Furnace does not ignite, burner never lights, display shows 01 lockout

Safety first: Turn off electrical power to the furnace and close the gas shutoff valve before removing covers. If you ever smell gas continuously, ventilate the area and contact a qualified technician and gas supplier immediately.

Step-by-step checks:

• 1. Reset the boiler: Use the Immergas control panel reset button (refer to your model manual). If 01 reappears after several attempts, continue with checks.
• 2. Verify gas supply: Ensure the external gas shutoff cock is fully open. Check that other gas appliances in the house work. If not, there may be a supply issue.
• 3. Inspect ignition electrode: Remove the combustion chamber cover. Check the ignition electrode for cracks, heavy oxidation, or soot. Clean the tip gently with fine emery cloth and ensure the gap and position match the service manual. Check the ignition cable for burns or cuts and that it is firmly connected to the ignition transformer on the main PCB.
• 4. Check flame detection (ionization) electrode: Clean the ionization electrode with fine abrasive pad. Ensure it is correctly positioned in the flame area and that the cable is firmly connected to the control board. Replace if the ceramic is cracked.
• 5. Gas valve operation: With power restored and gas on, a technician can measure voltage at the gas valve coil during ignition. If there is correct voltage but no gas flow, the gas valve may be stuck or defective and must be replaced by a certified technician.
• 6. Air in gas line: After long shutdowns, air may be in the gas line. A technician can purge the line and perform a combustion check.

When to call a professional: If you are not trained to work on gas components, do not attempt to adjust or replace the gas valve or work inside the sealed combustion chamber. Contact an authorized Immergas service center.