How do I enable or disable the filter reminder feature?
Press MORE, then EDIT to access the filter settings. Press the up or down arrows to select the desired reminder interval in days (options range from off to 365-day run time intervals), then press DONE. After changing your filter, press RESET to restart the timer. System setting function 0500 governs the filter interval.
From the official Honeywell RET97B5D100 Home Programmable Thermostat manual, page 43
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