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Installation, Operation & Application Guide

For more information on our complete range of American-made 
products – plus wiring diagrams, troubleshooting tips and more, 
visit us at 

www.icmcontrols.com

ICM2914

Gas Ignition Replacement Board

• Controls blower motors, gas valve, & spark ignitor in sequence
• Protects against short cycling
• Selectable Heat/Cool blower off-delay time
• Flash codes from the onboard LED indicate specific problems for easier troubleshooting
• Repeated ignition failures or flame losses will disable heat operation for safety

FEATURES

The ICM 2914 is a form, fit, and functional replacements for the boards shown in the cross-reference 

section of this guide. The control boards are designed as automated gas ignition controls which monitor 

the ignition sequence including the inducer, pressure switch, spark ignition, gas valve, flame sense, and 

circulating blower while maintaining full safety circuit monitoring including the high limit switch, roll out 

switch and auxiliary limit switch circuits. Onboard diagnostics will indicate when a fault condition exists.

INTRODUCTION

• Line voltage: 460 VAC 

• Line frequency: 50/60 Hz

• Control voltage: 18-30 VAC

• Circulating blower: 4FLA @ 277 VAC

• Hi-efficiency blower: 10 mA @ 24 VAC

• Inducer blower: 10 mA @ 24 VAC

• Combined gas valve load: 1.5 A @ 24 VAC

• Minimum flame signal threshold: 0.75 uA

SPECIFICATIONS

TRANE P/N #: D674712P01

REPLACES

CAUTION! To service control, and prior to disconnection, label all wires. Failure to do so may 

result in wiring errors that can cause dangerous operation.
1. Turn thermostat to the OFF position or set it to the lowest possible setting.
2. Turn OFF the electrical supply to furnace.
3. Turn OFF the gas supply to furnace.
CAUTION! Failure to turn off gas and electric supplies can result in explosion, fire, death or 

personal injury.
4. Remove the furnace blower and control access doors.
5. Disconnect the thermostat wires and humidifier wires (if equipped with a humidifier).
6. Disconnect the line voltage, blower, electronic air cleaner wires (if equipped) and transformer wires.
7. Remove screws and any other fasteners and the old circuit board.
8. Examine the control and the control box for water stains.
9. Make repairs if any sources of water leakage are found. Be sure to check humidifiers, evaporator 

coils and vent systems in the area of the control.

REMOVE EXISTING CONTROL

1. Ground yourself. When handling the circuit board; hold it by the edges.

2. Fasten the circuit board with the retaining screws.

3. Connect all line voltage, low voltage and accessory wires.

4. Verify the sequence of operation.

INSTALL NEW CONTROL

The control will go into a 1-hour soft lockout if the following faults are detected:

•  Limit switch open 4 times in one heat call

•  Ignition failed (flame not sensed) 4 times in one heat call

•  Flame lost after successful ignition 3 times in one heat call

•  Gas valve sensed on when it should not be

•  Gas valve sensed off when it should be on, 10 times in one heat call

Flame sensed while the gas valve is closed puts the control in lockout state, but lockout clears after the 

blower off delay is complete (90 seconds or 60 seconds, depending on jumper selection).

LOCKOUT

Function

Time

Units

Heat “ON” delay

45

Sec

Cool “ON” delay

2

Sec

Flame recognition time

0.8

Sec

Flame establishing period

7

Sec

Flame failure response time (before 10 

seconds after trial for ignition period)

2

Sec

Flame failure response time (otherwise) 0.8 

Sec

Recycle time

27

Sec

Lockout time

300

Sec

Pre–purge time

20 

Sec

Post–purge time

5

Sec

Auto-restart purge time

5

Sec

Trial for ignition period

7

Sec

Interpurge time

60

Sec

Auto restart time

60.

Min

Retry

2

Each

Recycle

10

Each

Heat fan OFF delay

60 or 90 sec., field selectable, default will be 90 sec.

Cool fan OFF delay

0 or 45 sec., field selectable, 45 sec. will be default for 

HEM, 45 sec. will be default for PSC.

(@ 25 VAC, 60 Hz, 25ºC unless noted)

TIMING

Fault code retrieval & clearing

When powering on, the control 

flashes the last four error codes that 

have occurred in the last 14 days. 

The control will flash the newest error 

first and oldest error last. The fault 

memory can be manually erased by 

powering on with a G call in place 

and toggling W 3 times.

Two LED’s on the board

• Status LED (Green)

  –  Slow Flash: Normal operation 

with no call for heat 

  –  Fast Flash: Normal operation with 

call for heat

• Fault LED (Red)

  –  See table

FAULT CODE TABLE

# of Flashes

Error

2

External lockout (retries or recycles 

exceeded)

3

Pressure switch/Inducer error

4

Open limit switch and rollout

5

Flame sensed when no flame should 

be present

6

Not used

7

External gas valve circuit error

8

Low flame sense

Solid Red

Internal board error

Solid Red w/solid 

‘STATUS’ LED

Continuous reset caused by an internal 

board error

On a call for heat (24 VAC on the W input), the following occurs:
• Upon a call for heat the control checks the status of the pressure switch; if the pressure switch is open, 

the control will energize the draft inducer.

• When the control verifies the pressure switch has closed, the control will start a 20-second prepurge.
• When the pre-purge time delay is over, the control will energize the gas valve and initiate spark.
• The ignitor must be de-energized when the flame is sensed or at the conclusion of the trial for ignition 

period, whichever comes first. 

• When flame is sensed, the control will energize the circulator fan within the ON-delay period.

When the call for heat is terminated, the following occurs:
• The control shall de-energize the gas valve and the draft inducer within the post purge period.
• When the heat mode fan OFF delay timer expires, the control will de-energize the circulator fan.

With a call for cooling, the following occurs:
On a call for cooling (24Vac on Y and G), the circulator fan is energized within the cool on delay period. 

The control will ignore a call for Y without a call for G. After the thermostat is satisfied, the compressor 

is de-energized and the jumper selected cool Off delay period begins. Following the cooling Off delay 

period, the circulator fan is de-energized.

OPERATION

Use caution when installing and servicing the furnace to avoid and control electrostatic 

discharge; ESD can impact electronic components. These precautions must be followed to 

prevent electrostatic discharge from hand tools and personnel. Following the precautions will 

protect the control from ESD by discharging static electricity buildup to ground.

1.  Disconnect all power to the furnace. Do not touch the control or the wiring prior to discharging your 

body’s electrostatic charge to ground.

2.  To ground yourself, touch your hand and tools to a clean, metal (unpainted) furnace surface near 

the control board.

3.  Service the furnace after touching the chassis. Your body will recharge with static electricity as you 

shuffle your feet or move around, and you must reground yourself.

4.  Reground yourself if you touch ungrounded items.

5.  Before handling a new control, reground yourself, this will protect the control. Store the used and 

new controls in separate; containers before touching ungrounded objects.

6. ESD damage can also be prevented by using an ESD service kit.

ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS

ELECTRICAL SHOCK HAZARD! Before installing this unit, turn off power at the 

main service panel by removing the fuse or switching the appropriate circuit breaker to 

the OFF position. Follow all Local, State and National Electrical Codes when installing 

this device.

CAUTION! Only trained personnel should install or service heating equipment. When 

working with heating equipment, be sure to read and understand all precautions in the 

documentation, on labels, and on tags that accompany the equipment. Failure to follow 

all safety guidelines may result in damage to equipment, severe personal injury or death.

> > > CAUTION < < <

Automatic Restart Purge

Lockout resets automatically after 1 hour. Whether a call is in place or not, the control activates the 

inducer blower for 5 seconds. The inducer will deactivate and ensure the pressure switch is not stuck 

closed before starting a new heat call.
Automatic Inducer Pre-purge Reset

If the pressure switch remains open after 2 minutes of draft inducer run time, the draft inducer will be de-

energized for 30 seconds. The sequence will start again checking for an open pressure switch.
Continuous Fan Off delay (single stage units only)

 On a call for continuous fan (24 VAC on G), the circulator fan is energized. During a call for cooling 

while the cool “On” delay is in place, the control will not respond to the fan input (G).  If the fan was 

called prior to the call for cool, the circulator fan will remain energized during the Cool “On” delay. When 

the call for continuous fan is terminated, the selected cool Off delay period begins. When the cool Off 

delay period expires, the circulator fan is de-energized. 

Note:

 If the fan is called prior to a call for heat, 

the circulator fan will remain energized during the entire call for heat sequence.
Fault Code Retrieval

When powering on, the control flashes the last four error codes that have occurred in the last 14 days. 

The control will flash the newest error first and oldest error last. The fault memory can be manually 

erased by powering on with a G call in place and toggling W three times.

Flame Sense Test Points

 

The ignition board is equipped with a set of flame sense test points. A multimeter can be used to test 

flame sense by placing the meters probes on the two test pins and taking a DC voltage reading while 

the flame sensor is in the presence of flame.  1VDC = 1µA flame current. Weak or poor flame sense is 

represented by a reading of 0.7 VDC or lower.

SPECIAL FEATURES

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