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1F85-275  
Heating & Air Conditioning  
5-1-1 Programmable/Non-programmable, Auto  
Changeover, Multi-Stage/Heat Pump Thermostat  
INSTALLATION INSTRUCTIONS  
Operator: Save these instructions for future use!  
FAILURE TO READ AND FOLLOW ALL INSTRUCTIONS CAREFULLY BE-  
FORE INSTALLING OR OPERATING THIS CONTROL COULD CAUSE PER-  
SONAL INJURY AND/OR PROPERTY DAMAGE.  
PREPARATIONS  
YOUR THERMOSTAT REPLACES  
Description  
Assemble tools required as shown below.  
1F85-275  
Yes  
Heat Pump (No Aux. or Emergency Heat)  
Heat Pump (with Aux. or Emergency Heat)  
Standard Heat & Cooling Systems  
Two Stage Heat & Two Stage Cool  
Standard Heat Only Systems  
Yes  
Yes  
Yes  
FLAT BLADE SCREWDRIVER  
WIRE CUTTER/STRIPPER  
Yes  
HAND OR POWER  
DRILL WITH 3/16 INCH  
DRILL BIT, IF NEEDED  
Millivolt Heat Only Systems – Floor or Wall Furnaces  
Standard Central Air Conditioning  
Gas or Oil Heat  
Yes  
Yes  
Yes  
Electric Furnace  
Yes  
Hydronic (Hot Water) Zone Heat – 2 Wires  
Hydronic (Hot Water) Zone Heat – 3 Wires  
Yes  
No  
REMOVING OLD THERMOSTAT  
CAUTION  
!
To prevent electrical shock and/or equipment damage,  
disconnect electric power to system at main fuse or  
circuit breaker box until installation is complete.  
Before removing wires from old thermostat's switching sub-  
base, label each wire with the terminal designation it was  
removed from.  
Y2  
C
R
E/W1  
Y1  
1. Shut off electricity at the main fuse box until installation is  
complete. Ensure that electrical power is disconnected.  
O
B
L W2 G  
Mounting  
Hole  
Mounting  
Hole  
ELEC.  
ON  
GAS  
2. Remove Old Thermostat: A standard heat/cool  
thermostat consists of three basic parts:  
a. The cover, which may be either a snap-on or  
hinge type.  
Elec-Gas  
Switch  
AUTO  
b. The base, which is removed by loosening all  
captive screws.  
Figure 1 – Thermostat base  
c. The switching subbase, which is removed by  
unscrewing the mounting screws that hold it on  
the wall or adaptor plate.  
ATTENTION! This product does not contain mercury. How-  
ever, this product may replace a unit which contains mercury.  
3. Remove the front cover of the old thermostat. With  
wires still attached, remove wall plate from the wall. If  
the old thermostat has a wall mounting plate, remove the  
thermostat and the wall mounting plate as an assembly.  
Do not open mercury cells. If a cell becomes damaged, do not  
touch any spilled mercury. Wearing non-absorbent gloves,  
clean up the spilled mercury and place into a container which  
can be sealed. If a cell becomes damaged, the unit should be  
discarded.  
4. Identify each wire attached to the old thermostat.  
5. Disconnect the wires from the old thermostat one at a  
time. DO NOT LET WIRES FALL BACK INTO THE  
WALL.  
Mercury must not be discarded in household trash. When the  
unit this product is replacing is to be discarded, place in a  
tion to send the product containing mercury.  
6. Install new thermostat using the following procedures.  
PART NO. 37-6488C  
Replaces 37-6488B  
0838  
White-Rodgers is a division  
of Emerson Electric Co.  
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MOUNTING AND WIRING  
CAUTION  
Take care when securing and routing wires so they do  
not short to adjacent terminals or rear of thermostat.  
Personal injury and/or property damage may occur.  
WARNING  
!
Do not use on circuits exceeding specified voltage.  
Higher voltage will damage control and could cause  
shock or fire hazard.  
!
Do not short out terminals on gas valve or primary  
control to test. Short or incorrect wiring will damage  
thermostat and could cause personal injury and/or  
property damage.  
Attach Thermostat Base to Wall  
1. Remove the packing material from the thermostat. Gently  
pull the cover straight off the base. Forcing or prying on  
the thermostat will cause damage to the unit.  
Thermostat installation and all components of the  
system shall conform to Class II circuits per the NEC  
code.  
2. Connect wires beneath terminal screws on base using  
appropriate wiring schematic (see figs. 2 through 3).  
3. Place base over hole in wall and mark mounting hole  
locations on wall using base as a template.  
Electric/Gas Switch (Fan Option)  
4. Move base out of the way. Drill mounting holes.  
This thermostat is configured from the factory to operate a heat/  
cool, fossil fuel (gas, oil, etc.), forced air system. It is configured  
correctly for any system that DOES NOT require the thermostat  
to energize the fan on a call for heat. If you system is an electric  
heat or heat-pump system that REQUIRES the thermostat to  
turn on the fan on a call for heat, locate the ELEC/GAS switch  
on the back of the thermostat (see fig. 1) and switch it to the  
ELEC position. This will allow the thermostat to energize the fan  
immediately on a call for heat. If you are unsure if the heating/  
cooling system requires the thermostat to control the fan,  
contact a qualified heating and air conditioning service person.  
5. Fasten base loosely to wall, as shown in fig. 1, using two  
mounting screws. Place a level against bottom of base,  
adjust until level, and then tighten screws. (Leveling is for  
appearance only and will not affect thermostat operation.)  
If you are using existing mounting holes, or if holes drilled  
are too large and do not allow you to tighten base snugly,  
use plastic screw anchors to secure subbase.  
6. Push excess wire into wall and plug hole with a fire-  
resistant material (such as fiberglass insulation) to  
prevent drafts from affecting thermostat operation.  
When the thermostat is configured for Heat Pump, the thermo-  
stat will always power the circulator fan on a call for heat in the  
HEAT mode. The ELEC/GAS switch must be set to match the  
type of Auxiliary heat your system uses for proper operation in  
the EMERgency mode.  
Battery Location  
2 “AA” alkaline batteries are included in the thermostat at the  
factory with a battery tag to prevent power drainage. You  
must remove the battery tag to engage the batteries.  
All wiring diagrams are for typical systems only. Refer to  
equipment manufacturers’ instructions for specific system wir-  
ing information.  
If “BATT” is displayed, the batteries are low and should be  
replaced. For best results, replace all batteries with new  
premium brand alkaline batteries such as Duracell® or  
Energizer®. To replace batteries, press system button to  
OFF, install the batteries along the top of the base (see Fig.  
1). The batteries must be installed with the positive (+) end to  
the left.  
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WIRING DIAGRAMS  
Heat Pump Connections  
Refer to equipment manufacturers' instructions for specific system wiring information. The thermostat can be configured for use  
with the following heat pump systems:  
HEAT PUMP TYPE 1 (HP 1). Single Stage compressor system; gas or electric backup, 2-heat/1-cool stages maximum.  
HEAT PUMP TYPE 2 (HP 2). Multi-Stage compressor or two compressor system with gas or electric backup, 3-heat/2-cool stages  
maximum.  
See figure 2 below to help you wire the thermostat properly. After wiring, see CONFIGURATION section for proper thermostat  
configuration.  
O
W2  
B
G
E/W1  
R
Y2  
C*  
L
Y1  
System  
NOTE: If your system  
does not provide an E  
connection, jumper W2 to  
E/W1 to use the Auxiliary  
Heat in the Emergency  
Mode.  
Heat Mode  
2nd Stage.  
Emergency  
Mode 2nd  
Stage  
Blower/  
Circulator  
Heat Pump 1  
(HP1)  
Fault  
Indicator  
or  
System  
Malfunc-  
tion  
No Output  
Energized in  
Heat, Off,  
Emergency  
Mode  
Fan Energized  
on Call for  
Heat or Cool.  
Set Elect/Gas  
Switch for  
Emergency  
Mode  
Emergency 24 Volt  
24 Volt  
(Common)  
Energized in  
Cool Mode  
Heat and  
Cool Mode  
1st Stage  
Mode  
(Hot)  
1st Stage  
Heat Mode  
3rd Stage.  
Emergency  
Mode 2nd  
Stage  
2nd Stage  
(Compressor)  
Heat Pump 2  
(HP2)  
(Compressor)  
Switch  
NEUTRAL  
120VAC  
24VAC  
HOT  
CLASS II  
TRANSFORMER  
Figure 2 – Heat Pump Systems  
*The 24 volt neutral connection to terminal C on the thermostat is not required if you replace the batteries once a year with fresh “AA” alkaline batteries.  
Single Stage/Multi-Stage Connections  
(No Heat Pump)  
Refer to equipment manufacturers' instructions for specific system wiring information. The thermostat can be configured for use  
with the following Single Stage and Multi-Stage systems:  
SINGLE STAGE (SS 1). Gas, oil or electric, 1-heat/1-cool stage maximum.  
MULTI-STAGE (MS 2). Gas, oil or electric, 2-heat/2-cool stages maximum.  
See figure 3 below to help you wire the thermostat properly. After wiring, see CONFIGURATION section for proper thermostat  
configuration.  
O
W2  
B
G
E/W1  
R
Y2  
C*  
L
Y1  
System  
Blower/  
Single  
Stage 1  
(SS1)  
No Output  
Circulator  
Fan Energized  
on Call for  
Cool (and  
Heat) if  
configured  
for Electric  
Heat  
No Output  
Energized  
Constantly  
in  
Heat, Off,  
Emergency  
Mode  
Fault  
Indicator  
(NOT  
Heat  
Mode  
1st Stage  
24 Volt  
(Hot)  
24 Volt  
(Common)  
Energized  
Constantly  
in  
Cool Mode  
1st Stage  
Heat Mode  
2nd Stage  
Cool Mode  
2nd Stage  
Multi-  
Stage 2  
(MS2)  
USED)  
Cool Mode  
NEUTRAL  
120VAC  
24VAC  
HOT  
CLASS II  
TRANSFORMER  
Figure 3 – Single Stage or Multi-Stage System (No Heat Pump)  
*The 24 volt neutral connection to terminal C on the thermostat is not required if you replace the batteries once a year with fresh “AA” alkaline batteries.  
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CHECK THERMOSTAT OPERATION  
Emergency System  
NOTE  
EMER bypasses the Heat Pump to use the heat source wired  
to terminal E on the thermostat. EMER is typically used when  
compressor operation is not desired, or you prefer back-up  
heat only.  
To prevent static discharge problems, touch side of  
thermostat to release static build-up before touching  
any keys.  
1. Press SYSTEM button to select EMER. “EMER” will flash  
on the display.  
If at any time during testing your system does not operate  
properly, contact a qualified serviceperson.  
2. Press  
to adjust thermostat setting above room  
temperature. The Aux. heating system will begin to  
operate. The display will show “STG1” flashing “EMER”  
Fan Operation  
If your system does not have a G terminal connection, skip to  
Heating System.  
and Flame icon ( ) to indicate that the Aux. system is  
operating.  
3. Adjust temperature setting to 3° above room temperature.  
The auxiliary heat system should begin to operate and  
the display should show “STG1+2”.  
1. Turn on power to system.  
2. Move FAN switch to ON position. The blower should be-  
gin to operate.  
3. Move FAN switch to AUTO position. The blower should  
stop immediately.  
4. Press  
to adjust the thermostat below room tempera-  
ture. The Aux. heating system should stop operating.  
CAUTION  
!
CAUTION  
To prevent compressor and/or property damage, if the  
outdoor temperature is below 50°F, DO NOT operate  
the cooling system.  
!
Do not allow the compressor to run unless the com-  
pressor oil heaters have been operational for 6 hours  
and the system has not been operational for at least 5  
minutes.  
Cooling System  
1. Press SYSTEM button to select the Snowflake icon ( ).  
Heating System  
1. Press SYSTEM button to select the Flame icon ( ). If  
the auxiliary heating system has a standing pilot, be sure  
to light it.  
2. Press  
to adjust thermostat setting below room  
temperature. The blower should come on immediately on  
high speed, followed by cold air circulation. The display  
should show “STG1”.  
2. Press  
to adjust thermostat setting to 1° above room  
3. Adjust temperature setting to 3° below room temperature.  
The second stage cooling should begin to operate and  
the display should show “STG1+2”.  
temperature. The heating system should begin to  
operate. The display should show “STG1”. However, if  
the setpoint temperature display is flashing, the compres-  
sor lockout feature is operating (see Configuration menu,  
item 5).  
4. Press  
to adjust the temperature setting above room  
temperature. The cooling system should stop operating.  
3. Adjust temperature setting to 3° above room temperature.  
If your system configuration is set at MS2, HP2 or HP1,  
the auxiliary heat system should begin to operate and the  
display should show “STG1+2”.  
4. Press  
to adjust the thermostat below room tempera-  
ture. The heating system should stop operating.  
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OPERATION  
Before you begin programming your thermostat, you should be  
familiar with its features and with the display and the location  
and operation of the thermostat buttons. Your thermostat con-  
sists of two parts: the thermostat cover and the base. To remove  
the cover, pull it straight out from the base. To replace the cover,  
line up the cover with the base and press until the cover snaps  
onto the base.  
The Thermostat Buttons and Switches  
Raises temperature setting  
Lowers temperature setting.  
TIME button.  
1
2
3
4
5
6
7
8
PRGM (program) button.  
RUN (run program) button.  
HOLD temperature button.  
FAN switch (ON, AUTO)  
SYSTEM button (COOL, AUTO, HEAT, EMER, OFF)  
The Display  
Figure 4 – Thermostat display, buttons and switches  
Indicates day of the week.  
9
Flame icon ( ) is displayed when the system is in  
HEAT mode. Snowflake icon ( ) is displayed when  
10  
Display ( ) when in keypad lockout mode.  
16  
17  
“EMER” is displayed flashing when the system is in  
EMER mode.  
the system is in COOL mode. Flame icon ( ) and  
Snowflake icon ( ) are displayed simultaneously  
when thermostat is in AUTO mode.  
The word “FAULT” will be displayed when there is a  
malfunction in the HEAT/COOL system.  
18  
19  
Displays “BATT” when the 2 "AA" batteries are low  
and should be replaced. Only “BATT” and “LO” in the  
minutes field are displayed when batteries are low and  
with no system power.  
11  
Display ( ) when limited HEAT/COOL range is activated.  
The “ ” icon will flash if an attempt is made to adjust  
the temperature beyond the limited HEAT/COOL  
temperature range.  
Alternately displays current time and temperature. Dis-  
plays “LO” in the minutes field when batteries are low.  
12  
13  
Stage1 & 2 indicators: The thermostat shall indicate  
when the first and second stage is energized except  
in emergency mode. The icon is “STG 1” for the first  
stage energized. The icons for the first and second  
stage energized are “STG1+2” located in the upper  
right side of the display.  
20  
The word “HOLD” is displayed when the thermostat is  
in the HOLD mode. “HOLD” is displayed flashing  
when the thermostat is in a temporary HOLD mode.  
Displays currently programmed set temperature (this  
is blank when SYSTEM is OFF).  
14  
15  
Displays “FLTR” when the system has run for the  
programmed filter time period as a reminder to change  
or clean your filter.  
CONFIGURATION MENU  
The configuration menu allows you to set certain thermostat 1) Single Stage, Multi-Stage or Heat Pump System  
Configuration – This control can be configured for Heat  
Pump or two stage heat/two stage cool Multi-Stage opera-  
tion. The display indicates “MS 2” (default for Multi-Stage  
mode) in the display. The Multi-Stage configuration can  
operating characteristics to your system or personal require-  
ments.  
Set SYSTEM button to OFF, then simultaneously press  
and  
to enter configuration menu. The display will  
changed to “SS1”, “HP2”, or “HP1” by pressing the  
or  
show the first item in the configuration menu.  
key. In Multi-Stage configuration, SYSTEM button will  
not have EMERgency mode.  
The configuration menu table summarizes the configuration  
options. An explanation of each option follows.  
2) Programmable Periods – This control can be configured  
for 4, 2 or 0 programmable periods. The display indicates  
“PRG 4” in the display as default. The programmable  
Press SYSTEM to change to the next menu item. To exit the  
menu and return to the program operation, press RUN. If no  
keys are pressed within fifteen minutes, the thermostat will  
revert to normal operation.  
periods can be toggled to 2 or 0 by pressing the  
or  
keys. With "PRG 0" selected for non-programmable, sys-  
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CONFIGURATION MENU  
Press the SYSTEM button until OFF is displayed, then press the  
and  
simultaneously  
INSTALLER/CONFIGURATION MENU  
Press  
Displayed  
Press  
or  
Step  
Button(s) (Factory Default)  
to select  
Comments  
1
System  
MS 2  
SS1, HP2, HP1  
Selects Single Stage, Multi-Stage, or Heat Pump  
(Single Stage or 2-stage) System Configuration  
2
3
System  
System  
PRG 4  
PRG 0, PRG 2  
Selects Programmable Periods  
4:00 HOLD  
0:15 to 8:00  
Selects Temporary Program Override Time  
(increments of 15 minutes)  
4
System  
EMR  
(ON)  
OFF  
Selects Energy Management Recovery OFF or ON  
5
6
System  
System  
FA  
SL  
Selects Fast or Slow Cycle Selection  
CL  
CL  
Selects Compressor Lockout CL OFF or ON  
(OFF)  
(ON)  
7
8
System  
System  
CDL  
(ON)  
CDL  
(OFF)  
Selects Backlight Display  
FA  
FA  
Selects Fast Second Stage ON or OFF  
(ON)  
(OFF)  
(Not available if SS1 is selected above)  
9
System  
System  
0 FLTR  
50-1950 (increments of 50)  
Selects filter replacement run time  
10  
0°F  
4 LO to 4 HI  
Selects Temperature Display Adjustment 4 LO to 4 HI  
(Room Temperature)  
11  
12  
13  
System  
System  
System  
°F  
°C  
OFF  
Selects temperature display or °C selection  
Selects AUTO Mode ON or OFF  
AU On  
LR  
LR 62 to LR89  
Selects Limited HEAT range  
(90)  
14  
15  
16  
17  
System  
System  
System  
Run  
LR  
(45)  
LR 46 to LR 82  
(ON)  
Selects Limited COOL range  
Selects Keypad Lockout  
(OFF)  
000  
001 to 999  
Selects Keypad lockout combination number  
Press System to set code  
Returns to the OFF position  
tem key selection will skip EMR (item 4) and temporary  
program override (item 3).  
go back to the program temperature and “HOLD” will  
no longer blink or display.  
3) Select Temporary Program Override Time – The thermo-  
stat can hold any temperature you set it to for the amount  
of time you select on this option. Your choices are 0:15 to  
8:00 hours in 15 minute increments.  
4) Select Energy Management Recovery OFF or ON –  
Energy Management Recovery (EMR) causes the thermo-  
stat to start heating or cooling early to make the building  
temperature reach the program setpoint at the time you  
specify. Heating will start 5 minutes early for every 1°  
of temperature required to reach setpoint. Cooling allows  
more time per degree because it takes longer to reach  
temperature.  
Example:  
a. You have selected 3:00 hours for the Temporary Pro-  
gram Override time period.  
b. With the thermostat set to Heat or Cool, press  
or  
Example: You select EMR and have your heating program-  
med to 65° at night and 70° at 7 AM. If the building temp-  
erature is 65° the difference between 65° and 70° is 5°.  
Allowing 5 minutes per degree the thermostat setpoint will  
change to 70° at 6:35 AM.  
to set the temperature to your preference.  
The thermostat will maintain this temperature setting  
for 3 hours with “HOLD” blinking to remind you it is  
in Temporary Hold. After 3 hours, the thermostat will  
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CONFIGURATION MENU  
5) Fast or Slow Cycle Selection – The factory default setting  
is fast cycle, which cycles 1st stage at approximately 1.2°F  
and 2nd stage 0.75°F. If you prefer slow cycle, press the  
11)Select F° or C° Readout – Changes the display readout  
to Centigrade or Fahrenheit as required.  
12)Selected Auto mode – This control will feature AUTO  
or  
key to change to SL. The 1st stage and 2nd  
changeover mode when AU on is selected (default). Press  
stage would be 1.5°F and 1.2°F respectively.  
the  
or  
keys in the menu mode to defeat the auto  
6) Select Compressor Lockout CL OFF or ON – Selecting  
CL ON will cause the thermostat to wait 5 minutes before  
turning on the compressor if the heating and cooling system  
loses power. It will also wait 5 minutes minimum between  
cooling and heating cycles. This is intended to help protect  
the compressor from short cycling. Some newer compres-  
sors already have a time delay built in and do not require  
this feature. Your compressor manufacturer can tell you if  
the lockout feature is already present in their system. When  
the thermostat compressor time delay occurs it will flash the  
setpoint for about five minutes.  
changeover mode (OFF).  
13)Limited Heat Range – This feature provides a maximum  
setpoint temperature for heat. The default setting is 90°F. It  
can be changed between 62°F and 89°F by pressing the  
or  
key.  
14)Limited Cool Range – This feature provides a minimum  
setpoint temperature for cool. The default setting is 45°F. It  
can be changed between 46°F and 82°F by pressing the  
or  
key.  
15 & 16) Keypad Lockout – This menu selection will display  
lock icon ( ) and “OFF” (default, keypad not locked out).  
The and are used to toggle the selection between OFF  
and ON (keypad locked out). When the keypad lockout  
selection is enabled (ON), and the SYSTEM button is  
pressed again, the display will indicate the number “0”  
7) Select Backlight Display – The display backlight improves  
display contrast in low lighting conditions. When the C  
terminal is powered, selecting backlight CdL ON will turn the  
light on continuously. Select backlight OFF will keep the light  
on momentarily after any key is pressed. When the C  
terminal is not powered, this selection has no effect.  
(default, still disabled) in the time digits. The  
and  
are  
used to set the combination number from 0 to 999. If a  
combination of 0 is selected and the SYSTEM button is  
pressed, the menu will be exited and keypad will not be  
locked. If 1 to 999 is selected and the SYSTEM button is  
pressed, the combination is stored into memory and the  
menu is exited. The ( ) will display designating keypad  
locked with a valid combination. The SYSTEM button will  
operate for 10 seconds after the menu mode is exited to  
allow the user to change the mode from OFF to the desired  
SYSTEM mode.  
8) Select (Fast) Second Stage ON or OFF (not available in  
Single Stage configuration) – In the run mode,  
if the setpoint temperature is manually raised by 3°F (2°C)  
or more above the actual temperature with the , and the  
fast second stage feature is enabled, FA ON, the second  
stage will energize immediately. With FA OFF, second  
stage will not energize until the setpoint temperature is 1°F  
or more above actual temperature for more than ten min-  
utes.  
9) Select filter replacement run time – The thermostat will  
display FLTR after a set time of operation. This is a remind-  
er to change or clean your air filter. This time can be set from  
0 to 1950 hours in 50 hour increments. A selection of 000  
will cancel this feature. When “FLTR” is displayed, you  
can clear it by pressing HOLD and RUN at the same time.  
This resets the timer and starts counting the hours until the  
next filter change. Contact your system manufacturer for a  
specific replacement/maintenance interval.  
While the keypad is locked out, a simultaneous press of  
and  
will enter the configuration menu from any  
mode instead of only OFF mode. When the menu is  
entered with the keypad lockout feature enabled, the first  
menu item displayed is the combination code 0. The  
or  
keys are used to set the combination unlock number  
from 0 to 999. If the unlock number matches exactly with  
the combination lock number stored in memory when the  
SYSTEM button is pressed, the keypad is unlocked and  
the ( ) is removed. If the unlock number does not match  
when the SYSTEM button is pressed, the menu is exited  
and the keypad remains disabled.  
10)Select Temperature Display Adjustment 4 LO to 4 HI –  
Allows you to adjust the room temperature display up to 4°  
higher or lower. Your thermostat was accurately calibrated  
at the factory but you have the option to change the display  
temperature to match your previous thermostat. The cur-  
rent or adjusted room temperature will be displayed on the  
left side of the display.  
To reset the combination code and unlock the keypad if  
the code is forgotten, see troubleshooting section.  
SPECIFICATIONS  
THERMAL DATA  
ELECTRICAL DATA  
Electrical Rating:  
Setpoint Temperature Range:  
45°F to 90°F (7°C to 32°C)  
Operating Ambient Temperature Range:  
32°F to 105°F  
Mv to 30 VAC 50/60 Hz or DC  
0.05 to 1.5 Amps (Load per terminal)  
2.5 Amps Maximum Total Load (All terminals combined)  
Operating Humidity Range:  
0 to 90% RH (non-condensing)  
Shipping Temperature Range:  
-40°F to 150°F  
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OPERATION  
• LOW BATTERY INDICATOR — If the 2 “AA” alkaline batter-  
ies are low and should be replaced, the display will be blank  
except for “LO BATT”. We recommend replacing batteries  
every 2 years. If the home is going to be unoccupied for an  
extended period (over 3 months), the batteries should be  
replaced before leaving. When the batteries are low, pressing  
any button will cause the display to operated for ten seconds.  
After ten seconds, the display will be blank except for “LO  
BATT”. You cannot program with low batteries, but you can  
override setpoint temperature. After “LO BATT” has been  
displayed for 4 weeks, the thermostat will raise the tempera-  
ture 10 degrees above your setpoint in COOL mode and will  
drop the temperature 10 degrees below your setpoint in  
HEAT mode. If the “LO BATT” condition continues, and  
when it reaches certain value, the thermostat will turn off all  
the loads and “LO BATT” will flash.  
The system "mode" is selected by pressing the SYSTEM  
button. Icons on the bottom right corner of the display will  
indicatethemode:COOL ( ), AUTO (  
),HEAT ( ),EMER,  
or OFF. In any mode except OFF, the setpoint temperature will  
be shown on the right side of the display. In OFF, this area will  
be blank. The current temperature will be displayed on the left  
side of the display.  
To operate properly in the AUTO mode, the heat setpoint  
temperature cannot be the same as or higher than the cool  
setpoint temperature. The heat setpoint must be at least 1°  
lower than the cool setpoint.  
Automatic System Changeover  
When the thermostat is in the AUTO mode, both the Flame and  
Snowflake icons are displayed. The thermostat will call for heat  
or cool depending on the room temperature. The setpoint  
temperature displayed will be that of the last mode called. If the  
lastsystemcyclewasheat, the HEAT setpointwillbedisplayed.  
IftheroomtemperatureraisesabovetheHEAT setpointandthe  
COOL setpoint and a call for cool is required, the temperature  
displayed will change to be the COOL setpoint.  
• SIMPLIFIED COPY DAY FUNCTION — This feature allows  
Monday’s program to be copied into the rest of the week’s  
programming. This feature is available the first time you  
programmed your thermostat. To use this feature, simply  
enter the program for Monday as described in ENTERING  
YOUR PROGRAM, then press RUN or HOLD. The only way  
to restore this feature is to complete a software reset (see  
Reset Operation under TROUBLESHOOTING section).  
Second Stage Time Delay  
Your thermostat is designed to determine the optimum time to  
activate the second stage. Simply raising the temperature in  
heating or lowering it in cooling will not always force the  
thermostat to bring the second stage on quickly. There is a time  
delay from 0-30 minutes depending on the performance of the  
first stage of the system.  
COPY DAY FUNCTION — This feature allows  
a selected day’s program to be copied to the desired day’s  
programming. To use this feature: in PRGM mode, select the  
day to be copied from by pressing the HOLD button. Enter the  
program for the selected day as described in ENTERING  
YOUR PROGRAM. Press and hold the TIME button for 4  
seconds to begin the COPY mode. The LCD will display  
“COPY” and the selected day to be copied. The day the  
program will copy to will be flashing. Press the HOLD button  
to select the day you want to copy to. Press TIME to complete  
the Copy Day operation and return to PRGM mode. Press  
RUN to exit.  
EXAMPLE: For the last 2 hours the thermostat is set on 70° and  
the room temperature is 70° with the equipment using only the  
first stage of heat. Since the equipment is keeping the tempera-  
ture within 1° of setpoint, the thermostat will delay second stage  
for a longer time if you manually raise the temperature or if the  
room temperature quickly changes. Once the second stage  
comes on, it will come on sooner the next time there is a  
difference between the setpoint and the room temperature. The  
net effect of the staging program is that when the first stage is  
capable of making temperature the second stage will delay  
longer. When the thermostat calculates that first stage cannot  
make temperature in a reasonable time, the second stage will  
come on sooner. This built in function automatically optimizes  
the use of additional stages of heat or cool.  
PROGRAMMING YOUR THERMOSTAT  
This section will help you plan your thermostat's program to  
meet your needs. For maximum comfort and efficiency, keep  
the following guidelines in mind when planning your program.  
• When heating (cooling) your building, program the temper-  
atures to be cooler (warmer) when the building is vacant or  
during periods of low activity.  
Manual Operation  
Permanent Program Override (HOLD) – With the SYSTEM  
button set to HEAT or COOL, press the HOLD button once and  
• During early morning hours, the need for cooling is usually  
minimal.  
Planning Your Program  
release. “HOLD” will be displayed. Use  
or  
to adjust the  
Look at the factory preprogrammed times and temperatures  
shown in the sample schedule. If this program will suit your  
needs, simply press the RUN button to begin running the factory  
preset program.  
temperature. The thermostat will hold the room temperature at  
the selected setting until you press RUN button to start program  
operation again.  
Temperature Program Override – Press  
or  
until the  
If you want to change the preprogrammed times and tempera-  
tures, follow these steps.  
display shows the temperature you want. The thermostat will  
override current programming and keep the room temperature  
at the selected temperature for a programmed time period.  
“HOLD” will be displayed and flashing. The thermostat will  
automatically revert to the program after programmed period.  
Determine the time periods and temperatures for your program.  
You can program four or two periods for each day (see Configu-  
rationmenu, item2). Youmayusethesameheatingandcooling  
temperatures for consecutive time periods. You can choose  
start times, heating temperatures, and cooling temperatures  
independently (for example, you may select 5:00 AM and 70° as  
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OPERATION  
5. Press TIME once again. The display will show the day of  
the week.  
the weekday 1st period heating start time and temperature and  
also choose 7:00 AM and 76° as the weekday 1st period  
cooling start time and temperature).  
6. Press  
week.  
or  
until you reach the current day of the  
Use the table to plan your program time periods and the  
temperatures you want during each period. Fill in the complete  
table to have a record of your programs.  
7. Press RUN once. The display will show the correct time  
and room temperature alternately.  
Enter Heating Program  
1. Move the SYSTEM switch to HEAT.  
SAMPLE  
Heating/Cooling Schedule Plan (Factory Program)  
ALL DAYS OF THE WEEK  
2. Press PRGM once. “MO TU WE TH FR” (indicating  
weekday program) will appear in the display. Also dis-  
played are the currently programmed start time for the 1st  
heating period and the currently programmed tempera-  
ture (flashing).  
Start Time  
6:00 AM  
8:00 AM  
5:00 PM  
10:00 PM  
6:00 AM  
8:00 AM  
5:00 PM  
10:00 PM  
Temperature  
70 F  
Period  
1ST  
2ND  
3RD  
4TH  
1ST  
2ND  
3RD  
4TH  
62 F  
70 F  
MO TU WE TH FR  
62 F  
AM  
EXAMPLE:  
78 F  
85 F  
This display window shows that for the 1st weekday  
period, the start time is 6:00 AM, and 70° is the  
programmed temperature (this example reflects factory  
preprogramming).  
78 F  
82 F  
3. Press  
or  
to change the displayed temperature  
Heating/Cooling Schedule Plan  
to your selected temperature for Monday’s 1st heating  
program period.  
SATURDAY  
(1 Day)  
SUNDAY  
(1 Day)  
WEEKDAYS  
(5 Day)  
4. Press TIME once (the programmed time will flash). Press  
Start  
Start  
Start  
Time  
Period  
Time  
Temp  
Time  
Temp  
Temp  
or  
until your selected start time appears. The time  
will change in 15-minute increments. When your selected  
time is displayed, press TIME again to return to the  
change temperature mode.  
1ST  
2ND  
3RD  
4TH  
1ST  
2ND  
3RD  
4TH  
5. Press PRGM once. The currently programmed start  
time and setpoint temperature for the 2nd heatingpro-  
gram period will appear.  
6. Repeat steps 3 and 4 to select the start time and heating  
temperature for the 2nd heating program period.  
7. Repeat steps 3 through 5 for the 3rd and 4th heating  
program periods. Weekday heating programs are now  
complete.  
8. Press PRGM once "SA" (indicating Saturday program)  
will appear in the display, along with the start time for the  
1st heating period and the currently programmed temp-  
erature.  
9. Repeat steps 3 through 7 to complete Saturday heating  
programming.  
Entering Your Program  
Set Current Time and Day  
1. Press TIME button once. The display will show the hour  
only.  
PM  
10.Press PRGM once to change to "SU" (Sunday) heating  
programming and repeat steps 3 through 7 to complete  
Sunday programming.  
EXAMPLE:  
2. Press and hold either  
or  
until you reach the  
11.When you have completed entering your heating pro-  
gram, press RUN.  
correct hour and AM/PM designation (AM begins at mid-  
night; PM begins at noon).  
3. Press TIME once again. The display window will show  
the minutes only.  
EXAMPLE:  
4. Press and hold either  
correct minutes.  
or  
until you reach the  
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OPERATION  
Enter Cooling Program  
CHECK YOUR PROGRAMMING  
Follow these steps to check your thermostat programming  
one final time before beginning thermostat operation.  
1. Press SYSTEM button to HEAT position.  
2. Press PRGM to view the 1st Monday heating period  
time and temperature. Each time you press PRGM, the  
next heating period time and temperature will be display-  
ed in sequence for each weekday, then Saturday and  
Sunday program periods (you may change any time or  
temperature during this procedure).  
CAUTION  
!
If the outside temperature is below 50°F, disconnect  
power to the cooling system before programming.  
Energizing the air conditioner compressor during  
cold weather may cause personal injury or property  
damage.  
1. Press SYSTEM button to COOL position.  
2. Follow Enter Heating Program for entering your cooling  
program, using your selected cooling times and tempera-  
tures.  
3. Press RUN.  
4. Press SYSTEM button to COOL position.  
5. Repeat step 2 to check cooling program.  
6. Press SYSTEM button to HEAT or COOL and press  
RUN to begin program operation.  
NOTE: Batteries are not required to keep your programming  
or menu data. With two optional "AA" batteries installed,  
your thermostat will maintain time and continuously  
display the temperature during a loss of AC power.  
Installed batteries will also allow programming prior to  
installation.  
YOUR THERMOSTAT IS NOW PROGRAMMED AND READY TO  
PROVIDE MAXIMUM COMFORT AND EFFICIENCY!  
TROUBLESHOOTING  
Reset Operation  
If a voltage spike or static discharge blanks out the display or causes erratic thermostat operation, you can reset the thermo-  
stat by removing the wires from terminals R and C and removing batteries for 2 minutes. After resetting the thermostat,  
replace the wires and batteries. If the thermostat has been reset and still does not function correctly, contact your heating/  
cooling service person or place of purchase.  
Possible Cause  
Corrective Action  
Symptom  
1. Blown fuse or tripped circuit breaker.  
2. Furnace power switch to OFF.  
Replace fuse or reset breaker.  
Turn switch to ON.  
No Heat/No Cool/No Fan  
(common problems)  
3. Furnace blower compartment door or  
panel loose or not properly installed.  
Replace door panel in proper position to engage  
safety interlock or door switch.  
1. Pilot light not lit.  
Re-light pilot.  
No Heat  
2. SYSTEM button not set to HEAT.  
Press SYSTEM button to HEAT and raise setpoint  
above room temperature.  
3. Loose connection to thermostat or  
system.  
Verify thermostat and system wires are securely  
attached.  
4. Furnace Lock-Out Condition. Heat  
may also be intermittent.  
Many furnaces have safety devices that shut down  
when a lock-out condition occurs. If the heat works  
intermittently contact the furnace manufacturer or  
local service person for assistance.  
5. Heating system requires service or  
thermostat requires replacement.  
Diagnostic: Press SYSTEM button to HEAT and  
raise the setpoint above room temperature. Within a  
few seconds the thermostat should make a soft click  
sound. This sound usually indicates the thermostat  
is operating properly. If the thermostat does not  
click, try the reset operation listed above. If the  
thermostat does not click after being reset contact  
your heating and cooling service person or place of  
purchase for a replacement. If the thermostat clicks,  
contact the furnace manufacturer or a service  
person to verify the heating is operating correctly.  
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TROUBLESHOOTING  
Possible Cause  
Corrective Action  
Symptom  
No Cool  
1. SYSTEM button not pressed to COOL. Press SYSTEM button to COOL and lower setpoint  
below room temperature.  
2. Loose connection to thermostat or  
system.  
Verify thermostat and system wires are securely  
attached.  
3. Cooling system requires service or  
thermostat requires replacement.  
Same procedure as diagnostic for No Heat condition  
except set the thermostat to COOL and lower the  
setpoint below the room temperature. There may be  
up to a five minute delay before the thermostat  
clicks in Cooling.  
1. Possible short in wiring.  
2. Possible short in thermostat.  
3. Possible short in heat/cool/fan  
system.  
Check each wire connection to verify they are not  
shorted or touching together. No bare wire should  
stick out from under terminal screws. Try resetting  
the thermostat as described above. If the condition  
persists the manufacturer of your system or service  
person can instruct you on how to test the Heat/Cool  
system for correct operation. If the system operates  
correctly, replace the thermostat.  
Heat, Cool or Fan  
Runs Constantly  
4. FAN Switch set to Fan On.  
1. The location of the thermostat and/or  
the size of the Heating System may  
be influencing the cycle rate.  
Digital thermostats normally provide precise  
temperature control and may cycle faster than some  
older mechanical models. A faster cycle rate means  
the unit turns on and off more frequently but runs for  
a shorter time so there is no increase in energy use.  
If you would like to increase the cycle time, choose  
SL for slow cycle in the menu, step 4. If an accept-  
able cycle rate is not achieved as received or by  
choosing slow cycle, contact a local service person  
for additional suggestions.  
Furnace  
(Air Conditioner)  
Cycles Too Fast  
or Too Slow (narrow or  
wide temperature swing)  
The thermometer can be adjusted +/- 4 degrees.  
See Temperature Display Adjustment in the  
Configuration Menu section.  
1. Thermostat thermometer setting  
requires adjustment.  
Thermostat Setting &  
Thermostat Thermometer  
Disagree  
Use the Reset Operation at top of previous page.  
1. Voltage spike or static discharge.  
Blank Display and/or  
Keypad Not Responding  
Change system mode to COOL. Raise the Cool  
setpoint. Return to HEAT mode and set desired  
temperature.  
1. The desired setpoint conflicts with the  
setpoint of the COOL mode.  
Heat Setpoint will  
not Respond to the  
Temperature Up Key  
Change system mode to HEAT. Lower the Heat  
setpoint. Return to COOL mode and set desired  
temperature.  
1. The desired setpoint conflicts with the  
setpoint of the HEAT mode.  
Cool Setpoint will  
not Respond to the  
Temperature Down Key  
CAUTION: This resets the thermostat to factory  
default settings of the configuration menu. After  
performing this reset, the thermostat will require  
configuration again. Be sure that you know the  
required configuration settings before resetting.  
Forgot Keypad  
Lockout Code  
With the thermostat in any mode, press  
and  
at  
the same time to enter the configuration menu at the  
point where the lockout code is to be entered. Press  
and  
and SYSTEM button at the same time to  
reset the lockout code, unlock the keypad and reset  
all configuration menu settings.  
Your thermostat is designed to determine the optimum  
time to activate the second stage. Simply raising the  
temperature in heating or lowering it in cooling will not  
always force the thermostat to bring the second stage  
on quickly. There is a time delay from 0-30 minutes  
depending on the performance of the first stage of the  
system.  
First stage is keeping up with demand.  
Why won’t my 2nd or  
3rd stage come on?  
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FAQ  
Symptom  
Corrective Action  
Your thermostat display can be set to display temperature in Fahrenheit or  
Celsius. This option can be set in the INSTALLER/CONFIGURATION MENU  
of your thermostat. See page 6 step 12.  
My thermostat is reading in Celsius.  
How do I change it to Fahrenheit?  
There is no need to select a time to stop a programming period. Starting a  
new programming period will stop the previous program period.  
Do I have to program a stop time for each  
program period?  
Unless the thermostat appears to be damaged it will follow the program that  
is in the memory. The most common reason a thermostat will appear not to  
be following the program is a programming error. Verify that the AM or PM  
settings are correct for each period. Also verify that the Day of the week is  
set correctly. Models with EMR (Energy Management Recovery) start early to  
make the temperature they are programmed for by the time specified in the  
program. See the CONFIGURATION MENU on page 6 step 3.  
My thermostat does not follow it’s  
program. What should I do?  
Any time you wish to turn your system off, simply press the SYSTEM button  
until “OFF” is displayed. This will not affect your thermostat’s programming  
in any way. To turn the system back on, press the SYSTEM button to HEAT  
or COOL and press RUN. The system will begin operating according to the  
current thermostat program. See under OPERATION page 8 & 9.  
Between heating and cooling seasons,  
I want to turn my system off. Will this  
change my program?  
Because it is soldered to the circuit board it is not possible to repair or  
replace.  
My display light does not work. Can it be  
fixed or replaced?  
No. This thermostat has permanent memory, although you will have to reset  
your clock.  
Do I have to reprogram my thermostat  
after I change the batteries?  
When the thermostat compressor time delay occurs it will flash the setpoint  
for about five minutes. This is intended to help protect the compressor from  
short cycling.  
My setpoint temperature is flashing.  
What does that mean?  
Visit our website at www.white-rodgers.com for operating manuals.  
How can I get a copy of the Operating  
Manual for my thermostat?  
My program or configuration menu is all  
messed up, how do I start from the  
beginning?  
You can perform software reset by pressing  
simultaneously when SYSTEM mode is OFF. See “Forget Keypad Lockout  
Code” under “TROUBLESHOOTING” for details.  
and SYSTEM buttons  
HOMEOWNER HELP LINE: 1-800-284-2925  
The Emerson logo is a  
trademark and service mark  
of Emerson Electric Co.