Honeywell RTH8500 Series User manual

Operating
Manual
RTH8500
Touchscreen Programmable Thermostat
69-2220EF-03

Read and save these instructions.
Need Help?
For assistance with this product please visit http://DIYthermostats.honeywell.com
or call Honeywell Customer Care toll-free at 1-800-468-1502
® U.S. Registered Trademark.
US Patent No. 6,595,430; 7,114,554; 7,274,972; 7,225,054; D520,386 and other patents pending.
Copyright © 2011 Honeywell International Inc. All rights reserved.
BE CAREFUL! Never use sharp instruments, such as a pencil
or pen, to press touchscreen keys. To prevent damage to the
thermostat, always press keys with your fingertip.
M28372
This thermostat contains a Lithium battery which may contain Perchlorate material.
Perchlorate Material—special handling may apply,
See www.dtsc.ca.gov/hazardouswaste/perchlorate
Note: Remove wallplate from the thermostat and see the label
on the back of the thermostat for model number.

1 69-2220EF—03
About your new thermostat
Thermostat features ..........................................2
Programming at a glance..................................3
Quick reference to controls...............................4
Quick reference to status display......................5
Programming & Operation
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
Appendices
Battery replacement/
Customer assistance .......................................18
In case of difficulty..........................................19
Limited warranty .............................................21
This thermostat is ready to go!
Your new thermostat is pre-
programmed and ready to go.
See page 3 to check settings.
Table of contents
CAUTION: EQUIPMENT DAMAGE
HAZARD. To prevent possible
compressor damage, do not oper-
ate cooling system when outdoor
temperature is below 50˚F (10˚C).
RTH8500

Operating Manual
69-2220EF—03 2
About your new thermostat
Congratulations! You’ve just purchased the world’s most advanced, easy-to-use ther-
mostat. It has been designed to give you many years of reliable service and touch-
screen climate control.
Features
• 7-day program schedules maximize comfort and economy.
• Armchair programming: Just pull thermostat from the wall to set schedules.
• One-touch temp control overrides program schedule at any time.
• Precise comfort control keeps temperature within 1°F of the level you set.
• Change/check reminders let you know when to replace filters and batteries.
• Large touchscreen display with backlight is easy to read—even in the dark.

RTH8500
3 69-2220EF—03
About your new thermostat
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).
This thermostat is ready to go!

Operating Manual
69-2220EF—03 4
SCHED HOLD CLOCK SCREENMORE
MON TUE WED THU FRI SAT SUN
AM
FAN
AUTO
SYSTEM
HEAT
Following
Schedule
Inside Set To
OK TO PICK MULTIPLE DAYS
70
6:01
70
M28373
Press day(s) to set program schedule (see page 11)
Press to select fan
operation (see page 7)
Press to select system
type (see page 8)
Press to set program
schedule (see page 11)
Press to adjust
temperature settings
(see pages 11-14)
Press for more options
(select models only)
Press to override
program schedule
(see pages 12-14)
Press to set clock
(see page 6)
Press to lock keypad for 30
seconds to clean screen
(see page 17)
Quick reference to controls

RTH8500
5 69-2220EF—03
SCHED HOLD CLOCKSCREEN MORE
WED
AM
FAN
AUTO
SYSTEM
HEAT
Following
Schedule
Inside Set To
Recovery
70
6:01
70
M28374
Current inside temperature Current day of week Temperature setting
Program schedule on
(does not display
when off)
Fan setting
Other display messages:
• Cool On: Cooling system is activated
• Heat On: Heating system is activated
• Aux Heat On: Auxiliary heating system is activated
(heat pump systems only)
Quick reference to status display
System setting
Current time
Smart Response®
Technology in effect
(see page 15)

Operating Manual
69-2220EF—03 6
To set the current time display, press CLOCK, then
press s or t to adjust the time. Press and hold s or
t to advance the time more quickly.
Press DONE to save & exit (or press CANCEL to exit
without changing the time).
Note: The real-time clock should never require
adjustment since it automatically updates for
daylight savings time, and stores all date/time
information.
Note: To change the current week day display, see
see System Setup in your Installation Guide.
Press CLOCK
Adjust time, then press DONE
SCHED HOLD CLOCK SCREEN MORE
WED
AM
FAN
AUTO
Inside Set To
70
6:01
70
M28375
DONE CANCEL
WED
AM
FAN
AUTO
Inside Set To
70
6:02
70
M28376
Clock setting

RTH8500
7 69-2220EF—03
Press FAN to select fan operation, then press DONE.
• On: Fan is always on.
• Auto: Fan runs only when the heating or
cooling system is on.
Press FAN
SCHED HOLDCLOCK SCREEN MORE
WED
AM
SYSTEM
HEAT
Following
Schedule
Inside Set To
70
6:01
70
FAN
AUTO
M28377
Fan setting

Operating Manual
69-2220EF—03 8
SCHED HOLD CLOCK SCREEN MORE
WED
AM
Following
Schedule
Inside Set To
70
6:01
70
FAN
AUTO
SYSTEM
HEAT
M28378
Press the SYSTEM button to select, then press DONE.
• Heat: Thermostat controls only the
heating system.
• Cool: Thermostat controls only the
cooling system.
• Auto: Thermostat automatically selects
heating or cooling depending on the
indoor temperature.
• Off: Heating and cooling systems are off.
• Em Heat (only for heat pumps with
auxiliary heat): Thermostat controls
Emergency and Auxiliary Heat.
Compressor is locked out.
System setting
Note: The Auto and Em Heat
system settings may not
appear, depending on how
your thermostat was installed.