Thermostat backlight stays on constantly or will not turn on

Safety first: No need to power down HVAC; changes are made at the thermostat.

Steps to troubleshoot:

• 1. Adjust backlight settings: In the thermostat menu, set backlight to 'Auto' or 'On Demand' as desired.
• 2. Reboot thermostat: Remove the thermostat from the wall plate for 30 seconds, then reattach.
• 3. Check ambient light/proximity sensor: If your model uses a sensor to control backlight, ensure it is not covered or obstructed.
• 4. Firmware update: Update the thermostat firmware via the app to resolve known display issues.

When to call a professional: If the backlight remains stuck on or off despite settings and reboot, the display assembly may be defective and the thermostat should be replaced.