Status LED flashes 2 times repeatedly; furnace will not fire or shuts down quickly

Safety first: Turn off power to the furnace before removing access panels. Do not bypass safety switches for operation.

• Inspect pressure switch tubing: Locate the round pressure switch and its rubber tubing to the inducer housing. Remove the tubing and check for water, debris, or cracks. Blow gently through the tube to clear obstructions and reinstall securely.
• Check for stuck contacts: With power off, disconnect the wires from the pressure switch and use a multimeter to check continuity. With no inducer running, the switch should be open. If it reads closed, the switch is stuck and should be replaced.
• Inspect inducer operation: Restore power and call for heat. The inducer motor should start before the pressure switch closes. If the inducer runs constantly or never stops, the control board may be misreading the switch.
• Check venting: Ensure PVC vent and intake pipes (for high-efficiency Rheem furnaces) are not blocked by snow, leaves, or nests, which can affect pressure readings.

If the pressure switch remains stuck closed even after tubing and vent checks, replacement of the pressure switch is recommended.