Furnace attempts to start but shuts down before ignition; E02 displayed on Alpha control module.

Safety: Disconnect power at the breaker and close the gas shutoff valve before working inside the furnace.

• Inspect the hot surface igniter: Remove the burner access panel. Locate the hot surface igniter (ceramic element near the burners with two wires). Visually inspect for cracks, chips, or white burn spots. Do not touch the element with bare fingers.
• Check wiring: Ensure the igniter plug is fully seated in the harness and the harness is firmly connected to the Alpha main control board. Look for burned or brittle insulation.
• Test operation: Restore power (leave gas off) and call for heat. Watch through the sight glass: the igniter should glow bright orange within 20–30 seconds. If it does not glow at all, the igniter or control board is likely faulty.
• Replace if needed: If the igniter is visibly damaged or does not glow, replace it with the correct Alpha Hot Surface Igniter Assembly specified for your model. Handle only by the ceramic base.

If a new igniter does not glow and E02 persists, the ignition circuit on the control board may be defective and should be diagnosed by a professional.