Display shows fan / air pressure error, burner does not ignite

Safety first: Turn off power and gas before working near the combustion chamber.

Step-by-step checks:

• Check air intake and flue: Ensure the air intake is not blocked and the flue terminal is clear.
• Listen for fan operation: When a demand is present, you should hear the fan start before ignition. If silent, the fan may not be receiving power or may be seized.
• Inspect pressure tubes: Locate the air pressure switch and its silicone tubes. Make sure they are firmly connected and not cracked or filled with condensate. Gently blow through the tubes (with power off) to clear any moisture.
• Check connectors: Verify that the fan and pressure switch electrical connectors are fully seated.

When to call a professional: Replacement of the combustion fan or pressure switch, and any combustion adjustments, must be done by a qualified technician.