Vailant Heat Pump Controller displays "Communication Fault" when adapter is connected

[simonaldrich]

Hi

I have the following setup:

• Version 4 ebus/wifi adapter
• Vaillant Arotherm Plus Air Source Heat Pump
• Vaillant VZW AI Heat Pump Controller
• Vaillant SensoComfort RF Heating and Hot Water Controls

I've spliced my v4 adapter into the existing ebus connection between the Heat Pump Controller and the Heating Controls (please forgive the temporary loose Wagos etc):

I understand that this should be acceptable for ebus connections since the installation manual states:

"You can branch the eBUS connection to the product at any part of the eBUS system" ¹

When running ebusd I seem to be able to read to and write from the bus (I read and set the date and time on the Heating Controls as a test) however after a couple of minutes (at most) I get a "Communication fault" error code displayed on the Heat Pump Controller's display:

The fault clears after a while but raises again shortly thereafter.

I think the problem must lie either in my connection or in the adapter since the fault is raised even when ebusd is stopped (i.e.:) the adapter is only powered on.

Hopeful someone can tell me what I'm doing wrong 🙏

Thanks very much, Simon 🙂

Footnotes

1. VWZ AI Installation Instructions §3.3 ↩

[danielkucera]

I suspect it's this one: https://github.com/danielkucera/esp8266-arduino-ebus#the-adapter-is-loosing-connectivity-breaking-other-ebus-components-communication-d7-is-blinking-wifi-is-disappearing-after-connecting-devices-on-the-bus-show-error-status-or-other-intermittent-failures

[simonaldrich]

Thanks, I'll try that 🙂

[speedfightnl]

@simonaldrich did an external psu fix your issue, as I’m having exactly the same setup and same issue.

update: can confirm connecting a 24v psu solved this!

[simonaldrich]

@speedfightnl I hadn't actually had time to try it out but I hooked up the PSU tonight to try this out. So far it looks like it's working 🤞 so I guess I'm wiring up an outlet in the airing cupboard in the near future 🙂

[syntos]

I'm havind the same error. I'm using the latest V6.1 version. Can I power the adapter using the USB-C port? Should I make some changes to the PCB? e.g. cut a jumper or remove a component? I'm not really sure what I need to do and I want to avoid breaking the module.

[danielkucera]

@syntos , please follow this:
https://github.com/danielkucera/esp8266-arduino-ebus#the-adapter-is-loosing-connectivity-breaking-other-ebus-components-communication-d7-is-blinking-wifi-is-disappearing-after-connecting-devices-on-the-bus-show-error-status-or-other-intermittent-failures

[syntos]

I've found this already but I'm not sure how to connect the external power supply. Is it possible to power the V6.1 version using the UCB-c port without any modifications to the PCB?

[danielkucera]

Yes, just remove the jumper

[hocomadvies]

Reading this because I have the problem that my V6.1 version is not powered up from e-bus at all. Investigated the board, but neither can find a jumper or as mentioned a 2.0 mm pitch. Having it with the usb kabel I can run it from the computer. But connected to the 2 e-bus wires it stays dead. Where can I find the jumper or pitch to remove. Or is my version already suitable for usb-C power 5v? (v6 2.34)

[danielkucera]

@hocomadvies , can you please post a picture of how is your adapter connected?

[hocomadvies]

I have two wires from my e-bus (vaillant heat pump) connected to the green connector. Even tried them reversed but still the same. I have two other vaillant modules connected VWZ and Connection module for the Thermostat.

[danielkucera]

I suspected this :) This is not adapter made by me. Please check https://adapter.ebusd.eu for info for this one.

[hocomadvies]

Ok I will check that out. Where can I obtain one of your adapters?

[danielkucera]

https://blog.danman.eu/ebus-adapter
For any other questions, please open a new issue, we are spamming several people in this thread.