I think this question relates specifically to using Ecobee thermostats via HomeKit Integration vs. via the Ecobee integration.
I recently added serveral Ecobee thermosats. The Ecobee Integration was not an option for me because of Ecobee’s apparent shutdown of the developer program as a way to access their API.
In my setup, the thermostats control Carrier heatpump systems with gas backups. There are certain situations where I may want to direct the systems to run off gas - for example, when I have an electrical outage and am running on generator.
There are two levels where Ecobee seems to give me some control over this. One is buried within the “installer settings” of the thermostat (afaik accessible only directly via the screen interface of the thermostat). The other is by switching the thermostat to the mode called “aux”. This latter option is available via the Ecobee app, but afaik is not available via Home Assistant using the HomeKit integration from Home Assistant.
Ecobee modes for my unit are {Heat, Cool, Heat/Cool (Auto), Aux, and Off}. Confusingly, the device page for the Ecobees in Home Assistant has a pull-down menu called “mode” but it does not actually set the thermostat mode. Instead it sets what Ecobee seems to correspond to what Ecobee calls “comfort settings” (by default {home, away, sleep}).
It seems using the dashboard interface, there is a button I can click that lets me select four out of these five modes, but not aux. Doh! So close.
So does anyone know of a way to switch my Ecobee thermostats from Home Assistant to switch to “aux” mode? This seems like an important gap in functionality when using Ecobee to control a heat pump system.