Boiler will not ignite; display shows E01 and burner never lights

Safety first: Turn off electrical power to the Crown boiler at the service switch and close the gas shutoff valve before removing any covers. Allow the boiler to cool fully.

• Check gas supply: Verify the manual gas shutoff valve to the boiler is fully open. If other gas appliances are also not working, contact your gas supplier.
• Inspect flame sensor: Remove the burner access panel. Locate the flame sensor rod near the burner on the Crown heat exchanger assembly. Gently clean the metal rod with fine emery cloth or a Scotch-Brite pad to remove oxidation, then wipe with a clean dry cloth. Reinstall securely.
• Inspect ignition electrode: Check the spark/igniter electrode for cracks, heavy deposits, or misalignment from the burner. Clean light deposits with a non-abrasive pad. Ensure the electrode tip is positioned per the Crown service manual (correct gap and orientation to burner).
• Check wiring: Inspect the ignition cable and flame sensor lead from the burner to the control board for loose connections, damaged insulation, or corrosion. Reseat connectors firmly on the Crown control module.
• Reset boiler: Restore power and gas, then follow the Crown boiler instructions to reset the lockout (usually by pressing the reset button on the control panel once). Observe ignition. If E01 returns repeatedly, stop resetting and call a qualified technician to test gas valve operation and combustion.