Furnace starts but shuts down; status LED flashes 4 times repeatedly.

Safety: Turn off power before removing blower doors or reaching into the blower compartment.

• Replace or clean air filter: Locate the furnace filter (in the return duct or blower compartment). Replace if dirty or clogged. Use the correct size and airflow rating recommended for Amana furnaces.
• Check supply and return vents: Ensure all registers and returns in the home are open and not blocked by furniture, rugs, or drapes.
• Inspect blower operation: Call for heat and observe the blower. It should start after the burners ignite. If it does not run, or runs slowly or noisily, the blower motor or capacitor may be failing.
• Check high limit switch wiring: Locate the high limit switch on the heat exchanger panel. Inspect wires and connectors for burns or loose connections. Reseat firmly.
• Reset and test: After correcting airflow issues, turn power off for 30 seconds to reset the board, then restore power and test a full heat cycle.

If the furnace continues to trip the high limit with a clean filter and good airflow, the heat exchanger or blower sizing may be an issue and should be evaluated by a professional.