When you see the word “Filter” flashing in the display of the thermostat, it is simply a reminder to change the filter in the blower of your heating\cooling system (totally separate from thermostat).
This feature does not affect the operation of thermostat in any way.
There is a Graphical Visual bar graph in the center of the screen , which shows the amount of air filter life remaining in %. It starts at 100% and goes down to 0%. When it gets to 0%, the bar graph will be empty and flash “FILTER”
Each dot in the filter bar graph equals 10 percent (example: 4 dots shown means 40 percent filter life)
TO RESET OR CHANGE THE AIR FILTER DURATION: