Lennox ComfortSense L3722C Operation Manual

OPERATION MANUAL

E2008 Lennox Industries Inc.

Dallas, Texas, USA

RETAIN THESE INSTRUCTIONS

FOR FUTURE REFERENCE

L3722C 7−Day Programmable Thermostat

The Lennox ComfortSenset 3000 Series model L3722C
7-day programmable electronic thermostat provides
excellent temperature control and has a large,
easy-to-read display. This product includes a
programmable filter change reminder, an equipment
maintenance reminder, and a system check indicator to
notify the user when the equipment requires service.

Thermostat model L3722C is suitable for non-heat pump,
two-stage heat/two-stage cool applications using a gas or
electric furnace. Also, the thermostat provides auto­changeover capability.

ComfortSenset 3000 Series
Model No. L3722C 7-Day
Programmable Thermostat

CONTROLS

506071−01
02/08
Supersedes 505,068M

Table of Contents

L3722C 7−Day Programmable Thermostat 1. . . . . . . .

General 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Initial Thermostat Power-up 1. . . . . . . . . . . . . . . . . . . . .

Buttons, Backlight, Timers & Settings 2. . . . . . . . . . . .

DAY/TIME − Set Day and Time 2. . . . . . . . . . . . . . . . . .

HEAT − Heat Mode 3. . . . . . . . . . . . . . . . . . . . . . . . . . . .

COOL − Cool Mode 3. . . . . . . . . . . . . . . . . . . . . . . . . . . .

AUTO − Using the Autochangeover Mode 4. . . . . . . . .

HOLD − Temperature Hold Mode 4. . . . . . . . . . . . . . . .

PROG − Thermostat Programming 4. . . . . . . . . . . . . . .

COPY − Copy a Program 6. . . . . . . . . . . . . . . . . . . . . . .

FAN − Controlling Fan Operation 5. . . . . . . . . . . . . . . . .

Displaying Outside Temperature 6. . . . . . . . . . . . . . . . .

SETTINGS − Filter /Maintenance Reminder 6. . . . . . .

Service Indicator 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Thermostat RESET 6. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Removing/Installing Thermostat 7. . . . . . . . . . . . . . . . .

Default Thermostat Settings 7. . . . . . . . . . . . . . . . . . . .

Thermostat Output Table 7. . . . . . . . . . . . . . . . . . . . . . .

Technical Specifications 7. . . . . . . . . . . . . . . . . . . . . . . .

Litho U.S.A.

General

These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
having jurisdiction before installation.

Check equipment for shipping damage. If you find any
damage, immediately contact the last carrier.

Introduction

This document describes the operation of Lennox model
L3722C thermostat. Refer to the installation manual for in­structions regarding installation and wiring of the thermo­stat.

Initial Thermostat Power-up

When power is initially applied to the thermostat, the dis­play will appear as shown in figure 1.

Copy tofrom

PROG

A B C D

HOLD

FAN ON
AUTO

FILTER

MAINTENANCE

OUTROOM

i88

Figure 1. Initial Power−Up Display

All display segments are momentarily activated. This oc­curs as a normal part of thermostat initialization.

Within a few seconds, the HOME screen appears (see fig­ure 2) with default settings as shown. After about 1 minute
of initialization time, the actual room temperature will be
displayed.

MO TU WE TH FR SA SU

AM

I8:88

PM

COOL SETPOINT

SERVICE

88

HEAT SETPOINT

°

88

°

COOL

OFF

AUTO

EMG.
HEAT

°

Hi
Lo

02/08 506071−01

*2P0208* *P506071-01*

NOTE − Tables 3 and 4 on page 7 show all system and
programming defaults.

PROG
A B C D

HOLD

FAN ON
AUTO

MO
AM

PM

ROOM

I0:26

COOL

AUTO

°

EMG.
HEAT

OFF

70

Figure 2. Home Screen

At this point, the thermostat will be fully functional; its de­fault temperature setpoint (not shown) is 70°F. At this
point, if the equipment has been fully powered and if a heat
demand were present, the system would begin operating.

NOTE − Temperature scale default is Fahrenheit units but
may be reset to show Celsius, if desired. See page 8.

Buttons, Backlight, Timers & Settings

Buttons are located behind the small door on the right−
hand side of the thermostat (see figure 3).

IMPORTANT

Do NOT begin pressing buttons until after you read
the following section describing each button.

A pale blue display backlight illuminates for 30 seconds
each time any button is pressed.

When PROG or DAY/TIME button is pressed, a field be­gins flashing, expecting another input. Start making
changes within 15 seconds or the HOME screen will re­turn.

Heat

Cool

Prog

Auto

Day/Time

Copy

Fan

Settings

Hold

Enter

(Outside)

(DOOR
OPEN)

Figure 3. Thermostat Buttons

When an Arrow, HOLD, HEAT, or COOL button is pressed,
SETPOINT and the temperature setting appears for 15
seconds. If desired, start making changes within 15 sec­onds or the HOME screen will return. The backlight will
turn off 15 seconds after the HOME screen reappears.

DAY/TIME − Setting the Day and Time

Press the DAY/TIME button and set the CURRENT hour,
minute, and day of week as follows:

1. AM12" will flash on the screen. Press the UP/DOWN
arrows to change the hour. (AM" or PM" must corre­spond to time of day.) Press DAY/TIME OR, if adjust-

ing for daylight savings time, pressing the ENTER but­ton stores the single change and exits to the HOME
screen, bypassing minutes and day of week.

2. Minutes will flash. Use the UP/DOWN arrow button to
display the minutes past the hour. Press DAY/TIME.

3. Day MO" (Monday) will flash. Use UP or DOWN arrow
buttons to display the current day. Day selections are
abbreviated as MO, TU", WE", TH", FR", SA",
and SU". Press DAY/TIME.

4. The HOME screen reappears; confirm day and time
are correct. This completes day and time setting.

506071−01 02/08

Page 2

HEAT − Using the Heat Mode

COOL − Using the Cool Mode

Enabling and Disabling Heat Mode

The thermostat must be in the heat mode to control the
heating equipment. Press the HEAT button to enable or
disable HEAT mode. If the thermostat is in cool or off
mode, pressing the HEAT button enables the heat mode
(indicated by HEAT in the lower right corner − see figure 4).

Heat

Cool

Prog

Auto

5:30

Day/Time

82

70

66

Figure 4. Turn Heat ON/OFF

If the thermostat is in heat mode, heat mode is disabled
when the HEAT button is pressed. This is indicated by OFF
near the right side of the display as shown in figure 5.

Copy

Fan

Settings

Hold

Enter

(Outside)

(DOOR
OPEN)

Enabling and Disabling Cool Mode

Use the COOL button to enable or disable cool mode as
desired. If the thermostat is in heat or off mode, cool mode
is enabled when the COOL button is pressed. This is indi­cated by COOL on the right side of the display (figure 8).

Heat

Cool

Prog

Auto

i0:30

Day/Time

70

75

66

Figure 7. Turn Cool ON/OFF

If the thermostat is in cool mode, pressing the COOL but­ton disables cool mode (indicated by OFF in the SYSTEM
box − see figure 5).

Copy

Fan

Settings

Hold

Enter

(Outside)

(DOOR
OPEN)

ROOM

°

HEAT SETPOINT

OFF

°

75

Figure 5. Heat/Cool Mode Disabled

Heating Demand

Set the thermostat to heat mode to control the heating
equipment. Then, if the room temperature is lower than the
temperature setpoint, as shown in figure 6, the thermostat
detects a heating demand and will activate the heating
equipment to satisfy the demand.

ROOM

°

72

Figure 6. Heating Demand

Heating operation is indicated by a flame icon in the lower
right corner. When the actual temperature rises above the
temperature setpoint, the flame icon will disappear. This
indicates that the heating demand has been satisfied and
that the heating equipment has been turned off.

If your system supports 2−stage heating (as does the
L3722C thermostat), you may notice various heating lev­els being delivered during a demand.

NOTE − Heating equipment is activated for at least 3 min­utes if no buttons are pressed during the demand interval.

75

HEAT SETPOINT

°

75

HEAT

Cooling Demand

Set the thermostat to cool mode to control the cooling
equipment. Then, if the room temperature is higher than
the temperature setpoint, as shown in figure 7, the thermo­stat detects a cooling demand and will activat e the cooling
equipment to satisfy the demand.

Cooling operation is indicated by flashing snowflake"
icons on the right side of the display. When the actual tem­perature drops below the temperature setpoint, the snow­flake icons will disappear. This indicates that the cooling
demand has been satisfied and that the cooling equipment
has been turned off.

If your system supports 2−stage cooling (as does the
L3722C thermostat), you may notice various cooling levels
being delivered during a demand. Also, if a small cooling
demand is present, "Lo" will be displayed in the SYSTEM
box. However, if a large cooling demand is present, "Hi" will
be displayed in the lower right corner (shown in figure 8).

FAN
AUTO

COOL SETPOINT

°

COOL

76

ROOM

80

Figure 8. Cooling Demand

HEAT SETPOINT

°

68

°

Hi

Lo

Page 3

L3722C 7−DAY PROGRAMMABLE THERMOSTAT

NOTE − If no buttons are pressed during a demand for
cooling, the equipment must operate for at least 4 minutes.
After a demand has been satisfied, cooling equipment op­eration is locked out for 5 minutes. If another cooling de­mand occurs during this 5−minute interval, COOL" and the
snowflakes will flash; however, the cooling equipment will
not operate until the 5−minute delay has elapsed.

AUTO − Using the Autochangeover Mode

When in either heat mode or cool mode, autochangeover
can be enabled or disabled by pressing the AUTO button. If
enabled, AUTO appears at the lower right corner of the dis­play. The thermostat will then automatically change over
from heating to cooling and vice versa, to keep the room
temperature in between the heating and cooling setpoints.
Autochangeover can be used in either of the thermostat
hold modes, or when the thermostat program is running.
These modes are described later.

HOLD − Using Temperature Hold Modes

When HOLD is displayed at the HOME screen, the ther­mostat is in a temperature hold condition. This means that
the temperature program data is ignored and the thermo­stat functions much like a non−programmable thermostat.

Adjusting Temperature Setpoint in Hold Mode

The temperature setpoint represents the desired tempera­ture of the space around the thermostat. The default heat
setpoint in hold mode is 70°F; the default cool setpoint in
hold mode is 78°F.

After the desired setpoint is reached, the HOME screen
will reappear after about 15 seconds.

Permanent Hold Mode

At any time the program is running, from the HOME
screen, set a permanent hold (program override) by press­ing the HOLD button (see figure 9). The thermostat now
functions much like a non−programmable thermostat. Use
the Up/Down arrow buttons to adjust the hold setpoint. To
return to the program, press the HOLD button again.

Temporary (2-Hour) Hold

At any time the program is running, from the HOME
screen, set a temporary 2-hour hold by pressing the Up/
Down arrow buttons until the desired setpoint is displayed;
HOLD" flashes (see figure 10). This overrides the pro­gram for 2 hours from the last button press, then returns to
the program.

While in Temporary Hold, press the HOLD button once to
switch to Permanent Hold (HOLD displays solid; PROG
not displayed); press the HOLD button again to return to
the program (PROG displays; HOLD not displayed).

Heat

Cool

Prog

Auto

i0:30

Day/Time

Copy

70

72

68

Fan

Hold

(DOOR
OPEN)

Heat

Cool

Prog

Auto

i0:30

Day/Time

78

80

70

Figure 9. Hold Temperature Mode

To adjust the setpoint, press the UP or DOWN (YB) arrow
buttons; the existing setpoint is displayed to the right of the
actual room temperature. Each button press adjusts the
setpoint up or down by 1 degree.

Copy

Fan

Settings

Hold

Enter

(Outside)

(DOOR
OPEN)

Settings

Enter

(Outside)

Figure 10. Temporary Hold Temperature Mode

PROG − Thermostat Programming

The L3722C thermostat can be programmed to perform a
set of both heating and cooling events for each day of the
week. Each day can be programmed for 4 unique events
per day, and each day can be different from any other day.

To Set Program Events and Temperatures

Figure 11 gives an example of how up to 7 different pro­grams can be set. Programs A and C reflect the desired
warmth while the home IS occupied (72°); B allows less
heating while the home is NOT occupied; D reflects a cool
sleeping temperature.

NOTE − This example shows heat setpoints; a similar pro­gram may be set for cool setpoints.

506071−01 02/08

Page 4

MONDAY PROGRAM: 72°

68°

64°

TUESDAY PROGRAM: 72°

68°

64°

WEDNESDAY PROGRAM: 72°

68°

64°

Heat

Prog

Copy

Fan

Cool

Auto

Day/Time

Hold

(DOOR
OPEN)

A

A

A

C

B

C

B

C

B

D

Copy from MO

D

D

THURSDAY PROGRAM: 72°

FRIDAY PROGRAM: 72°

SATURDAY PROGRAM: 72°

SUNDAY PROGRAM: 72°

A

68°

64°

A

68°

64°

68°

64°

68°

64°

A

A

6AM NOON 6PM MID 6AM

C

B

C

B

C

B

C

B

NIGHT

D

D

D

D

Figure 11. 7 Day Program Example

NOTE − Pressing the ENTER button during the following
programming steps, saves and exits to the HOME screen.

To program events and temperatures, perform the follow­ing steps.

1. Press and release the PROG button. "MO" (Monday),
"AM 6:00", period "A", "COOL SETPOINT 78", and
"HEAT SETPOINT 70" are displayed. "AM 6" flashes.

2. Use the Up/Down arrow buttons to select the desired
hour; press the PROG button when the desired hour
is reached; use the Up/Down arrow buttons again to
select desired minute. The selected hour/minute is
when the program will start. Press the PROG button.

3. Use the Up/Down arrow buttons to select the desired
heat setpoint; press the PROG button.

4. Use the Up/Down arrow buttons to select the desired
cool setpoint; press the PROG button.

5. Repeat steps 1 − 4 for Monday, periods B, C, and D.

6. COPY A PROGRAM − If the program entered for
Monday is satisfactory for other days of the week, do
the following to repeat the same program for other
days:
A Press the PROG button, then press the COPY

button. The display clears the screen except for
Copy from MO with MO" flashing. Press the
COPY button again to copy Monday’s program.

B The display changes to Copy to MO". Use the ar-

row buttons to scroll to the desired day where you
want the same program as Monday. Press the
COPY button.

C Repeat steps A and B for as many days as you

want the same program.

Settings

Enter

(outside)

Figure 12. Copy a Programmed Day to Another

Day

7. Repeat steps 1 − 5 to program different times and tem­peratures for days not yet programmed.

FAN − Controlling the Fan Operation

Use the FAN button to select either continuous fan mode or
auto fan mode.

To change from continuous to auto fan mode (or vice ver­sa), press the FAN button. Note whether a fan icon in the
FAN box is present (indicating that the fan is running) or not
(fan not running).

If continuous fan mode is enabled (ON displayed in FAN
box − see figure 13), the fan will run continuously regard­less of whether the heating or cooling equipment is run­ning.

Heat

Cool

Prog

Auto

i0:30

Day/Time

Copy

Fan

72

Hold

Figure 13. Using Fan ON

If auto fan mode is selected (AUTO displayed in FAN box −
see figure 14), the fan will only run when the heating or
cooling equipment is running.

Heat

Cool

Prog

Auto

i0:30

Day/Time

Copy

Fan

72

Figure 14. Using Fan AUTO

Hold

Page 5

L3722C 7−DAY PROGRAMMABLE THERMOSTAT

Displaying Outside Temperature

(1st

)

(Off, 1, 3, 6, 12); f

then Arrows

example, to remind yourself when to

Pressing the ENTER (Outside) button at the HOME
screen displays the outside temperature (see figure 15) for
several seconds, then returns to room temperature.

Fan

Settings

Hold

Enter

(Outside)

88

Figure 15. Check Outside Temperature

SETTINGS − Filter/Maintenance Reminders

The L3722C thermostat is designed to remind you when
the filter needs changing or when routine maintenance is
required, as (and if) defined, by you. These optional re­minders are not enabled until you activate them. To do so,
press the SETTINGS button once or twice for the desired
reminder as shown in figure 16 and as described in table 1.

OFF

For FILTER, press SETTINGS
button 1 time

FILTER

MAINTENANCE

Figure 16. Reminder Settings Display

The default setting for the reminders is OFF (disabled).
Press Up/Down arrow buttons to select the desired re­minder intervals.

Table 1. Filter and Maintenance Reminders

Buttons to

Use

Settings

press

then Arrows

to scroll

selections

Settings

(2nd press)

then Arrows

to scroll

selections call a technician for perodic

Enter Stores settings.

Reminder

FILTER

MAINTE-

NANCE

For MAINTENANCE, press
SETTINGS button 2 times

Available Settings and
How to Use

Total fan run time expressed in
months
example, if fan runs 12 hours a day,
1 month reminder displays in 2
calendar months.

Elapsed chronological time in
months (Off, 6, 12). Use this, for
example, to remind yourself when to
perform routine checks or when to

preventive maintenance.

or

PROG
A B C D

HOLD

FAN ON
AUTO

FILTER SERVICE
MAINTENANCE

MO
AM

ROOM

I0:26

PM

°

COOL

OFF

AUTO

EMG.

HEAT

Filter &

Maintenance

Indicators

76

FAN ON
AUTO

FILTER SERVICE
MAINTENANCE

ROOM

COOL

OFF

AUTO

°

EMG.
HEAT

Service
Indicator
Flashing

76

Figure 17. Reminders

After the filter has been changed or maintenance per­formed, reset the reminder by pressing the SETTINGS
button for 4 seconds at the corresponding reminder set­tings screen. The screen will blink for a few moments to in­dicate that the timer has been reset.

Service Indicator

When abnormal equipment operation is detected, the
SERVICE indicator will flash on the screen (see figure 17).
This indicates that the equipment requires service from a
qualified service technician.

Thermostat RESET

Under some abnormal conditions, it may be necessary to
reset" the thermostat to its default condition. Such a RE­SET would delete all programming and settings and there­fore should only be used on rare occasions when the the
thermostat fails to function as designed and/or as pro­grammed. Such an instance can occur as a result of a pow­er surge or similar electrical disturbance (e.g. after an elec­trical storm or power outage). The RESET button can be
used to recover from this situation.

CAUTION

When the RESET button is pressed, ALL settings re­vert back to the defaults, including the default pro­gram (see tables 3 and 4).

NOTE − The HOME screen will reappear about 15 seconds
after the final arrow button press. OR, press the ENTER
button at any time to store any changes and exit to the
HOME screen.

After either programmed interval has elapsed, the remind­er will be displayed as shown in figure 17.

506071−01 02/08

The RESET button is an unlabeled, recessed button lo­cated behind the door on the right−hand side of the thermo­stat, below the SETTINGS button (see figure 3). Use a pa­per clip or small pencil to press the RESET button; ALL
thermostat settings will be reset to the defaults listed in the
Default Thermostat Settings section.

Page 6

Removing and Installing Thermostat

The thermostat hinges on tabs on the top of the subbase;
no tool is needed to remove the thermostat from the sub­base. Pivot the bottom of the thermostat outward (releas­ing the snaps), then lift up to remove.

To install it, first position the top tilted toward the wall brack­et and align it until you feel the tabs and slots engage; then,
while the top is in place, pivot the bottom toward the wall
until the thermostat snaps into place.

Thermostat Output Table

Table 2 depicts the L3722C thermostat output states for
various input conditions. The following notes described
terms used in the table.

Table 2. Thermostat Outputs

Condition W1 W2 Y1 Y2 G

Gas Heat, Auto Fan

Heat Demand, SMALL X
Heat Demand, LARGE X X
Cool Demand, SMALL X X
Cool Demand, LARGE X X X
No Demand

Gas Heat, Continuous Fan

Heat Demand, SMALL X X
Heat Demand, LARGE X X X
Cool Demand, SMALL X X
Cool Demand, LARGE X X X
No Demand X

Electric Heat, Auto Fan

Heat Demand, SMALL X X
Heat Demand, LARGE X X X
Cool Demand, SMALL X X
Cool Demand, LARGE X X X
No Demand

Electric Heat, Continuous Fan

Heat Demand, SMALL X X
Heat Demand, LARGE X X X
Cool Demand, SMALL X X
Cool Demand, LARGE X X X
No Demand X

NOTE − X = output is activated with 24VAC.
NOTE − The temperature ranges expressed in the following def-

initions of SMALL/LARGE" demands are for guidance only; ac­tual temperatures may vary.

With a SMALL heat demand, temperature is:
below

setpoint –0.5F but above setpoint –1.5F

AND 30-minute upstage timer HAS NOT expired.
With a LARGE heat demand, temperature is:

less than
OR

With a SMALL cool demand, temperature is:
above setpoint +0.5F but below setpoint +1.5F
AND 30-minute upstage timer HAS NOT expired.

With a LARGE cool demand, temperature is:
above setpoint +1.5F
OR 30-minute upstage timer HAS expired.

setpoint –1.5F

30-minute upstage timer HAS expired.

Default Thermostat Settings

Default thermostat settings are in table 3 and the default
program is shown in table 4.

Table 3. Default Thermostat Settings

Mode Heat (Perm. Hold)
Heat Setpoint (Perm Hold) 70°F (or 21°C)
Cool Setpoint (Perm Hold) 78°F (or 26°C)
Fan Auto
Filter Reminder OFF
Maintenance Reminder OFF
Equipment Protection Timers Reset Back to Zero
Autochangeover OFF

Table 4. Default Program Settings (Time/Temp)

Programs Time Temp.− Heat Temp.− Cool

All days − A 6:00am 70_F / 21°C 78_F / 26°C
All days − B 8:00am 62_F / 17°C 85_F / 29°C
All days − C 6:00pm 70_F / 21°C 78_F / 26°C
All days − D 10:00pm 62_F / 17°C 82_F / 28°C

Technical Specifications

Thermostat TypeElectronic programmable thermo-

stat for 2−Stage (gas or electric) Heat/2-Stage Cool, non−
heat pump, non−power robbing applications.

Table 5. L3722C Terminal Designations

Terminal Description

R 24VAC
Y1 First-stage cooling
W1 First-stage heating
Y2 Second-stage cooling
W2 Second-stage heating
G Fan control
L Service Indicator
C 24VAC common
T Outdoor temperature sensor connection 1
T Outdoor temperature sensor connection 2

Power Supply Range18VAC − 30VAC (24VAC nomi-

nal), 60Hz

CAUTION

24VAC is present on the terminals of the thermostat
bracket. If removing the thermostat from the wall,
use caution and avoid touching any of the connec­tor terminals on the wall bracket.

Also, when working with the thermostat dip
switches, use a non−conductive tool and take cau­tion to avoid making any contact with the circuit
board, its imprinted circuitry and its connector
prongs.

Temperature DisplayDisplay Scale: Fahrenheit or

Celsius user selectable (via DIP switch; see figure 18)

Display range 35°F (2°C) to 99°F (37°C). . . . . . . . . . . . .

Display resolution 1°F (1°C). . . . . . . . . . . . . . . . . . . . . . . .

Display Accuracy +/−1°F. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Page 7

L3722C 7−DAY PROGRAMMABLE THERMOSTAT

If the Fahrenheit/Celsius display must be changed, use a
plastic, non−conductive tool to push the dip switch to the
right position (see figure 18).

1
2
3
4
5
6
7

PLUG IN (Use Care To Avoid Bending Prongs.)

F/C (Fahrenheit/Celsius) switch
shown in Celsius position

Figure 18. Changing Fahrenheit/Celsius Setting

Indoor Temperature Measurement Range

Measurement Scale Fahrenheit. . . . . . . . . . . . . . . . . . . .

Measurement Range 35°F to 99°F. . . . . . . . . . . . . . . . . .

Measurement Resolution 0.5°F. . . . . . . . . . . . . . . . . . . . .

Measurement Accuracy +/−1°F. . . . . . . . . . . . . . . . . . . . . .

Field Offset via DIP switches to +/−3°F. . . . . . . . . . . . . .

Sampling Method: temperature measurements sampled
every 15 seconds. Displayed temperature is the average
of the last four measurements.

Outdoor Temperature Measurement Range

Measurement Scale Fahrenheit. . . . . . . . . . . . . . . . . . . .

Measurement Range −22°F to 122°F. . . . . . . . . . . . . . . .

Measurement Resolution 1°F. . . . . . . . . . . . . . . . . . . . . . .

Measurement Accuracy +/−2°F. . . . . . . . . . . . . . . . . . . . . .

Temperature Setpoint Range

Setting range 50°F (10°C) to 90°F (32°C). . . . . . . . . . . .

Setting resolution 1°F (1°C). . . . . . . . . . . . . . . . . . . . . . . . .

Smart Setback Recovery (via DIP switch #6)

Smart Setback Recovery (SSR) affects the way the ther­mostat responds to program events. If SSR is disabled, the
thermostat will react to a program event at the time the
event occurs. However, if SSR is enabled, the thermostat
will react to a program event before the event occurs such
that the desired temperature is reached at the time of the
event, not after.

Autochangeover Deadband Selection (via DIP
switch #7)

or 6 degrees. When autochangeover is enabled (via the
AUTO button), the thermostat will automatically change
over from heating to cooling and vice versa, to keep the
room temperature in between the heating and cooling set­points. The deadband is the minimum difference between
the heating and cooling setpoints.

Autochangeover deadband can be set to 4

Fan ControlAUTO or ON modes, gas or electric heat

compatible via DIP switches (also see Thermostat Output
section).

I/O RelaysAll thermostat relays are latching type to

minimize power consumption.

Equipment Protection Timers

Minimum Compressor OFF time 5 minutes. . . . . . . . . . .

Minimum Compressor ON time 4 minutes. . . . . . . . . . . .

Minimum Furnace ON time 3 minutes. . . . . . . . . . . . . . .

Minimum furnace cycle time (elapsed time between any
furnace activation & next furnace activation) 6 minutes
Minimum elapsed time between any compressor activa-

tion and the next compressor activation 6 minutes. . . .

NOTE − All protection timers (except the compressor OFF
timer) can be over−ridden if a heating or cooling demand is
initiated or terminated using the UP, DOWN, HEAT, or
COOL buttons.

Equipment Protection OverrideBoth the minimum

compressor OFF timer and the minimum equipment cycle
timer can be over−ridden by pressing and holding either the
HEAT or COOL button down for 4 seconds.

Over Temperature ProtectionThermal-mechanical

switch opens W1 and W2 at 93°F+/−6°F.

Filter ReminderSettings of Off, 1, 3, 6 or 12 (months

of fan run time) are available. When programmed time has
elapsed, a FILTER indicator is displayed.

Maintenance ReminderSettings of Off, 6 or 12

(months of chronological time) are available. When pro­grammed time has elapsed, a maintenance indicator
MAINTENANCE" is displayed.

Service ReminderThe SERVICE indicator is dis-

played only under the following conditions:

S if the thermostat Y1 terminal has been activated with

24VAC for at least 5 minutes, AND the L terminal is
shorted to the R terminal;

OR

S if the thermostat Y1 terminal has been activated with

24VAC for at least 5 minutes, AND the L terminal is
shorted to the C terminal.

Power Loss/RecoveryThermostat memory is re-

tained for a minimum of 24 hours during a power loss (in­cludes retention of clock setting, program information,
HOLD status, programmed temperature setpoint, heat/
cool and fan mode settings, filter reminder status, mainte­nance reminder status, and equipment protection timers).
After 24 hours of power loss, programmed settings will be
lost and replaced with default settings.

IMPORTANT

Power must be applied for at least six consecutive
hours prior to a power loss in order for memory to
be retained for the specified time.

LCD BacklightActivated for 30 seconds when any

button is pressed.

NOTE − During an electrical storm or similar disturbance,
the backlight may activate for a few seconds. This is nor­mal and will no longer occur after the electrical disturbance
has passed.

Thermostat Operating Conditions 35°F to 105°F.

5% to 90% RH. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Thermostat Storage Conditions −40°F to 185°F. .

5% to 95% RH. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

506071−01 02/08

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