Furnace attempts to start but shuts down quickly; LED status light flashes twice repeatedly.

Safety: Turn off power to the furnace before opening any panels. Do not blow into gas lines or modify venting without proper training.

Steps to check:

• Inspect pressure switch tubing: Locate the round pressure switch near the inducer motor. Remove the small rubber or silicone tube and check for water, debris, or cracks. Blow gently through the tube (away from the furnace) to clear any blockage. Reattach firmly.
• Check vent and intake: If your Maytag furnace is a high-efficiency model with PVC venting, go outside and inspect the intake and exhaust pipes for leaves, snow, ice, or nests. Clear any obstructions.
• Test switch operation: With power off, disconnect the wires from the pressure switch and check continuity with a multimeter. The switch should be open with the inducer off. If it reads closed all the time, the switch may be stuck or shorted and should be replaced.
• Inspect wiring: Check the harness from the pressure switch to the control board for pinched or shorted wires.

When to call a technician: If the pressure switch remains closed with the tube removed, or if you suspect vent sizing or combustion air issues, have a licensed HVAC technician evaluate the system.