Furnace does not start, no burner ignition, control panel shows E01 shortly after a call for heat.

Safety first: Turn off power to the furnace at the breaker and close the gas shutoff valve before removing any panels. Wait for all hot surfaces to cool.

Steps to check:

• Verify gas supply: Ensure the manual gas shutoff valve near the Atlantic furnace is fully open. Check that other gas appliances in the home work normally.
• Inspect the hot surface igniter: Remove the burner access panel. Locate the ceramic hot surface igniter near the burner assembly. Look for cracks, white spots, or breaks in the element. If damaged, replace the igniter with an Atlantic-compatible hot surface igniter rated for your model.
• Check igniter wiring: Confirm the igniter harness is firmly connected to the ignition output on the Atlantic control board. Look for burnt connectors or brittle insulation.
• Observe ignition sequence: Restore power and call for heat. Watch through the sight glass: you should see the inducer start, then the igniter glow bright orange. If the igniter never glows but has correct resistance (typically 40–200 Ω, check your manual), the ignition control circuit on the main PCB may be faulty.
• Check gas valve operation: During the ignition attempt, listen for a click at the gas valve. If the igniter glows but there is no click and no flame, the gas valve coil or its wiring may be defective. This test is best confirmed with a manometer and multimeter by a qualified technician.

When to stop: If you smell gas, hear repeated clicking with no ignition, or are not comfortable testing live voltage, stop and contact a licensed gas technician. Do not bypass safety devices.