Lennox 16B27 Instruction Manual

©2017 Lennox Industries Inc.
Dallas, Texas, USA
CONTROLS
KITS AND ACCESSORIES
506461-03
11/2017
Supersedes 506461-02
AIR HANDLER CONTROL FIELD
REPLACEMENT KIT
Guidelines for Air Handler Control Field Replacement (16B27)
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, personal
injury or loss of life. Installation and service must be
performed by a licensed professional HVAC installer or
equivalent, service agency, or the gas supplier.
CAUTION
As with any mechanical equipment, contact with sharp
sheet metal edges can result in personal injury. Take
care while handling this equipment and wear gloves and
protective clothing.
WARNING
Electric Shock Hazard! – Disconnect all
power supplies before servicing.
Replace all parts and panels before
operating.
Failure to do so can result in death or
electrical shock.
WARNING
ELECTROSTATIC
DISCHARGE
(ESD)
Precautions and
Procedures
Electrostatic discharge can affect
electronic components. Take care
during unit installation and service to
protect the unit’s electronic controls.
Precautions will help to avoid control
exposure to electrostatic discharge
by putting the unit, the control and the
technician at the same electrostatic
potential. Touch hand and all tools
on an unpainted unit surface before
performing any service procedure to
neutralize electrostatic charge.
Table of Contents
Shipping and Packing List ..............................2
General .............................................................2
Air Handler Control Removal and
Installation ........................................................2
For All Applications ............................................................ 2
For Non-Communicating Applications Only....................... 2
Field Control Wiring ........................................5
Control and Sensor Connection Requirements................. 7
Discharge Sensor (DAT).................................................... 7
Outdoor Air Sensor (OAS)................................................. 7
Indoor Blower Signal 6-Pin Connector (P7)....................... 7
Air Handler Control 9-Pin Connector (P8) ......................... 7
Air Handler Control Button and Display ........8
Push Button....................................................................... 8
Seven-Segment Display.................................................... 8
Air Handler Jumpers ..................................... 11
Delay Prole 1 ................................................................ 12
Delay Prole 2 ................................................................. 12
Delay Prole 3 ................................................................. 12
Delay Prole 4 ................................................................. 12
Seven-Segment Display.................................................. 12
Target CFM Tables .........................................13
Unit Operating Sequences ............................17
Conguring Unit ............................................19
Checkout ......................................................................... 19
Unit Size Code................................................................. 20
Electric Heat .................................................................... 21
EvenHeat Operation........................................................ 22

Page 2
Shipping and Packing List
Check package contents for shipping damage. Consult
last carrier immediately if damage is found.
1 – Control
1 – Wiring diagram (537202-02)
1 – Jumper, Link Guide and Diagnostic Code Sheet
General
This document provides general guidelines on eld re-
placement of air handler control and unit conguration.
This kit replaces Kit # 65W70 and #13Y22 and is back-
wards compatible.
Air Handler Control Removal and
Installation
For All ApplicAtions
1. Disconnect power to the unit.
2. Remove unit access panel. See unit installation
instruction for access panel removal procedure.
3. Recommend removing each wire connected to the
control individually and connecting to the new control.
Alternate method recommended is to mark each wire
as it is removed from control.
4. Once all connections have been transferred to the new
control. Remove the old control by removing the two
screws securing the control mounting bracket to the
control box (see “Figure 1. Air Handler Control Removal
and Installation”). Also see “Air Handler Control Button
and Display” on page 8.
5. Remove the four plastic standoffs that secure the
control to mounting bracket
6. Secure the new indoor control to the mounting bracket
using existing four plastic standoffs.
7. Secure control mounting bracket to control box using
existing two screws.
For non-communicAting ApplicAtions only
1. Note position of all jumpers on the existing air handler
control and relocate same jumpers to those positions
on the new air handler control. Also see “Air Handler
Control Button and Display” on page 8.
2. Congure new Control for non-communicating
systems using the procedures outline in “Conguring
Unit” on page 19. For communicating systems, refer
to the iComfort®thermostat installation instructions for
system conguration.
WARNING
This product contains a chemical known to the State
of to cause cancer, birth defects, or other
reproductive harm.
CONTROL
BOARD
CONTROL MOUNTING
BRACKET
CONTROL BOX
CONTROL MOUNTING
BRACKET SCREWS
Figure 1. Air Handler Control Removal
and Installation
IMPORTANT
Control board must be installed in proper orientation for
all wiring to reconnect to the control board. Please refer
to Figure 1 diagram above for control board orientation.
Same orientation whether unit is congured for up-ow,
down-ow, horizontal right or horizontal left.
WARNING
Electric Shock Hazard.
Can cause injury or death.
Foil-faced insulation has conductive
characteristics similar to metal. Be sure there
are no electrical connections within 1/2ʺ
of the insulation. If the foil-faced insulation
comes in contact with electrical voltage, the
foil could provide a path for current to pass
through to the outer metal cabinet. While
the current produced may not be enough to
trip existing electrical safety devices (e.g.,
fuses or circuit breakers), the current can be
enough to cause an electrical shock hazard
that could cause personal injury or death.

Page 3
Non−Communicating System
The unit will operate based on jumper and link settings on
the control. All setting changes must be done at the control
board. The Lennox ComfortSense®7500 thermostat may be
used, as well as other non−communicating thermostats.
Communicating System
The jumper and link settings aredefault settings and ONLY
control system operation if configuration settings in the iComfort
thermostat are not available. The Lennox iComfort®thermostat
must be used in communicating applications.
STEP 2
STEP 1
NOTE − Error code troubleshooting is included in all kit and unit installation instructions.
MAIN CONTROL Set−up
Use the procedures provided in this instruction or that of the
unit installation instruction.
Set jumpers and clip links to match parameters of equipment
Unit Size Code
See Figure 7 for details on this procedure.
Set Unit Size Code by following configuration procedure
provided in this instruction or unit installation instructions.
Configure Electric Heat
Configuring / Detecting Electric Heat Section .
System Operation Configuration
Confirm or configure system operation using iComfort®
Thermostat Installer System Setup Guide.
Configure Electric Heat
Indoor Unit NEW MAIN CONTROL Catalog Number
Verify OLD CONTROL jumper settings, links and wiring connections. Use
the same settings and wiring connections for theNEW CONTROL. See
Figure 10 for location of jumpers and loop location.
Remove OLD MAIN CONTROL
Install NEW MAIN CONTROL
Transfer OLD CONTROLwire connections to NEW CONTROL
(See figure 3 in this instruction for location of single
character display, push button, jumpers and links.)
AIR HANDLER CONTROL (AHC)
AIR HANDLER CONTROL (AHC)
REPLACEMENT PROCEDURE
®
See Figure 8 for details on this procedure.
CBA38MV − Kit # 16B27
TURN OFF ALL POWER TO UNIT BEFORE SERVICING
Configuring System
During configuration, this pop-up
will confirm that model and serial
number have been copied to the
new control board.
Air Handler Control has the ability to detect the number of field-
installed electric heat stages present. The manual process for
detecting electric heat is outlned in Figure 8.
Configuring / Detecting Electric Heat Section .
CBX40UHV /
CBX32MV /
Figure 2. Replacement Procedure

Page 4
OUTDOOR
AIR SENSOR
HEAT
1234
COOL
1234
DELAY
1234
ADJUST
NORM + −
HUMIDIFICATION
SMART AUTO
EVENHEAT
1234
BLOWER
ONLY CFM
100
115
130
85
Y1−Y2 2−STAGE COMPR R−O
HEAT
PUMP R− DS
DEHUM
OR
C
W1
W2
G
Y2
Y1
C
R
DH
H
L
O
DS
W3
FACTORY
JUMPER
FUSE3AMP
XFMR 24V
24 VAC
COM
3
6
9
1
4
7
XFMR LINE
G
DEHUMIDIFICATION−
HARMONY LINK
(JUMPERS R to DS)
HEAT PUMP LINK
(JUMPERS R to O)
2−STAGE
COMPRESSOR LINK
(JUMPERS Y1 to Y2)
ON−BOARD LINK
OPTION SELECTION
1
CBA38MV, CBX32MV &
CBX40UHV
JUMPER & LINK GUIDE
−CUT ON−BOARD LINK (SOLDER TRACE) COMPLETELY
THROUGH BOTH LAYERS ON THE CONTROL BOARD
1
COOLING BLOWER RAMPING
DELAY PROFILE #3
OFF−82%−100%−OFF
DELAY PROFILE #2
HP: OFF−30sOFF−100%−100% OFF
DELAY PROFILE #1
OFF−100%−OFF
DELAYPROFILE #4
OFF−50%−82%−100%−50%−OFF
*
(COOLING MODE UNLESS NOTED)
1234
1234
1234
1234
*
HUMIDIFICATION MODE
SMART MODE
− ”H” ENABLED WHEN
HEAT ACTIVE
(HP or ELECT. HT)
AUTO MODE
− ”H” ENABLED WHEN
BLOWER ACTIVE
& NO CLG
OR DEHUM
HUMIDIFICATION MODE
24VAC OUTPUT ON ”H”
FOR HUMIDIFIER OR
ACCESSORY INTERLOCK
SMARTAUTO
SMART
AUTO
FACTORY DEFAULT SETTING
*
COOLING MODE
BLOWER SPEED
HIGH
SPEED
MEDIUM−LOW
SPEED
LOW
SPEED
1234
MEDIUM−HIGH
SPEED
*
1234
1234
1234
(COOLING & HP MODE)
STANDARD
HEAT MODE
(STAGED BY TSTAT)
STANDARD HEAT MODE
(DEFAULT)
85
110
115
130
HEATING MODE
BLOWER SPEED
*
(ELECTRIC HT MODE)
1234
1234
1234
1234
LOW
SPEED
MEDIUM−LOW
SPEED
MEDIUM−HIGH
SPEED
HIGH
SPEED
NORM
+−
NORM
+−
NORM
+−
BLOWER
ADJUST SELECTION
NORMAL
(+ 10%)
SETTING
(−10%)
SETTING
*
*
EVENHEATER

MODE
85
DEGREE TARGET
DISCHARGE
TEMPERATURE
100
DEGREE
TARGET
115
DEGREE
TARGET
130
DEGREE
TARGET
85
110
115
130
−ENABLED WITH OPTIONAL
DISCHARGE AIR SENSOR
85
110
115
130
85
110
115
130
85
110
115
130
PUSH
BUTTON
HIGH
SPEED
(100%)
MEDIUM−HIGH
SPEED
(70%)
LOW
SPEED
(28%)
*MEDIUM−LOW
SPEED
(38%)
1234
1234
1234
1234
CONTINUOUS FAN
BLOWER SPEED
IMPORTANT: USE CARE WHEN CUTTING LINKS TO
PREVENT DAMAGE TO CONTROL.
2
5
8
P8
L1
L2
L2 L1 INDOOR
BLOWER
POWER
EARTH
INDOOR BLOWER
SIGNAL
45 6
12 3
A92
INTEGRATED
CONTROL
OUTDOOR UNIT
LINK
I +I−
I +I−RC
I +I−RC
THERMOSTAT
HUMIDITROL
DH
DISCHARGE
AIR SENSOR
HARMONY
R−DS
DEHUM
or
NO HARMONY ZONING
OR NO
COMFORTSENSE 7000
W/ DS CONNECTION
DO NOT CUT
HARMONY ZONING
OR
C0MFORTSENSE 7000
W/ DS CONNECTION
CUT LINK
HARMONY
R−DS
DEHUM
or
HARMONY
1
A/C UNIT HEAT PUMP UNIT
R−0
HEAT
PUMP
R−0
HEAT
PUMP
1
DO NOT CUT CUT LINK
2 STAGE
COMPR
1−STG COMPRESSOR 2−STG COMPRESSOR
Y1−Y2
1
DO NOT CUT CUT LINK
*
*
*
2 STAGE
COMPR
Y1−Y2
AC: FF−100%−100%−OFF
SINGLE
CHARACTER
DISPLAY
(Non-Communicating)
Figure 3. Air Handler Conguration (Non-Communicating)

Page 5
Field Control Wiring
Figure 4. CBA38MV, CBX32 and CBX40 Air Handler Unit Typical Wiring Diagram

Page 6
SENSOR
(CENTER SIDE-T0 -SIDE)
9-PIN
CONNECTOR
SECURING
SCREWS
AIR HANDLER
CONTROL
AIR HANDLER CONTROL
L-BRACKET MOUNTING PLATE
19 IN.
(483 MM)
5-1/2 IN.
(140 MM)
9-PIN CONNECTOR
ELECTRIC HEAT RELAY
PART NO. 49W91
22V DIRECT CURRENT COIL
30 AMP CONTACT RATING
FASTEN THE PROBE
BRACKET TO THE
PLENUM WITH TWO
SELF-TAPPING SHEET
METAL SCREWS.
CONNECT WIRES TO DISCHARGE AIR SENSOR
TERMINAL ON AIR HANDLER CONTROL.
PLENUM
AIR HANDLER CONTROL
DISCHARGE SENSOR
(DAT)
TEMPRESISTANCE
ºF (OHMS)
30 34,566
40 26,106
50 19,904
60 15,313
70 11,884
80 9,298
90 7,332
100 5,826
DETAIL A
NOTE — EVENHEAT MODE CANNOT BE ENABLED WITH HARMONY III DUE
TO EACH CONTROL REQUIRING ITS OWN DISCHARGE AIR SENSOR.
THE AIR HANDLER CONTROL (AHC) HAS TWO
SCREW TERMINALS MARKED DISCHARGE AIR
SENSOR. THE SENSOR IS REQUIRED FOR
EVENHEAT OPERATION, IS FIELD-MOUNTED
AND MUST BE ORDERED SEPARATELY
(CATALOG # 88K38).
DETAIL B
TEMPERATURE RESISTANCE
CHART
NOTE - Due to varying duct designs
and airflow conditions, relocation of the
discharge sensor may be required to
insure accurate sensing.
NOTE — REFER TO TABLE 1 FOR 6-PIN CONNECTOR
DESIGNATIONS.
Figure 5. Component Connections

Page 7
control And sensor connection requirements
The following are sensor connections and wiring require-
ments for the discharge air and outdoor air sensors.
dischArge sensor (dAt)
The air handler control has two screw terminals marked
Discharge Air Sensor. The sensor is REQUIRED for
EVENHEAT operation and is eld mounted and ordered
separately using Lennox Catalog # 88K38.
outdoor Air sensor (oAs)
This is a two screw terminal for connection to a Lennox
X2658 outdoor temperature sensor.
indoor Blower signAl 6-pin connector (p7)
This is the connection between the air handler control and
the B3 Indoor Blower Motor.
Table 1. . Indoor Blower Signal (P7)
Position Function / Description
1 TX
2 C
3 Not used
4 RX
5 +V
6 Not used
Air hAndler control 9-pin connector (p8)
1. Air Handler (no electric heat) – Two wire factory harness
(wired to pins 7 and 8) which provides 230 VAC power
to air handler control.
2. Air Handler (with electric heat) – Eight wire factory
harness (all pin position are wired as noted in table 2).
NOTE – See gure 4, Detail B for wire colors.
Table 2. . Electric Heat Connection (P8)
Position Function / Description
1 Heat stage 1 relay coil
2 Heat stage 2 relay coil
3 Relay coil return
4 Heat stage 3 relay coil
5 Heat stage 4 relay coil
6 Heat stage 5 relay coil
7 L1 230VAC supply from heater kit
8 L2 230VAC supply from heater kit
9 Not used
This section provides information on communicating and
non-communicating control connections and wire run
lengths.
Table 3. . Air Handler Control Connections –
Communicating
Item Label Function
Thermostat
R24VAC
i+ RSbus data high connection
i- RSbus data low connection
C24VAC command (ground)
Outdoor Unit
R24VAC
i+ RSbus data high connection
i- RSbus data low connection
C24VAC command (ground)
Table 4. . Air Handler Control Connections –
Non-Communicating
Label Function
W1 First-stage heating demand
W2 Second-stage heating demand. W1 input
must be active to recognize second stage
heat demand.
W3 Third-stage heating demand. W1 and W2 in-
puts must be active to recognize third stage
heat demand.
GIndoor blower demand
Y1 and
Y2
First- and second-stage cooling demands
C24VAC common
R24VAC power
DH 24VAC output for dehumidication for com-
municating systems.
H24VAC output for humidication
OReversing valve demand. (Energized by
thermostat in cooling mode.)
DS Blower speed control input for non-com-
municating Harmony zoning or thermostat
dehumidication control.
WARNING
Electric Shock Hazard. Can cause injury or
death. Unit must be properly grounded in
accordance with national and local codes.
Line voltage is present at all components
when unit is not in operation on units with
single-pole contactors. Disconnect all remote
electric power supplies before opening
access panel. Unit may have multiple power
supplies.

Page 8
Air Handler Control Button and Display
IMPORTANT
Before changing any clippable links or jumper settings,
make sure the motor has completely stopped. Any
changes will not take place while the motor is running.
push Button
An on-board push button is provided for the purpose of
placing the air handler control in different operation modes
and can be used to recall stored error codes. When button
is pushed and held, air handler control will cycle through
a menu of options depending on current operating mode.
Every three seconds a new menu item will be displayed.
If the button is released while that item is shown on the
display, air handler control will enter displayed operating
mode, or execute dened operation sequence for that
menu option. Once all items on menu have been dis-
played the menu resumes from the beginning (if button
is still held).
seven-segment displAy
Table 5. AHC Single-Character Display
AHC Single-
Character
Display
Action
Letter or Number Unit size code (number or letter)
displayed represents air handler model
size and capacity. See Conguring Unit
Size Codes in gure 6.
≡If three horizontal bars are displayed,
board does not recognize air handler
model size and capacity. See
Conguring Unit Size Codes in gure 6.
•Idle mode (decimal point / no unit
operation)
ARequested CFM. Example: A 1200
CStage Cooling (shows active cooling
stages) C1 or C2
dDehumidication mode (unit in
dehumidication mode only)
d f Shown only while in active defrost (Y, W
and O call)
HStage heating (shows number of active
electric heat pilot relays) H1 or H2 or H3
hStage heat pump (shows active heat
pump stages) h1 or h2
UDischarge air sensor temperature
(indoor blower must be operating) U105
Table 6. AHC Conguration, Test and Error Recall
(Fault and Lockout) Function
NOTE – AHC MUST BE IN IDLE MODE
Single
Character
LED Display
Action
Solid – Push and hold button until solid appears,
release button. Display will blink.
Blinking – Push and hold button until required symbol
displays. H A or P
CONFIGURING ELECTRIC HEAT SECTIONS
Solid H
Release push button - control will cycle the
indoor blower motor on to the selected heat
speed and stage the electric heat relays on
and off to automatically detect number of
electric heat sections. AHC has the ability to
detect the number of eld-installed electric
heat stages present in application. Detection
is utilized by sensing current through
external relay coils controlling heat stages.
Control will store the number of electric
heat sections. Control will automatically exit
current active mode
INDOOR BLOWER TEST
Solid A
Release push button - control cycles
indoor blower on for ten seconds at 70%
of maximum air for selected capacity size
unit. Control will automatically exit current
active mode.
CONFIGURING UNIT SIZE CODES
Single
Character
LED Display
Action
Solid P
RELEASE push button - This mode allows
the eld to select a unit size code (number
or letter) that matches the air handler model
size and capacity.
IMPORTANT — All eld replacement
controls MUST be manually congured
to conrm air handler model size and
capacity.
Blinking P
1. When the correct Unit Size Code is
displayed, RELEASE push button.
Selected code will ash for 10 second
period.
2. During ten second period, HOLD push
button until code stops blinking (three
seconds minimum).
3. Air handler control will store code in
memory and exit current active mode. LED
display will go blank and then the Unit Size
Code will display for 2 to 5 seconds.
NOTE: If ten second period expires, or push
button is held less than 3 seconds,
control will automatically exit current
active mode and go into IDLE Mode
without storing unit size code. If this
occurs, then Unit Size Code conguring
procedure must be repeated.

Page 9
Table 7. Seven-Segment Status Display
Operation Description
Idle Mode:
Decimal point blinks at 1 Hz Decimal point blinks at 1 Hz (0.5 second on, 0.5 second off). Display OFF.
Soft Disabled
Top & Bottom horizontal line and decimal point blink at 1
Hz
Top & Bottom horizontal line and decimal point blink at 1 Hz (0.5 second on, 0.5 sec-
ond off). See additional information below this table.
OEM Test Mode All segments ashing at 2 Hz (unless error is detected)
Electrical Heating stage
Shows number of currently active electric heat pilot relays.
Following string is repeated if one stage Heat is active with 850 CFM:
H 1 pause A 8 5 0 pause
Cooling Stage
Shows what stage of cooling is currently operating.
Following string is repeated if second stage cooling is active with 1235 CFM:
C 2 pause A 1 2 3 5 pause
Heat Pump Stage
Shows what stage of heat pump is currently operating.
Following string is repeated if rst stage heat pump is active with 925 CFM and no
Electrical Heat:
h 1 pause H 0 pause A 9 2 5 pause
Heat pump & electrical heating stage
Shows current heat pump operating stage and number of
active electric heat pilot relays.
Following string is repeated if one stage electrical heat and second stage heat pump is
active with 600 CFM:
h 1 pause H 1 pause A 1 6 5 0 pause
Defrost Mode
Shown only while in an active defrost. (Simultaneous Y, W,
and O)
Following string is repeated if defrost is active with two electrical heat stages active
and 975 CFM:
d f pause H 2 pause A 9 7 5 pause
Dehumidication mode
Shows that the unit is providing dehumidication in
stead of straight cooling.
Following string is repeated if dehumidication is active with 685 CFM:
d pause A 6 8 5 pause
Indoor Blower only (G demand)
Shows the current CFM delivery of the main blower in
actual CFM.
If indoor blower is providing 1600 CFM: following string is repeated:
A 1 6 0 0 pause
Diagnostic recall
Shows the last 10 stored diagnostic error codes. Initiated
by a 2-second button press. Button press interrupts the
current display pattern. After all codes are displayed,
current display status will resume operation.
If rst error is 250, second 231:
E pause 2 5 0 pause E pause 2 3 1
Next codes (up to 10) are show using same method.
If there is no error codes stored:
E pause 0 0 0
Fault Memory clear
After the fault memory is cleared following string is displayed with 0.5 seconds charac-
ter on/off time:
0 0 0 0 pause
Active Error in AHC Idle mode
Shown all active error(s) codes
Following string is repeated if Error E125 and E201 are present:
E1 2 5 pause E 2 0 1
Active Error in Run Mode
Shown current status and all active error(s) codes
Following string is repeated if Error E311 is present while blower aped at 880CFM:
A 8 8 0 pause E 3 1 1
Discharge Air Temperature Sensor (DATS)
Any time DAT is sensed in operating range value is dis-
played if indoor blower is running.
Following string is repeated if three stage el. heat is active with 850 CFM & DAT is
104° F:
H 3 pause A 8 5 0 pause U 1 0 4 pause
Soft Disable
Steps to follow if the damper control module is displaying the soft disable code:
1. Conrm proper wiring between all devices (Thermostat, damper control module,
indoor and outdoor)
2. Cycle power to the control that is displaying the soft disable code.
3. Put the room thermostat through Set Up.
4. Go to setup / system devices / thermostat / edit / push reset.
5. Go to setup / system devices / thermostat / edit / push resetAll.

Page 10
Table 8. AHC Conguration, Test and Error Recall (Fault and Lockout) Function
ERROR CODE RECALL MODE (NOTE — CONTROL MUST BE IN IDLE MODE)
Solid ETo enter Error Code Recall function — PUSH and HOLD button until solid E appears, then RELEASE button. Control will
display up to ten error codes stored in memory. If E000 is displayed, there are no stored error codes.
Solid
_
_
_
To exit Error Code Recall function — PUSH and HOLD button until solid three horizontal bars appear, then
RELEASE button.
NOTE - Error codes are not cleared
Solid cTo clear error codes stored in memory, continue to HOLD push button while the three horizontal bars are displayed.
Release push button when solid c is displayed. Display will blink.
Blinking cPush button to conrm command to delete codes. Error codes are cleared.
Table 9. AHC Single Character Display — Error Codes (Communicating and Non-Communicating)
Error Codes Status of Air Handler
E 105 Device communication problem - No other devices on BUS (Communication system).
E 114 No 60 hertz power (Check voltage and frequency)
E 115 Low 24 volts (18 or less volts) - Control will restart if the error recovers.
E 120
Unresponsive Device2 - Indicates a device on the RSbus is not responding to a message sent to it by another device. Error code
is applicable to all communicating devices on the RSbus (thermostat, indoor and outdoor units). Normally indicates a malfunc-
tioning device.
E 12Y
Active Subnet Controller Missing for > 180 seconds. This indicates a data connection has been lost between a communicating
device and the communicating thermostat. Device (indoor or outdoor unit) sends the alarm if no communication is established be
tween device and thermostat within three minutes.
E 130 Conguration jumper(s) is missing on board.
E 131 Non-volatile data corruption.
E 132 Internal hardware failure.
E 1B0 Outdoor air temperature sensor (OAS) out of range.
E 201 Indoor Blower communication failure - (includes indoor blower power outage)
E 202 Incorrect air handler model size and capacity selected or wrong motor. Check for proper conguring under Conguring Unit Size
Codes.
E 203 No air handler model size and capacity selected. Check for proper conguring under Conguring Unit Size Codes.
E 292 Indoor blower motor unable to start (seized bearing, stuck wheel, etc.).
E 295 Indoor blower motor over temperature (motor trip on internal protector)
E 310 Discharge air temperature sensor (DATS) out of range.
E 312 Restricted airow — Indoor blower motor is running at a reduced CFM (cutback mode **)
E 313 Indoor and outdoor unit capacity mismatch.
E 331 Global network connection error. This usually indicates there is a short or overladed resistance is too low condition between
thermostat and indoor or outdoor units.
E 345 Jumper for second-stage cooling not removed.
E 346 Jumper for heat pump operation not removed.
E 347 Relay Y1 failure.

Page 11
Table 9. AHC Single Character Display — Error Codes (Communicating and Non-Communicating)
Error Codes Status of Air Handler
E 3Y8 Relay Y2 failure.
E 350 Heat call with non-congured or mis-congured electric heat. Check for proper conguring under Conguring Electric Heat Stag-
es.
E 351 Heat section / Stage 1 failed (Pilot relay contacts did not close or the relay coil in electric heat did not energize)
E 352 Heat section / Stage 2 failed.
E 353 Heat section / Stage 3 failed.
E 354 Heat section / Stage 4 failed.
E 355 Heat section / Stage 5 failed.
Error codes 401 through 409 are only displayed when the Control’s L terminal is connected to a non-communicating outdoor unit’s LSOM
device.
E 401 Compressor ran more than 18 hours in air conditioning mode.
E 402 Compressor system pressure trip.
E 403 Compressor short-cycling - running less than four minutes.
E 404 Compressor rotor locked.
E 405 Compressor open circuit.
E 406 Compressor open start circuit.
E 407 Compressor open run circuit.
E 408 Compressor contactor is welded.
E 409 Compressor low voltage.
E 420 Defrost cycle lasts longer than 20 minutes. Check heat pump operation. Cleared when W1 signal is removed. Applicable only in
communicating mode with non-communicating heat pump.
** Cutback Mode — The variable speed motor has pre-set speed and torque limiters to protect the motor from damage caused by operating out of
its designed parameters (0 through 0.80 in. w.g. total external static pressure).
Air Handler Jumpers
Jumpers are used for non-communicating mode only. Use
gure 2 as reference for jumper settings. If any of the ref-
erence jumpers are missing, the air handler control will
display Error code 130 and the air handler control will au-
tomatically use the factory default setting.
1. Humidication – Controls the status of Hterminal on
the thermostat block. Congurations are as follows:
• If jumper is installed in SMART Humidication posi-
tion (Default), Hterminal is active if heat demand is
present and indoor blower is running.
• If jumper is installed in AUTO Humidication posi-
tion, Hterminal is energized whenever indoor blow-
er is running.
2. EvenHeat – Target Discharge Air Temperature
selection is used to set discharge air temperatures for
EvenHeat operation.
NOTE - Optional Discharge Air Temperature Sensor, Len-
nox Catalog # 88K38 is REQUIRED for EVENHEAT oper-
ation and must be ordered separately.
1. Blower Only CFM – Used to select Indoor blower CFM
for continuous operation.
2. Heat – Used to select Indoor blower CFM for electric
heat by placing the jumper in proper position. Actual
CFM values for different air handler sizes are shown in
Targeted CFM Tables.
3. Cool – Used to select cooling indoor blower CFM
by placing the jumper in proper position. Actual CFM
values for different air handler sizes are shown in
Targeted CFM Tables starting.

Page 12
4. Adjust - Used to select the indoor blower CFM
adjustment value by placing the jumper in appropriate
position.
• If NORM is selected, indoor blower runs at normal
speeds.
• If +is selected, indoor blower runs at approximately
10% higher speed than NORM setting.
• If –is selected, indoor blower runs at approximately
10% lower speed than NORM setting.
• If the jumper is missing, the air handler control will
activate the Conguration Jumper is Missing alarm
and will automatically use the default factory setting.
Actual CFM values for different air handler sizes are
shown in Targeted CFM Tables.
• Delay – Indoor blower cooling prole, delay for cool-
ing and heat pump operations.
• When operating a heat pump, delay proles 1 and 2
are only applicable.
• When operating a heat pump, and proles 3 and 4
are selected, the air handler control will default to
prole 1.
If the jumper is missing, the air handler control will activate
the Conguration Jumper is Missing alarm and will auto-
matically use the default factory setting.
delAy proFile 1
A - When cool or heat demand is initiated, motor ramps
up to 100% and runs at 100% until demand is
satised.
B - Once demand is met, motor ramps down to stop.
A
B
OFFOFF
100%
CFM
COMPRESSOR
DEMAND
delAy proFile 2
Cooling – Air Conditioner and Heat Pump:
A
BC
OFF
F
OFF 100% CFM 100% CFM
45 SEC.
COMPRESSOR
DEMAND
A - When cool demand is initiated, motor ramps up to
100% and runs at 100% until demand is satised.
B - Once demand is met, motor runs at 100% for 45
seconds.
C - C Motor ramps down to stop.
Heating – Heat Pump only:
OFF
OFF 100% CFM 100% CFM
HEATING DEMAND
45 SEC.
30 sec
delay
AB
CD
A - When heat demand is initiated, 30 seconds motor-on
delay starts
B - After the motor-on delay expires, motor ramps up to
100% and runs at 100% until demand is satised.
C - Once demand is met, motor runs at 100% for 45
seconds.
D - Motor ramps down to stop.
delAy proFile 3
OF
F
OFF 82%CFM 100% CFM
COOLING DEMAND
7 1/2 MIN
A
B
C
A - When cool demand is initiated, motor ramps up to
82%
B - Motor runs at 82% for approximately 7.5 minutes
and then ramps up to 100% (unless the demand has
been satised) and motor runs at 100% until demand
is satised.
C - Once demand is met, motor ramps down to stop
delAy proFile 4
OFF
OFF
1/2 MIN
50% CFM
COOLING DEMAND
7 1/2 MIN
82% CFM
100%
CFM 1/2 MIN
50% CFM
B
A
C
DE
A - When cool demand is initiated, motor ramps up to
50%
B - Motor runs at 50% for 30 seconds and ramps up to
82%
C - Motor runs at 82% for approximately 7.5 minutes
and then ramps up to 100% (unless the demand has
been satised) and motor runs at 100% until demand
is satised.
D - Once demand is met, motor runs at 50% for 30
seconds.
E - Motor ramps down to stop
seven-segment displAy
An on-board single character display (see gure 2 for dis-
play location) indicates general system status information
such as mode of operation, indoor blower CFM and error
codes. Multi-character strings are displayed with character
ON for one second, OFF for 0.5 seconds and one second
pause between the character groups.

Page 13
Target CFM Tables
CBX32MV-018/024 BLOWER PERFORMANCE
0 through 0.80 in. w.g. External Static Pressure Range
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed “COOL” Speed
1 2 3 4 1 2 3 4
cfm cfm cfm cfm cfm cfm cfm cfm
[phone] 465 690 900 1050
NORM 670 770 900 1035 425 620 825 950
–580 700 800 930 385 560 735 850
NOTES - The effect of static pressure, lter and electric heater resistance is included in the air volumes listed.
First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the
same second-stage COOL speed selected, minimum 250 cfm.
Lennox iHarmony®Zoning System applications - minimum blower speed is 250 cfm.
CBX32MV-024/030 BLOWER PERFORMANCE
0 through 0.80 in. w.g. External Static Pressure Range
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed “COOL” Speed
1 2 3 4 1 2 3 4
cfm cfm cfm cfm cfm cfm cfm cfm
[phone] 660 880 1100 1320
NORM 725 850 975 1100 600 800 1000 1200
–655 765 880 990 540 720 900 1080
NOTES - The effect of static pressure, lter and electric heater resistance is included in the air volumes listed.
First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the
same second-stage COOL speed selected, minimum 250 cfm.
Lennox iHarmony®Zoning System applications - minimum blower speed is 250 cfm.
CBX32MV-036 BLOWER PERFORMANCE
0 through 0.80 in. w.g. External Static Pressure Range
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed “COOL” Speed
1 2 3 4 1 2 3 4
cfm cfm cfm cfm cfm cfm cfm cfm
[phone] 1545 900 1225 1380 1545
NORM 1120 1215 1315 1400 810 1125 1275 1400
–1010 1185 1200 1265 730 1000 1135 1265
NOTES - The effect of static pressure, lter and electric heater resistance is included in the air volumes listed.
First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the
same second-stage COOL speed selected, minimum 250 cfm.
Lennox iHarmony®Zoning System applications - minimum blower speed is 250 cfm.
CBX32MV-048 and cbx32MV-060 BLOWER PERFORMANCE
0 through 0.80 in. w.g. External Static Pressure Range
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed “COOL” Speed
1 2 3 4 1 2 3 4
cfm cfm cfm cfm cfm cfm cfm cfm
+1850 1960 2090 2150 1625 1820 2055 2145
NORM 1705 1800 1900 2005 1425 1625 1805 2005
–1560 1625 1720 1770 1205 1375 1555 1725
NOTES - The effect of static pressure, lter and electric heater resistance is included in the air volumes listed.
First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the
same second-stage COOL speed selected, minimum 450 cfm.
Lennox iHarmony®Zoning System applications - minimum blower speed is 450 cfm.

Page 14
CBX32MV-068 BLOWER PERFORMANCE
0 through 0.80 in. w.g. External Static Pressure Range
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed “COOL” Speed
1 2 3 4 1 2 3 4
cfm cfm cfm cfm cfm cfm cfm cfm
+1875 1975 2090 2150 1640 1840 2075 2150
NORM 1760 1825 1920 2030 1465 1625 1800 2000
–1550 1650 1725 1800 1250 1390 1560 1720
NOTES - The effect of static pressure, lter and electric heater resistance is included in the air volumes listed.
First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the
same second-stage COOL speed selected, minimum 450 cfm.
Lennox iHarmony®Zoning System applications - minimum blower speed is 450 cfm.
CBX40UHV-024 BLOWER PERFORMANCE
0 through 0.80 in. w.g. External Static Pressure Range
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed “COOL” Speed
1 2 3 4 1 2 3 4
cfm cfm cfm cfm cfm cfm cfm cfm
[phone] 465 690 900 1050
NORM 670 770 900 1035 425 620 825 950
–580 700 800 930 385 560 735 850
NOTES - The effect of static pressure, lter and electric heater resistance is included in the air volumes listed.
First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the
same second-stage COOL speed selected, minimum 250 cfm.
Lennox iHarmony®Zoning System applications - minimum blower speed is 250 cfm.
CBX40UHV-030 BLOWER PERFORMANCE
0 through 0.80 in. w.g. External Static Pressure Range
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed “COOL” Speed
1 2 3 4 1 2 3 4
cfm cfm cfm cfm cfm cfm cfm cfm
[phone] 660 880 1100 1320
NORM 725 850 975 1100 600 800 1000 1200
–655 765 880 990 540 720 900 1080
NOTES - The effect of static pressure, lter and electric heater resistance is included in the air volumes listed.
First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the
same second-stage COOL speed selected, minimum 250 cfm.
Lennox iHarmony®Zoning System applications - minimum blower speed is 250 cfm.

Page 15
CBX40UHV-036 BLOWER PERFORMANCE
0 through 0.80 in. w.g. External Static Pressure Range
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed “COOL” Speed
1 2341234
cfm cfm cfm cfm cfm cfm cfm cfm
[phone] 1545 900 1225 1380 1545
NORM 1120 1215 1315 1400 810 1125 1275 1400
–1010 1185 1200 1265 730 1000 1135 1265
NOTES - The effect of static pressure, lter and electric heater resistance is included in the air volumes listed.
First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the
same second-stage COOL speed selected, minimum 380 cfm.
Lennox iHarmony®Zoning System applications - minimum blower speed is 380 cfm.
CBX40UHV-042 BLOWER PERFORMANCE
0 through 0.80 in. w.g. External Static Pressure Range
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed “COOL” Speed
1 2341234
cfm cfm cfm cfm cfm cfm cfm cfm
[phone] 1760 1100 1320 1540 1760
NORM 1000 1200 1400 1600 1000 1200 1400 1600
–900 1080 1260 1440 900 1080 1260 1440
NOTES - The effect of static pressure, lter and electric heater resistance is included in the air volumes listed.
First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the
same second-stage COOL speed selected, minimum 450 cfm.
Lennox iHarmony®Zoning System applications - minimum blower speed is 450 cfm.
CBX40UHV-048 AND CBX40UHV-060 BLOWER PERFORMANCE
0 through 0.80 in. w.g. External Static Pressure Range
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed “COOL” Speed
1 2341234
cfm cfm cfm cfm cfm cfm cfm cfm
+1850 1960 2090 2150 1625 1820 2055 2145
NORM 1705 1800 1900 2005 1425 1625 1805 2005
–1560 1625 1720 1770 1205 1375 1555 1725
NOTES - The effect of static pressure, lter and electric heater resistance is included in the air volumes listed.
First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the
same second-stage COOL speed selected, minimum 450 cfm.
Lennox iHarmony®Zoning System applications - minimum blower speed is 450 cfm.
CBA38MV-018/024 BLOWER PERFORMANCE
0 through 0.80 in. w.g. External Static Pressure Range
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed “COOL” Speed
1 2 3 4 1 2 3 4
cfm cfm cfm cfm cfm cfm cfm cfm
[phone] 465 690 900 1050
NORM 425 620 825 950 425 620 825 950
–385 560 735 850 385 560 735 850
NOTES - The effect of static pressure, lter and electric heater resistance is included in the air volumes listed.
First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the
same second-stage COOL speed selected, minimum 250 cfm.
Lennox iHarmony®Zoning System applications - minimum blower speed is 250 cfm.

Page 16
CBA38MV-030 BLOWER PERFORMANCE
0 through 0.80 in. w.g. External Static Pressure Range
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed “COOL” Speed
1 2 3 4 1 2 3 4
cfm cfm cfm cfm cfm cfm cfm cfm
[phone] 660 880 1100 1320
NORM 600 800 1000 1200 600 800 1000 1200
–540 720 900 1080 540 720 900 1080
NOTES - The effect of static pressure, lter and electric heater resistance is included in the air volumes listed.
First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the
same second-stage COOL speed selected, minimum 250 cfm.
Lennox iHarmony®Zoning System applications - minimum blower speed is 250 cfm.
CBA38MV-036 BLOWER PERFORMANCE
0 through 0.80 in. w.g. External Static Pressure Range
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed “COOL” Speed
1 2 3 4 1 2 3 4
cfm cfm cfm cfm cfm cfm cfm cfm
[phone] 900 1225 1380 1545
NORM 810 1125 1275 1400 810 1125 1275 1400
–730 1000 1135 1265 730 1000 1135 1265
NOTES - The effect of static pressure, lter and electric heater resistance is included in the air volumes listed.
First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the
same second-stage COOL speed selected, minimum 250 cfm.
Lennox iHarmony®Zoning System applications - minimum blower speed is 250 cfm.
CBA38MV-042 BLOWER PERFORMANCE
0 through 0.80 in. w.g. External Static Pressure Range
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed “COOL” Speed
1 2 3 4 1 2 3 4
cfm cfm cfm cfm cfm cfm cfm cfm
[phone] 1760 1100 1320 1540 1760
NORM 1000 1200 1400 1600 1000 1200 1400 1600
–900 1080 1260 1440 900 1080 1260 1440
NOTES - The effect of static pressure, lter and electric heater resistance is included in the air volumes listed.
First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the
same second-stage COOL speed selected, minimum 450 cfm.
Lennox iHarmony®Zoning System applications - minimum blower speed is 450 cfm.
CBA38MV-048 BLOWER PERFORMANCE
0 through 0.80 in. w.g. External Static Pressure Range
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed “COOL” Speed
1 2 3 4 1 2 3 4
cfm cfm cfm cfm cfm cfm cfm cfm
[phone] 2145 1625 1820 2055 2145
NORM 1425 1625 1805 2005 1425 1625 1805 2005
–1205 1375 1555 1725 1205 1375 1555 1725
NOTES - The effect of static pressure, lter and electric heater resistance is included in the air volumes listed.
First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the
same second-stage COOL speed selected, minimum 450 cfm.
Lennox iHarmony®Zoning System applications - minimum blower speed is 450 cfm.

Page 17
CBA38MV-060 BLOWER PERFORMANCE
0 through 0.80 in. w.g. External Static Pressure Range
“ADJUST”
Jumper
Setting
Jumper Speed Positions
“HEAT” Speed “COOL” Speed
1 2 3 4 1 2 3 4
cfm cfm cfm cfm cfm cfm cfm cfm
[phone] 2150 1640 1840 2075 2150
NORM 1465 1625 1800 2000 1465 1625 1800 2000
–1250 1390 1560 1720 1250 1390 1560 1720
NOTES - The effect of static pressure, lter and electric heater resistance is included in the air volumes listed.
First stage cooling air volume is 70% of COOL speed setting. Continuous fan speed is approximately 28%, 38%, 70% and 100% (Jumper selectable) of the
same second-stage COOL speed selected, minimum 450 cfm.
Lennox iHarmony®Zoning System applications - minimum blower speed is 450 cfm.
Unit Operating Sequences
This section details unit operating sequence for non-communicating systems. For communicating systems, see the
iComfort®thermostat installation instruction.
Table 10. Air Handler with ComfortSense 7500 Thermostat and Single-Stage Outdoor
Unit Operating Sequence
Operating Sequence System Demand System Response
System
Condition Step
Thermostat Demand Relative Humidity
Comp
Air Han-
dler CFM
(COOL)
Comments
Y1 Y2 O G W1 W2 Status D
NO CALL FOR DEHUMIDIFICATION
Normal
Operation 1 On On On Acceptable 24 VAC High 100%
Compressor and indoor
air handler follow ther-
mostat demand
BASIC MODE (Only active on a Y1 thermostat demand)
Normal
Operation 1 On On On Acceptable 24 VAC High 100% ComfortSense 7500
thermostat energizes Y1
and de-energizes D on a
call for dehumidication.
NOTE: No over cool-
ing.
Dehumidication
Call 2 On On On Demand 0 VAC High 70%
PRECISION MODE (Operates independent of a Y1 thermostat demand)
Normal
Operation 1 On On On Acceptable 24 VAC High 100% Dehumidication mode
begins when humidity is
greater than set point
Dehumidication
call 2 On On On Demand 0 VAC High 70%
Dehumidication
call ONLY 1 On On On Demand 0 VAC High 70%
ComfortSense 7500
will keep outdoor unit
energized after cooling
temperature setpoint has
been reach in order to
maintain room humidity
setpoint.
NOTE: Allow to over
cool 20F from
cooling set
point.

Page 18
Table 11. Air Handler with ComfortSense 7500 Thermostat and Two-Stage
Outdoor Unit Operating Sequence
Operating Sequence System Demand System Response
System
Condition Step
Thermostat Demand Relative Humidity
Compressor
Air
Handler
CFM
(COOL)
Comments
Y1 Y2 O G W1 W2 Status D
No Call for Dehumidication
Normal
Operation
- Y1
1 On On On Acceptable 24 VAC Low 70% Compressor and indoor air
handler follow thermostat
demand
Normal
Operation
- Y2
2 On On On On Acceptable 24 VAC High 100%
Room Thermostat Calls for First-Stage Cooling
BASIC MODE (Only active on a Y1 thermostat demand)
Normal
Operation 1 On On On Acceptable 24 VAC Low 70% ComfortSense 7500 thermostat energizes Y2 and
de-energizes D on a call for
dehumidication
NOTE: No over cooling.
Dehumidication
Call 2 On On On On Demand 0 VAC High 70%
PRECISION MODE (Operates independent of a Y1 thermostat demand)
Normal
Operation 1 On On On Acceptable 24 VAC Low 70% Dehumidication mode begins
when humidity is greater than
set point
Dehumidication
call 2 On On On On Demand 0 VAC High 70%
Dehumidication
call ONLY 1 On On On On Demand 0 VAC High 70%
ComfortSense 7500
thermostat will keep outdoor
unit energized after cooling
temperature setpoint has been
reached in order to maintain
room humidity setpoint.
NOTE: Allow to over cool
20F from cooling set
point.
Room Thermostat Calls for First- and Second-Stage Cooling
BASIC MODE (Only active on a Y1 thermostat demand)
Normal
Operation 1 On On On On Acceptable 24 VAC High 100% ComfortSense 7500 thermostat energizes Y2 and
de-energizes D on a call for
dehumidication
NOTE: No over cooling.
Dehumidication
Call 2 On On On On Demand 0 VAC High 70%
PRECISION MODE (Operates independent of a Y1 thermostat demand)
Normal
Operation 1 On On On On Acceptable 24 VAC High 100% Dehumidication mode begins
when humidity is greater than
set point
Dehumidication
call 2 On On On On Demand 0 VAC High 70%
Dehumidication
call ONLY 1 On On On On Demand 0 VAC High 70%
ComfortSense 7500
thermostat will keep outdoor
unit energized after cooling
temperature setpoint has been
reached in order to maintain
room humidity setpoint.
NOTE: Allow to over cool
20°F from cooling set
point.

Page 19
Conguring Unit
This section identies the requirements for conguring the air handler in non-communicating mode for unit size, heat mode
selection and EvenHeat. For communicating conguration see the iComfort®installation instruction.
checkout
Air Handler
Control Checkout
Power-up- Unit Size Code (Number or letter) displayed
represents unit size code (air handler model size and capacity).
If three horizontal bars displays, air handler control (AHC) does
not recognize unit size code (air handler model size and
capacity).
AHC
recognizes
Unit Size
Code?
Electric
heat
Installed?
Finished
Which Heat
Mode?
Refer to EVENHEAT operation flow diagram, air handler or
ECB40 Electric Heat installation instructions.
W1 Call?
Ye sNo
Ye s
Standard EVENHEAT
Refer to Heat Pump or Cooling
Sequence of Operation flow
diagrams, Air Handler or ECB40
Electric Heat installation
instructions.
A call for electric heating first, second or third stage is
initiated when 24 VAC (R) is detected on W1, W2 and
W3 inputs on AHC. (Factory mounted metal jumpers
connect W1 to W2 and W2 to W3.)
At the completion of each heat section demand (W1,
W2, and W3), the control board will immediately
de-energize the corresponding pilot relay(s).
At the completion of all heating demands, the indoor
blower will run for an additional 10 seconds before
de-energizing.
No
Ye s
NOTE - If the call for lower heat section is removed,
AHC will automatically de-energize higher heat
sections.
Indoor blower will immediately start to delivery CFM as
set by heating mode jumper on board with activation of
first electric heat pilot relay.
22 VDC pilot relays on board are energized one at a
time. There is a minimum of 10 seconds delay between
pilot relay activations.
After all electric heat installations, AHC must be
manually configured to detect number of heat sections.
Refer to Configuring/Detecting electric heat sections
flow diagram, Air Handler or ECB40 Electric Heat
installation
IMPORTANT: Field replacement controls
MUST be manually configured to validate
air handler unit size code.
Refer to Configuring Unit Size Codes flow
diagram, Air Handler or ECB40 Electric Heat
installation instructions.
ONE (H1)
H1
TWO (H1-H2)
H1
H2
H2
THREE
(H1-H3)
H1
H2
H3
FOUR (H1-H4)
H1 AND H2
H3
H4
FIVE (H1-H5)
H1 AND H2
H3 AND H4
H5
T-STAT CALL
W1
W2
W3
NUMBER OF HEAT SECTIONS DETECTED
NOTE - AHC will not recognize higher heat section
demand if lower heat demand is not present.
AIR HANDLER CONTROL (AHC)
PUSH
BUTTON
No (Display
Alarm Code 302)
SINGLE
CHARACTER
DISPLAY
Figure 6. Checkout

Page 20
unit size code
Conguring Unit Size Codes (Model Number)
Power-up — Unit Size Code (number or letter) displayed represents unit size code (air handler model size and capacity).
If three horizontal bars display, then Air Handler Control (AHC) does not recognize unit size code.
AHC in IDLE mode
(No heating, cooling or indoor fan operation)
To enter unit size code
conguration mode ; PUSH and
HOLD button next to single
character LED display until dash
symbol appears, RELEASE button.
Turn room thermostat toOFF. If connected to iComfort control
PUSH and HOLD button until the solid P
symbol is displayed on the single
character LED display, then RELEASE
button. This mode allows the user to
select a unit size code (number or letter)
that matches the air handler model size
and capacity.
Solid dash starts blinking
on single character LED
display.
Solid P starts
blinking on single
character LED
display.
PUSH and HOLD button to allow AHC to display unit size
code (letter or number) for each dierent air handler model
for three seconds.
Ye sNo
IMPORTANT — Field replacement controls may need to be
manually configured to validate air handler unit size code.
AIR HANDLER MODEL
CBX32MV-018/024
CBX32MV-024/030
CBX32MV-036
CBX32MV-048
CBX32MV-060
CBX32MV-068
CBX40UHV-024
CBX40UHV-030
CBX40UHV-036
CBX40UHV-042
CBX40UHV-048
CBX40UHV-060
UNIT SIZE CODE
0
1
2
3
4
5
6
7
8
9
L
U
1. When the correct Unit Size Code is displayed, RELEASE
push button. Selected code will ash for 10 second period.
2. During that 10 second period, HOLD push button until code
stops blinking (three seconds minimum).
3. Air Handler Control will store code in memory and exit current
active mode. LED display will go blank and then the Unit Size
Code will display for 2 to 5 seconds.
NOTE - If 10 second period expires, or push button is held less than
three seconds, control will automatically exit current active mode
and go into IDLE Mode without storing unit size code. If this occurs,
then Unit Size Code conguring procedure must be repeated.
LED displays correct
Unit Size Code .
Unit enters IDLE
Mode .
YES
NO
CBA38MV-018/024
A
CBA38MV-030
C
CBA38MV-036
E
CBA38MV-042
F
CBA38MV-060
Y
CBA38MV-048
H
system, remove R, i+, i- and C wired from the control board.
Figure 7. Congure Unit Size Codes