The ICM 282 Furnace Control Board is an aftermarket replacement part for several gas furnace models manufactured by Carrier. The microprocessor-based board controls the function of several furnace components, including the gas valve, the blower motor, the inducer and the humidifier. The board features an LED fault code indicator to facilitate troubleshooting. When the board has a problem carrying out one of its functions, it indicates the nature of the problem by displaying a series of LED light flashes that are coded to specific problem areas. You can interpret the meaning of these flashes by referring to the manufacturer's Fault Code Label.
Locate the service panel on the lower front of the furnace.
Turn the furnace off and then remove the front service panel door by either sliding or popping it out with your hands. Tools are generally not necessary.
Locate the control board, which is usually near the front of the furnace by the power supply.
Locate the small flashing LED light on the control board. It is labeled LED-1.
Determine the flash pattern by observing the frequency and length of each flash.
Refer to the manufacturer's fault code label to determine the type of problem indicated by the flash pattern displayed by the LED. For example, continuous rapid flashing indicates a line voltage polarity reversal or a twinning problem, while a short flash followed by a long flash indicates that a component test process is necessary.