Lennox T7300 User manual

Page 1
505,103M
1/2007
Supersedes 12/2005
Commercial Touchscreen
Thermostat
©2005 Lennox Industries, Inc.
Dallas, Texas, USA
INSTALLATION INSTRUCTIONS
APPLICATION
The Lennox Commercial Touchscreen Thermostat provides electronic control of 24 Vac heating and cooling
systems. See Table 1 for a description.
Table 1 − Thermostat Description
Feature Description
Powering Methods SBattery only
SDirection connection to a 24 Vac transformer only.
SDirect connection to a 24 Vac transformer with battery backup.
System Types SConventional (up to 2 heat, 2 cool stages)
SHeat Pump (up to 3 heat, 2 cool stages)
Changeover Manual or automatic changeover (selectable)
System Settings Heat−Off−Cool−Auto
Fan Settings Auto−on
MERCURY NOTICE
If this control is replacing a control that contains
mercury in a sealed tube, do not place your old control
in the trash. Dispose of properly.
Contact your local waste management authority for
instructions regarding recycling and the proper
disposal of an old control.
INSTALLATION
When Installing this Product...
1. Read these instructions carefully. Failure to follow
them could damage the product or cause a
hazardous condition.
2. Check ratings given in instructions and on the
product to ensure the product is suitable for your
application.
3. Installer must be a trained, experienced service
technician.
4. After installation is complete, check out product
operation as provided in these instructions.
CAUTION
Electrical Shock or Equipment Damage
hazard.
Can shock individuals or short equipment
circuitry.
Disconnect power supply before installation.
Select Thermostat Location
Select a location for the thermostat about 5 feet (1.5m)
above the floor in an area with good air circulation at
average temperature (see figure 1).
YES
NO
NO
NO
5 FEET
(1.5 METERS)
Figure 1 − Select Thermostat Location
Do not install the thermostat where it can be affected by:
− Drafts or dead spots behind doors and in corners.
− Hot or cold air from ducts.
− Radiant heat from sun or appliances.
− Concealed pipes and chimneys.
− Unheated (uncooled) areas such as an outside
wall behind the thermostat.

Page 2
Separate Wallplate from Thermostat
1− Separate the wallplate from the thermostat (see
figure 2).
THERMOSTAT
WIRE HOLE
M22267
WALLPLATE
Figure 2 − Separate Wallplate from Thermostat
Install Wallplate (See Figure 3)
Mount the thermostat horizontally on the wall:
1. Pull the wires through the wire hole on the
wallplate.
2. Position the wallplate on the wall with the arrow
pointing up. Level the wallplate for appearance only.
3. Use a pencil to mark the mounting holes.
WA L L
MOUNTING
HOLES
M19916
MOUNTING
SCREWS (2)
WALL ANCHORS (2)
WIRES THROUGH WALL
AND WIRE SLOT
Figure 3 − Install Wallplate
4. Remove the wallplate from the wall and drill two
3/16 inch holes in in the wall (if drywall) as marked.
For firmer material such as plaster, drill two 7/32
inches holes. Tap the wall anchors (provided) into
the drilled holes until flush with the wall.
5. Pull the wires through the wire hole on the wallplate
and position the wallplate over the wall anchors.
6. Insert the mounting screws into the wall anchors
and tighten.
WIRING
IMPORTANT
− All wiring must agree with applicable codes,
ordinances and regulations
− Use 18 gauge thermostat wire. Shielded cable is
not required.
NOTES:
− Sensor wires must have a cable separate from the
thermostat control cable.
− Refer to Table 2 for terminal designation
descriptions.
− See figure 7 through 10 for wiring diagrams from
specific equipment applications.
1. Select conventional set of terminal identifications
which correspond to the system type (conventional
or heat pump (see figure 4). Lennox commercial
equipment does not use the heat pump system
terminals.
S1
S2
Y2
W1
RC
C
Y2
L
A
W2
S1
S2
HEAT PUMP
CONVENTIONAL
L
A
RC
R
W
Y
G
C
SCREW
TERMINALS
R
O/B
Y
G
Figure 4 − Terminal Identifications for System Type
2. Loosen screw terminals used for the application.
3. Insert the wires into the terminal block and tighten
each screw terminal (see figure 5).
M19917
Figure 5 − Insert Wires into Terminal Block
4. Push excess wire back into the wall opening and
restrict wires to the shaded area (see figure 6).
5. Plug the wall opening with non−flammable
insulation to prevent drafts from affecting the
thermostat.

Page 3
WALLPLATE
WALL OPENING
WIRE
SHADED AREA
Figure 6 − Restrict Wires to Shaded Area of Wire
Hole
Table 2 − Terminal Designation Descriptions
Terminal
Designation Description
Rc (see note 1) Power for cooling−connect to secondary side of cooling system transformer.
R (see note 1) Power for heating−connect to secondary side of heating system transformer.
YCompressor output.
C (see note 2) Command wire from secondary side of cooling system transformer.
WHeat relay.
GFan relay.
W2 Second stage heat relay.
Y2 Second stage cooling.
O/B (see note 3) Changeover valve for heat pumps. Terminal not used with Lennox commercial equipment.
A (see note 4) Economizer/Time−of−Day (TOD) output−powered via R terminal.
S1 (see note 5) Optional outdoor or indoor remote sensor.
S2 (see note 5) Optional outdoor or indoor remote sensor.
LPowers red LED behind plastic in upper right corner of the thermostat.
NOTES:
1. When used in a single−transformer system, leave
metal jumper wire in place between Rc and R. If
used on a two−transform system, remove metal
jumper wire between Rc and R.
2. Common wire is optional when thermostat is used
with batteries. When using separate transformer
for heating and cooling, the common must come
from the cooling transformer.
3. Lennox commercial heat pumps do not use this
terminal to energize the reversing valve.
Thermostat will always be conventional type.
4. Reference economizer literature for wiring details.
When set for economizer operation, the A terminal
provides the occupancy signal. (Power indicates
occupied.)
5. Sensor wires must have a cable separate from the
thermostat control cable.
Terminal A Wiring Details for
Economizers
− Wire the A" terminal as shown in diagrams in
figures 7, 8, 9 and 10.
− The A" signal is powered from the R" terminal and
energizes the economizer to signal occupied status
and drive the damper to the set minimum position.

Page 4
18
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
UNIT
TB1
RT2
A2
THERMO-
STAT
Figure 7 − Wire LG/LC/LH/SG/SC Units.
UNIT
TB1
RT2
A2
THERMO-
STAT
Figure 8 − Wire TG/TC/TH 090−300S Units
UNIT
TB1
RT2
A2
THERMO-
STAT
Figure 9 − Wire TG/TC/TH 036−060 Units
1
2
3
4
5
6
7
8
9
10
12
11
13
UNIT
TB1
A2
THERMO-
STAT
RT2
Figure 10 − Wire CB/CBH17 Used with HS29 and
HP29 Units

Page 5
Sensor Wiring for Temperature Averaging
SUBBASE
20K Ohm
20K Ohm20K Ohm
20K Ohm
S1 S2
SUBBASE
10K Ohm 10K Ohm
S1 S2
SUBBASE
20K Ohm
20K Ohm
10K Ohm
S1 S2
SUBBASE
20K Ohm
10K Ohm20K Ohm
20K Ohm
S1 S2
10K Ohm
All combinations of sensors shown here have an equivalent resistance
of 20K ohms. Select option 4 on installer setup number 0340.

Page 6
POWER THE THERMOSTAT
You can choose from three methods to power the
thermostat:
− Batteries only (AAA alkaline).
− 24 Vac direct connection only.
− 24 Vac direct connection with battery backup (AAA
alkaline).
Wiring 24 Vac Common
− Single−Transformer System−Connect the common
side of the transformer to the C screw terminal of
the thermostat wallplate. Leave the metal jumper
wire in place between Rc and R.
− Two−Transformer System−Connect the common
side of the cooling transformer to the C screw
terminal of the thermostat wallplate. Remove the
metal jumper wire between Rc and R.
Installing Batteries
1. Install three AAA alkaline batteries on the back of
the thermostat as marked (see figure 11).
BATTERIES (3)
Figure 11 − Installing Batteries
2. Locate and remove the tab labeled Remove (see
figure 12).
IMPORTANT
This tab must be removed in order to set
the real−time clock.
REMOVE DURING
INSTALLATION
REMOVE
TAB
REMOVE DURING
INSTALLATION
Figure 12 − Remove tab labeled REMOVE from
thermostat back.
Setting Calendar and Time
Setting Calendar
This thermostat is designed to, under normal use,
automatically keep current time and day in memory for
up to ten years once the calendar is set. There are two
ways to set the calendar for this thermostat:
SETTING CALENDAR WHEN THERMOSTAT IS
FIRST POWERED
When the thermostat is first powered, the display is
ready to set the calendar and time. The thermostat
proceeds through a sequence of setup screens (see
figure 13).
SETTING CALENDAR AFTER THERMOSTAT IS
ALREADY FUNCTIONING
See steps 1 through 4, in the Advanced Settings section
to set year, month and day.
DONE
MONMON TUE WEDWED THUTHU FRIFRI S ASA SUN
CHANGE FILTER UV LAMP HUMIDIFIER PAD
OK TO PICK MUL TIPLE DAYS SCREEN LOCKED
DONE
MONMON WEDWED THUTHU FRIFRI SASA SUN
PM
CHANGE FILTER UV LAMP HUMIDIFIER PAD
OK TO PICK MUL TIPLE DAYS SCREEN LOCKED
SET CURRENT DAY
SET MONTH
USE ARROWS TO SET YEAR AND TIME
Figure 13 − Setting Date and Time after Initial Powerup

Page 7
Mount Thermostat to Wallplate
1. Align the terminal screw blocks with the pins on the
back of the thermostat.
2 Push the thermostat straight onto the wallplate until
it snaps into place (see figure 14).
WA L L
REMOVE DURING
INSTALLATION
Figure 14 − Mount Thermostat to Wallplate.
Advance Settings
The thermostat has advanced settings to match the
HVAC system. These settings can be adjusted to match
specific needs. Access to these settings is obtained as
follows:
1. From the main screen, press SYSTEM. Five blank
touch keys show on the bottom on the screen
between DONE and CANCEL.
2. Press and hold the two blank keys on either side of
the center blank key for approximately five seconds
(see figure 15).
3. The Setup Number displays to the lower−left area of
the screen. It is a four−digit code beginning with
zero. The current setting is displayed to the right.
NOTE: To cycle through the Setup Numbers, press the
up or down arrow.

Page 8
INSTALLER SETUP NUMBERS, SETTINGS AND TESTS
OED N
MO
CANC
SA SU
SSE
M
EM
HEAT
O
Y T
FF
g
Sc
Followin
eduhel
sde SeIn i ot T
M19923
Figure 15. Entering Installer Setup.
Installer System Tests
Use the Installer System Test to test the heating, cooling
and fan. Refer to the latter portion of Table 3.
CAUTION
Equipment Damage hazard.
Minimum compressor off time is by-
passed during installer system test.
Avoid cycling compressor quickly.
IMPORTANT
Use Installer System Test to test heating, cooling
and fan. The setting chosen for System Type
(Installer Setup Number 0170) can prevent some
System Test Numbers from appearing.
Table 3 − Installer Setup Menu
Installer
Setup
Number
Installer
Setup Name
Default
Setting All Settings Notes
0120 Date (Year
Upper) 20 20−22xx 21−21xx Available year range:2001−2178
0130 Date (Year
Lower) 04 00−99 Available year range:2001−2178
0140 Date (Month) 6 1−12
0150 Date (Day) 15 1−31 (Month Dependent)
0160 Schedule
Options 40−Non−Programmable 4−Programmable
0170 System
Selection 8
1−1H/1C
2−1H/1C HP*
3−1H w/o fan
4−1H with fan
6−1C
7−2H/1C HP*
8−2H/2C Conv
9−2H/1C Conv
10−1H/2C Conv
11−2H/2C HP*
12−3H/2C HP*
*Setting not used with Lennox commercial
equipment.
0175
TOD/Econo-
mizer output
(terminal A)
0
0−Unused
1−TOD
2−Economizer
Economizer energizes A during a call for cool.
TOD energizes A during Occupied period and
de−energizes A during Unoccupied. Use 1−TOD.
0180 Heat Fan
Operation 00−Fossil 1−Electric
Only shown for conventional system with heat
stages and fan capability selected. If heat pump is
selected, fan defaults to electric.
0185 Pre−occupancy
Purge Duration 0
0−No duration
1−One hour
2−Two hours
3−Three hours
Shown only if system has fan and schedule pro-
grammable. Pre−occupancy purge enabled by
nonzero duration (and sends economizer to
minimum position).
0190 Reversing
Valve O/B 00−O (O/B On Cool) 1−B (O/B On Heat)
O or B setting not used with Lennox commercial
equipment.
0220
Cycles Per
Hour (CPH) for
first stage com-
pressor
3 1−6
Only shown for system with cool stages. Selec-
tion in this stage changes default CPH of sec-
ond stage cool.

Page 9
Table 3 − Installer Setup Menu (Continued)
Installer
Setup
Number
Installer
Setup Name
Default
Setting All Settings Notes
0230
CPH for
second stage
compressor
3 1−6 Only shown if two stages of cool selected.
0240
CPH for first
stage conven-
tional heat
5 1−12
Only shown if system is conventional with heat
stages.
Selection in this stage changes default CPH of
second stage heat.
0250
CPH for sec-
ond stage con-
ventional heat
5 1−12 Only shown with at least two stages convention-
al heat or 2H/1C heat pump selected.
0260 CPH for third
Stage Heat 9 1−12 Only shown if 3H/2C heat pump is selected.
0270 CPH for Auxil-
iary Heat 9 1−12 Only shown if multi−stage heat pump is selected
(heat pump with more heat than cool stages).
0280 Continuous
Backlight 00−No
1−Yes
Always shown. If AC power not present the op-
tion is overridden and normal backlight opera-
tion occurs.
0300 Changeover 1 0−Manual
1−Auto
Only shown if system has both heat and cool
stages.
0310 Deadband 3°F
(2°C)
2 (1.5)−2°F (1.5°C)
3 (2.0)− 3°F (2.0°C)
4 (2.5)− 4°F (2.5°C)
5 (3.0)− 5°F (3.0°C)
6 (3.5)− 6°F (3.5°C)
7 (4.0)−7°F (4.0°C)
8 (4.5)− 8°F (4.5°C)
9 (5.0)− 9°F (5.0°C)
Only shown if Automatic Changeover Selected
0320
Temperature
Indication
Scale
00−°F
1− °C
0330 Daylight
Saving 2
0−Disabled,
1−Enabled (US, 1987)
2−Enabled (2007),
3−Enabled (Europe)
0340
Remote
Temperature
Sensor
0
0−None
1−Outdoor for Display
2−Outdoor for Control
3−Remote 10K Indoor
4−Remote 20K Indoor
Averaging would not include on− board sensor. It
is accomplished by series/parallel combinations.
2 applies only to Heat Pump applications (allow-
ing compressor lockout while displaying temper-
ature). Set for total equal resistance for com-
bination of sensors.
0350
Heat Pump
Compressor
Lockout
0
0− None
15(−9.5)−15°F(−9.5°C)
20(− 6.5)−20°F(− 6.5°C)
25(− 4.0)−25°F(− 4.0°C)
30(− 1.0)−30°F(− 1.0°C)
35(1.5)−35°F(1.5°C)
40(4.5)−40°F(4.5°C)
45(7.0)−45°F(7.0°C)
Lennox commercial equipment does not use
heat pump mode. Only shown for heat pump
systems with more heat stages than cool se-
lected and remote sensor selection is outdoor
for control. Must enforce a dead band be-
tween this and Auxiliary Lockout

Page 10
Table 3 − Installer Setup Menu (Continued)
Installer
Setup
Number
Installer
Setup Name
Default
Setting All Settings Notes
0360
Heat Pump
Auxiliary Lock-
out
0
0− None
40(4.5)−40°F(4.5°C)
45(7.0)−45°F(7.0°C)
50(10.0)−50°F(10.0°C)
55(13.0)−55°F(13.0°C)
60(15.5)−60°F(15.5°C)
Lennox commercial equipment does not use
heat pump mode. Only shown for heat pump
systems with more heat stages than cool se-
lected and remote sensor selection is outdoor
for control. Must enforce a dead band between
this and Heat Pump Compressor Lockout.
0535
Temporary Oc-
cupied Duration
Limit
3
0−None
1−one hour
2−two hours
3−three hours
4− four hours
0 means no limit
0540 Number of Pe-
riods 42− 2 Periods 4− 4 Periods
Does not appear if Non− programmable is cho-
sen. Applies to all days of the week. With 2 se-
lected the Cancel Period option does not ap-
pear on the display.
0580
Minimum Com-
pressor Off
Time
0
0− Off
2− 2 minutes
3− 3 minutes
4− 4 minutes
5− 5 minutes
Only shown if system has cool stages. Set to 0.
Not needed for 3 phase systems.
0600
Heat Tempera-
ture Range
Stops
90 40 to 90°F (4 to 32°C) Only shown if system has heat stages.
0610
Cool Tempera-
ture Range
Stops
50 50 to 99°F (10 to 37°C) Only shown if system has cool stages.
0640 Clock Format 12 12−12 Hour 24− 24
Hour
0650 Extended Fan−
on time Heat 00−Off 90− 90 seconds
Not displayed with fan set to fossil or with cool−
only systems.
0660 Extended Fan−
on time Cool 00−Off 40− 40 seconds Only shown if system has cool stages.
0670 Keypad Lock-
out 0
0−Unlocked
1−Partial Lockout 1
2−Partial Lockout 2
3−Fully Locked
Unlocked: All functions accessible.
Partial 1: Locks all but Holiday, Override, and
Up/Down.
Partial 2: Locks all but Holiday and Override.
Full: Entire interface locked/non−functional.
0680 Temperature
Control Heat 2
1−Less Aggressive
2−Standard
3−More Aggressive
Only shown if system has heat stages.
Only integral gains affected. Affects control op-
eration in all control regimes (not just recovery
or setpoint change).
More Aggressive stops signal prior to reaching
the setpoint. (For use with oversized equip-
ment.)

Page 11
Table 3 − Installer Setup Menu (Continued)
Installer
Setup
Number
Installer
Setup Name
Default
Setting All Settings Notes
0690 Temperature
Control Cool 2
1−Less Aggressive
2−Standard
3−More Aggressive
Only shown if system has cool stages.
Only integral gains affected. Affects control op-
eration in all control regimes (not just recovery
or setpoint change).
More Aggressive stops signal prior to reaching
the setpoint. (For use with oversized equip-
ment.)
0685 Recovery Heat
Ramp Rate 5 0−20°F/hour
Only shown if system has heat stages.
0 disables ramped recovery (step setpoint
change at period start time).
0695 Recovery Cool
Ramp Rate 3 0−20°F/hour
Only shown if system has cool stages.
0 disables ramped recovery (step setpoint
change at period start time).
0700 Temperature
Display Offset 0
−3 (−1.5) −3°F(−1.5°C)
−2 (−1.0)− −2°F (−
1.0°C)
−1 (−0.5)− −1°F
(−0.5°C)
0 (0.0)−0°F (0.0°C)
1 (0.5)−1°F (0.5°C)
2 (1.0)− 2°F (1.0°C)
3 (1.5)−3°F (1.5°C)
This offset applies to both the control tempera-
ture and to the display temperature for indoor
sensor (and remote indoor sensor).
0710 Restore Facto-
ry Defaults 00 −No
1−Yes
Resets all ISU parameters to default values and
resets the schedule to default Energy Star. Re-
tains only calendar settings and time.
INSTALLER TESTS
Test 1 Installer Test Cool 0
0−Off
1−Cool Stage 1
2−Cool Stage 2
Test 2 Installer Test Fan 00−Off
1−Fan On
Test 3 Installer Test Heat 0
0−Off
1−Heat Stage 1
2−Heat Stage 1 and 2
3− Heat Stage 1, 2 and 3
Test 4 Installer Test Auxil-
iary Heat 00−Auxiliary Heat Off 1−Auxiliary Heat On
Test 8 Installer Test TOD/
Economizer 00−TOD/Economizer Off
1−TOD/Economizer On
NOTE: Press the Done button to exit the Installer System Test.

Page 12
OPERATION
System Settings
Heat−Thermostat controls the heating system.
Off−both heating and cooling systems are off.
Cool−Thermostat controls the cooling system.
Auto−Thermostat automatically changes between heat
and cool operation, depending on indoor temperature.
Fan Settings
Auto−Fan runs only when heating/cooling system is on.
On−Fan runs continuously.
Table 4 shows default program settings. See Owner’s
Guide for complete instructions to change the program.
Table 4 − Energy Star Default Program Settings
Schedule
Time
Setpoints Fan
Schedule
Period Time Heat Cool
Fan
Setting
Occ1 08:00
am
70oF
(21oC)
75oF
(24oC) Auto
Unocc1 10:00
pm
55oF
(10oC)
85oF
(29.5oC) Auto
Occ2a−−−−
Unocc2a−−−−
aThe thermostat default setting is two period only. To use
four periods, change the appropriate setup parameter.
Outdoor or Indoor Temperature
Sensor
Allow outdoor or indoor temperature sensor to absorb
the air for a minimum of five minutes before taking a
reading. See the Sensor instructions for more
information.
Economizer/TOD Logic (Table 5)
Table 5 − Terminal A Operation
Effective Call for Terminal A
Effective
Occupancy
Call
for
Cool TOD
Occupied − Energized
Unoccupied
Yes De−energized
Unoccupied No De−energized
Override − Energized

Page 13
TROUBLESHOOTING (TABLE 6)
Symptom Possible Cause Action
Display does not come
on.
Thermostat is not being
powered.
Check for 24 Vac between C and Rc.
Check that AAA batteries are installed correctly and are
good.
Temperature
tti d t h
The upper or lower tempera-
ture limits were reached.
Check temperature setpoints.
Check Installer Setup Numbers 0600 and 0610; modify as
needed.
settings do not change.
The keypad is fully locked. Check Installer Setup Number 0670 to change keypad
locked options.
Thermostat minimum off−
time is activated. Wait up to five minutes for the system to respond.
Heating or cooling does
not come on.
System selection not set to
Heat or Cool. Set system Selection to correct position.
not
come
on
.
System type Selection is in-
correct.
Check Installer Setup Number 0170 and make sure cor-
rect System type is chosen.
Thermostat is calling for
Heat (Heat on) or Cool
(Cool on) but no heating or
cooling is running.
Heating or cooling equip-
ment is not operating.
Check wiring.
Check Installer Setup Number 0170 and make sure cor-
rect system type is chosen.
Verify operation of equipment in System Test mode.
Heat does not turn on
(Heat On is solid in the
display).
Heating equipment failure.
Check for 24Vac at the equipment on the secondary side
of the transformer between power and common. If volt-
age is not present, check the heating equipment to find
the cause of the problem.
Check for 24 Vac between the heat terminal (W) and
transformer common. If 24 Vac is present, the thermostat
is functional. Check the heating equipment to find the
cause of the problem.
Loose or broken wire con-
nection between thermo-
stat and heating equip-
ment.
Check for 24 Vac between the heat terminal (W) and
transformer common. If voltage is not present, check
wire connection (loose or broken) between the thermostat
and the heating equipment.
Both the heating and cool-
ing equipment are run-
nin
g
at the same time.
The heating equipment is
not a heat pump but the
System Type (Installer Set-
up Number 0170) is set to
Heat Pump.
Set System Type (Installer Setup Number 0170) to match
the installed heating and/or cooling equipment
ning
at
the
same
time
.
Heating and cooling wires
are shorted together. Separate the shorted heating and cooling wires.
Cooling does not turn on
(Cool On is solid in the dis-
play).
Cooling equipment failure.
Check for 24 Vac at the equipment on the secondary side
of the transformer between power and common. If volt-
age is not present, check the cooling equipment to find
the cause of the problem.
Check for 24 Vac between the cool terminal (Y) and trans-
former common. If 24 Vac is present, the thermostat is
functional. Check the cooling equipment to find the cause
of the problem.
Loose or broken wire con-
nection between thermostat
and cooling equipment.
Check for 24 Vac between the cool terminal (Y) and
transformer common. If voltage is not present, check
the wire connection (loose or broken) between the ther-
mostat and the cooling equipment.

Page 14
Fan does not turn on in a
call for heat (electric fur-
nace).
Fan Control in Heating is set
to Gas or Oil Furnace (Set-
ting 0180).
Set Fan Control in Heating to Electric Furnace (Setting
0180).
Heating equipment is
running in the cool mode.
Heating equipment is not a
heat pump but System Type
(Installer Setup Number
0170) is set to Heat Pump.
Set System Type (Installer Setup Number 0170) to match
the installed heating and/or cooling equipment.
Heating equipment does
not turn off and heat tem-
perature setting is set be-
low room temperature
(Heat On is not in the dis-
play).
Heating equipment is not a
heat pump but System Type
(Installer Setup Number
0170) is set to Heat Pump.
Set System Type (Installer Setup Number 0170) to
match the installed heating and/or cooling equipment.
Cannot set the system
setting to Heat.
System Type (Installer Set-
up Number 0170) is set to
Cool Only.
Set System Type (Installer Setup Number 0170) to match
the installed heating and/or cooling equipment.
Cannot set the system
setting to Cool.
System Type (Installer Set-
up Number 0170) is set to
Heat Only or Heat Only with
Fan.
Set System Type (Installer Setup Number 0170) to match
the installed heating and/or cooling equipment.
Heat On is not in the dis-
play.
System setting is not set to
Heat and/or temperature
setting is not set above room
temperature.
Set the system setting to Heat and set the temperature
setting above the room temperature.
Cool On is not in the dis-
play.
System setting is not set to
Cool and/or the tempera-
ture setting is not set below
room temperature.
Set the system setting to Cool and set the temperature
setting below the room temperature.
Wait is in the display. Compressor minimum off
timer is active.
Wait up to five minutes for the cooling or heating (heat
pump) equipment to turn on.
Screen Locked" appears
on the screen and all or
some of the keys do not
respond.
The keypad is fully or partial-
ly locked. Check ISU 0670 to change keypad locked options.

Page 15
SPECIFICATIONS
Electrical Ratings:
W (Heating) 20 − 30 Vac 0.02 − 1.0A
Y (Cooling) 20 − 30 Vac 0.02 − 1.0A
G (Fan) 20 − 30 Vac 0.02 − 0.60A
A (Economizer/TOD) 20 − 30 Vac 0.02 − 1.0A
Temperature Setting Range:
Heating: 40°F to 90°F (4.5°C to 32°C).
Cooling: 50°F to 99°F (10°C to 37°C).
Operating Ambient Temperature:
0°F to 120°F (−18°C to 49°C).
Shipping Temperature:
−30°F to 150°F (−34.4°C to 65.6°C).
Operating Relative Humidity (Non−condensing):
5% to 90%.
Thermostat Dimensions: 3−3/4 in. (95mm) high x 6
in. (152mm) wide x 1−3/8 in. (35mm) deep.
Accessories:
X4148 Outdoor Sensor: 10K ohm NTC.
29M55 Wall−Mount Remote Indoor Sensor: