Honeywell T8635L User manual

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USER’S GUIDE
T8635L Microelectronic Communicating
Programmable Thermostat
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CONTENTS
USING THIS GUIDE .......................................................................................................................................... 5
FEATURES ........................................................................................................................................................ 6
KEYBOARD AND DISPLAY DESCRIPTION .................................................................................................... 7
Keyboard ............................................................................................................................................................ 7
Display ............................................................................................................................................................... 7
ADAPTIVE INTELLIGENT RECOVERY™ CONTROL ..................................................................................... 10
Optimum Comfort and Energy Savings……………………………………………………………………………….. 11
OPERATING YOUR THERMOSTAT ................................................................................................................. 13
Setting System and Fan Keys ............................................................................................................................ 13
Setting the System Key .................................................................................................................................. 14
Setting the Fan Key ........................................................................................................................................ 14
Setting Temporary Temperatures ....................................................................................................................... 15
Changing Temperature to Temporary Setting Until Next Schedule Period .................................................... 15
Changing and Holding Temperature Setting Indefinitely ................................................................................ 17
Changing Temperature Setting Until a Designated Day and Period (Vacation Hold) ..................................... 18
Using the (Information) Key ......................................................................................................................... 21
Displaying Outdoor Temperature .................................................................................................................... 21

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Contents (Cont)
Displaying Current Settings ............................................................................................................................ 22
Filter Indicator .................................................................................................................................................... 23
Setting or Resetting Filter Indicator ................................................................................................................ 23
LED Indicators ................................................................................................................................................... 25
Remote Override Temperature Indicator ............................................................................................................ 25
SETTING THE CLOCK...................................................................................................................................... 26
Set Current Day and Time ................................................................................................................................. 26
Daylight Saving Time ......................................................................................................................................... 28
PROGRAMMING YOUR THERMOSTAT .......................................................................................................... 29
7-Day Program and Operation ........................................................................................................................... 29
7-Day Preprogrammed Schedule ................................................................................................................... 30
Customizing Your Own 7-Day Schedule ........................................................................................................ 31
Programming the First Day ............................................................................................................................ 32
Copying a Day ................................................................................................................................................ 37
Clearing a Program Period ............................................................................................................................. 40
TROUBLESHOOTING....................................................................................................................................... 42
WARRANTY ...................................................................................................................................................... 45
CUSTOMER ASSISTANCE ............................................................................................................................... 47

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USING THIS GUIDE
The T8635L is a multi-functional thermostat. This means it can be used in several different ways such as single
or multi-zone applications, conventional furnaces or heat pump equipment.
The following symbols will help you identify the features that apply to your system:
– Triple layer of thermostats with the word, zoning, below. These features are available when more
than one thermostat is connected and used with the optional W8703 Damper Interface Module.
– Compressor with the word, heat pump, below. These features are available when used with a heat
pump with auxiliary heat.
–Tip symbol. Look for helpful tips throughout the guide when you see this symbol.
80
90
70
60
90
80
70
60
ZONING
HEAT PUMP

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FEATURES
•Adaptive Intelligent Recovery™ Control for comfort
and energy savings.
•Customize the program schedule—program your
own schedule to fit your needs.
•Temporary schedule override—set the thermostat
higher or lower for the current program schedule.
•Permanent schedule override—set the thermostat
higher or lower indefinitely.
•Vacation mode (1 to 255 days) for added comfort
and energy savings. Set the temperature higher or
lower for energy savings while on vacation. At the
same time, set the comfort level you want when
you return.
• Set the filter indicator (0, 15, 30, 60, 90, or
120 days) to remind you to change the filter.
•Information at the press of a button—use the
(information) key to see the outdoor tempera-
ture (C7089B Outdoor Temperature Sensor
optional accessory), the current setpoints, or
the filter status.
•No batteries needed—your thermostat retains the
schedule for the life of the product. You never have
to reprogram the schedule even after a power
outage. (You may need to reset the day and time
after an extended power outage.)
• Daylight Time key for quick time changes between
Daylight and Standard time.
•Backlit display for improved readability—set the
backlight feature for backlighting on demand
(press any key to activate) or continual backlight-
ing. Ask your installer to program this feature.
• Optional outdoor temperature display—ask your
installer to install an outdoor temperature sensor to
activate this feature.

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KEYBOARD AND DISPLAY DESCRIPTION
Keyboard
The keyboard is located behind the thermostat cover. Three frequently used keys, increase ▲or decrease ▼
and , are located next to the display. See Fig. 1.
Display
The thermostat displays important information such as day, time, schedule period, temperature, filter information,
system and fan operation. See Fig. 2.

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Fig. 1. Thermostat keyboard description.
M17459
Time Set Program
Run
Program
Hold Temp
Set Current
Day/Time
Day Heat/Cool
Settings
Wake
Fan
System
Copy
Daylight
Time
Leave Return Sleep
INCREASE
RAISES TEMPERATURE SETTING
DECREASE
LOWERS TEMPERATURE SETTING
INFORMATION
DISPLAYS CURRENT HEAT/COOL
TEMPERATURE SETTING
PROGRAM SCHEDULING
WAKE LEAVE RETURN SLEEP
ENTERS PROGRAMMING MODE
FAN
SELECTS AUTO/ON
SYSTEM
SELECTS HEAT/OFF/COOL (AUTO)
DIGITAL
DISPLAY
SET CURRENT
DAY/TIME
SETS CURRENT
DAY AND TIME
RUN PROGRAM
RETURNS THERMOSTAT TO
NORMALOPERATING MODE
HEAT/COOL SETTINGS
SWITCHES BETWEEN HEAT SETPOINTS AND
COOL SETPOINTS WHILE PROGRAMMING
TIME / TIME
SETS TIME
FORWARD OR BACK
HOLD TEMP
SETS A HOLDTEMPERATURE
SETTING AND ACTIVATES
VACATION HOLD FEATURE
DAYLIGHT TIME
SELECTS STANDARD TIME
OR DAYLIGHT SAVING TIME
COPY
COPIES SETTINGS FROM ONE DAY TO
ANOTHER DAY FOR QUICKPROGRAMMING
Filter
FILTER
SELECTS FILTER TIMER REMINDER
PERIOD (0, 15, 30, 60, 90, 120 DAYS)
DAY
SETS DAY OF THE WEEK
WAKE
SET WAKE TIMES
AND
TEMPERATURES
LEAVE
SET LEAVE TIMES
AND
TEMPERATURES
RETURN
SET RETURN TIMES
AND
TEMPERATURES
SLEEP
SET SLEEP TIMES
AND
TEMPERATURES

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Fig. 2. Example of thermostat display.
Auto
System
Fan
Off
Auto
Wake
Mon Room
AM
Recovery
Hold for
Filter Days
On
DST
Cool
TueWedThuFriSatSun
Leave Return Sleep
Set Program Set Day/Time Wait Temporary Setting
Em Heat
M17756
DISPLAYS
EITHER CURRENT
TIME OF DAY OR
PROGRAM TIMES
SHOWS
THERMOSTAT
IS IN THE
SET CURRENT
DAY/TIME MODE
SHOWS
TEMPERATURE
SETTING CHANGED
FOR THIS
PROGRAM
PERIOD
SHOWS TEMPERATURE
DISPLAYED IS THE CURRENT
SET TEMPERATURE
SHOWS
TEMPERATURE
DISPLAYED IS THE
CURRENT ROOM
TEMPERATURE
SHOWS FILTER TIMER
EXPIRED (TIME TO
REPLACE FILTER)
DISPLAYS EITHER ROOM
OR SET TEMPERATURE
SHOWS CURRENT FAN
KEY POSITION ON/AUTO
SHOWS THERMOSTAT IS
CALLING FOR THE FAN
SHOWS SMART
RESPONSE IS OFF
AND CONVENTIONAL
RECOVERY IS ON
SHOWS THERMOSTAT IS
PROCESSING INFORMATION
AND WAITING TO CALL FOR
HEAT OR COOL
SHOWS SMART
RESPONSE IS CHANGING
THE TEMPERATURE
TO MEET THE
CURRENT PROGRAM
SHOWS THAT THERMOSTAT
IS CALLING FOR
HEAT OR COOL
SHOWS CURRENT
SYSTEM KEY POSITION
HEAT/OFF/COOL
SHOWS CURRENT
PROGRAM PERIOD
OR PERIOD BEING
PROGRAMMED
SHOWS CURRENT
DAY OR DAYS BEING
PROGRAMMED
SHOWS WHEN
THERMOSTAT
IS IN THE
PROGRAMMING
MODE
SHOWS VACATION
HOLD DURATION
SHOWS SYSTEM ON
DAYLIGHT SAVING TIME
SHOWS THERMOSTAT
TEMPERATURE IS
BEING SET REMOTELY

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ADAPTIVE INTELLIGENT
RECOVERY™ CONTROL
Your new thermostat is so smart, it’s almost human.
You perceive temperature from a variety of sources,
not only from the air in the room, but also from your
surrounding walls, windows and furnishings. Humans
feel differences in temperature as slight as two
degrees Fahrenheit. Common household thermo-
meters and standard thermostats sense only air temp-
erature, which may not reflect how hot or cold the
room actually feels to you. Your new thermostat reads
both the temperature of the wall and in the air, and
responds to temperature changes as little as one
degree Fahrenheit, so room temperature is more
likely to feel right to you and your family.
The thermostat acts like a computer. When calculat-
ing the time to turn on your heating or cooling system,
it considers air temperature, wall temperature, and the
time you want to reach the comfort temperature. After
considering these three things, Adaptive Intelligent
Recovery™ control gradually changes the tempera-
ture from the energy savings setting to the comfort
setting (for example, from a heating temperature of
62°at night to 70°in the morning).
The system runs continuously until the comfort
temperature you choose is reached without over-
shooting the setting. This saves energy. How do you
know when the system is in recovery? The thermostat
displays “Recovery” whenever the thermostat
activates Adaptive Intelligent Recovery™ control. See
Fig. 3. So, “Recovery” displays during the recovery
time from Sleep to Wake and from Leave to Return.
Fig. 3. Example of “Recovery” indication.
M14561
Mon
Sleep
Room
System
Fan
Em Heat
Auto
AM
Heat
Recovery