ICM271
Fan Control
Center
Specifications
• Input Voltage
- Terminals: PR-1, PR-2, L1 and L2................................................120 VAC
- Terminals: SEC-1 and SEC-2....................................................18-30 VAC
• Line Frequency...................................................................................60 Hz
• Operating Temperature......................................................-40ºF to +176ºF
• Maximum Operating Humidity....................................................95% R.H.
Non-condensing @ 50ºC
• Time Delays
- Heat ON................................................................................... 75 Seconds
- Heat OFF............................................................................... 105 Seconds
- Cool OFF................................................................................. 90 Seconds
Pre-Installation Instructions
• Turn off gas supply and electrical power to equipment before servicing
CAUTION!: This device should be installed by a qualified technician
with due regard for safety as improper installation could
result in hazardous conditions.
CAUTION!: Failure to carefully read and follow these instructions
before servicing or operating this control, could result in
personal injury, death and/or property damage.
CAUTION!: Do not short out terminals on the gas valve or the
ignition control module. A short or incorrect wiring will
burn out the thermostat heat anticipator. It could also
result in personal injury, death and/or property damage.
Replacement Description
The ICM271 Fan Control Center is a solid state control designed and
engineered for the replacement market. The ICM271 is designed specifically
to replace the Carrier/BDP Gas Furnace Control Centers that have been
used in new equipment for many years. The ICM271 is a form, fit and
functional replacement of the OEM control requiring no modifications to the
original wiring or to the appliance’s sheet metal.
The ICM271 is a form, fit and functional replacement of the OEM control for
the following Carrier/BDP part numbers:
302075-3
CES0110017
CES0110018
HH84AA010
HH84AA011
HH84AA012
HH84AA013
HH84AA020
P771-7002
2.If the JW1 jumper is cut, a constant low-speed blower will occur without
any thermostat signal. Also, a signal applied to the GC or Y terminals will
not bring on the hi-speed blower during the cooling mode. Therefore, the
JW1 jumper must not be cut on cooling applications.
C1
M1
CR3
CR1
CR2
CR4
LIM-1
LIM-2
G
P4
W3
R7
W5
W4
C8
C8
C8
GAS1
GAS3
W6
6
4.The ICM271 has an easy-to-remove vent damper jumper plug. This
jumper plug is factory assembled for use on applications not having a
vent damper. If the application has a vent damper, remove the jumper
plug and connect the vent damper wiring harness connector to the
ICM271 circuit board.
Vent
Damper
Plug
Connection
The GAS1-to-GAS3 connection is made by a three-wire flame-proof
switch, but in some standing-pilot applications this device is not present. In
such applications, a jumper must be installed between GAS1 and GAS3
terminals.
Vent
Damper
A jumper should only be used on applications where a jumper exists on the
previous furnace fan control board. This jumper should also include a male
1/4” spade connector to connect to your current gas valve’s wiring harness.
GAS2
D2
R25
1
W
R20
R13
R12
R14
R19
C13
R
3 AMP
Note:On the ICM271, a blown fuse will cause the lo-speed blower to
come on and remain on until the fuse has been replaced.
Blower
Option
C9
R16
R18
JW-1
GH
C8
C14
GC
BLOWER OPTION
R24
R17
TEST
R11
C3
R9
R15
R8
W2
P2
P1
C12
Y
SEC-1
SEC-2
C15
R23
R21
R6
R4
U1
C16
R22
Q1
R1
R2
D1
Z1
LO
HI
R10
1
C8
R5
CR5
R3
C2
K2
COIL
NC
FROM-C
NO
C
SPCB-1
PCB500-1
L1
L2
PR-2
COM
C11
EAC-2 EAC-1
C
3.The 24 volt circuit is fuse protected which is not true on earlier Carrier/
BDP models. A 3 amp automotive type fuse is used to protect the
thermostat and transformer circuits from shorts.
C4
CR6
C5
PR-1
C
COIL
NO
C7 C6
K1
CR7
Q2
Blower Relays
C10
Note:Some older Carrier models did not have a cooling fan relay.
1.On older Carrier/BDP models, the low-speed blower would still function
if the 24 volt transformer malfunctions. This will not happen with the
ICM271.
ICM271 Component Layout
1
Operational Differences
The ICM271 has the same features and functions as the current Carrier/
BDP replacement (HH84AA020). The ICM271 has additional optional
features and some slight operational differences than the older obsolete
Carrier/BDP units. These options and operational differences are listed
below.
F1
C
Y
GC
GH
Wall Thermostat
Terminal Block
R
To
Gas
Valve
W
JW-1
ATO 3-amp Fuse
S3
S1
GA
GA
W
Blower Speed Output
• Turn off gas supply and electrical power to equipment before servicing
WARNING!: Troubleshooting should be performed by qualified
technicians only. High voltage is dangerous and can
cause injuries, death or property damage.
CAUTION!: Do not use this option on paired furnace applications.
The ICM271 has different blower speed options to match a specific
application (see chart). The blower speed option used on the original
furnace control may be very difficult to determine.
1.If the old Carrier/BDP unit has (2) black relays just like the ICM271, then
look for the JW1 jumper and R17 resistor on the Carrier/BDP board. They
will be in the same location as the JW1 and R17 on the ICM271. If either
one (JW1 or R17) has been cut, then cut the ICM271 equivalent. This will
match the original Carrier/BDP blower speed option.
Troubleshooting
Symptom
Remedy
Low speed fan runs
continuously
• Verify you have 24 VAC between the R and C terminals
• Verify the high temperature limit switch is not open
• Check fuse to verify it is not blown
• Verify the fusible link is not damaged
• Temporarily bypass limits for troubleshooting only
No power to the
thermostat (between
R and C terminals)
• Verify you have 24 volts between the SEC-1 and SEC-2
terminals
• Verify that the high temperature limit switch is not open
• Check fuse to verify it is not blown
• Verify the fusible link is not damaged
• Make sure the door interlock is bypassed while
troubleshooting
No fan output in cool
mode
• Verify that you have 24 volts between GC and C
• Check fan connections at HI and COM
• Verify high speed fan operates correctly
No fan output in heat
mode
• Verify that you have 24 volts between W and C
• Make sure you have continuity between the GAS1 and
GAS3 terminals
• Check fan connections at LO and COM
• Verify low speed fan operates correctly
Fan cycles on and off
• Transformer may be damaged and creating an irregular
sine wave
• Thermostat output signal may be outputting an irregular
sine wave (especially solid state thermostats)
Blower Operating Modes
Input From
Thermostat
W
ICM271
As Shipped
G Blower Operation
(Cut R17 Resistor)
Lo-Speed Heating Blower with
75 seconds ON Delay and 105 seconds OFF Delay
G
High-speed cooling blower
Lo-speed heating blower
Y
No blower
Hi-speed cooling blower with 90 second OFF delay
Installation Instructions
1.Be sure all electrical power is turned off.
2.Remove control box cover, exposing the old Carrier/BDP gas furnace
control center.
3.If furnace is equipped with a vent damper, disconnect the plug connector
from the old board.
4.Tag each wire as it is disconnected from the old furnace control center.
Disconnect all of the wiring hookups.
Wiring Diagram
5.Remove the old Carrier/BDP furnace control center from the control box.
ITLK
6.Install the ICM271 fan control center into the control center box. Be sure
the top edge of the ICM271 is in the mounting slot, just like the original
board.
MTR
LINE-1
BLWR
HI/LO
Legend:
HI
Note: If the ICM271 is not installed correctly (i.e. behind the slot), an
electrical short could occur.
COM
7.Reconnect all of the wires (removed in Step 4, above) to the proper
terminals.
EAC-1
8.If the appliance had a vent damper, break the vent damper jumper
plug from the ICM271. Connect the original vent damper plug onto the
ICM271.
EAC-2
FL
*BVSS
PR-1
PR-2
115 VAC
TRANS
FUSE
LIM-1
LS
9.Restore electrical power to the furnace and put the furnace into operation.
Allow the furnace to run through one complete heating or cooling cycle.
10.If the furnace is functioning properly, replace all panels and leave this
instruction sheet with the homeowner.
LINE-2
*CAP
LO
24 VAC
SEC-1
SEC-2
*AUXLS
BLWR
LIM-2
R
JW-1
GH
MICROPROCESSOR
HI/LO
W
AUXLS Auxiliary limit switch,
manual reset (SPSTNC)
(Down flow furnace
models only)
BLWR Blower motor relay
(SPST-NO)
BVSS Blocked vent shut-off
switch, manual reset
(SPST-NC)
CAP
Run capacitor
FL
Fusible link
HI/LO Blower motor speed
change relay (DPST)
ITLK
Blower door interlock
switch (SPST-NO)
LS
Limit switch auto reset
(SPST-NC)
MTR
Motor blower
TRANS Transformer
VDP
Vent damper jumper
plug
Printed circuit
board terminal
VDP
24 VAC wiring
115 VAC wiring
Circuit on printed
circuit board
GC
Y
C
GAS1
GAS3
Screw terminal
GAS2
Equipment ground
Jumper
position
(if required)
*
Not on all furnace
models
ONE-YEAR LIMITED WARRANTY
The Seller warrants its products against defects in material or workmanship for a period of one (1)
year from the date of manufacture. The liability of the Seller is limited, at its option, to repair, replace
or issue a non-case credit for the purchase prices of the goods which are provided to be defective.
The warranty and remedies set forth herein do not apply to any goods or parts thereof which have
been subjected to misuse including any use or application in violation of the Seller’s instructions,
neglect, tampering, improper storage, incorrect installation or servicing not performed by the Seller.
In order to permit the Seller to properly administer the warranty, the Buyer shall: 1) Notify the Seller
promptly of any claim, submitting date code information or any other pertinent data as requested by
the Seller. 2) Permit the Seller to inspect and test the product claimed to be defective. Items claimed
to be defective and are determined by Seller to be non-defective are subject to a $30.00 per hour
inspection fee. This warranty constitutes the Seller’s sole liability hereunder and is in lieu of any other
warranty expressed, implied or statutory. Unless otherwise stated in writing, Seller makes no warranty
that the goods depicted or described herein are fit for any particular purpose.
Patent No. 424,953
7313 William Barry Blvd., North Syracuse, NY 13212
(Toll Free) 800-365-5525 (Phone) 315-233-5266 (Fax) 315-233-5276
www.icmcontrols.com
LIAF044-1