I recently disabled the rule that shuts off the thermostat/fan on a smoke/CO alarm. I had two reasons and two suggestions for ADC to improve this feature:
1) I keep forgetting to turn the thermostat back on after the smoke alarm is cleared. During winter, my reminder is realizing that it’s starting to get cold inside. Earlier this week, I didn’t realize that until I woke up in the morning in a 64 degree bedroom. I then rushed to my newborn baby to make sure she was ok…a little scary.
Recommendation: Create an option to “Restore Last Settings” to the thermostat once a smoke alarm is cleared with a disarm code/command.
2) In case of a CO alarm, it actually would be advantageous to keep the fan running. Shutting off the fan immediately when it was running prior to the alarm could increase CO concentration at the location in question, making it more likely than an occupant will be overcome before exiting to fresh air.
Recommendation: Allow separate settings for thermostat/fan shutoff for smoke and CO alarms. This is how Nest handles this.