass=<redacted>
        --device=ens:192.168.1.204:9999
        --mqttport=1883
        --mqttjson
        --mqttint=/etc/config/mqtt-hassio.cfg
        --mqttvar=filter-direction=r|u|^w
        --accesslevel=*

MQTT Discovery:

Device: ebusd

        Entities:
            ENTITY_ID: binary_sensor.ebusd_global_running
                STATE: on
                ATTRIBUTES:
                    - device_class: running
                    - friendly_name: ebusd global running
            ENTITY_ID: sensor.ebusd_global_scan
                STATE: "finished"
                ATTRIBUTES:
                    - friendly_name: ebusd global scan
            ENTITY_ID: binary_sensor.ebusd_global_signal
                STATE: on
                ATTRIBUTES:
                    - device_class: connectivity
                    - friendly_name: ebusd global signal
            ENTITY_ID: update.ebusd_global_updatecheck
                STATE: unknown
                ATTRIBUTES:
                    - auto_update: False
                    - display_precision: 0
                    - installed_version: None
                    - in_progress: False
                    - latest_version: None
                    - release_summary: None
                    - release_url: None
                    - skipped_version: None
                    - title: None
                    - update_percentage: None
                    - friendly_name: ebusd global updatecheck
                    - supported_features: 4
            ENTITY_ID: sensor.ebusd_global_uptime
                STATE: 576
                ATTRIBUTES:
                    - state_class: total_increasing
                    - unit_of_measurement: s
                    - device_class: duration
                    - friendly_name: ebusd global uptime
            ENTITY_ID: switch.ebusd
                STATE: on
                ATTRIBUTES:
                    - entity_picture: /api/hassio/addons/2ad9b828_ebusd/icon
                    - icon: mdi:puzzle
                    - friendly_name: eBUSd

Device: ebusd eBUS device

        Entities:
            ENTITY_ID: sensor.ebusd_cpu_percent
                STATE: 0.07
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: %
                    - friendly_name: eBUSd CPU percent
            ENTITY_ID: sensor.ebusd_memory_percent
                STATE: 0.41
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: %
                    - friendly_name: eBUSd Memory percent
            ENTITY_ID: sensor.ebusd_newest_version
                STATE: 26.1.8
                ATTRIBUTES:
                    - friendly_name: eBUSd Newest version

Device: ebusd bai

        Entities:
            ENTITY_ID: sensor.ebusd_bai_counterstartattempts1
                STATE: 35
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: °C
                    - device_class: temperature
                    - friendly_name: ebusd bai CounterStartattempts1 
            ENTITY_ID: sensor.ebusd_bai_counterstartattempts2
                STATE: 35
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: °C
                    - device_class: temperature
                    - friendly_name: ebusd bai CounterStartattempts2 
            ENTITY_ID: sensor.ebusd_bai_counterstartattempts3
                STATE: 32
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: °C
                    - device_class: temperature
                    - friendly_name: ebusd bai CounterStartAttempts3 
            ENTITY_ID: sensor.ebusd_bai_counterstartattempts4
                STATE: 32
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: °C
                    - device_class: temperature
                    - friendly_name: ebusd bai CounterStartAttempts4 
            ENTITY_ID: sensor.ebusd_bai_deactivationstemplimiter
                STATE: 0
                ATTRIBUTES:
                    - state_class: measurement
                    - device_class: temperature
                    - friendly_name: ebusd bai DeactivationsTemplimiter 
            ENTITY_ID: sensor.ebusd_bai_displaymode
                STATE: 2
                ATTRIBUTES:
                    - friendly_name: ebusd bai DisplayMode 
            ENTITY_ID: sensor.ebusd_bai_expertlevel_returntemp_temp
                STATE: -1.81
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: °C
                    - device_class: temperature
                    - friendly_name: ebusd bai Expertlevel_ReturnTemp temp
            ENTITY_ID: sensor.ebusd_bai_externalflowtempdesired
                STATE: unknown
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: °C
                    - device_class: temperature
                    - friendly_name: ebusd bai ExternalFlowTempDesired 
            ENTITY_ID: sensor.ebusd_bai_extflowtempdesiredmin
                STATE: unknown
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: °C
                    - device_class: temperature
                    - friendly_name: ebusd bai ExtFlowTempDesiredMin 
            ENTITY_ID: sensor.ebusd_bai_fanhours
                STATE: 5310
                ATTRIBUTES:
                    - state_class: total_increasing
                    - unit_of_measurement: h
                    - friendly_name: ebusd bai FanHours 
            ENTITY_ID: sensor.ebusd_bai_fanstarts
                STATE: 15991
                ATTRIBUTES:
                    - state_class: total_increasing
                    - friendly_name: ebusd bai FanStarts 
            ENTITY_ID: sensor.ebusd_bai_flowtemp_temp
                STATE: 63.94
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: °C
                    - device_class: temperature
                    - friendly_name: ebusd bai FlowTemp temp
            ENTITY_ID: sensor.ebusd_bai_flowtempdesired
                STATE: 70.0
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: °C
                    - device_class: temperature
                    - friendly_name: ebusd bai FlowTempDesired 
            ENTITY_ID: sensor.ebusd_bai_flowtempmax
                STATE: 87.75
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: °C
                    - device_class: temperature
                    - friendly_name: ebusd bai FlowTempMax 
            ENTITY_ID: sensor.ebusd_bai_hchours
                STATE: 4495
                ATTRIBUTES:
                    - state_class: total_increasing
                    - unit_of_measurement: h
                    - friendly_name: ebusd bai HcHours 
            ENTITY_ID: sensor.ebusd_bai_hcpumpmode
                STATE: unknown
                ATTRIBUTES:
                    - options: ['post_run', 'permanent', 'winter']
                    - device_class: enum
                    - friendly_name: ebusd bai HcPumpMode 
            ENTITY_ID: sensor.ebusd_bai_hcpumpstarts
                STATE: 29582
                ATTRIBUTES:
                    - state_class: total_increasing
                    - friendly_name: ebusd bai HcPumpStarts 
            ENTITY_ID: sensor.ebusd_bai_hcstarts
                STATE: 10500
                ATTRIBUTES:
                    - state_class: total_increasing
                    - friendly_name: ebusd bai HcStarts 
            ENTITY_ID: sensor.ebusd_bai_hcunderhundredstarts
                STATE: 32
                ATTRIBUTES:
                    - state_class: total_increasing
                    - friendly_name: ebusd bai HcUnderHundredStarts 
            ENTITY_ID: sensor.ebusd_bai_hourstillservice
                STATE: unknown
                ATTRIBUTES:
                    - state_class: total_increasing
                    - unit_of_measurement: h
                    - friendly_name: ebusd bai HoursTillService 
            ENTITY_ID: sensor.ebusd_bai_hwchours
                STATE: 113
                ATTRIBUTES:
                    - state_class: total_increasing
                    - unit_of_measurement: h
                    - friendly_name: ebusd bai HwcHours 
            ENTITY_ID: sensor.ebusd_bai_hwcpostruntime
                STATE: unknown
                ATTRIBUTES:
                    - unit_of_measurement: s
                    - friendly_name: ebusd bai HwcPostrunTime 
            ENTITY_ID: sensor.ebusd_bai_hwcstarts
                STATE: 12200
                ATTRIBUTES:
                    - state_class: total_increasing
                    - friendly_name: ebusd bai HwcStarts 
            ENTITY_ID: sensor.ebusd_bai_hwctemp_temp
                STATE: -13.5
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: °C
                    - device_class: temperature
                    - friendly_name: ebusd bai HwcTemp temp
            ENTITY_ID: sensor.ebusd_bai_hwctempdesired
                STATE: 60.0
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: °C
                    - device_class: temperature
                    - friendly_name: ebusd bai HwcTempDesired 
            ENTITY_ID: sensor.ebusd_bai_hwctempmax
                STATE: unknown
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: °C
                    - device_class: temperature
                    - friendly_name: ebusd bai HwcTempMax 
            ENTITY_ID: sensor.ebusd_bai_hwcunderhundredstarts
                STATE: 98
                ATTRIBUTES:
                    - state_class: total_increasing
                    - friendly_name: ebusd bai HwcUnderHundredStarts 
            ENTITY_ID: sensor.ebusd_bai_maintenancedata_hwctempmax
                STATE: 0.0
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: °C
                    - device_class: temperature
                    - friendly_name: ebusd bai Maintenancedata_HwcTempMax 
            ENTITY_ID: sensor.ebusd_bai_outdoorstempsensor_temp
                STATE: -60.44
                ATTRIBUTES:
                    - state_class: measurement
                    - unit_of_measurement: °C
                    - device_class: temperature
                    - friendly_name: ebusd bai OutdoorstempSensor temp
            ENTITY_ID: sensor.ebusd_bai_overflowcounter
                STATE: yes
                ATTRIBUTES:
                    - options: ['no', 'yes']
                    - device_class: enum
                    - friendly_name: ebusd bai OverflowCounter 
            ENTITY_ID: sensor.ebusd_bai_prapscounter
                STATE: 0
                ATTRIBUTES:
                    - friendly_name: ebusd bai PrAPSCounter 
            ENTITY_ID: sensor.ebusd_bai_prenergycounthc1
                STATE: 12514571
                ATTRIBUTES:
                    - state_class: total_increasing
                    - device_class: energy
                    - friendly_name: ebusd bai PrEnergyCountHc1 
            ENTITY_ID: sensor.ebusd_bai_prenergycounthc2
                STATE: 0
                ATTRIBUTES:
                    - state_class: total_increasing
                    - device_class: energy
                    - friendly_name: ebusd bai PrEnergyCountHc2