Ebus

[kylegordon]

A discussion on how to use an ebus adapter to connect to a Vaillant system

Adapters available from https://adapter.ebusd.eu/index.en.html
Ebusd software available from https://github.com/john30/ebusd/
MQTT broker available from https://mosquitto.org/
Integrate Home-Assistant with MQTT through the MQTT integration - https://www.home-assistant.io/integrations/mqtt/

The above is a very high level list of basic requirements...

[jdiviney]

This link is the key for being able to write rather than just read values
john30/ebusd#1177

The ebusd HA add on gives HA entities that look like you can set them, but they just revert back, the only way to change values is to set via MQTT.

E.G HA action to set target temperature to 21

action: mqtt.publish
enabled: true
data:
qos: "1"
retain: true
topic: ebusdcustom2/basv/z1ActualRoomTempDesired/set
payload: 21

[PV-Joe]

This looks very interesting but quite complicated to the me.
Hoping for an easy solution for my Vaillant heating system.

[MichaelLachmann]

Is the adapter receiving the power from the ebus? Or do you need an extra power supply for the adapter? I believe the adapter shield can be ordered very easy in Europe.

[kylegordon]

The adaptor is powered by USB. Connect one side to the ebus bus, connect the other to wifi, ethernet, USB, etc. I think the Wifi and Ethernet versions require power over USB

[MichaelLachmann]

The only thing which makes me fearful is that you do not know if the address where you write to, is duing that what you think it does. And nowone knows if you can change the value back after you changed it .... or what the system starts to do when you change a wrong value ...

I did a similar project with a self written Arduino-Program and a Viessmanm heating system ten years ago. That time I've read all the bus values first and prayed that i didn't destroy anything :-D

[kylegordon]

Yes... it gives me the fear too. That's why I've refrained from investigating the write options :-D

[jdiviney]

At least there's a layer of interpretation from the ebusd config files, you're not the first person writing and you're not writing hex values directly, just choosing from options others have deciphered first

[zolakt]

Can somone tell me if "quick veto" works by default in ebusd, or does it require some special configuration? That is my main concern.

All of my thermostatas are in time controlled mode, and change on a schedule. If I just crank up the heating manually over the ebusd climate entity, will that start a "quick veto" session the same as the phisicaly termostat and the api integration do?

[jdiviney]

It's not the most intuitive but you can get the quick veto functionality.
Discussion and links from here john30/ebusd-configuration#423

[rj2s]

Hi, thanks to share this info. Just for my understanding, is this Ebus connectivity compatible (or not) with the VR940f ? Can we use both ?

[jdiviney]

Ebus sits in complete parallel so doesn't remove any native functionality and you can read without writing or do both and everything syncs up as it's all on the same bus

[camhef]

I have an eBUS Adapter Shield v5 connected to my Valliant system in read only mode as I don't trust myself not to move a slider and change something important.
If you have Ambisense radiator valves then you'll be out of luck as they are not exposed to the eBUS or MQTT. I have to use the myVaillant integration to view and control the TRVs.

[MichaelLachmann]

Is there a list of compatible systems and what values you can retrieve or what things you can do/change?

[roblan]

@kylegordon You have both sensonet and ebusd adapter installed on the same bus?

does this mean that both adapter and vr 940f could work at the same time?

[jdiviney]

Yes, both can be on the bus at the same time. I could start a hot water boost in home assistant via ebusd and cancel it via the Vaillant app

[roblan]

perfect.

Do you know if it is possible to connect multiple appliances to one ebusd adapter? (I have both water heater and a heat pump)

[kylegordon]

I think so. I believe eBUS allows for multiple devices. One master, and multiple slaves. The system figures it all out automatically, or one core device is set as master, like the heat pump.

[YukoKoch]

Hi there,
Which add-on repository do I need to add to Home Assistent to find the correct ebusd add-on?
I have the C6 adapter.
Thanks!

[mike4001]

Just looking for 10 minutes myself ... ;-)

And I found it: https://github.com/LukasGrebe/ha-addons

Look in the Known issues and Discussions on https://github.com/john30/ebusd/ => much to read and understand there.

[YukoKoch]

Thank you! Yes, that's the Add-on I'm using as well, but then I also need an integration for ebusd (at least I read that everywhere). I just don't know which one and how to get it.
If it's the default HA one that needs to be added through the configuration.yaml, what are the parameters that need to be set?
Thanks!

[YukoKoch]

Ah sorry, at the time I wrote this question I also didn't know which add-on to use, since I didn't manage to install the one from john30. I then used the one from Lukas Grebe.
Now I got that set up, but am still missing which Integration to use and how to set it up to start to see values.

[mike4001]

Ah sorry, at the time I wrote this question I also didn't know which add-on to use, since I didn't manage to install the one from john30. I then used the one from Lukas Grebe. Now I got that set up, but am still missing which Integration to use and how to set it up to start to see values.

You just need a working MQTT integration in Home Assistant. Then the eBUSd addon should auto-configure MQTT and send the data to Home Assistant.

Previously there was an ebus integration for Home Assistant bis this is bascially from before MQTT was integrated into the ebus Addon.

[kylegordon]

Found this handy climate card discussion - https://community.home-assistant.io/t/mqtt-climate-card-broken-for-temperature-changes-ebusd/656133

I have a climate card that has valid data now, using ebus, and whilst commands are published using MQTT, with the system responding with a similar ebusd/basv/z1ActualRoomTempDesired value, after a minute or so it just resets back to the previous state. Not sure what combination of events need published.

[jdiviney]

You need to edit the basv config as writing to Z1desired.... doesn't work with the stock config file

john30/ebusd-configuration#539

[kylegordon]

You need to edit the basv config as writing to Z1desired.... doesn't work with the stock config file

john30/ebusd-configuration#539

Excellent! Thank you, climate card now controls the basics of Zone 1

[YukoKoch]

Hi there,

I've installed the adapter with USB connection, mosquitto and ebusd Add-ons are running, but I can't see any values.
Which integration would I need to add? I can't see any when I type "ebus". Would I need to add some special repository? I didn't manage to add the one from john30. The Add-on I have is from Lukas Grebe.
Should I see the values already in the Add-on or the MQTT integration from HA?

Thanks!

[peroni1000]

Thanks guys. I now have this working beautifully!
Two things that I was hoping to achieve - please help me if you can:

1. I would like to read the flow rate, but i cant see a sensor for that in MQTT
2. I really wanted to calculate energy per day separately for HC and HWC like I can in the myVAILLANT API, but the current separate values seem to round up at the nearest 1kWh! ebusd_ctlv3_prenergysumhc

[zolakt]

I just got the adapter and I'm reading how to set it up.

I see there are 2 options: ebusd and micro-ebusd, and I find some things a little confusing:

1. am I right to assume if I use micro-ebusd I don't need to run the ebusd HA addon?
2. a token needs to be purchased for micro-ebusd. Currently, they don't sell them due to some tax issues, and it's free. How much did it cost while it was being sold?
3. for micro-ebusd, since a token is required, do I need to put the adapter on a VLAN that has internet access, or can I cut off internet regardless?
4. as far as configuration goes, are there are differences between ebusd and micro-ebusd? Can one do something that the other one can't? e.g. can both write data? Do more complex options like quick veto work with the micro-ebusd version?
5. which one would you suggest in general, what is the better option?

[signalkraft]

https://github.com/signalkraft/ebusd-vaillant-component

After recent outages and increased quota errors, I also got myself an eBUS adapter (the C6 stick) and created this integration to be able to connect locally and still have fully functional climate / water heater entities. Testing is limited to my system (VRC720), but there's some diagnostic tools to make extending it pretty easy.

Compared to the raw ebus HA entities, I'm trying to create something more along the lines of the mypyllant-component, with working climate entities & features like quick veto and away mode out of the box. There's a long way to go, but I'd appreciate some testing.

[MarkBovee]

I built a local HA custom_component that connects to ebusd directly over TCP (no MQTT, no cloud). It auto-discovers all registers via the ebusd find command and creates HA entities dynamically — currently ~254 live sensors from my aroTHERM + VRC720 system.

https://github.com/MarkBovee/vaillant-ebus

It's a pure custom_component, installable via HACS. You still need the ebusd addon running (LukasGrebe repo), but no separate MQTT broker or additional integration setup required — just point it at ebusd's TCP port 8888.

For me this is a 1-on-1 replacement of the mypyllant API integration — it exposes climate entities (quick veto, away mode via calendar), water_heater entities (DHW boost, temp control), and all the sensors I had before, but fully local.

Features that aren't available through the standard ebusd MQTT path: away mode (calendar-based scheduling), room humidity (CTLV2, runtime-defined register), and proper climate/water_heater entities — all work out of the box.

Main difference from the existing ebusd-vaillant-component: this one generates entities directly from ebusd's register discovery rather than hardcoding specific register mappings, so new registers appear automatically after a rescan.

Would love feedback from others testing it on different hardware configurations.

[peroni1000]

I changed the adapter from serial to TCP enhanced and reconfigured eBUSd app

eBUSd
s6-rc: info: service legacy-services successfully started
[16:06:20] INFO: eBUSd addon version 26.1.8
[16:06:20] WARNING: mqtt-hassio.cfg exists in config folder but seed_mqtt_cfg is false and no --mqttint in commandline_options — the file will not be used by ebusd.
[16:06:20] INFO: ebusd --foreground --updatecheck=off --mqtthost=core-mosquitto --mqttport=1883 --mqttuser= --mqttpass= --device=ens:192.168.86.24 --accesslevel=* --port=9999 --enabledefine
2026-07-24 16:06:20.416 [device notice] transport opened
2026-07-24 16:06:20.418 [main notice] ebusd 26.1.26.1 started with broadcast scan on device: 192.168.86.24, TCP, enhanced
2026-07-24 16:06:20.625 [bus notice] bus started with own address 31/36
2026-07-24 16:06:20.625 [device notice] reset, supports info
2026-07-24 16:06:20.625 [bus notice] signal acquired
2026-07-24 16:06:20.626 [mqtt notice] connection established
2026-07-24 16:06:20.633 [device notice] extra info: firmware 1.1[6704].1[6704], jumpers 0x0b

Vaillant eBUS (ebsud) app still fails to connect:
Host: ens: 192.168.86.24
Port: 9999
Update interval: 60

[MarkBovee]

I will write a more detailed guide later, but these are the steps I followed:

1. Connect the C6 eBUS adapter to a PC using USB-C, configure WiFi, and assign a fixed IP address.
2. Connect the C6 adapter to the Vaillant heat pump and switch the adapter to TCP enhanced mode.
3. Install the ebusd Home Assistant addon and configure it to point to the C6 adapter IP address.
4. Start ebusd and verify that it connects.
5. Install my Integration and configure it to connect to the ebusd endpoint on Home Assistant (port 8888) with the ip address of home assistant, not the stick.

[peroni1000]

OMFG Mark - you absolute legend!!!!!!!!!!!!!!!!!!!

[peroni1000]

Mark. Where and how would you like my feedback. I have been using myVaillant and MQTT eBUSd for over a year now. I can send you a comparison table and screenshots, but better still would be a screen share call to show you comparisons and you make your own notes. Regards Mick

[MarkBovee]

Hi Mick,

Thanks, this is exactly the kind of input I'm looking for. I just set up GitHub Discussions for this: https://github.com/MarkBovee/vaillant-ebus/discussions

Could you post your comparison in the "Comparisons & Feedback" category? Table + screenshots work great there, and it stays searchable for other myVaillant/MQTT users who run into the same questions. If anything's hard to capture in text, a short screen recording (Loom or unlisted YouTube) works well too.

Heads up: I'm on holiday this week, so a call really isn't an option for now - async is the way to go for the time being. I'll read through everything properly once I'm back.

Thanks again for putting in a year's worth of experience into this - looking forward to reading it.

Mark

[zolakt]

I kept postponing the switch to ebusd, because I never managed to find the time to put all of that into a usable HA component. So it's great to see that people have done that already. Thank you both @signalkraft and @MarkBovee for the effort on:
https://github.com/signalkraft/ebusd-vaillant-component
https://github.com/MarkBovee/vaillant-ebus

I have a few questions if someone could please answer:

• do these work with micro-ebusd or do I have to run the addon?
• which one is further along and more stable? I need it for a VRC720 with 2 circles/zones

[MarkBovee]

I run my integration alongside the ebusd Home Assistant addon (https://github.com/LukasGrebe/ha-addons/tree/main/ebusd). The addon handles the eBUS communication, while my integration translates the raw eBUS data into proper Home Assistant devices, entities, and controls.

It should work with multiple heating zones. I currently only have a single-zone VRC720, so I haven't been able to test a multi-zone setup myself, but the code automatically creates additional zones when data is available.

I also use a VRC720 (single zone) and replaced my previous myVAILLANT API integration with the eBUS integration this weekend. So far it has been running very stable without any issues. If you run into anything specific with a 2-zone VRC720, let me know. I can use that to improve support.

The next release will focus on exposing even more values from registers that are currently not available as entities.

[zolakt]

Thanks for the reply. Just regarding micro-ebusd (the one that runs on the adapter, without the HA addon), do you know up-front it won't work with your component, or it's just untested and worth giving a try? I honestly don't know how it works exactly, but it does expose all values to MQTT directly from the adapter, without the need for the HA ebusd addon.

[MarkBovee]

As far as I know, micro-ebusd doesn't expose all the data that the full ebusd daemon does. It also publishes raw MQTT values, whereas my Home Assistant integration turns the data into native Home Assistant entities and controls like climate, water_heater, number, and select.

[zolakt]

I guess I'll just give it a try. I know micro-ebusd won't expose HA entities, neither does the full daemon. They just expose MQTT. The only question is can your component turn the micro-ebusd data into HA entities, or for reason it only works with the full daemon

[MarkBovee]

I only created it with the full ebusd, no mqtt.