Emerson 1F98EZ-1621, Blue Wireless Easy Install 1F98EZ-1621 Installation Instructions Manual

1F98EZ-1621

Emerson® Blue™ Wireless Easy Install™

Provides Wireless Control for up to 4 Heat/2 Cool Heat Pump Stages

or up to 2 Heat/2 Cool Stages on Conventional Systems

INSTALLATION INSTRUCTIONS

FAILURE TO READ AND FOLLOW ALL INSTRUCTIONS CAREFULLY
BEFORE INSTALLING OR OPERATING THIS CONTROL COULD CAUSE
PERSONAL INJURY AND/OR PROPERTY DAMAGE.

Comfort Interface

Optional Remote

[

Sensor(s) not included

Comfort Interface

Equipment Control

Module

[

Includes Comfort/User Interface, Equipment Control

1F98EZ-1621 will accept

up to 3 remote sensors

congured for indoor and 1

remote sensor congured

Model 1F98EZ-1641

for outdoor.

and one Wireless Remote Sensor

Return Air Sensor

(RAS)

Remote Sensor
(outdoor location)

Equipment Control

Module

www.emersonclimate.com

PART NO. 37-7235A

www.white-rodgers.com

1114

!

INDEX

Mount Return Air Sensor and Equipment Control
Equipment Control Module Wiring to HVAC Equipment
Install Batteries
Installer Quick Reference

Congure Comfort Interface for System

Check System Operation
Locate and Mount Comfort Interface
View Wireless Devices
Troubleshooting

APPLICATIONS

Page

3
4
5
5
6
7
8
8

10

Conguration Options Applications

Single Stage Gas, Oil, Electric, Heat Only, Cool Only or Heat Cool Systems

Multi-Stage Gas, Oil, Electric, Heat Only, Cool Only or Heat Cool Systems

Heat Pump Single or Two Compressor Systems with up to 2 Stages of Aux / Em Heat

Heat Pump with Dual Fuel Single or Two Compressor Systems with up to 2 Stages of Fossil fuel Heat

Maximum

SPECIFICATIONS

Electrical Rating:

Input-Hardwire ....................................................... 20 to 30 VAC

Terminal Load ................................................................ 1.0A per terminal, 2.5A maximum all terminals combined

Setpoint Range .............................................................. 45° to 99°F (7° to 37°C)

Operating Ambient ........................................................ 32°F to +105°F (0° to +41°C)

Operating Humidity ....................................................... 90% non-condensing max.

Shipping Temperature Range ......................................... -40° to +150°F (-40° to +65°C)

Dimensions Interface ..................................................... 4-1/2”H x 6”W x 1-1/4”D

Dimensions Control ....................................................... 5-1/2”H x 5-3/4”W x 1-1/2”D

Stages

1/1

2/2

4/2

4/2

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.

WARNING

Comfort Interface installation and all components of the
control system shall conform to Class II circuits per the NEC
code.

2

ATTENTION: MERCURY NOTICE

This product does not contain mercury. However, this product
may replace a product that contains mercury.

Mercury and products containing mercury must not be
discarded in household trash. Do not touch any spilled
mercury. Wearing non-absorbent gloves, clean up any spilled
mercury and place in a sealed container. For proper disposal of
a product containing mercury or a sealed container of spilled
mercury, place it in a suitable shipping container. Refer to
www.thermostat-recycle.org for location to send product
containing mercury.

MOUNT RETURN AIR SENSOR AND EQUIPMENT CONTROL

IMPORTANT

Return Air

Sensor (RAS)

The RAS monitors temperature of the return air and is needed at
all times for system operation.

Drill 1/4” hole in return air duct at least 18” upstream from

humidier, dehumidier or any other HVAC accessories.

Insert RAS into duct and fasten with two sheet metal screws.

If the system is hydronic, locate return air sensor in conditioned
space.

Return Air Duct

Return

Air Sensor

(Required)

Equipment Control

Module

Supply

Duct

Do not provide battery power to Comfort Interface or remote
sensor (if installed) until instructed. All wireless components
in the kit are congured to communicate at the factory.

Mount Equipment Control Module on wall near HVAC equipment,
or on the air handler. Do not install Equipment Control Module
inside of the HVAC equipment. Use screws to securely fasten
control in place. Do not drill into critical furnace components. Wall
anchors and screws are provided for dry wall mounting (3/16”).
See next page for wiring.

Wiring Steps

1. Remove the cover from the Equipment Control Module.

2. Plug Return Air Sensor (RAS) lead into return air sensor

connection on the Equipment Control Module (required).
Route the sensor lead into the wiring channel and out the top
of the control.

3. Use thermostat wire to make the connections from Equipment
Control Module to the HVAC equipment or terminal strip. Strip
the sheath of the wire bundle back approximately 10”.

4. Insert wire bundle into the bottom of Equipment Control
Module. Two slots are provided if more than one bundle of wire
are required.

5. Route two wires from the bundle to the left side of the
Equipment Control Module for terminals R and C.

6. Route the rest of the wires in the bundle to the right side of the
Equipment Control Module and fasten loosely with wire ties.

7. Trim wires to length for each connection required, strip ends
and insert into control quick connect block.

Refer to wiring diagram for terminal functions and wire routing.

Note: Ten (10) feet of wire is supplied with the RAS.

R and C

from HVAC

Terminal Strip

or System

Transformer

Wire Tie

To Return Air Sensor (RAS) Required

POWER

R

R

RC

RC
RH

C

C

Connect

Equipment Control Module

Wire Tie

LED On/Off

SYS

SYS

W/E

W2

Y2

O/B

HM

HM2

DRY

DHM

DHM2

Y

G

L

DRY

W/E

to terminal

W2

connections on

Y

HVAC equipment

Y2

G

O/B

L
R
C

HM

DHM2 DHM HM2 HM LSYSTEM

HM2

DHM

DHM2

3

EQUIPMENT CONTROL WIRING TO HVAC EQUIPMENT

Return Air Duct

- Connect dehumidifier to DHM and DHM2

**To use the HVAC transformer to power humidification/dehumidification switch HM/DHM

switches to “SYS” position:

- Connect humidifier to HM

- Connect dehumidifier to DHM

If humidifier or dehumidifier has a separate transformer switch HM or DHM switch to “DRY” position:

- Connect humidifier to HM and HM2 (or)

**HM Switch

Button Switch

Connect Push

Status LED

Connect

Terminal Strip

Transformer

from HVAC

or System

RC

RH

C

R and C

RC

POWER

R

Sensor Socket

7-Segment LED

Status/Fault

LED On/Off

Return Air Sensor (RAS) Required

**DHM Switch

disconnecting one transformer, the two commons must be jumpered

together.

* For two transformer system, cut and tape off one transformer. If

transformer safety circuits are only in one of the systems, remove

the transformer of the system with NO safety circuits. If required,

replace remaining transformer with a 75 VA Class II transformer. After

NEUTRAL

*HVAC Transformer

24 VAC

120 VAC

SYS

DHM2

DHM

DRY

DHM2 DHM HM2 HM LSYSTEM

DHM2

DHM

Humidification Relay / Connection (for dry contacts)

Humidification Relay / Connection

HOT

SYS

HM2

HM

DRY

HM2

HM

Dehumidification Relay / Connection (for dry contacts)

Dehumidification Relay / Connection

O/B

Y2

G

L

R

C

L

24 VAC Transformer Hot

Comfort Alert Connection

24 VAC Transformer Neutral

Y

O/B

Y2

G

Y

O/B

Y2

G

Y

Changeover Relay Heat Pump

Fan Relay

Stage 1 - Outdoor Condenser (Conventional or HP)

Stage 2 - Outdoor Condenser (Conventional or HP)

W2

W2

W2

Button Switch

LED Push

W/E

W/E

W/E

Heat Stage 2 - Indoor Unit or Furnace (Conventional Gas, Oil, Elec) or HP 2 Stage Aux/Em

Heat Stage 1 - Indoor Unit or Furnace (Conventional Gas, Oil, Elec) or HP 1 Stage Aux/Em

O/B

Y2

C

Y

Indoor Air Handler/Furnace Connections

(if Heat Pump)

Outdoor Condenser

(A/C or Heat Pump)

4

INSTALL BATTERIES

Room

Day

IMPORTANT

Wireless communication for the Comfort Interface and

Equipment Control Module have already been congured at

the factory. It is not necessary to press the connect buttons at
installation.

INSTALLER QUICK REFERENCE

Time of Day

Wireless

Icon

Install batteries in the Comfort Interface.

Temperature

of Week

+

+

--+

+

4 “AA” Batteries

Comfort Interface

Setting
Temperature

-

-

Battery Status

Full charge

Half capacity

Change = Replace

System

Indicator

Heat Button

A/C

Button

Fan
Button

Setting
Up/Down

Menu Button

Run Button

Fan
Indicator

OFF Button

5

CONFIGURE COMFORT INTERFACE FOR SYSTEM

Before operating the heating and cooling system enter the installer menu and congure the Comfort Interface for the system

Entering and Navigating the Advanced Installer Conguration Menu

On the Home Screen Display, press and hold the Menu button for approximately 5 seconds to enter the Comfort Interface Options
Conguration Menu. Press and hold the Menu button again for approximately 5 seconds to enter the Advanced Installer Conguration
Menu. Press Next button to step through conguration menu items.

Menu

Reference

Number

6

SS1

MS2

01

 

02



 

03

04



05



06



07

08

09

 

10

 

11

 

12

 

13

 

14 MS2

15 MS2

HP1
HP2

Displayed

(Factory Default)

MS2 SS1, HP2, HP1

(GAS) ELE Gas setting: Furnace controls blower

(ELE) GAS













(O)

On

Heat-A/C-O Heat-A/C Auto-O,

Aux Heat-A/C-O Aux Heat-A/C Auto-O,

Aux Heat-O, A/C-O

(ME)

CR Heat

(ME)

CR A/C

(ME)

CR Heat A/C

(FA)

CR Aux Heat

(O)

CA

(O)

Id DeHum

(O)

ID Hum

(O)

CL

(O)

CO

(ON)

FA Heat

(On)

FA A/C

Press

Heat-O, A/C-O

Aux Heat-Fan-O,

or

to select options Description

System Conguration

MS2 = Multi-Stage conventional (no heat pump)
HP1 = Single compressor
HP2 = 2 compressor 2 speed compressor
SS1 = Single Stage conventional (no heat pump)

Elec setting: Comfort Interface controls blower

B Changeover Relay

Heat-Fan-O,

FA, SL

FA, SL

FA, SL

SL

On Comfort Alert active protection On or O.

On Independent Dehumidication

On Independent Humidication

On Compressor Lockout

On Compressor Optimization

O Fast Heat Stages

O Fast Cool Stages

“O” Energizes O/B reversing valve terminal in cooling
“B” Energizes O/B reversing valve terminal in heating

Switch Conguration for SS1 or MS2

Switch Conguration for HP1 or HP2

Adjustable Anticipation for MS2 or SS1. If longer cycles are desired, set to SL.

Heat cycle rate: Fast, Med, and Slow

Adjustable Anticipation for MS2 or SS1

Cool cycle rate: Fast, Med, and Slow

Adjustable Anticipation for Heat Pump (HP1 or HP2)

Heat Pump cycle rate: Fast, Med, and Slow

Adjustable Anticipation for Auxiliary (HP1 or HP2)

Auxiliary cycle rate: Fast, Med, and Slow

On - Enables active protection for the compressor. If the CA module sends alerts for condition
number #2, 3, 4, 6 or 7 the interface will cancel the call for cool to protect compressor. The
interface will blink setpoint and display “Call for Service” as well as the Comfort Alert numbers.
(see troubleshooting for Comfort Alert)
OFF - Will disable the active protection for the compressor

Dehumidies in both heat and cool modes. (Independent of a call for heat or cool)
OFF (default cancels independent dehumidication option. To return to dehum O press “+”

past 80% until O appears
Selecting On energizes the DHM terminal(s) and fan terminal (G) when humidity is above the

de-humidication setting. This feature is often used for dehumidication systems independent

from the heating and cooling system.

Note: You must have the Dehumidication feature activated. (See Homeowner Conguration

Menu #8)

Humidies in both heat and cool modes. (Independent of a call for heat or cool)

OFF (default) cancels independent humidication option.
On energizes the HM terminal(s) and fan terminal (G) when humidity is below the humidication

setting. This feature is often used on steam systems and is independent from the call for heat or cool.

Note: You must have the humidication feature activated. (See Homeowner Conguration

Menu #7)

CL ON - Will cause the interface to wait 5 minutes between cooling cycles. This is intended to help
protect the compressor from short cycling. Some newer compressors 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 Comfort Interface compressor time delay

occurs, it will ash the setpoint for up to ve minutes.

CL OFF - Will disable the feature

CO ON - provides a delay in circulator fan operation after the compressor turns on or o.
When compressor turns on (for a call for heat in heat pump or a call for cool) the fan will be

delayed for ve seconds before turning on to allow the air to be heated or cooled. After the
compressor turns o for a call for cool, the fan will continue to run for 20 seconds to capture

additional cooling from the system.
CO OFF - There will be no delay in fan operation

ON - Will enable this feature if you need to rapidly heat your home. Manually changing the
setpoint by 3 degrees or more will enable all stages of heat.
OFF - May not bring on secondary rapidly because it allows the Comfort Interface to compute
the optimum time to stage.

ON - Will enable this feature if you need to rapidly cool your home. Manually changing the
setpoint by 3 degrees or more will enable all stages of cool.
OFF - May not bring on secondary rapidly because it allows the Comfort Interface to compute
the optimum time to stage.

CHECK SYSTEM OPERATION

NOTE

Installer can operate the Comfort Interface at the equipment
before mounting to wall. This is more convenient than
walking back and forth between Comfort Interface and HVAC
system checking components are energized.

Apply power to Equipment Control Module.

Fan Operation

If your system does not have a G terminal connection, skip to

Heating and Cooling System section.

1. Press FAN button. Blower should turn on.

2. Press FA N button. The blower should stop immediately.

3. “

Heating and Cooling System

1. Press Heat or A/C button to heat or cool. Run temperature

2. For staging systems, run temperature 3

3. Run temperature to below or above room temperature. The

” indicates fan is in auto mode.

o

1

above or below room temperature. The heating or cooling

system should start.

o

above or below room

temperature. Heat or Cool - LED display will be indicated on
equipment control.

system should shut o.

Humidication/Dehumidication Operation

1. Heating/Humidier and Cooling/Dehumidier

To set humidication or dehumidication setpoint, refer to the

Homeowner Conguration Menu #7 and 8.

Second Stage Time Delay

Your Comfort Interface 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
Comfort Interface to bring the second stage on quickly. There is a

time delay from 0-30 minutes depending on the performance of
the rst stage of the system.

EXAMPLE: For the last 2 hours the Comfort Interface is set on 70
and the room temperature is 70o with the equipment using only the

rst stage of heat. Since the equipment is keeping the temperature

within 1o of setpoint, the Comfort Interface will delay the 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 dierence
between the setpoint and the room temperature. The net eect
of the staging program is that when the rst stage is capable of

making temperature the second stage will delay longer. When

the Comfort Interface calculates that rst 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.

o

After Advanced Installer Conguration, LEDs on the control will

indicate the selections of the Comfort Interface. The following
tables show the LED indications if LED indications are turned on.
Remove Equipment Control Module cover and press the LED switch

to view LEDs. Press the button again to turn LED indicators o.

Conventional Pump

Gas or Elect Gas or Elect

Amber Amber W/E
Amber Amber

W2

Amber Green Y
Amber Green

Y2

Amber Green G
Amber Green O/B

RH DRY

Green Amber HM

RH DRY

Green Amber DHM

W/E
W2
Y

Y2
G
O/B

HM

DHM

Equipment Control Cover

LED Indicator legend:

= Amber

= Green

O = O

LED’s will be on constant to show conguration.
LED’s will ash to indicate the terminal output is active.

W/E – 1st Stage Heating or Auxiliary

W2 – 2nd Stage Heating or Auxiliary

Y – 1st Stage Cooling

Y2 – 2nd Stage Cooling

G – Fan

HM – Humidication

DHM – Dehumidication

7

LOCATE AND MOUNT COMFORT INTERFACE

IMPORTANT

Before drilling holes for mounting the Comfort Interface, verify the areas chosen for mounting to allow good wireless
communication. Place the Comfort Interface where it will be mounted (but do not drill holes yet) and follow steps in “View
Wireless Devices (see below).” If the Comfort Interface is out of range, the display will read “Failed” so a dierent location may
be required.

Comfort Interface

1. Locate Comfort Interface on interior wall approximately 5

feet o the ground in an area representative of average room

temperature.

2. Pull the Comfort Interface o the base. Forcing or prying

Interface will cause damage to the unit.

3. Place sub-base on wall and mark mounting hole locations on
wall using base as a template.

4. Move sub-base out of the way. Drill mounting holes. Use
plastic screw anchors if needed to secure the base.

5. Fasten sub-base snugly to wall using two mounting screws.

Leveling is for appearance only and will not aect Comfort

Interface operation.

6. Comfort Interface can be attached after checking operation.

Mounting Holes

Sub-base

Comfort Interface

VIEW WIRELESS DEVICES

Enter wireless set-up menu - checking wireless components
installed.

At Comfort Interface, press the Menu button once and

1

release

Press the Connect button once and release. The Comfort

2

Interface will indicate “Searching” and then display “CTL”
(for Equipment Control Module) when communication has
been conrmed. If no communication, it will show “Failed”
or CTL will not appear on screen.

(see Troubleshooting)

8

VIEW WIRELESS DEVICES

4

Equipment Control

Module (Required)

Press the Next button once, RS-1 (Remote sensor) should

3

be displayed if a remote sensor is installed. Press Next
again to conrm additional sensor(s) RS-2, RS-3, ORS-4
(outdoor), RAS.

Remote Sensor 1 (if installed) Remote Sensor 2 (if installed)

Outdoor Remote Sensor (if installed)

Press the Run button to return to Home screen.

Note: The battery life for each wireless device is shown as it is being displayed on the Comfort Interface display.

Remote Sensor 3 (if installed)

Return Air Sensor (required)

9

TROUBLESHOOTING

Reset Operation

If a voltage spike or static discharge blanks out the display or
causes erratic Comfort Interface operation, you can reset it by
removing batteries for 2 minutes. After resetting it, replace the
batteries and reset clock. If it still does not function correctly,
press

and and Fan button simultaneously. The Comfort

Symptom Possible Cause Correction Action

Communication Failure

Failed

Comfort Interface
temperature disagrees with
another device

Furnace (Air Conditioner)

Cycles Too Fast or Too Slow

(narrow or wide temperature
swing)

No Cooling Cooling system requires service. Verify you are set to cool. Lower the setting below the room

No Heating (conventional
furnace or Heat Pump Aux)

Heat, Cool or Fan Runs

constantly

Forgot Keypad Lockout Code Press

1. Loss of 24 volt power to Equipment
Control Module.

2. Comfort Interface & Equipment Module
are located too far apart.

3. Too much interference between devices.

Comfort Interface display setting requires
adjustment.

The location of the Comfort Interface and/
or the size of the heating system may be

inuencing the cycle rate.

1. Furnace lock-out condition. Heat may also
be intermittent.

2. Heat pump system requires service.

3. Pilot light not lit.

1. Possible short in wiring.

2. Possible short in Comfort Interface.

3. Possible short in heat/cool/fan system.

4. Fan Switch set to Fan ON.

Interface should go blank and then all segments will be displayed
momentarily.

Note: Be sure to review the installer conguration menu settings.
When Comfort Interface is reset, installer conguration menu

settings and programming will reset back to factory settings.

1. Check 24 volt power at R-C on Equipment Control Module.

2. Relocate Comfort Interface closer to the Equipment Control Module.

3. Relocate Comfort Interface away from obstruction or closer to

Equipment Control Module.

The display can be adjusted +/-5
Adjustment in the Comfort Interface Conguration Menu Section.

Digital Comfort Interfaces provide precise control and cycle faster

than older mechanical models. The system turns on and o more

frequently but runs for a shorter time so there is no increase in energy
use. If you would like an increased cycle time, choose SL for slow cycle

in the Advance Installer Conguration menu.

temperature.

Check Easy Install module Y terminal(s) LED’s. If ashing, Comfort
Interface/Equipment Control Module is calling for cool. Check for
broken or shorted wire from Equipment Control Module to HVAC
Equipment. If LED is OFF or solid ON Comfort Interface not calling.

Check 24 volt power to C - Y, G from Equipment Control Module to
HVAC Equipment.

See fault code table for Comfort Alert Systems.

1. Verify you are set to heat. Raise setpoint above the room
temperature.

Check Easy Install module terminal(s) LED’s. If ashing, Comfort

Interface/module is calling for heat. Check for broken or shorted
wire from module to HVAC Equipment. If LED is O or solid ON
Comfort Interface not calling.

Check for 24 volt power to C- W/E, W2 from module to HVAC

Equipment.

2. Many furnaces have safety devices that shut down when a lock­out condition occurs. If the heat works intermittently, contact the
furnace manufacturer or local HVAC service person for assistance.

See fault code table for Comfort Alert Systems.

3. Re-light pilot.

Check each wire connection from module to HVAC Equipment to
verify they are not shorted or touching together.

Check Equipment Control Module LED’s. If ashing, Comfort Interface/

Equipment Control Module is calling for heat, cool or fan. If heat or
cool runs with LED OFF solid ON check for shorted wire from module
to HVAC Equipment.

and hold the Menu button for a minimum of 15 seconds. The Comfort

Interface lock icon will be removed and Comfort Interface will return
to normal operation.

o

. See Temperature Display

Note: For troubleshooting Wireless Remote Temperature Sensors, refer to Installation Instructions for F145RF-1600.

10

TROUBLESHOOTING

Rebooting Wireless Devices

If the system does not operate or communicate properly using
the previous troubleshooting page, follow the steps below. This
procedure removes and reconnects all wireless devices in the
system to assure communication.

Remove Wireless Devices

1. At the Comfort Interface, press Menu button once.

2. Press the Connect button.

3. Press and release the Next button until the display shows the

device you want to delete, CTL, RS 1, RS 2, RS 3 or ORS.
CTL (Equipment Control Module )
RS 1 (Indoor remote sensor 1)
RS 2 (Indoor remote sensor 2)
RS 3 (Indoor remote sensor 3)
ORS (Outdoor remote sensor 4)
RAS (Return Air Sensor - do not delete)

4. Press and hold the

delete each device. Press Next until the display shows the

next device to delete.

5. Press the Run button to exit the menu.

and buttons simultaneously to

Add Wireless Devices

1. Power the device.

2. Go to Equipment Control Module and press the Connect

button. Equipment Control Module Status LED will ash
green indicating searching for wireless devices.

3. Press the Connect button on the device you want to add.

Conrm Wireless Devices are Communicating

1. Using the Comfort Interface, press the Menu button once.

2. Press the Connect button once and release. Comfort Interface

will display (CTL) control and wireless icon.

3. Continue pressing and releasing the Next button to view all
connected and communicating wireless devices. They will
appear in the following order to a maximum of:

CTL (Equipment Control Module)
RS 1 (Indoor remote sensor 1)
RS 2 (Indoor remote sensor 2)
RS 3 (Indoor remote sensor 3)
ORS (Outdoor remote sensor 4)
RAS (Return Air Sensor)

11

TROUBLESHOOTING

Note: This is only applicable for systems featuring Comfort Alert (or similar) technology.

Comfort Alert

TM

Troubleshooting

Indicator

Equipment

Comfort Alert

Module

Green “POWER” Module has power Supply voltage is present at module terminals

Red “TRIP” Flash Comfort Interface en-

Yellow “ALERT”

Flash 1

Yellow “ALERT”

Flash 2

Yellow “ALERT”

Flash 3

Yellow “ALERT”

Flash 4

Yellow “ALERT”

Flash 5

Yellow “ALERT”

Flash 6

Yellow “ALERT”

Flash 7

Yellow “ALERT”

Flash 8

Yellow “ALERT”

Flash 9

Red Trip Flash and

Yellow Alert Flash

at the same time

On Comfort Alert Module, ash code number corresponds to a number of LED ashes, followed by a pause and then repeated.

Control Module
7-Segment LED

1

2

3

4

5

6

7

8

9

Status LED

Description Comments

ergizing “Y” terminal
to call for cool but the
compressor is not run­ning

Long Run Time
Compressor is running
extremely long run
cycles

System Pressure Trip
Discharge or suction
pressure out of limits or
compressor overloaded

Short Cycling
Compressor is running

only briey

Locked Rotor

Open Circuit

Open Start Circuit
Current only in run
circuit

Open Run Circuit
Current only in start
circuit

Welded Contactor
Compressor always runs

Low Voltage Control
Circuit < 17 VAC

Control circuit voltage
too low for operation

1. Compressor protector is open. Check high head pressure and compressor supply
voltage.

2. Check for open unit power disconnect, circuit breaker or fuses, low pressure switch
if present in system or Compressor contact or has failed open.

3. Broken wire or connector not making contact.

1. Low refrigerant charge.

2. Evaporator blower is not running. Check blower relay, blower motor capacitor,

motor failure or blockage, wiring and connectors, blower control board, Comfort
Interface wiring for open circuit.

3. Evaporator coil is frozen. Check for low suction pressure, low Comfort Interface

setting, evaporator air ow (blockages in coil, return air lter, ductwork or registers)

4. Condenser coil is dirty, liquid line restriction (lter drier blocked if present in system)

5. Check Comfort Interface sub-base or wiring for short circuit, Comfort Interface

installation (location, level)

6. Faulty TXV (Thermostatic Expansion Valve). Check TXV bulb installation (size,

location and contact) also if TXV/xed orice is stuck closed or defective.

1. High head pressure. Check high pressure switch if present in system, overcharge
with refrigerant, non-condensable in system.

2. Condenser coil poor air circulation (dirty, blocked, damaged)

3. Condenser fan not running. Check fan capacitor, wiring and connectors, motor for

failure or blockage.

4. Return air duct has substantial leakage

5. If low pressure switch present in system, check Flash Code 1 information.

1. Comfort Interface demand signal is intermittent

2. Time delay or control board defective

3. If high pressure switch present go to Flash Code 2 information

4. If low pressure switch present go to Flash Code 1 information

1. Run capacitor has failed.

2. Low line voltage (contact utility if voltage at disconnect is low) check wiring.

3. Excessive liquid refrigerant in compressor. Compressor bearings are seized,

measure compressor oil level.

1. Open Outdoor unit power disconnect, circuit breaker, fuse(s). Compressor
contactor failed to open. Check wiring on compressor contactor and between
supply and compressor, contactor failure (burned, pitted), low pilot voltage at
compressor contactor coil.

2. High pressure switch is open and requires manual reset.

3. Unusually long compressor protector reset time due to extreme ambient

temperature.

4. Compressor windings are damaged. Check compressor motor winding resistance.

1. Run capacitor has failed.

2. Open circuit in compressor start wiring or connections. Check wiring and

connectors between supply and the compressor “S” terminal.

3. Compressor start winding is damaged. Check compressor motor winding resistance.

1. Open circuit in compressor run wiring or connections. Check wiring and connectors

between supply and the compressor “R” terminal.

2. Compressor run winding is damaged. Check compressor motor winding resistance.

1. Compressor contactor has failed closed

2. Comfort Interface demand signal not connected to module

1. Control circuit transformer is overloaded

2. Low line voltage (contact utility if voltage at disconnect is low). Check wiring

connections

White-Rodgers is a division
of Emerson Electric Co.

The Emerson logo is a
trademark and service mark
of Emerson Electric Co.

www.white-rodgers.com

www.emersonclimate.com