Status LED on Armstrong Air furnace control board is solid ON with no flashing; furnace may or may not operate.

Note: A steady ON LED on many Armstrong Air furnace boards indicates normal operation or standby with no active fault.

Steps to check if there is no heat:

• Verify thermostat mode: Ensure the thermostat is set to HEAT and the setpoint is above room temperature.
• Check furnace switch and breaker: Confirm the furnace service switch is ON and the circuit breaker is not tripped.
• Inspect filter and airflow: Replace dirty filters and ensure registers are open.
• Observe operation: Call for heat and watch the sequence: inducer start, ignitor glow, burner ignition, blower start. If the sequence stops without an error code, the issue may be intermittent or related to the thermostat or low-voltage wiring.