Monthly Archives: February 2025

Plumbing & Heating

Ideal Vogue Max Opentherm Control via Home Assistant

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Updated 26th February 2025

Experimentation – Work in Progress

I have an Ideal Vogue Max 18kW System Boiler with Weather Compensation, using Hive to control the schedules and room temperature, I also have individual radiator Hive TRVs but these are set to 23oC to limit overtemperature, ideally the system is set to ‘open loop’ control.

The above graph from Open Energy Monitor shows my systems efficiency over the period to be between 98% and 74% and I read that utilizing Opentherm Gateway hardware with Smart Autotune Thermostat integration in Home Assistant could make energy efficiencies, hence this blog.

Overview –

Evolving system proposal as I learn more from forum experts, who are brilliant.

Currently, Hive is used for timing schedules for hot water and heating whilst using opentherm for greater gas modulation control on heating, rather than the Hives’ on/off control.

This is definitely work in progress.

Project Information Sources –

Opentherm Gateway (OTGW) – This was bought from Nodo-Shop, I chose the Wi-Fi version and paid to have the WeMos D1 Mini Wi-Fi module pre-programmed, I also bought a case for the completed gateway.

The PCB needed a small amount soldering, but they also offer this service.

Completed OTGW and Ideal Halo Lite thermostat.

OTGW installed and powered up, I did have a small hiccup when I originally built the OTGW in that it didn’t work for me, I followed the fault finding instructions and the forums were brilliant at giving pointers.

It turned out that a replacement PIC chip solved the issue, I must say a big thanks to Nodo-Shop who were great.

Getting it to work –

On Home assistant I installed Mosquitto Broker Add-on to manage MQTT messages from the OTGW, to do this I followed tutorials on YouTube and set up additional Home Assistant (HA) user accounts for the MQTT broker and Client as directed.

The Smart Autotune Thermostat (SAT) integration was also downloaded and installed on HA.

As I bought a pre-programmed Wi-Fi module, all I had to do is power it up and use my mobile phone to find its Wi-Fi and set up the network details, after this I could find it on my network and add all the relevant MQTT details, once done, HA discovers it and everything worked magically for me.

Now I knew the OTGW network IP address, I could connect to OM Monitor which reads the opentherm traffic, in my case the boilers return water temperature was not being read for some reason, however, their are some real experts on the forums ever willing to share information and I was told to disconnect the Halo Lite thermostat and miraculously all readings populated :-).

Learning-

I’m going to use this space as a dynamic journal, asking myself questions and finding out answers to best suit my set up, posting them here.

  • The Sonoff thermostat I’ve been using updates every 5 minutes, the recommended update time is 30 seconds and Xiaomi LYWSD03MMC was suggested as was changing the firmware. I’ve ordered a couple of these and will try to flash them with Tasmota, I’ve not done this before…the journey continues 🙂