Home Assistant/MQTT Bridge

Home Assistant gurus,

Has anyone had any experience running multiple instances of Home Assistant?

A bit of background…
Currently our hot water is controlled with a ‘Climate’ integration (in my existing HA instance) which toggles a relay to fire the gas boiler.
Now on Octopus Go; I am looking to heat the water via the immersion connected to HEMS during specific times, and to the temperature requested on the HA climate integration.


I have been looking into an MQTT bridge, but can’t get my head around it!
I know the immersion heater has it own thermostat, but I would like the ability to adjust the water temperature.

Any ideas would be greatly appreciated!


1 Like

Do you have an MQTT broker running already on your custom HA or would this be a new service?

Hi Ben,
Yeh I have an MQTT server (mosquitto) running on my HA. Is it possible to publish messages to two brokers?


Yes there are a few options. Its difficult for us to modify config of MQTT broker on HEMS but if you are able to run a MQTT bridge on your other device (Hass OS+Raspberry Pi?) then we can probably make it work. I would suggest running a separate mosquitto initially instead of trying to combine with any existing one on your custom HA. Is the layout like below:

1 Like


After some playing around with a config file on my existing HA instance, I can now listen to the HEMS MQTT. Setup is now as per the image below.

Thanks for the support!

1 Like

Thats great Graham. Makes sense.