DIGITAL THERMOSTAT

MODEL P374-1100FM

Installation

Instructions

I2:00

Mo

72

Am

74

C

OOL

AUTO

H

EAT

70

HEAT

COOL

&

HEAT

PUMP

MULTI-STAGE PROGRAMMABLE

TOTALINE

Replacement Components Division Carrier Corporation 11/98

Table Of Contents

WIRING DIAGRAMS

CALIBRATION

5

8

CAUTION

Follow Installation Instructions carefully.

DISCONNECT POWER TO THE HEATER -

AIR CONDITIONER BEFORE REMOVING

THE OLD THERMOSTAT AND INSTALLING

THE NEW THERMOSTAT.

WARNING

Replacement Components Division - Carrier Corporation

Model No. P374-1100FM

This device complies with Part 15 of the FCC rules.

Operation is subject to the following 2 conditions:

(1) This device may not cause harmful interference, and (2) This device must accept any interference received, including interference that may cause undesired operation.

Page 1

STEP #1 PREPARATION

Proper installation of the thermostat will be accomplished by following these step by step instructions. If you are unsure about any of these steps, call a qualified technician for assistance.

Assemble tools & recommended

Junction Box.

FLATSTAT

EXTENDS

LESS THAN

3/8” FROM

THE WALL.

FlatStat in Small

J-Box

Flat Blade

Screwdriver

Wire cutter

& Stripper

.366”

Make sure your Heater/Air Conditioner is working properly before beginning installation of the thermostat.

Carefully unpack the thermostat.

Save the screws, wall anchors, and instructions.

Turn off the power to the Heating/Air

Conditioning system at the main fuse panel. Most residential systems have a separate breaker for disconnecting power to the furnace.

Page 2

STEP #2 REMOVE & REPLACE OLD THERMOSTAT

Remove the cover of the old thermostat.

If it does not come off easily check for screws.

Loosen the screws holding the thermostat base or subbase to the wall, and lift away.

Disconnect the wires from the old thermostat. Tape the ends of the wires as you disconnect them, and mark them with the letter of the terminal for easy reconnection to the new thermostat.

Keep the old thermostat for reference purposes, until your new thermostat is functioning properly.

Remove the white plastic wire connector from the rear of the thermostat. Install wires as directed.

Press the wired connector on the back of the thermostat.

Lift Connector straight up to remove.

For best operation, install the thermostat in a junction box that is free from drafts that originate inside the wall.

Page 3

STEP #3 WIRE CONNECTIONS

If the terminal designations on your old thermostat do not match those on the new thermostat, refer to the chart below,

or the wiring diagrams that follow.

Wire from the old thermostat terminal marked

G or F

Y1, Y or C

W1, W or H

Rh, R, M, Vr, A

C

O/B

Y2

Function

Fan

Cooling

Heating

Power

Common

Rev. Valve

2nd Stage Cool

W2

RS+5

RS

RS G

CK1

CK2

2nd Stage Heat

Remote Sensor +5vdc

Remote Sensor Signal

Remote Sensor Ground

Dry Contact Switch 1

Dry Contact Switch 2

Install on the new thermostat connector marked

G

Y1

W1,O,B

R

C *

W1,O,B**

Y2

W2

RS+5

RS

GND

* C may not be used on all systems.

** O/B is used if your system is a Heat Pump.

Page 4

Sample Wiring Diagrams

5 Wire, 1 Stage Cooling, 1 Stage Gas Heat

W2 Y2 R

O

W1 Y1 G C

Residential Gas or Electric Heat *,

Electric Cool, split systems & package units

Thermostat

24 vac common fan relay compressor relay

1st stage heat circuit

24 vac return

* If using electric heat this option must be

selected on during advanced setup.

W1

R

Y2

W2

G

Y1

O

L

E

C

4 Wire, 1 Stage Cooling, 1 Stage Gas Heat

W2 Y2 R

O

W1 Y1 G C

Thermostat

Residential Gas or Electric Heat *,

Electric Cool, split systems & package units compressor relay

* If using electric heat this option must be

selected on during advanced setup.

Page 5 fan relay

1st stage heat circuit

24 vac return

R

Y2

W2

G

Y1

O

W1

L

E

C

Sample Wiring Diagrams

6 Wire, 2 Stage Cooling, 1 Stage Heat

W2 Y2 R

O

W1 Y1

G

C

Thermostat

Residential 2 Stage Cooling, with

Gas or Electric Heat*

24 vac common fan relay compressor relay

1st stage heat circuit

24 vac return

2nd stage compressor relay

* If using electric heat, this option must

be selected during advanced setup.

6 Wire, 1 Stage Cooling, 2 Stage Heat

W2 Y2 R

O

W1 Y1 G C

Residential & commercial 1 Stage Cooling, with 2 Stage Gas or Electric Heat*

Thermostat

W1

R

Y2

W2

G

Y1

O

L

E

C

2nd stage heat circuit

Page 6

24 vac common fan relay compressor relay

1st stage heat circuit

24 vac return

R

Y2

W2

G

Y1

O

W1

L

E

C

Sample Wiring Diagrams

7 Wire, 2 Stage Cooling, 2 Stage Heat

W2 Y2 R

O

W1 Y1

G

C

Commercial Gas or Electric Heat ***,

Electric Cool, split systems & package units including Commercial Heat Pumps **

Thermostat

24 vac common fan relay compressor relay

1st stage heat circuit

24 vac return

2nd stage compressor relay

** Commercial heat pumps do not have

the heat pump turned on in advanced setup.

2nd stage heat circuit

*** If using electric heat, this option must

be selected on during advanced setup.

5 Wire, 1 Stage Cooling, 1 Stage Heat - Heat Pump*

W2 Y2 R

O

W1 Y1 G C

Thermostat

No auxiliary heat, residential Heat Pumps , split systems & package units

W1

R

Y2

W2

G

Y1

O

L

E

C

* If using residential heat pump, this option

must be selected on during advanced setup.

Page 7

24 vac common fan relay compressor relay reversing valve

24 vac return

W1

R

Y2

W2

Y1

O

C

G

L

E

Sample Wiring Diagram

6 Wire, 1 Stage Cooling, 2 Stage Heat, Heat Pump *

W2 Y2 R

O

W1 Y1

G

C

Most residential split and package heat pumps with auxiliary heat

Thermostat

24 vac common fan relay compressor relay

1st stage heat circuit

24 vac return

W1

R

Y2

W2

G

Y1

O

L

E

C

* The heat pump option must be selected

on during advanced setup.

2nd stage heat circuit

Calibration

Every thermostat is calibrated before it leaves the factory.

Under normal circumstances there will never be a need to recalibrate the thermostat again.

To accommodate special needs, the thermostat may be recalibrated following these steps:

1. While holding the mode button in, press the down button for

2 seconds. After all the icons in the display appear, release

the buttons.

2. Press the mode button.

3. Press the up or down buttons until the flashing number

equals the current room temperature.

4. Press the mode button to return to normal operation.

Page 8

STEP #4

TEST OPERATION

Turn the power on to the Heating/Air

Conditioning system.

Press the MODE button repeatedly until the HEAT icon appears on the display.

Press the up/down buttons until the set temperature is 10 degrees above room temperature. The furnace should turn on.

Press the MODE button repeatedly until the COOL icon appears on the display.

Press the up/down buttons until the set temperature is 10 degrees below room temperature. The air conditioner should turn on. NOTE: Most equipment has a

time delay of 5 minutes between cool cycles. This feature is defeatable on the thermostat. Consult the Owner's Manual under Setup, cycles per hour.

Press the MODE button to OFF. Press the FAN button to Fan On. The fan should turn on and run continuously.

Page 9

TROUBLESHOOTING

SYMPTOM: When using 4 wires (R, G, W, Y),

the air conditioning equipment tries

repeatedly to turn on, but cannot. At

times the display dims or disappears.

CAUSE: There is not enough power available

to "power share".

REMEDY: Connect a 270 ohm, 10 watt power

resistor at the furnace as shown below.

R G W Y C

TR300-10w

SYMPTOM: The air conditioning does not

attempt to turn on.

CAUSE: The compressor timer lockout may

prevent the air conditioner from

turning on, for a period of time.

REMEDY: Consult the Owner's Manual in

the Setup section to defeat the

cycles per hour and compressor

timeguard.

SYMPTOM: The display is blank.

CAUSE: Lack of proper power.

REMEDY: Make sure power is turned on to

the furnace and 24vac between R & W.

If C is used, 24vac between R & C.

Page 10

TROUBLESHOOTING

SYMPTOM: When controlling a residential heat

pump, and asking for cooling, the heat

comes on.

CAUSE: Heat pump is not selected "on" in the

Advanced Setup.

REMEDY: Select heat pump on during Advanced

Setup programming. Consult the Owner's

Manual.

SYMPTOM: When calling for cooling, both

the heat and cool come on.

CAUSE: The Advanced Setup is configured

to control a heat pump, and the hvac

the thermostat is controlling is a

"conventional" (non heat pump)

system.

REMEDY: Consult the Owner's Manual in

the Advanced Setup section to turn

off the heat pump.

FlatStat P374-1100FM

F C

Tested to Comply with FCC Standards

FOR HOME OR OFFICE USE

4Z95

P/N 88-114

Page 11