Emerson Blue Wireless Easy Install 1F98EZ-1621 User manual

www.white-rodgers.com
www.emersonclimate.com
PART NO. 37-7235A
1114
Provides Wireless Control for up to 4Heat/2Cool Heat Pump Stages
or up to 2Heat/2 Cool Stages on Conventional Systems
1F98EZ-1621
Emerson® Blue™ Wireless Easy Install™
FAILURE TO READ AND FOLLOW ALL INSTRUCTIONS CAREFULLY
BEFORE INSTALLING OR OPERATING THIS CONTROL COULD CAUSE
PERSONAL INJURY AND/OR PROPERTY DAMAGE.
INSTALLATION INSTRUCTIONS
Equipment Control
Module
Comfort Interface
Remote Sensor
(outdoor location)
Model 1F98EZ-1641
Includes Comfort/User Interface, Equipment Control
and one Wireless Remote Sensor
Comfort Interface
Equipment Control
Module Return Air Sensor
(RAS)
1F98EZ-1621 will accept
up to 3remote sensors
congured for indoor and 1
remote sensor congured
for outdoor.
Optional Remote
Sensor(s) not included
[ [

2
WARNING
!
Comfort Interface installation and all components of the
control system shall conform to Class II circuits per the NEC
code.
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.
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.
APPLICATIONS
INDEX
Conguration Options Applications Maximum
Stages
Single Stage Gas, Oil, Electric, Heat Only, Cool Only or Heat Cool Systems 1/1
Multi-Stage Gas, Oil, Electric, Heat Only, Cool Only or Heat Cool Systems 2/2
Heat Pump Single or Two Compressor Systems with up to 2 Stages of Aux / Em Heat 4/2
Heat Pump with Dual Fuel Single or Two Compressor Systems with up to 2 Stages of Fossil fuel Heat 4/2
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
Page
Mount Return Air Sensor and Equipment Control 3
Equipment Control Module Wiring to HVAC Equipment 4
Install Batteries 5
Installer Quick Reference 5
Congure Comfort Interface for System 6
Check System Operation 7
Locate and Mount Comfort Interface 8
View Wireless Devices 8
Troubleshooting 10

3
DHM2 DHM HM2 HM LSYSTEM
POWER
RC
R
C
LED On/Off
to terminal
connections on
HVAC equipment
Connect
W/E
W2
Y
Y2
G
O/B
L
DHM
DHM2
HM2
HM
R
C
To Return Air Sensor (RAS) Required
W/E
W2
Y
Y2
G
O/B
L
HM
HM2
DHM
SYS
DRY
SYS
DHM2
RC
RH
R
C
DRY
R and C
from HVAC
Terminal Strip
or System
Transformer
Wire Tie
Wire Tie
MOUNT RETURN AIR SENSOR AND EQUIPMENT CONTROL
IMPORTANT
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.
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.
Equipment Control Module
Return Air Duct
Supply
Duct
Equipment Control
Module
Return
Air Sensor
(Required)
Return Air
Sensor (RAS)
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.

4
**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) - Connect dehumidifier to DHM and DHM2
* 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
disconnecting one transformer, the two commons must be jumpered together.
DHM2 DHM HM2 HM LSYSTEM
W/E
W2
Y
Y2
G
O/B
POWER
RC
Status/Fault
7-Segment LED LED On/Off
Return Air Duct Sensor Socket
Connect
**HM Switch **DHM Switch
Outdoor Condenser (A/C or Heat Pump)
Y
Y2
O/B
C
(if Heat Pump)
DHM
DHM2
HM2
W/E
W2
Y
Y2
G
O/B
L
HM
Indoor Air Handler/Furnace Connections
Heat Stage 1 - Indoor Unit or Furnace (Conventional Gas, Oil, Elec) or HP 1 Stage Aux/Em
Heat Stage 2 - Indoor Unit or Furnace (Conventional Gas, Oil, Elec) or HP 2 Stage Aux/Em
Stage 1 - Outdoor Condenser (Conventional or HP)
Stage 2 - Outdoor Condenser (Conventional or HP)
Fan Relay
Changeover Relay Heat Pump
Comfort Alert Connection
R
C
24 VAC Transformer Hot
24 VAC Transformer Neutral
Dehumidification Relay / Connection
Dehumidification Relay / Connection (for dry contacts) Humidification Relay / Connection
Humidification Relay / Connection (for dry contacts)
Return Air Sensor (RAS) Required
W/E
W2
Y
Y2
G
O/B
L
HM
HM2
DHM
SYS
DRY
SYS
DHM2
RC RH
R
C
*HVAC Transformer
24 VAC
HOT
NEUTRAL
120 VAC
DRY
Connect Push
Button Switch
LED Push
Button Switch
R and C
from HVAC
Terminal Strip
or System
Transformer
Status LED
EQUIPMENT CONTROL WIRING TO HVAC EQUIPMENT

5
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.
INSTALL BATTERIES
INSTALLER QUICK REFERENCE
Install batteries in the Comfort Interface.
Room
Temperature
Time of Day
System
Indicator
Heat Button A/C
Button
Setting
Temperature
Day
of Week
Fan
Indicator
Run Button
Menu Button
Setting
Up/Down
Fan
Button
OFF Button
Wireless
Icon
Battery Status
Full charge
Half capacity
Change = Replace
Batteries
+
+
-
-
+
+
-
-
4“AA” Batteries
Comfort Interface

6
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 5seconds 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
SS1
MS2
HP1
HP2
Displayed
(Factory Default)
Press or
to select options Description
01   MS2SS1, HP2, HP1System 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)
02 (GAS) ELE Gas setting: Furnace controls blower
Elec setting: Comfort Interface controls blower
  (ELE) GAS
03 (O)
On
BChangeover Relay
“O” Energizes O/B reversing valve terminal in cooling
“B” Energizes O/B reversing valve terminal in heating
04 Heat-A/C-O Heat-A/C Auto-O,
Heat-Fan-O,
Heat-O, A/C-O
Switch Conguration for SS1or MS2
Aux Heat-A/C-O Aux Heat-A/C Auto-O,
Aux Heat-Fan-O,
Aux Heat-O, A/C-O
Switch Conguration for HP1or HP2
05 (ME)
CR Heat
FA, SL Adjustable Anticipation for MS2 or SS1. If longer cycles are desired, set to SL.
Heat cycle rate: Fast, Med, and Slow
06 (ME)
CR A/C
FA, SL Adjustable Anticipation for MS2 or SS1
Cool cycle rate: Fast, Med, and Slow
07 (ME)
CR Heat A/C
FA, SL Adjustable Anticipation for Heat Pump (HP1 or HP2)
Heat Pump cycle rate: Fast, Med, and Slow
08 (FA)
CR Aux Heat
SL Adjustable Anticipation for Auxiliary (HP1 or HP2)
Auxiliary cycle rate: Fast, Med, and Slow
09   (O)
CA
On Comfort Alert active protection On or O.
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
10   (O)
Id DeHum
On Independent Dehumidication
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)
11   (O)
ID Hum
On Independent Humidication
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)
12   (O)
CL
On Compressor Lockout
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
13   (O)
CO
On Compressor Optimization
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
14 MS2(ON)
FA Heat
O Fast Heat Stages
ON - Will enable this feature if you need to rapidly heat your home. Manually changing the
setpoint by 3degrees 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.
15 MS2(On)
FA A/C
O Fast Cool Stages
ON - Will enable this feature if you need to rapidly cool your home. Manually changing the
setpoint by 3degrees 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.
CONFIGURE COMFORT INTERFACE FOR SYSTEM

7
W/E
W2
Y
Y2
G
O/B
HM
DHM
Equipment Control Cover
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
= Amber = Green O = O
LED Indicator legend:
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
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 Gterminal connection, skip to
Heating and Cooling System section.
1. Press FAN button. Blower should turn on.
2. Press FAN button. The blower should stop immediately.
3. “ ” indicates fan is in auto mode.
Heating and Cooling System
1. Press Heat or A/C button to heat or cool. Run temperature
1o above or below room temperature. The heating or cooling
system should start.
2. For staging systems, run temperature 3oabove or below room
temperature. Heat or Cool - LED display will be indicated on
equipment control.
3. Run temperature to below or above room temperature. The
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 70o
and the room temperature is 70owith the equipment using only the
rst stage of heat. Since the equipment is keeping the temperature
within 1oof 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.

8
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.
LOCATE AND MOUNT COMFORT INTERFACE
VIEW WIRELESS DEVICES
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.
Sub-base Comfort Interface
Mounting Holes
1At Comfort Interface, press the Menu button once and
release
Enter wireless set-up menu - checking wireless components
installed.
2Press the Connect button once and release. The Comfort
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)

9
VIEW WIRELESS DEVICES
3Press the Next button once, RS-1(Remote sensor) should
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.
Equipment Control
Module (Required)
Remote Sensor 1(if installed) Remote Sensor 2(if installed)
Outdoor Remote Sensor (if installed)
Remote Sensor 3(if installed)
Return Air Sensor (required)
4
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.

10
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
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.
Symptom Possible Cause Correction Action
Communication Failure
Failed
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.
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.
Comfort Interface
temperature disagrees with
another device
Comfort Interface display setting requires
adjustment.
The display can be adjusted +/-5o. See Temperature Display
Adjustment in the Comfort Interface Conguration Menu Section.
Furnace (Air Conditioner)
Cycles Too Fast or Too Slow
(narrow or wide temperature
swing)
The location of the Comfort Interface and/
or the size of the heating system may be
inuencing the cycle rate.
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.
No Cooling Cooling system requires service. Verify you are set to cool. Lower the setting below the room
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, Gfrom Equipment Control Module to
HVAC Equipment.
See fault code table for Comfort Alert Systems.
No Heating (conventional
furnace or Heat Pump Aux)
1. Furnace lock-out condition. Heat may also
be intermittent.
2. Heat pump system requires service.
3. Pilot light not lit.
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, W2from module to HVAC
Equipment.
2. Many furnaces have safety devices that shut down when a lock-
out 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.
Heat, Cool or Fan Runs
constantly
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.
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.
Forgot Keypad Lockout Code Press 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.
Note: For troubleshooting Wireless RemoteTemperature Sensors, refer to Installation Instructions for F145RF-1600.

11
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 3or 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 and buttons simultaneously to
delete each device. Press Next until the display shows the
next device to delete.
5. Press the Run button to exit the menu.
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)

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www.emersonclimate.com
White-Rodgers is a division
of Emerson Electric Co.
The Emerson logo is a
trademark and service mark
of Emerson Electric Co.
Comfort AlertTM Troubleshooting
Indicator
Comfort Alert
Module
Equipment
Control Module
7-Segment LED
Status LED
Description Comments
Green “POWER” Module has power Supply voltage is present at module terminals
Red “TRIP” Flash Comfort Interface en-
ergizing “Y” terminal
to call for cool but the
compressor is not run-
ning
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.
Yellow “ALERT”
Flash 1
1Long Run Time
Compressor is running
extremely long run
cycles
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.
Yellow “ALERT”
Flash 2
2System Pressure Trip
Discharge or suction
pressure out of limits or
compressor overloaded
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.
Yellow “ALERT”
Flash 3
3Short Cycling
Compressor is running
only briey
1. Comfort Interface demand signal is intermittent
2. Time delay or control board defective
3. If high pressure switch present go to Flash Code 2information
4. If low pressure switch present go to Flash Code 1information
Yellow “ALERT”
Flash 4
4Locked Rotor 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.
Yellow “ALERT”
Flash 5
5Open Circuit 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.
Yellow “ALERT”
Flash 6
6Open Start Circuit
Current only in run
circuit
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.
Yellow “ALERT”
Flash 7
7Open Run Circuit
Current only in start
circuit
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.
Yellow “ALERT”
Flash 8
8Welded Contactor
Compressor always runs
1. Compressor contactor has failed closed
2. Comfort Interface demand signal not connected to module
Yellow “ALERT”
Flash 9
9Low Voltage Control
Circuit < 17 VAC
1. Control circuit transformer is overloaded
2. Low line voltage (contact utility if voltage at disconnect is low). Check wiring
connections
Red Trip Flash and
Yellow Alert Flash
at the same time
Control circuit voltage
too low for operation
On Comfort Alert Module, ash code number corresponds to a number of LED ashes, followed by a pause and then repeated.
TROUBLESHOOTING
Note: This is only applicable for systems featuring Comfort Alert (or similar) technology.