Viessmann interconnections?

Hardware
1

Does anyone know of a guide to the interconnection technologies used by current Viessmann devices?

My old Viessmann Vitodens 200-W gas condensing system boiler (type WB2C) will soon need to be replaced. The various parts of the system are interconnected using the proprietary KM-Bus 2-wire bus. Works fine but no external connection.

I really wanted to replace it with a Viessmann Vitocal 200-A air source heat pump (ASHP). After a lengthy investigation, I have concluded that even with the UK government grant the disruption and cost are higher than I am prepared to accept. It supports the proprietary KM-Bus so some of the existing system could have been reused. If I later decided to upgrade my MVHR to a Viessmann Vitovent 300-C then that could be connected using Modbus which is also used between the internal and external units of the ASHP. The Vitocal 200-A has a WiFi option for external connection.

So I’m thinking of replacing the old Vitodens 200-W with the latest Vitodens 200-W (type B2HF). Should be simple, right? The latest model uses the proprietary PlusBus 2-wire bus. The wiring can be reused but the KM-Bus devices will need to be replaced with PlusBus devices. It does have integral WiFi for external connection. No Modbus for possible future direct integration with the Vitovent 300-C. The Vitodens 200-W appears to have CAN bus with a very expensive option for a WAGO MB/RTU gateway.

To add to the confusion the Vitodens 200-W (type B2HF) is compatible with the Vitotrol 300-E. This has an encrypted 2.4 GHz low power radio connection to the boiler and an optional 2.4 GHz WiFi connection for automatic software updates. Would be really handy if it is a Matter or Zigbee certified device! However, the low power radio connection could be proprietary.

Is the Vitotrol 300-E low power radio connection the future for connecting Viessmann domestic devices? I see from Funkfernbedienung Vitotrol 300-E that the Vitoair FS ventilation unit is supported (maybe it is an alternative to the Vitovent 300-C)?.

Any advice or pointers to further information?

2

Find out who is manufacturer of that. Viessmann? Midea? Some other…?

3

This may be relevant: News Smart Home Start-Up insolvent: Viessmann takes over Wibutler (in German). Here is a more recent article about Wibutler: Too many applications for one standard alone which contains a link to DBT Digital Building Technology. It’s possible that the Vitotrol 300-E is based on the Wibutler Pro.

A Certified Products Search for “Viessmann” didn’t find any products. However, Viessmann Elektronik GmbH appears to be a member of the Connectivity Standards Alliance.

Viessmann has used Zigbee. Their ViCare radiator thermostat bears a very strong family resemblance to the Danfoss Ally™ Radiator Thermostat and is one of the three Viessmann devices in Zigbee2MQTT Supported Devices.

Even if the Vitotrol 300-E was a Zigbee (or Matter) Certified Product there is no guarantee than it could be used by Home Assistant.

It would be interesting to hear from anyone who has experience with the Vitotrol 300-E. Otherwise, I will have to wait until I have a new gas boiler installed and try one myself …

4

Viessmann One Base VITOVENT 300-W contains the following:

1538 Low power radio (“ZigbeeEnable”)
Activation of low power radio. Required for connecting
external sensors such as the ViCare climate sensor
and remote control units such as the Vitotrol 300-E.

A strong hint that the low power radio is Zigbee.