Heater attempts to start but shuts down with E02 on the display

Safety first: Turn OFF electrical power and close the gas shutoff valve before servicing. Allow the heater to cool.

• Listen for ignition sequence: Restore power and call for heat. You should hear the inducer fan (if equipped) and then a click from the gas valve and/or see the igniter glow or spark. If there is no glow or spark, suspect the igniter or ignition control.
• Inspect the igniter: With power OFF, locate the hot surface igniter or spark igniter assembly. Check for cracks, chips, or broken ceramic. Ensure the wiring harness is firmly connected and not heat-damaged.
• Clean burner and orifices: Remove the burner tray and inspect for rust, debris, or spider webs in the burner ports and gas orifices. Clean with a soft brush and compressed air. Do not enlarge orifices.
• Check gas valve position: Confirm the manual gas shutoff is fully open and that the gas valve on the heater is not in the OFF position.
• Test again: Reassemble, restore gas and power, and call for heat. If the igniter still does not glow/spark or the burner does not light and E02 persists, the gas valve or ignition control board may require replacement and should be tested by a qualified technician.

Warning: Do not attempt to adjust internal gas valve regulators or work on gas piping unless you are licensed to do so.