McQuay LIA303 Operation Manual

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Page 1

Installation, Operation & Application Guide

LIA303

Group: WSHP Supercedes: N/A Date: 03-23-09

Programmable Electronic Thermostat

1 Heat/1 Cool, Auto Changeover, Fan Speed Control, Hardwire Part No. 668811301

For replacement parts call 1-800-377-2787

• 7-Day, 5-2-Day or 5-1-1-Day Programmable

• Congurable

• Single-Stage Heat/Cool Systems

• Single-Stage Heat Pump Systems

• Two-Speed Fan Speed Selection

• Large Display With Backlight

• Selectable Fahrenheit or Celsius

• Compatible with Gas, Oil, or Electric

• SimpleSet™ Field Programming

• Status Indicator Light

• Relay Outputs (minimum voltage drop in thermostat)

• Remote Sensor Compatible

• Ideally Suited for: – Residential (New Construction/Replacement)

– Light Commercial

Page 2

Table of Contents

Parts Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Icon Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Specications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Important Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Package Contents/Tools Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

To Remove Existing Thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

To Install Thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Remote or Outdoor Sensor Installation (Optional) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Conguration Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Conguration Mode Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Mode of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Testing the Thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Setting the Time and Day of the Week . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Lockout Feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Factory Preprogramming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Personal Program Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

SimpleSetTM Field Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Page 3

RESET CONFIG

Parts Diagram

Conguration switch

Reset switch

Left (system) button

Right (fan) button

Down button

Up button

Field programming pins

RC/RH jumper

Fan Speed Switch

Page 4

Speciﬁcations

Icon Descriptions

Fan operation icon

Cooling operation icon

Heating operation icon

Lock mode

activated

Room temperature offset

activated

Electrical rating: • 24 VAC (18-30 VAC)

• 1 amp maximum per terminal

• 3 amp maximum total load

Temperature control range: 45°F to 90°F (7°C to 32°C) Accuracy: ± 1°F (± 0.5°C) System conﬁgurations: 1-stage heat, 1-stage cool, heat pump, gas, oil, electric Timing:

Anti-short Cycle:

4 minutes Backlight Operation Terminations: S1, S2, Y, W/O/B, G2, G1, RC, RH, C

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Package Contents/Tools Required

Package includes: McQuay thermostat on base, thermostat cover, wiring labels, screws and wall anchors,

Installation, Operation and Application Guide

Tools required for installation: Drill with 3/16” bit, hammer, screwdriver

Important Safety Information

1. Turn off power to the heating and cooling system by removing the fuse or switching the appropriate circuit

breaker off.

2. Remove cover of old thermostat. This should expose the wires.

3. Label the existing wires with the enclosed wire labels before removing wires.

4. After labeling wires, remove wires from wire terminals.

5. Remove existing thermostat base from wall.

6. Refer to the following section for instructions on how to install this thermostat.

To Remove Existing Thermostat

WARNING

ELECTRICAL SHOCK HAZARD – Turn off power at the main service panel by removing the fuse or

switching the appropriate circuit breaker to the OFF position before removing the existing thermostat.

• This thermostat is for 24 VAC applications only; do not use on voltages over 30 VAC

• Do not short across terminals of gas valve or system control to test operation; this will damage your thermostat

and void your warranty

• All wiring must conform to local and national electrical and building codes

• Use this thermostat only as described in this manual

WARNING

Always turn off power at the main power supply before installing, cleaning, or removing thermostat.

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To Install Thermostat

IMPORTANT: Thermostat installation must conform to local and national building and electrical codes and

ordinances.

Note: Mount the thermostat about ve feet above the oor. Do not mount the thermostat on an outside wall, in

direct sunlight, behind a door, or in an area affected by a vent or duct.

1. Turn off power to the heating and cooling system by removing the fuse or switching the appropriate circuit

breaker off.

2. To remove cover, pull gently at the seam at the top.

3. Put thermostat base against the wall where you plan to mount it (Be sure wires will feed through the wire

opening in the base of the thermostat).

4. Mark the placement of the mounting holes.

5. Set thermostat base and cover away from working area.

6. Using a 3/16” drill bit, drill holes in the places you have marked for mounting.

7. Use a hammer to tap supplied anchors in mounting holes.

8. Align thermostat base with mounting holes and feed the control wires through slit in thermal intrusion barrier and

into wire opening.

9. Use supplied screws to mount thermostat base to wall.

10. Insert stripped, labeled wires in matching wire terminals.

WARNING

Be sure exposed portion of wires does not touch other wires.

WARNING

ELECTRICAL SHOCK HAZARD – Turn off power at the main service panel by removing the fuse or

switching the appropriate circuit breaker to the OFF position before removing the existing thermostat.

11. Gently tug wire to be sure of proper connection. Double check that each wire is connected to the proper

terminal.

12. Turn on power to the system at the main service panel.

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Hardwired

5-Wire, Single Transformer

Wiring Diagrams

13. Congure thermostat (see Page 12) to match the type of system you have.

14. Replace cover on thermostat by snapping it in place.

15. Test thermostat operation as described in “Testing the Thermostat” (Page 19).

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Hardwired

6-Wire, Two Transformer

(Both transformers must be in phase)

Hardwired

5 or 6-Wire, Single Transformer

IMPORTANT: Before wiring, remove pre-installed

RC/RH jumper.

Page 9

Hardwired

Cool or Heat Active Reversing Valve

Page 10

Hardwired

5-Wire, Single Transformer

Page 11

Remote or Outdoor Sensor Installation (Optional)

1. Remove cover from remote sensor housing.

2. Select an appropriate location for mounting the remote sensor.

3. Mount remote sensor unit using hardware provided.

4. Install two strand shielded wire between remote sensor and thermostat. Shielded wire must be used. Do not run remote

sensor wire in conduit with other wires.

• Wire 1 should run between the S1 terminal on the thermostat and the S1 terminal on the remote sensor

• Wire 2 should run between the S2 terminal on the thermostat and the S2 terminal on the remote sensor

• Connect the shielding of the wire to the S2 terminal on the thermostat

5. Congure the thermostat to operate with the remote sensor (see Conguration Mode setting 10, Page 14).

Note: Remote or outdoor sensor reading can be displayed by simultaneously pressing the Down and SYS

buttons.

Remote Sensor

(Optional)

Page 12

Conﬁguration Mode

OFF

1. Verify the McQuay thermostat is in the OFF mode. Press the SYS (left) button until off mode displays.

2. Remove the cover of the thermostat by gently pulling near one of the corners at

the top of the thermostat.

3. Press the CONFIG button for 1 second while the McQuay thermostat is in OFF

mode.

To exit conguration mode, press the CONFIG switch for 1 second.

Press the up or down button to change settings within each screen.

Down

button

Press the right button to advance to the next screen.

Note: Pressing the

left

button will return you to the previous screen.

Left

button

Right button

The conguration mode is used to set the McQuay thermostat to match your heating/cooling system. The McQuay thermostat functions with heat pump, air conditioning, gas, oil or electric heat systems.

To congure the McQuay thermostat, perform the following steps:

S1 S2 Y W

O/B

G RC RH C

RESET CONFIG

CONFIG

Page 13

Conﬁguration Mode Settings

The setup screens for Conguration Mode are as follows:

3. Deadband (1°F - 9°F) (1°C - 5°C) Set the minimum number of degrees between your heat setpoint and your cool setpoint

in Autochangeover mode. Press the up or down button to set deadband value. Press the right button to advance to the next screen.

2. Temperature Differential (1°F to 5°F) (0.5°C to 2.5°C)

Set the number of degrees between your “setpoint” temperature and your “turn on”

temperature. Press the up or down button to set differential value. Press the right button to advance to the next screen.

1. Temperature Scale (F or C) Choose Fahrenheit or Celsius. Press the up or down button to select. Press the

right

button to advance to the next screen.

Page 14

Press the up or down button to select. Press the right button to advance to the next screen.

4. System – Set for heat pump, non-heat pump, reversing valve operation and number of compressors in your

system. Choose between two heat pump settings or gas/oil or electric.

Choose System

Reversing

Valve Active

Number of Compressors

or Compressor Stages

Type of

Heat

Heat Pump

HP O – Cool Active 1

HP b – Heat Active 1

Non-Heat

Pump

Heat Gas/Oil

Heat Electric

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5. Lockout (0-8°, NITE, COOL-HEAT) Select the number of degrees set temperature can be changed during keypad lockout

or select to lockout during NITE period only. COOL-HEAT lockout allows adjustment of the set temperatures to the maximum heat set temperature selected in Step 6 and

minimum cool set temperature selected in Step 7.

Note: The mode cannot be changed when the thermostat is locked. Press the up or down button to select. Press the right button to advance to the next screen.

6. Maximum Heat Setpoint (45°F to 90°F) (7°C to 32°C)

Adjust to control the maximum heat set temperature allowed.

Press the up or down button to select. Press the right button to advance to the next screen.

7. Minimum Cool Setpoint (45°F to 90°F) (7°C to 32°C)

Adjust to control the minimum cool set temperature allowed.

Press the up or down button to select. Press the right button to advance to the next screen.

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10. Temperature Sensor (1-4)

1. Only on-board sensor determines room temperature.

2. Only remote sensor determines room temperature.

3. Average temperature of on-board and remote sensor.

4. Only on-board sensor will be used until NITE period, and then only remote sensor

is used. Press the up or down button to select. Press the right button to advance to the next screen.

9. Maximum Cycles Allowed Per Hour (- -, 2-6)

- - = as many as needed, 2-6 = maximum cycles/hour

Press the up or down button to select. Press the right button to advance to the next screen.

8. Room Temperature Offset (+9°F to -9°F) (+5°C to -5°C)

Adjust to calibrate displayed room temperature to match actual room temperature.

Note: When not set to 0, will display Press the up or down button to select. Press the right button to advance to the next screen.

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12. Status Indicator Light (Led 0 or 1) 0 = Status indicator never on

1 = Status indicator on with rst stage

Press the up or down button to select. Press the CONFIG button for 2 seconds to exit conguration.

OFF

11. Cooling Fan Delay Off Time (0, 30, 60, 90 seconds) Select the fan purge time for cooling.

Press the up or down button to select. Press the right button to advance to the next screen.

Note: The McQuay control board provides a minimum Fan Off delay of 30

seconds, even if the thermostat is set for a 0 second delay.

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Mode of Operation

The McQuay thermostat is a programmable, manual or auto changeover, single-stage heat, single-stage cool thermostat. It functions with air conditioning, heat pumps, gas, oil or electric heat systems.

The thermostat activates the heating appliance when the room temperature is below the set heat temperature (by the differential temperature) and the red indicator light (congurable) on the thermostat will light. The McQuay thermostat will stop outputting and the red light will turn off when the call for heat has been satised. With heat pumps, the thermostat will not let the compressor come on for 4 minutes after it turns off. This protects your

compressor.

When the room temperature is greater than the set cool temperature (by the differential temperature), the cooling device is activated and the green indicator light (congurable) on the thermostat will turn on. The McQuay thermostat will stop outputting and the green light will turn off when the call for cooling is satised. The thermostat will not let the compressor come on for 4 minutes after it turns off. This protects your compressor.

The McQuay thermostat has ve possible operating modes: OFF, Heat, Cool, Heat & Cool, and Program mode. In off mode, the thermostat will not turn on heating or cooling devices. The manual fan can be turned on in all operating modes using the fan button, and the fan speed can be set in all operating modes using the fan speed switch. In heat

mode, the thermostat controls the heating system. In the cool mode, the thermostat controls the cooling system. In

heat & cool mode, the thermostat controls both the heating and cooling systems. In program mode, the thermostat will automatically be controlled by the set program. Program mode can function with heat mode, cool mode, or heat & cool mode. The clock display alternates with the set temperature display for heat & cool mode.

The program schedule can be overridden by changing the set temperature (up or down button). This puts the McQuay thermostat thermostat into a 2-hour temporary hold. After 2 hours, it will automatically return to the program

schedule. The programmable fan feature can be used to recirculate air while in Program mode. It is activated during the

program schedule set up.

The McQuay thermostat also has a button lockout feature. This enables the thermostat to be set to the proper mode and temperature and locked so it cannot be tampered with.

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Operating Modes

There are ve possible operating modes for the McQuay thermostat. Off, Cool, Heat, and Cool & Heat modes are accessed by pressing the SYS (left) button. Program mode is accessed by pressing the SYS (left) and FAN (right) buttons simultaneously.

OFF Mode

• In this mode, the thermostat will not turn on the heating or cooling devices

Note: The fan speed can be set in all operating modes using the fan speed

switch.

OFF

Heat Mode

• In this mode, the thermostat controls the heating system. When the heat outputs,

the ame icon

apprears on the display.

Note: For heat pumps, there is a four minute delay for your compressor to

restart after it has turned off.

Cool Mode

• In this mode, the thermostat controls the cooling system. When the cooling

outputs, the snowake icon

apprears on the display.

Note: There is a four minute delay for your compressor to restart after it has

turned off.

Page 20

PROG

Cool and Heat Mode (Auto Changeover)

• In this mode, the thermostat controls the cooling and heating systems, automatically

changing over from one to the other as needed.

• The timing display alternates with the set temperature every 10 seconds in the cool

and heat mode.

Program Mode

• In this mode, the program function is on (PROG displays), and the thermostat

will automatically be controlled by the set program schedule. Program mode can function with heat mode, cool mode, or heat & cool mode. The program schedule can be overridden by changing the set temperature (up or down button). After 2 hours, the program schedule will automatically be resumed. To manually return to the program schedule, press the PROG button twice.

Page 21

Testing the Thermostat

Once the thermostat is congured, it should be thoroughly tested.

Heat Test

1. Press SYS (left) button until heat mode is displayed.

2. Adjust the set temperature so it is 5 degrees above the room temperature.

3. Heat should come on within a few seconds. Red LED may turn on.

4. Adjust the set temperature 2 degrees below the room temperature and the heat should turn off.

There may be a fan delay on your system.

Note:

For heat pumps, there is a four-minute delay to protect your compressor after it turns off. To bypass the compressor time delay, go to OFF mode for 5 seconds.

Cool Test

1. Press SYS (left) button until cool mode is displayed.

2. Adjust set temperature so it is 5 degrees below room temperature.

3. A/C should come on within a few seconds. Green LED may turn ON.

4. Adjust the set temperature 2 degrees above the room temperature and the A/C should turn off.

There may be a fan delay on your system.

Note:

There is a four-minute time delay to protect the compressor after it turns off.

To bypass the compressor time delay, go to OFF mode for 5 seconds.

Fan Test

1. Press FAN (right) button. Fan displays. Indoor fan turns ON.

2. Press FAN (right) button. Indoor fan turns OFF.

OFF

CAUTION

Do not energize the air conditioning system when the outdoor temperature is below 50 degrees.

It can result in equipment damage or personal injury.

Page 22

Setting the Time and Day of the Week

TODAY MON

5. Press the FAN (right) button once to select day of the week (TODAY ashing). Press the up or down button to select current day of the week.

Note: At any time, press the SYS (left) button to return to the previous screen or

press the FAN (right) button to advance to the next screen.

Press the PROG button in for 2 seconds to lock values into memory and return to the

OFF mode or press the FAN (right) button once to enter programming.

4. Press the FAN (right) button once to select minutes (minutes ashing).

Press the up or down button to adjust the minutes.

3. Time displays (hour ashing). Press the up or down button to adjust the hour.

2. Press and hold the PROG button (SYS (left) and FAN (right) buttons pressed

simultaneously) in for 6 seconds.

1. Press the SYS (left) button until you are in the OFF mode.

The time and day of the week must be set for your program schedule to operate correctly.

Page 23

Programming

Setting the program schedule:

1. Press the SYS (left) button until you are in OFF mode.

2. Press and hold the PROG button (SYS and FAN buttons pressed simultaneously) for 6 seconds.

3. Press the FAN (right) button 3 times.

4. SUN thru SAT are blinking.

SUN MON TUE WED THU FRI SAT

PROG

From this screen you have 2 options:

1. Press the FAN (right) button to begin programming all 7 days at one time, or

2. Press the

button to see the other programming options.

Note: The days of the week shown on the display will be programmed simultaneously.

The screens are listed below.

Screen 1 SUN MON TUE WED THU FRI SAT Screen 2 MON TUE WED THU FRI Screen 3 MON

Screen 4 TUE Screen 5 WED

Screen 6 THU Screen 7 FRI Screen 8 SUN SAT Screen 9 SAT

Screen 10 SUN

Program Overview

The McQuay programmable thermostat has four periods (MORN, DAY, EVE, NITE) that are customizable for each day of the week. Each period will have a start time, heat temperature, cool temperature and programmable fan option. The McQuay thermostat monitors the day and time, while maintaining the specic conditions you have chosen for each period in your program.

Page 24

From any of the screens on Page 21, you can press the FAN (right) button to begin entering your program schedule. The days shown on the display will all be programmed simultaneously.

Once the FAN (right) button is pressed, MORN blinks.

Use the up or down button to select a different period (MORN, DAY, EVE, NITE).

Press FAN (right) button to advance to the next screen. Transition time hour blinks. Use the up or down button to select a different hour.

Press FAN (right) button to advance to the next screen. Transition time minutes blink. Use the up or down button to select different minutes.

Press FAN (right) button to advance to the next screen. Heat set temperature displays. Use the up or down button to adjust the heat set temperature.

Press FAN (right) button to advance to the next screen. Cool set temperature displays. Use the up or down button to adjust the cool set temperature.

Press FAN (right) button to advance to the next screen. Programmable fan screen displays. Use the up or down button to select:

Choose Off – Programmable fan disabled On – Indoor fan on continuously

Note: Programmable fan operates in Program mode only.

Repeat above steps to program the four periods per day.

When the program schedule is complete, press and hold the PROG button (SYS and FAN buttons pressed simultaneously) in for 2 seconds to return to the OFF mode.

Page 25

Lockout Feature

The McQuay thermostat has a button lockout feature so the mode cannot be changed and the temperature adjustment is limited. Select the appropriate lockout from Conguration Mode Settings (Step 5, Page 13) of this guide.

To activate the LOCK feature:

1. Simultaneously press the SYS, FAN and UP buttons for 10 seconds.

will display and the lockout function will be enabled.

To deactivate the LOCK feature, repeat steps 1 and 2 above.

Page 26

Factory Preprogramming

MORN 6:00 AM DAY 8:00 AM EVE 6:00 PM NITE 10:00 PM

HEAT 70°F HEAT 62°F HEAT 70°F HEAT 62°F

COOL 78°F COOL 85°F COOL 78°F COOL 82°F

FAN Off FAN Off FAN Off FAN Off

MONDAY

thru

SUNDAY

Personal Program Schedule

MORN DAY EVE NITE

HEAT HEAT HEAT HEAT

COOL COOL COOL COOL

FAN FAN FAN FAN

MONDAY

TUESDAY

MORN DAY EVE NITE

HEAT HEAT HEAT HEAT

COOL COOL COOL COOL

FAN FAN FAN FAN

WEDNESDAY

MORN DAY EVE NITE

HEAT HEAT HEAT HEAT

COOL COOL COOL COOL

FAN FAN FAN FAN

Use the following personal program schedule to record your settings:

The McQuay thermostat comes preprogrammed with the following schedule

Page 27

Personal Program Schedule (continued)

THURSDAY

FRIDAY

SUNDAY

SATURDAY

MORN DAY EVE NITE

HEAT HEAT HEAT HEAT

COOL COOL COOL COOL

FAN FAN FAN FAN

MORN DAY EVE NITE

HEAT HEAT HEAT HEAT

COOL COOL COOL COOL

FAN FAN FAN FAN

MORN DAY EVE NITE

HEAT HEAT HEAT HEAT

COOL COOL COOL COOL

FAN FAN FAN FAN

MORN DAY EVE NITE

HEAT HEAT HEAT HEAT

COOL COOL COOL COOL

FAN FAN FAN FAN

Page 28

SimpleSetTM Field Programming

This feature is used for transferring conguration and program schedule from the master to the target thermostat. All thermostats for a job can be mounted and powered up. Congure and program one thermostat. This will be the master. The master will be used to copy the program to the rest of the thermostats.

Preparing the master to Send:

1. The master must be powered with 24 VAC.

2. Verify the master thermostat is in OFF mode.

3. Press SYS (left) button until OFF mode displays.

4. Remove cover of the master thermostat by gently pulling near one of the corners at the top

of the thermostat.

5. Press the up and down buttons and CONFIG switch simultaneously for 5 seconds.

6. The OUT screen displays indicating the master thermostat is ready to transfer data.

Note: Press the up and down buttons and CONFIG switch simultaneously for 5

seconds to exit from data transfer mode and to return the master to the OFF

mode.

7. Turn off power to the master and remove it from the wall.

8. Connect the master to the target using the 3 wire connector. Attach one end to the Master’s

FP pins and the other end to the Target’s FP pins.

Note: Target thermostat must be powered with 24 VAC for eld

programming to occur

When the connection has been made correctly, the master thermostat will power up and the target will count from 5 down to 1. It will then display the LOCK conrming the data has been saved in memory.

When all target thermostats have been completed, reinstall the master thermostat.

Press the up and down buttons and the CONFIG switch simultaneously for 5 seconds to exit from the data transfer mode and to return the master thermostat to the OFF mode.

OFF

FP pins

S1 S2 Y W

O/B

G RC RH C

RESET CONFIG

Requires SimpleSetTM Transfer Cable (668817901)

Page 29

Troubleshooting

Symptom Remedy

No display Check for 24 VAC at thermostat; display is blank when 24 VAC is not present

Time and day of week must be reset after extended power loss

System fan does not come on properly Verify wiring is correct, check Gas/Electric Conguration (see Setting 4, Page 12)

All thermostat buttons are inoperative Verify 24 VAC is present; unit locks out when 24 VAC is not present

No response with rst button press First button press activates backlight only

Program schedule activates at the wrong time Check time (AM/PM) set on thermostat (see Setting the Time, Page 20)

Thermostat turns on and off too frequently Adjust temperature differential (see Conguration Mode Setting 2, Page 11)

Thermostat does not follow program Verify it is operating in program mode (PROG displays); check time (AM/PM); check if in 2

hour program override

Fan runs continuously Press FAN (right) button to turn fan off

Fan turns on occasionally

Program Mode: Check programmable fan setting in program schedule

(see Page 22)

Status indicator light not on during call Turn status indicator function on (see Conguration Mode Setting 12, Page 15)

Room temperature is not correct Calibrate thermostat (see Conguration Mode Setting 8, Page 14)

If remote sensor is used, check S1 and S2 terminal connections

displays when any button is pressed Thermostat has the button lockout function activated (see Lockout Feature, Page 23 and

Conguration Mode Setting 5, Page 13)

on display instead of room temp. Check for a bad connection at S1 and S2 terminals, if used (see Conguration Mode Setting

10, Page 14)

Heat or Cool not coming on Verify wiring is correct, verify RC/RH jumper is in place (for single transformer system)

Remote or outdoor sensor not accurate Press SYS and Down buttons simultaneously to display remote or outdoor temperature. Verify

connections at S1 and S2 terminals.

Problem not listed above Press Reset button once*

* Reset Button Function:

Time and day are reset, conguration and program settings are unchanged.

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McQuay Training and Development

Now that you have made an investment in modern, efcient McQuay equipment, its care should be a high priority. For training information on all McQuay HVAC products, please visit us at www.mcquay.com and click on training, or call 540-248-9646 and ask for the Training Department.

Warranty

All McQuay equipment is sold pursuant to its standard terms and conditions of sale, including Limited Product Warranty. Consult your local McQuay Representative for warranty details. Refer to Form 933-43285Y. To nd your local McQuay Representative, go to www.mcquay.com.

This document contains the most current product information as of this printing. For the most up-to-date product information, please go to www.mcquay.com.

LIA303 / Version B: 03-23-09

For replacement parts call 1-800-377-2787