Honeywell RTH8500 User Manual

Thermostat features ............................... 2
Programming at a glance ....................... 3
Quick reference to controls .................... 4
Quick reference to status display ........... 5

Clock setting ........................................... 6
Fan setting .............................................. 7
System setting ........................................ 8
Using program schedules ....................... 9
Program schedule overrides ................ 12
Vacation hold ........................................ 14
Screen cleaning .................................... 15
Furnace filter reminder ......................... 16
Special features .................................... 17

Battery replacement/ 
Customer assistance ............................ 18
In case of difficulty ................................ 19
Limited warranty ................................... 21

Your new thermostat is pre-
programmed and ready to go.  
See page 3 to check settings.

CAUTION: EQUIPMENT DAMAGE 
HAZARD. To prevent possible  
compressor damage, do not operate 
cooling system when outdoor  
temperature is below 50˚F (10˚C).