Bosch has internet gateways for selected EMS boilers and heatpumps. It’s a range of models like the KM50, KM100, KM200 and MBLAN 2. Depending on the brand there are small variations. Nefit just calls it ‘Internet module’. There is an external model for existing boilers and an internal module for heat pumps. With this gateway and an app on your phone you can see (partly) what your boiler is doing.
The BBQKees EMS Gateways also give insight into boiler parameters.
I often get questions about the difference between the EMS Gateway and the Bosch KM200 Internet gateway. In this article I’ll explain it in more detail.
How does the KM200 work
The KM200 (and the other Bosch internet gateways) connect to the CAN or EMS bus of the boiler or heatpump and your home network. The data it captures from the bus is then sent to the cloud.
You need to install an app on your phone to see the data. The app does this by connecting to the cloud and retrieving your boiler data from the cloud. So all your boiler data is stored in the cloud.
It provides a link between your boiler and an app via the cloud.
How does the EMS Gateway work
The EMS Gateways also connect to the EMS bus of your boiler or heatpump and your home network. The data it captures is then sent to your home automation like Home Assistant or Domoticz.
It depends on how you configured your home automation on how you can access the data. Likely via a web interface on your pc but probably also via an app.
The EMS Gateway provides a link between your boiler and your home automation solely via your home network. So you do not need an external cloud service. All boiler data is stored locally in your home automation system.
Amount of available datapoints
Existing owners of a KM200 are often surprised by the amount of datapoints/entities the EMS Gateway provides over the KM200. With the EMS Gateway you usually get 60 entities of just the boiler alone. With some boilers and heat pumps this may add up to much more (100+). For thermostats and mixer modules it depends on the specific model but there are always some interesting values coming out.