Replacing a Honeywell thermostat with an ecobee
Replacing a Honeywell VisionPRO IAQ (TH9421C1004 + EIM) with an ecobee Smart Thermostat Enhanced Trigger Warning: I used AI extensively throughout this process, including writing this article. If this bothers you, stop reading now. tl;dr: I asked ChatGPT how I could replace my proprietary Honeywell IAQ thermostat with an ecobee. It asked for some photos and took me through the whole process from start to finish. It was amazing. This article is still a work-in-progress, so check back for updates. ...