ESP32/ESP8266 based solution for Bosch GreenTherm 9000

Looking for an ESP32/ESP8266 based solution to connect my Bosch GreenTherm 9000 series tankless gas water heater to HA. Even just monitoring usage stats would be helpful.

I’m aware there’s an OEM WiFi module (expensive and unavailable), so I’m hoping there’s something similar to Mitsubishi2MQTT or an ESPHome-based project that documents how to connect to the water heater.

I do know the OEM module is not EMS based, so I do think some bit of reverse engineering might be in order.

Happy to help test if anyone wants to take this on!

(Cross posted to projects; will remove there if necessary).

I’m also looking for this for my bosch water heater.
I would be happy to do the reverse engineering if I could get my hands on the existing WiFi accessory.

I ordered one I found online for a somewhat reasonable price (last one) during black friday, but I need several more – think we could work together to do the reverse engineering? I’m somewhat familiar with the reverse engineering process, but haven’t yet had the need/opportunity to reverse engineer a physical component start-to-finish.

I am happy to build and package the add-on/integration if we are able to successfully sort things out.