Water heater does not ignite; display shows A01 and burner never lights

Safety first: Turn the appliance OFF, close the gas isolation valve, and disconnect power before removing any covers. If you ever smell gas, ventilate the area immediately and call a qualified technician or gas supplier.

Step-by-step checks:

• 1. Reset the heater: Use the reset button or power cycle the unit according to the user manual. If A01 reappears, continue.
• 2. Verify gas supply: Ensure the main gas cock to the Beretta water heater is fully open. Check that other gas appliances in the home work. If none work, contact your gas provider.
• 3. Check gas pressure (visual/user level): If the heater struggles more when other gas appliances are on, there may be low gas pressure. Do not attempt to adjust the gas valve yourself; this requires a certified technician with a manometer.
• 4. Inspect ignition electrode through viewing window: With the cover on and unit running, you should hear a rapid clicking during ignition. If there is no clicking, the ignition module or electrode wiring may be faulty.
• 5. Clean ignition and ionization electrodes (technician-level): After isolating power and gas, remove the front cover. Carefully remove the burner assembly. Clean the electrodes with fine emery cloth, ensuring correct gap and position as per Beretta service manual. Replace if cracked or heavily corroded.
• 6. Check electrode wiring: Ensure the high-voltage ignition cable is firmly connected at both the ignition transformer and electrode. Look for burn marks or damaged insulation.
• 7. Gas valve check (technician-level): A professional should verify that the Beretta gas valve coil is powered during ignition and that inlet and outlet pressures are within specification. Replace the gas valve if it does not open or modulate correctly.

When to stop: If you are not trained to work on gas components, limit yourself to visual checks and resets, then contact an authorized Beretta service center.