Honeywell T8665C Thermostat User Manual


 
23 69-1538
Filter Indicator
Your thermostat monitors the amount of time
the fan is running and lets you know when to
replace the filter, based on the number of fan
run-time days you select. On expiration,
thermostat displays “Filter.”
One fan run-time day equals 24 fan run-time
hours. (If fan is on only one-
third of the time each day, it
takes three days to deduct
one fan run-time day.)
Setting or Resetting Filter Indicator
Your thermostat comes preset to a 30-day
setting. To change this setting or reset after
filter expiration:
1. Press Filter key to enter Filter
mode.
Press Filter key to display filter information. Example
display shows current fan run time set to 30 days with
filter set to expire in five days.
2. Press and hold Filter key for
at least three seconds to
reset fan run time.
FILTER EXPIRATION INDICATOR
Wake
Room
Filter
System
Fan
Em Heat
Auto
AM
DST
Tue
M20899
M1457
7
80
90
70
60
90
80
70
60
Filter
Filter