Heater intermittently shows AO or AF and shuts down during operation, especially in windy conditions.

Safety First: Turn off power and gas before adjusting venting or opening the heater.

• Check vent termination: Ensure the vent cap is installed per Hayward and local code requirements and is not blocked or undersized.
• Inspect vent joints: Look for loose or separated vent sections that could allow pressure fluctuations. Repair or reseal as needed.
• Evaluate blower: Listen for unusual noises or slow start-up. A failing blower motor or capacitor can cause marginal airflow.
• Secure air tubing and switch: Make sure the air pressure switch tubing is tight and not vibrating loose. Replace brittle tubing.
• Consider wind baffle: In very windy locations, consult a professional about adding approved wind protection or reconfiguring venting.