ICM CONTROLS ICM2915 Trane Replacement Furnace Board User Guide

ICM CONTROLS ICM2915 Trane Replacement Furnace Board

Product Information

• Product Name: ICM2915 Gas Ignition Replacement Board
• Trane Part Number: D674713P01
• Replaces: [Specify the models it can replace]

Product Usage Instructions

1. Before installing the unit, turn off power at the main service panel by removing the fuse or switching the appropriate circuit breaker to the OFF position.
2. Follow all Local, State, and National Electrical Codes when installing this device.
3. Remove any existing control, coils, and vent systems in the area of the control.
4. Ground yourself and hold the circuit board by the edges when handling it.
5. Fasten the circuit board with the retaining screws.
6. Connect all line voltage, low voltage, and accessory wires.
7. Verify the sequence of operation.

Fault Codes, Status Lights, and Troubleshooting:

B on the
control board & check power on both the primary and secondary
sides of the stepdown transformer. Check the control board fuse.
Powered up in standby (no call) or powered up with a cool call or
fan call in place.
Slow Flash| Normal operation with a heat call in place| Normal heat call operation.
2| System lockout| Check the high-temperature limit, check the flame sensor, and check the gas
valve. See lockout conditions in this guide.
3| Pressure switch fault| Check for obstructed pressure switch tubing or defective
pressure switch. Check for oxidation on terminals, broken wires, or
defective inducer motor. Check for proper voltage at the inducer
motor input.
4| High-temperature limit switch open| Check for blocked airflow, blocked ductwork, and dirty filters.
Check the main blower is working and not bogged down with dirt.
Check or replace the high-limit switch if defective.
5| False flame sensed| The flame was sensed without the gas valve open, or the flame was sensed
without a heat call. Check the flame sensor and all grounds.
6| Flame rollout switch open| Check for blocked exhaust ductwork and check for cracked heat
exchangers.

FEATURES

• 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
• 2-stage low-heat and high-heat

INTRODUCTION

The ICM2915 is a form, fit, and functional replacement for the boards shown in the cross-reference section of this guide. The control boards are designed as automated gas ignition controls that monitor 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. In addition, the ICM2915 offers 2-stage low heat and high heat functions for better efficiency.

SPECIFICATIONS

• Line voltage: 240 VAC
• Line frequency: 50/60 Hz
• Control voltage: 18-30 VAC
• Hi-efficiency blower: 10mA @ 24 VAC
• Inducer blower: 0.7 FLA, 1.5 LRA @ 240 VAC
• Combined gas valve load: 1.5A @ 24 VAC
• Minimum fl ame signal threshold: 0.75 uA

REPLACES

• TRANE P/N: D674713P01

OPERATION

• *  **Single stage operation**  

  Upon a thermostat call for W1, the single-stage heat mode is initiated.

  • The control will verify the initial state of the pressure switch and other safeties then engage the draft inducer.
  • The control then verifies the closure of the pressure switch and enters a 20-second pre-purge (15 seconds at high speed followed by 5 seconds at low speed).
  • After the inducer pre-purge completes, the control energizes the first stage of the gas valve and initiates a spark that ignites the flame.
  • Once the flame is detected and verified, a 45-second delay for the indoor blower is initiated.
  • Following the delay, the indoor blower is energized at a low speed.
  • When the W1 call from the thermostat is satisfied, the gas valve de-energizes, the flame sense is lost, and the control starts a 5-second draft inducer post-purge along with a field selected 60 or 90-second indoor blower post-purge delay.
  • After their delay times expire, the inducer and indoor blowers will be de-energized.

• Second stage operation

  • When a call for second-stage heat (W2) occurs during a first-stage heat call (W1), the control changes the draft inducer speed from low to high speed.
  • Also, the control will switch the first-stage gas heat to the second-stage gas heat.
  • Once the call for second-stage heat (W2) is satisfied, the draft inducer is switched from high speed to low speed, the gas valve is switched from second stage to first stage, and the indoor blower speed will switch from high to low within 30s.
  • The first stage and second stage called together at the same time
  • The control initially processes the call as a single-stage heat call. Once fl ame is established, the control begins to process a second stage heat call operation after 10 minutes.
  • Note: A call for W2 without a call for W1 will not be recognized.

• Cooling mode

  • Upon a thermostat call for cooling (Y) energized or (Y&G) energized, the control energizes the indoor blower at high speed.
  • When the thermostat is satisfied, the control executes a field selectable 0 or 45-second indoor blower post-purge off-delay. When the off-delay ends, the Indoor blower is turned off.

• Continuous fan mode

  • Upon a singular (G) input which indicates a call for continuous indoor blower operation, the control will energize the indoor blower at the low heat speed.

CAUTION

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.

REMOVE EXISTING CONTROL

CAUTION! To service control, and prior to disconnection, label all wires. Failure to do so may result in wiring errors that can cause dangerous operations.

1. Turn the thermostat to the OFF position or set it to the lowest possible setting.
2. Turn OFF the electrical supply to the furnace.
3. Turn OFF the gas supply to the 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.

INSTALL NEW 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.

TROUBLESHOOTING

FAULT CODES, STATUS LIGHTS AND TROUBLESHOOTING

the control board & check power on both the primary and secondary sides of the stepdown transformer. Check the control board fuse.
Steady ON| Normal operation| Powered up in standby (no call) or powered up with a cool call or fan call in place.
Slow Flash| Normal operation with a heat call in place| Normal heat call operation.
2| System lockout| Check the high-temperature limit, check the flame sensor, and check the gas valve. See lockout conditions in this guide.
3| Pressure switch fault| Check for obstructed pressure switch tubing or defective pressure switch. Check for oxidation on terminals, broken wires, or defective inducer motor. Check for proper voltage at the inducer motor input.
4| High-temperature limit switch open| Check for blocked airflow, blocked ductwork, and dirty filters. Check the main blower is working and not bogged down with dirt. Check or replace the high-limit switch if defective.
5| False flame sensed| The flame was sensed without the gas valve open, or the flame was sensed without a heat call. Check the flame sensor and all grounds.
6| Flame rollout switch open| Check for blocked exhaust ductwork and check for cracked heat exchangers.
7| W2 called without W1 call from the thermostat| Check to see if W1 & W2 are wired incorrectly.
8| Low flame signal| Check, clean, or replace the flame sensor. Check gas valve pressure.

NOTE: At power up, the control will flash the last 4 faults stored in memory within the last 14 days 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 the oldest error last. The fault memory can be manually erased by powering on with a G call in place and toggling W 3 times.

LOCK OUT CONDITION

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 when it should not be
• The gas valve sensed off when it should be on, 10 times in one heat call
  • NOTE: 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).

FLAME LOSS DIAGNOSTICS

Weak or intermittent spark| Make sure the furnace frame is grounded to earth ground. Ensure the common of the 24 VAC is grounded to Earth ground. Check or replace the spark igniter. Check the primary and secondary voltage of the transformer for proper voltage.
---|---
Flame Loss| •  Check for bad or dirty flame sensor

•  Check thermostat

•  Check for proper flame sense signal at flame sense test pins

•  Check for proper earth ground on the furnace.

•  4 flame losses in a single heat call will put the control into a one-hour lockout.

No flame/Ignition failure| •  Check the thermostat

•  Check the pressure switch

•  Check gas valve operation

•  Check for good spark & check for good earth ground

Flame out of sequence| Flame out of sequence represents a scenario where the flame is sensed while the gas valve is closed. The control goes into a lockout state when the flame is out of sequence and the indicator LED blinks the appropriate code (see “lockout” section).

•  Check and replace the flame sensor

The furnace does not ignite and the main blower runs continuously| Check the high-temperature limit switch for the open circuit. Check all safeties. Clean or replace the air filter. Check ductwork and return air ducts for blockages.

WIRING DIAGRAM

CONNECTION DIAGRAM

LEGEND

9-PIN CONNECTION

1. Stage two of gas valve (HI)
2. Stage one of gas valve (LO)
3. Pressure switch in
4. Flame sensor
5. N/A
6. Fusible link (Roll out switch)
7. Common (24 VAC), B
8. Limit switch (out)
9. Limit switch (in)

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.

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