The first step would be to remove and re-enroll that thermostat to the panel.
If it is using a C wire, be sure to learn it in while it is powered off of AC, if paired while running on battery only it will function in a power save mode from then on.
The first step would be to remove and re-enroll that thermostat to the panel.
If it is using a C wire, be sure to learn it in while it is powered off of AC, if paired while running on battery only it will function in a power save mode from then on.