Planning to move from Ecobee 4 to a Honeywell thermostat for a few reasons but one is lack of ERV control (another is the screen lights up in the middle of the night waking my wife despite my trying to make the screen as dim and unresponsive as possible). Currently I can only set a minimum run time per hour in the Ecobee app. I would love to be able to set this to run via HA and use triggers such as CO2 reported by AirThings, etc.
The Honeywell site seems to suggest that only the T10 Pro is capable of running the ventilator. I see few posts here about that one since it does not have the Zwave abilities of the T6 and thus is not local.
Would greatly appreciate any info on which thermostat is required for HA control of an ERV/Ventilator and any other suggestions you may have on moving from Ecobee to a Honeywell device. Open to alternatives as well.
I have a T6 (WiFi Version) and can confirm that I can not set it up to run in fan-only mode from the HA Integration (via HomeKit), while the Resideo app itelf offers this option.
I installed a workaround for my AC/Furnace with a relay that does this (i.e. connects the respective wires) and drive it from HA like a switch with scripts, automations, and timers as necessary.
I have not, but I found it pretty straightforward to implement.
I’m using a 4-channel switch because I wanted to be able to run both zones of my AC/Furnace in fan-only mode and add a time-based option for each one of my AC units (rather than relying on the thermostat alone). I’d purchased this one because it was advertised as a Sonoff Zigbee device, but - even after sending it back to have it swapped out for what I actually ordered - I ended up with a WiFi version
I’d previously used a one-channel relay combined with a temperature sensor for about 10 days when my thermostat died (that’s how long it took to get a one-for-one replacement), so I knew I could do this for the AC part of my setup.
To connect the AC/Furnace units to the switch, I simply added a 2nd thermostat wire to each one of the main boards:
Some of the necessary logic, e.g. don’t allow the AC to be turned on within 5(?) minutes after it has been turned off, to avoid damage to the AC units seems to be built into the AC/Furnace unit itself, so I didn’t have to account for that in my automations/scripts.
Right now, I’m just using 15min timers to initiate the fan-only and temperature-override actions of the thermostat-driven activities.
