Honeywell RTH8500 Series User manual

Operating
Manual
RTH8500
Touchscreen Programmable Thermostat
69-1901ES-1

Read and save these instructions.
Need Help?
For assistance with this product please visit http://yourhome.honeywell.com
or call Honeywell Customer Care toll-free at 1-800-468-1502
® U.S. Registered Trademark.
US Patent No. 6595430, D520,386 and other patents pending.
Copyright © 2007 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.
This thermostat contains a Lithium battery which may contain Perchlorate material.
Perchlorate Material—special handling may apply,
See www.dtsc.ca.gov/hazardouswaste/perchlorate

1
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
Special features................................... 15
Screen cleaning................................... 16
Furnace filter reminder........................ 17
Appendices
Battery replacement............................ 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
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.
• EnergyStar®compliant to greatly reduce your heating/cooling expenses.
• 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
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
4
SCHED HOLD CLOCK SCREEN MORE
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
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
SCHED HOLD CLOCK SCREEN MORE
WED
AM
FAN
AUTO
SYSTEM
HEAT
Following
Schedule
Inside Set To
Recovery
70
6:01
70
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
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
DONE CANCEL
WED
AM
FAN
AUTO
Inside Set To
70
6:02
70
Clock setting

RTH8500
7
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 HOLD CLOCK SCREEN MORE
WED
AM
SYSTEM
HEAT
Following
Schedule
Inside Set To
70
6:01
70
FAN
AUTO
Fan setting

Operating Manual
8
SCHED HOLD CLOCK SCREEN MORE
WED
AM
Following
Schedule
Inside Set To
70
6:01
70
FAN
AUTO
SYSTEM
HEAT
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
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
10
This thermostat is pre-set to use EnergyStar®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 °
EnergyStar®settings for maximum cost savings

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11
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
DONE WAKE LEAVE RETURN SLEEPEDIT CANCEL
WED
AM
Following
Schedule
Inside Set To
70
6:00
70
FAN
AUTO
Press SCHED
DONE WAKE LEAVE RETURN SLEEP CANCEL
MON TUE WED THU FRI SAT SUN
AM
CANCEL
PERIOD
HEAT
COOL
OK TO PICK MULTIPLE DAYS
70
6:00
78
FAN
AUTO

Operating Manual
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

RTH8500
13
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

Operating Manual
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
SCHED HOLD CLOCK SCREEN MORE
CANCEL
WED
Inside
DAYS
Hold Temperature
Until
Set To
55
14
70
FAN
AUTO
SYSTEM
HEAT

RTH8500
15
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
16
About your new thermostatScreen 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
operation, 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)
SCHED HOLD CLOCK SCREEN MORE
WED
PM
Following
Schedule
Inside Set To
SCREEN LOCKED
70
6:00
70
FAN
AUTO
OK TO
CLEAN
SCREEN
30

RTH8500
17
Furnace 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
Press RESET after changing filter.
DONE
Filter
Days
60

Operating Manual
18
About your new thermostatBattery replacement
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 warn-
ing 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.
Grasp thermostat and pull to
remove fom wallplate
Insert 3 fresh AAA alkaline batteries