ICM6700 12VDC Direct Spark Ignition Control

Suburban Replacement. This ignition control circuit board works on all Suburban 12V furnaces and Suburban water heater model 520820.

When the thermostat calls for heat, the ICM6700 will verify the sail switch is open before energizing the inducer blower. Once the inducer blower is energized, the ICM6700 will verify the sail switch has closed and begin a 15 second pre-purge cycle. Following the inducer blower pre- purge cycle, the gas valve and spark ignitor are energized and the ICM6700 will verify the presence of flame.

If flame has not been sensed after 7 seconds; the control will attempt 2 more trials for ignition, if flame is not sensed after 3 trials for ignition, the ICM6700 will enter a 1-hour lockout. If flame is detected, the spark ignitor is turned off and the gas valve remains energized. Once the thermostat is satisfied, the gas valve is de-energized immediately and a 90 second post-purge cycle of the inducer blower is enforced. After the 90 second post purge cycle, the inducer blower is turned off. Note: Lockout is cleared by recycling the input voltage.