What you need
Today Emthera runs on a box you buy separately, next to your boiler, and works together with Home Assistant, a smart home system you run in your own home.
- Current version
- 1.4.6
- Boilers
- EMS (Nefit, Buderus, Bosch, Junkers, Worcester)
- Control
- Home Assistant and the box itself
- Languages
- English, Dutch
What you need
- A BBQKees Gateway E32 V2, connected to your boiler. You buy it separately from BBQKees Electronics.
- A boiler with EMS: most Nefit, Buderus, Bosch, Junkers and Worcester. If your boiler's manual or your installer says "EMS", you are fine.
- Home Assistant 2026.10.0 or newer, with an MQTT broker such as the Mosquitto add-on.
- The Emthera firmware on the box. It is not available for public download at the moment.
How to start
- Read the installation guide. It also describes installing the firmware. Allow about an hour and a half.
- In Home Assistant, open Settings → Marketplace, choose Add from link at the top right and enter github.com/dielessen/openthermostat-ha. Then install OpenThermostat. On 2026.10 and older this goes through HACS.
- Add the integration under Settings → Devices & services. Everything after that is in the manual.
What works today, and what does not yet
| Works today | In development, not for sale or use yet |
|---|---|
| The software runs on an existing box from another maker: the BBQKees Gateway E32 V2. | Emthera's own Hub, with Ethernet, Wi-Fi, Bluetooth and connections for EMS and OpenTherm. The first test boards have been ordered; there is no working one yet. |
| Boilers with EMS. Newer EMS+ boilers are read. | OpenTherm. The connection will be on the Hub; the software for it still has to be built. |
| Control through Home Assistant and through the pages on the box itself. | A new design for the pages on the box. |
| The Home Assistant integration, free through the Marketplace. | A battery room thermostat with a small screen and plus and minus. |
| Version 1.4.6 of the firmware and the integration. | A case for the Hub. |
Until 13 November 2026 Emthera was called OpenThermostat. Home Assistant and the manual still use that name.