Honeywell RTH8500 User Manual

Your new thermostat is pre-programmed and ready to go. All you have to do is set the 
time and day. Then check the settings below and change if needed:
1. 

Set clock ......................................................................................................... See page 6

2. 

Select fan setting: Preset to Auto ...............................................To change, see page 7

3. 

Select system setting: Preset to Heat ........................................To change, see page 8

4. 

Program schedules: Preset to energy-saving levels  

while you’re at work or asleep (assumes you  

wake at 6 am, leave at 8 am, return at 6 pm  

and go to bed at 10 pm) .......................................................To change, see pages 10-13

ONE-TOUCH TEMP CONTROL: You can override the program schedule at any time, and 
manually adjust the temperature (see pages 12-14).