Boiler frequently locks out with generic flame failure but no specific F-code shown on basic models

Safety first: Turn off power and gas before accessing burner components.

• Clean flame sensor: Remove and gently clean the flame rod with fine abrasive pad. Reinstall and ensure a tight electrical connection.
• Check ground connections: Verify the boiler chassis ground is secure and that the burner assembly has a solid metal-to-metal connection to ground.
• Inspect burner: Clean dust and debris from the burner surface. Ensure all burner ports are open.
• Monitor gas supply: If other gas appliances cause the boiler to fail when they start, gas pressure may be marginal and should be checked by a gas technician.

Professional help: A technician can measure flame signal microamps and adjust or replace components as needed.