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.

RTH8500
9 69-2220EF—03
Save money by setting program schedules
It’s easy to program your system for maximum energy savings. You can program four
time periods each day, with different settings for weekdays and weekends.
Set to the time you awaken and the temperature you want
during the morning, until you leave for the day.
Set to the time you leave home and the temperature you
want while you are away (usually an energy-saving level).
Set to the time you return home and the temperature you
want during the evening, until bedtime.
Set to the time you go to bed and the temperature you want
overnight (usually an energy-saving level).
WAKE
6:00 am
70 °
LEAVE
8:00 am
62 °
RETURN
6:00 pm
70 °
SLEEP
10:00 pm
62 °

Operating Manual
69-2220EF—03 10
This thermostat is pre-set to use energy saving program settings. We recommend these settings, since
they can reduce your heating/cooling expenses by as much as 33%. (See next page to adjust times
and temperatures of each time period.)
Wake
(6:00 am)
Leave
(8:00 am)
Return
(6:00 pm)
Sleep
(10:00 pm)
Cool (Mon-Fri)Heat (Mon-Fri) Heat (Sat-Sun) Cool (Sat-Sun)
70 °78 °70 °78 °
62 °85 °62 °
[Or cancel period]
85 °
[Or cancel period]
70 °78 °70 °
[Or cancel period]
78 °
[Or cancel period]
62 °82 °62 °82 °
Energy saving settings for maximum cost savings

RTH8500
11 69-2220EF—03
DONE WAKE LEAVE RETURN SLEEP CANCEL
MON TUE WED THU FRI SATSUN
AM
CANCEL
PERIOD
HEAT
COOL
OK TO PICK MULTIPLE DAYS
70
6:00 78
M28381
To adjust program schedules
1. Press SCHED,then EDIT.
2. Press day buttons (MON-SUN) to select day(s).
3. Press s or t to set Wake time for selected
day(s).
4. Press s or t to set Heat and Cool
temperature for this time period.
5. Press other time periods (LEAVE, RETURN, SLEEP) to
set time and temperatures for each.
6. Press DONE to save & exit (or press CANCEL to exit
without saving changes).
Note: You can press CANCEL PERIOD to eliminate any unwanted
time period.
Set time for program
period to start
Press EDIT
Select day(s) Set heat/cool levels
SCHED HOLD CLOCK SCREEN MORE
WED
AM
Following
Schedule
Inside Set To
70
6:00
70
FAN
AUTO
M28379
DONE WAKE LEAVE RETURN SLEEPEDIT CANCEL
WED
AM
Following
Schedule
Inside Set To
70
6:00
70
FAN
AUTO
M28380
Press SCHED

Operating Manual
69-2220EF—03 12
Program schedule override (temporary)
Press s or t to immediately adjust the tem-
perature. This will temporarily override the
temperature setting for the current time period.
The new temperature will be maintained only
until the time you set. When the timer expires,
the program schedule will resume and set the
temperature to the level you’ve programmed
for the current time period.
To cancel the temporary setting at any time, press
CANCEL (or SCHED). The program schedule will resume.
Adjust temperature
Press to set timer
Press CANCEL (or SCHED) to
resume program schedule
Heat On
SCHED HOLD CLOCK SCREEN MORE
CANCEL
WED
AM
Inside
Hold Temperature
Until
Set To
73
8:00
70
FAN
AUTO
SYSTEM
HEAT
M28382

RTH8500
13 69-2220EF—03
Program schedule override (permanent)
Press HOLD Adjust temperature Press HOLD to permanently adjust the temperature. This
will turn off the program schedule.
Whatever temperature you set will be maintained 24
hours a day until you manually change it or press
CANCEL (or SCHED) to cancel “Hold” and resume the
program schedule.
Press CANCEL (or SCHED) to
resume program schedule
Heat On
SCHED HOLD CLOCK SCREEN MORE
CANCEL
WED
AM
Inside Set To
Permanent
Hold
73
8:00
70
FAN
AUTO
SYSTEM
HEAT
M28383

Operating Manual
69-2220EF—03 14
Vacation hold
This feature can suspend the program sched-
ule for extended periods of time.
Press s or tto set the temperature you want, then
press s or tto set the time of day you want the
schedule to resume when you return. Press HOLD twice,
then press s or tto select the number of days.
Whatever temperature you set will be main-
tained 24 hours a day for the number of days
you select. After this number of days have
elapsed, the previously programmed schedule
will resume at the time you set.
If you return earlier than expected, press CANCEL (or
SCHED) to cancel “Hold” and resume the program
schedule.
1. Set temperature
2. Press to set time for
schedule to resume
3. Press HOLD twice
4. Press to select number of days
SCHED HOLD CLOCK SCREEN MORE
CANCEL
WED
PM
Inside
Hold Temperature
Until
Set To
55
6:00
70
FAN
AUTO
SYSTEM
HEAT
M28384
SCHED HOLD CLOCK SCREEN MORE
CANCEL
WED
Inside
DAYS
Hold Temperature
Until
Set To
55
14
70
FAN
AUTO
SYSTEM
HEAT
M28385

RTH8500
15 69-2220EF—03
Screen cleaning
Press SCREEN to lock the screen for cleaning. The
screen will remain locked for 30 seconds so you can
clean the screen without changing any settings.
After 30 seconds, press DONE to resume normal opera-
tion, or press SCREEN again if you require more time for
cleaning.
Note: Do not spray any liquid directly on the
thermostat. Spray liquids onto a cloth, then use
the damp cloth to clean the screen. Use water or
household glass cleaner. Avoid abrasive cleansers.
Press SCREEN
Screen lock timer (30 seconds)
SCHEDHOLD CLOCK SCREEN MORE
WED
PM
Following
Schedule
Inside Set To
SCREEN LOCKED
70
6:00
70
FAN
AUTO
M28386
OK TO
CLEAN
SCREEN
30
M28387

Operating Manual
69-2220EF—03 16
About your new thermostatFurnace filter reminder
If activated during installation, the furnace filter
reminder alerts you when it is time to replace
your filter.
Press RESET after changing the filter, to restart the
timer.
To change the reminder interval:
1. Press MORE, then EDIT.
2. Press s or tto select the desired interval, then
press DONE.
3. Press RESET.
4. Press DONE to save and exit.
Press MORE to change reminder interval.
SCHED HOLD CLOCK SCREEN MORE
WED
PM
RESET
CHANGE FILTER
Inside Set To
55
6:00
70
FAN
AUTO
SYSTEM
HEAT
M28388
Press RESET after changing filter.
DONE
Filter
Days
60
M28389

RTH8500
17 69-2220EF—03
Special features
Smart Response®Technology: This feature allows the thermostat to “learn” how
long the furnace and air conditioner take to reach programmed temperature settings,
so the temperature is reached at the time you set. For example: Set the Wake time to
6 am, and the temperature to 70°. The heat will come on before 6 am, so the tempera-
ture is 70° by the time you wake at 6. The message “Recovery” is displayed when the
system is activated before a scheduled time period.
Compressor Protection: This feature forces the compressor to wait a few minutes
before restarting, to prevent equipment damage. During the wait time, the message
“Wait” is displayed on screen.
Auto Changeover: This feature is used in climates where both air conditioning and
heating are used on the same day. When the system is set to Auto, the thermostat
automatically selects heating or cooling depending on the indoor temperature. Heat
and cool settings must be at least 3 degrees apart. The thermostat will automatically
adjust settings to maintain this 3-degree separation.
CAUTION: To avoid possible compressor damage, do not use Auto Changeover if the outside temperature
drops below 50°F (10°C).

Operating Manual
69-2220EF—03 18
About your new thermostat
M28391
Battery replacement/Customer assistance
Batteries are optional (to provide backup
power) if your thermostat was wired to run on
AC power when installed.
Install fresh batteries immediately when the LO BATT
warning begins flashing. The warning flashes about 30
days before batteries are depleted.
Even if the warning does not appear, you
should replace batteries once a year, or before
leaving home for more than a month.
For assistance with this product, please visit
http://DIYthermostats.honeywell.com
or call Honeywell Customer Care toll-free at
1-800-468-1502.
Grasp thermostat and pull to
remove fom wallplate
Insert 3 fresh AAA alkaline batteries
M28390