American Standard ACONT900AC43UA User manual

69-1820-04
OWNER’S GUIDE
Pub No. 12-5046-02
ACONT900AC43UA Communicating,
Programmable Comfort Control

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2 69-1820—04
TABLE OF CONTENTS
Page Contents
3Features
4 Home Screen
6 Programming Your Heating and Cooling Schedule
14 Operating Your Comfort Control
21 Cleaning Your Comfort Control Screen
22 Reading Your Outdoor Temperature
26 Reading Your Inside Humidity Level
27 Controlling Your Inside Dehumidification Setting
29 Controlling Your Inside Humidification Setting
34 Advanced Settings
36 User Setup Menu
47 Error Codes
48 Frequently Asked Questions and Answers
49 Limited Five-Year Warranty
51 Customer Assistance
IMPORTANT
The Comfort Control has a touch screen interface. Touch keys appear, as necessary, to
complete tasks. Always press the keys with your fingertips. Sharp instruments like a pen or
pencil point can damage the Comfort Control.

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FEATURES
•Large, Clear Display with Backlighting – current temperature, set temperature and time are
easy-to-read and all are displayed on the home screen.
•Menu Driven Programming – Guides you through the scheduling process, showing only
necessary information and choices on each screen.
•Ability to Select Multiple Days – allows you to easily customize the Comfort Control for your
unique schedule.
•Real-Time Clock – keeps time during power failure; automatically updates for daylight savings.
•Precise Temperature Control (+/- 1°F) (+/- .5°C) – reliable, consistent comfort.
•Multiple HOLD options – allows you to modify schedule indefinitely or for a specific time.
•Change Reminders – reminds you to service or replace the air filters and/or humidifier pad.
•Programmable Fan – increases air quality when combined with a whole-house air cleaner.
•Outdoor Temperature Indication – shows current outdoor temperature on the display to help
you plan outdoor activities.
NOTE: The home screen may differ slightly, depending on the heating and/or cooling system you
have and the Comfort Control settings for your system type.

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HOME SCREEN
Key Description
SC
HE
D
H
O
L
D
C
L
OCK
SC
REE
N
M
O
R
E
T
U
E
AM
FAN
A
U
T
O
S
Y
S
TE
M
HEAT
Followin
g
Sc
h
edu
l
e
In
s
i
de
S
et T
o
M19952
FAN
SELECTS ON/AUTO/CIRC
SYSTEM
SELECTS EM. HEAT/HEAT/OFF/COOL/AUTO
SCHED
ENTERS SCHEDULING MODE
HOLD
SETS A PERMANENT HOLD AND
ACTIVATES VACATION HOLD
SCREEN
LOCKS OUT THE SCREEN TO ALLOW FOR CLEANING
CLOCK
SETS THE TIME FORWARD OR BACK
UP ARROW
RAISES TEMPERATURE SETTING
DOWN ARROW
LOWERS TEMPERATURE SETTING
MORE (SELECT MODELS)
SHOWS ADDITIONAL SYSTEM
INFORMATION

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HOME SCREEN
Display Description
SC
HE
D
H
O
L
D
C
L
OCK
SC
REE
N
M
O
R
E
T
UE
AM
FAN
A
U
T
O
S
Y
S
TE
M
HEA
T
Followin
g
Sc
h
edu
l
e
In
s
i
de
S
et T
o
M19953
FAN
SHOWS FAN SETTING
T
UE
S
H
O
W
S
CU
RRENT DAY
O
F THE WEE
K
SYSTEM
SHOWS CURRENT SYSTEM POSITION
TIME
DISPLAY CURRENT TIME OF DAY,
HOLD TIME REMAINING OR NUMBER
OF VACATION DAYS REMAINING
IN
S
IDE TEMPERAT
U
R
E
S
H
O
W
S
THE
CU
RRENT IN
S
IDE TEMPERAT
U
R
E
SET TO TEMPERATURE
SHOWS THE CURRENT
SET TEMPERATURE
FOLLOWING SCHEDULE
SHOWS THE THERMOSTAT IS
FOLLOWING THE PROGRAMMED
SCHEDULE

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PROGRAMMING YOUR HEATING AND COOLING SCHEDULE
Your Comfort Control can control up to four different schedule periods per day:
Wake – Period when you awaken and want your home at a comfortable temperature.
Leave – Period when you are away from home and want an energy-saving temperature.
Return – Period when you return home and want your home back to a comfortable temperature.
Sleep – Period when you are asleep and want an energy-saving temperature.

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NOTE: Schedule times are in 15-minute intervals.
Preprogrammed Energy Star Settings
Table 1 shows default program settings. Visit the Energy Star web site at www.energystar.gov for
additional education and resources on programmable Comfort Controls.
Table 1. Energy Star Default Program Settings.
Schedule Period Time Setpoints Fan Setting
Heat Cool
Wake 6:00 AM 70°F (21°C) 78°F (25.5°C) Auto
Leave 8:00 AM 62°F (16.5°C) 85°F (29.5°C) Auto
Return 6:00 PM 70°F (21°C) 78°F (25.5°C) Auto
Sleep 10:00 PM 62°F (16.5°C) 82°F (27.8°C) Auto

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EDITING SCHEDULE
1. Press Sched key.
2. Press Edit key.
SCHED HOLD CLOCK SCREEN
FRI
AM
PM
FAN
AUTO
SYSTEM
HEAT
Following
Schedule
Inside Set
M22445
SCHED
SCHED
HOLD
HOLD
CLOCK SCREEN
DONE WAKE LEAVE RETURN SLEEP CANCEL
MON TUE WED THU FRI SA SUN
AM
PM
PM
FAN
AUTO
SYSTEM
EM HEAT
HEAT
OFF
COOL
AUTO
CANCEL
PERIOD
HEAT
COOL
Following
Schedule
Inside Set
OK TO PICK MULTIPLE DAYS SCREEN LOCKED
M22553
EDIT

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3. It is OK to pick multiple days. Select any combination of days to edit. These days are sched-
uled with the same times and temperatures. Check marks appear next to days selected.
4. Press Wake key. Once pressed, Wake flashes to show it is selected.
5. Press Up and Down keys to modify time and heat and cool temperatures from this screen.
NOTE: The Fan setting can be programmed for On, Auto, or Circ for each period selected. See
“Fan Schedule” on page 19 for more information.
DONE WAKE LEAVE RETURN SLEEP CANCEL
MON TUE WED THU FRI SAT SUN
AM
FAN
ON
AUTO
CIRC
CANCEL
PERIOD
HEAT
COOL
OK TO PICK MULTIPLE DAYS
M19955

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6. Press Leave key and repeat step 5.
7. Press Return key and repeat step 5.
8. Press Sleep key and repeat step 5.
9. When complete, press Done key. “Saving Changes” appears on the screen to indicate
changes are being saved to the day(s) modified.
NOTE: To set a Program Schedule for the remaining days of the week, repeat steps 1-9.
Example: If Mon - Fri was selected first, go back and repeat steps 1-9 for Sat and Sun.
10. To exit schedule without saving changes, press Cancel key any time.
MON TUE WED THU FRI
SAVING
CHANGES
M19956

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CANCELING A SCHEDULE PERIOD
NOTE: You may want to cancel a period to match your lifestyle; for example, if someone is always
home during the day on Tuesday, you can cancel the Leave and Return periods (the Com-
fort Control would then control to the Wake temperature until the Sleep period).
1. Press Sched key.
2. Press Edit key.
3. Select the Day(s) of the week desired.
4. Press schedule period you want to cancel (Wake, Leave, Return or Sleep). Once selected, the
period flashes.
5. Press Cancel Period key.
SCHEDSCHED HOLDHOLD CLOCK SCREEN
DONE WAKE LEAVE RETURN SLEEP CANCEL
MON TUE WED THU FRI SAT SUN
AM
PMPM
FAN
AUTO
SYSTEM
EM HEAT
HEAT
OFF
COOL
AUTO
CANCEL
PERIOD
HEAT
COOL
Following
Schedule
Inside Set To
OK TO PICK MULTIPLE DAYS SCREEN LOCKED
M22446

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NOTE: Note that the time, temperature(s) and fan setting disappear. The bar above the selected
period is removed, indicating the scheduled period was cancelled. To reinstate a schedule
period, press arrow keys to set desired time and temperatures.
6. Press Done key.
NOTE: When changing from non-programmable to programmable mode, the screen displays “Per-
manent Hold” under the time icon. This goes away when the schedule key is hit or the
schedule menu is entered.
SCHEDSCHED HOLDHOLD CLOCK SCREEN
DONE WAKE LEAVE RETURN SLEEP CANCEL
MON TUE WED THU FRI SAT SUN
AM
PMPM
FAN
AUTO
SYSTEM
EM HEAT
HEAT
OFF
COOL
AUTO
CANCEL
PERIOD
HEAT
COOL
Following
Schedule
Inside Set To
OK TO PICK MULTIPLE DAYS SCREEN LOCKED
M22446

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SETTING TIME
1. Press Clock.
2. Use arrows to set current time.
3. Press Done key.
IMPORTANT
The current day of the week should already be set correctly. If not, see “Advanced Settings”
on page 34 to set the day.
SCHEDSCHEDHOLDHOLDCLOCK SCREEN
DONE
TUE
AM
PMPM
M19958

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OPERATING YOUR COMFORT CONTROL
Setting Fan and System Keys
SETTING FAN KEY
The Fan key selections vary based on your heating and/or cooling system type.
On – Fan runs continuously. Use this setting for improved air circulation or for more efficient central
air cleaning. The American Standard Proprietary Humidity Control might disable continuous fan
function. See “American Standard Proprietary Humidity Control” on page 28 for additional
information.
Auto – Fan follows fan program schedule. See “Fan Schedule” on page 19 for more information.
Circ – Circulation control will provide a variable circulation determined by the Adaptive Intelligent
Circulation (AIC) algorithm running the fan between 20% and 60% of the time.
SETTING SYSTEM KEY
The System key selections vary based on your heating and/or cooling system type.
Heat – Controls your heating system.
Off – Both heating and cooling systems are off.
Cool – Controls your cooling system.
Auto (when enabled) – Controls both your heating and cooling system based on temperature.
Em. Heat – Compressor is locked out and auxiliary heat cycles to maintain temperature. (Used only
for heat pump systems with backup heat)

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Setting Temperature Overrides
Your Comfort Control has three temperature override options: Hold Temperature Until, Permanent
Hold and Vacation Hold.
HOLD TEMPERATURE UNTIL (TEMPORARY HOLD)
Holds temperature temporarily until the next scheduled period time or until the time the user sets.
1. Press Up or Down arrow next to the temperature you want to adjust. “Hold Temperature Until”
time appears on the screen. The Hold Temperature Until time defaults to the start time of the
next scheduled period.
NOTE: The Time Up and Down arrows are shown for approximately seven seconds. Pressing on
the screen time (where the Hold Temperature Until time is shown) allows the arrows to
reappear.
2. Press Up or Down arrow next to the Time key to set desired time for the Comfort Control to
resume schedule.

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3. Press the Cancel or Sched key to cancel “Hold Tem-
perature Until” and resume schedule.
NOTE: Once “Hold Temperature Until” time is reached, the
comfort control shows “Following Schedule” on the
screen to indicate that “Temporary Hold” has ended.
PERMANENT HOLD
Permanent Hold changes the temperature setting until
Permanent Hold is cancelled.
1. Press Hold key. “Permanent Hold” appears on the
screen.
2. Press Up or Down arrow next to the temperature you
want to set during “Hold”.
3. Press Cancel key to cancel “Permanent Hold” and
resume the schedule.
NOTE: In ISU 0160, when changing from nonprogrammable
to programmable mode, the screen displays “Per-
manent Hold” under the time icon. This goes away
when the schedule key is hit or the schedule menu
is entered.
SCHED HOLD CLOCK SCREEN
CANCEL
TUE
PM
FAN
AUTO
SYSTEM
HEAT
Inside
Hold Temperature
Until
Set
M19959
SCHED HOLD CLOCK SCREEN
CANCEL
TUE
AM
FAN
AUTO
SYSTEM
HEAT
Inside Set To
Permanent
Hold
M19960

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VACATION HOLD
Changes temperature setting for a selected number of days, from 1 to 365 days.
1. Press the Up and Down arrow keys to set the desired temperature while away on vacation.
Notice that “Hold Temperature Until” time is shown on the screen. (This is the time the
Vacation Hold override expires after the number of days ends.)
2. Press Hold key twice. Screen shows “Hold Temperature Until” one day.
3. Press Up and Down arrow keys to change the number of Days you desire Comfort Control to
override the schedule.
NOTE: Days Up and Down arrows appear for approximately seven seconds. Pressing just below
Hold Temperature Until on the screen allows the Days Up and Down arrows to reappear.
NOTE: When the number of days of Vacation Hold expires, the screen shows “Following
Schedule” to indicate that Vacation Hold has ended.

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4. To cancel the Vacation Hold override early, press the Cancel key.
SCHED CLOCK SCREEN
CANCEL
THU
FAN
AUTO
SYSTEM
HEAT
Inside
DAYS
Hold Temperature
Until
Set To
M19961

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Fan Schedule
Press Fan key while in the Scheduling Screen to program the System Fan. Choices available from
the Scheduling Screen:
On – Fan runs continuously. Use this setting for improved air circulation or for more efficient central
air cleaning.
Auto – (default position) Fan runs with equipment. Programmable for all schedule periods (Wake,
Leave, Return and Sleep).
Circ – Circulation control will provide a variable circulation determined by the Adaptive Intelligent
Circulation (AIC) algorithm running the fan between 20% and 60% of the time.
SCHED
SCHED
HOLD
HOLD
CLOCK SCREEN
DONE WAKE LEAVE RETURN SLEEP CANCEL
MON TUE WED THU FRI SAT SUN
AM
PM
PM
FAN
AUTO
SYSTEM
EM HEAT
HEAT
OFF
COOL
AUTO
CANCEL
PERIOD
HEAT
COOL
Following
Schedule
Inside Set To
OK TO PICK MULTIPLE DAYS SCREEN LOCKED
M22447

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Fan Status Displayed on Home Screen
If the Fan program is scheduled, Auto is shown and any programmable mode that is set; for
example, if during Wake period, Fan is set to Auto, only Auto is shown in the Fan area. However, if
during the Wake period, fan is scheduled to On, both Auto and On are shown. Auto indicates fan is
running its schedule; On indicates Fan schedule is set to On.
Manual Override of Fan Schedule
On –Fan runs continuously. Use this setting for improved air circulation or for more efficient
central air cleaning. The American Standard Proprietary Humidity Control might disable continuous
fan function. See “American Standard Proprietary Humidity Control” on page 28 for additional
information.
Auto –(default position) Fan follows fan program schedule. See “Fan Schedule” on page 19 for
more information.
Circ –Circulation control will provide a variable circulation determined by the Adaptive
Intelligent Circulation (AIC) algorithm running the fan between 20% and 60% of the time.
SCHED HOLD CLOCK SCREEN
THU
AM
FAN
ON
AUTO
SYSTEM
HEAT
Following
Schedule
Inside Set
M19962