OpenTherm Boiler Control via MQTT

This project enables the control of an OpenTherm-compatible boiler using MQTT.

Hardware Requirements

• OpenTherm Shield
• WeMos D1 Mini ESP32

Prerequisites

• OpenTherm-compatible boiler
• MQTT server

Setup and Installation

1. Update WiFi credentials and MQTT settings in config.h. Modify the fields marked with TODO.
2. Compile the code using your preferred IDE.
3. Upload the compiled firmware to the D1 Mini ESP32.

MQTT Topics

Published Topics

The device publishes boiler status updates and logs to the following MQTT topics:

• boiler/status
  Example payload:

  {"heating": "ON", "hotwater": "OFF", "flame": "ON", "modulation": 25, "pressure": 1.5, "temperature": 45.0, "return_temperature": 38.0}

• boiler/target
• boiler/wifi
• boiler/log/info
• boiler/log/error

Subscribed Topics

The device listens for control commands on the following topics:

• boiler/control/heating Example payload:

  "ON"

• boiler/control/hotwater Example payload:

  "ON"

• boiler/control/heating_setpoint Example payload:

  45.0

License

This project is open-source and provided under the MIT License.

Contributing

Contributions and improvements are welcome. Please submit issues or pull requests via the repository.

Contact

For support or inquiries, please open an issue in the repository.