REPLACES:

Nordyne: 624631, 624631B (for use with G3, G4, G5, G6, M2 and M3 furnace modules)

Generic control board replaces Nordyne 624631 and 903106-kit.  Board is typically found on G3R, G4R, G5R Nordyne furnaces, among other models as listed below.  

Nordyne circuit board for M2 and M3 series of furnaces. Also used in G3, G4, G5 & G6 units. For a spare or replacement fuse, order 3A fuse G32-189.  To purchase the original version of this board, see part # 903106. 

Replaces 624538, 6245380, 624557, 6245570, 624564, 6245640, 624-5640, 624591, 6245910, 624628, 6246280, 624631, 624631A, 624631-A, 624631B, 624631-B, 6246310, 902378, 902696, 902896, 903106.

CONTROL LIGHT STATUS
RED
Steady ON Control OK
Steady OFF No power
Rapid Flash - False flame or gas valve relay shorted
1 Flash - Limit circuit open or external load on "W" (does not apply to deck switch, see below) .
2 Flashes - Pressure switch is stuck open with inducer blower running.
3 Flashes - Pressure switch is closed with inducer off
4 Flashes - Ignition failure (check ground)
5 Flashes 115 vac & neutral reversed or no ground

YELLOW
Steady ON - Good flame signal
Blinking - Weak flame signal
Steady OFF - No flame signal

Control board operation:

• Controls gas valve, inducer draft motor, circulating blower and hot surface ignitor
• Monitors timing, trial for ignition, flame sensing, lockout, plus pressure, rollout and limit switches.
• Microprocessor-based precision
• Twinning compatible with another ICM2805 furnace control
• Diagnostic LEDs aid in testing and troubleshooting
• Ignitor: 5A, 120 VAC
• Cool Blower: 10A, 2HP, 240 VAC
• Heat: 5A, ½ HP, 250 VAC
• Inducer Blower: 4A, 120 VAC
• Gas Valve: 1A, 24 VAC
• Humidifier Motor: 0.5A, 24 VAC
• Electronic Air Cleaner: 1A, 120 VA