Goodman GMSS920803BN Error Code 8 Flashes: Igniter Circuit Fault

What Does Code 8 Flashes Mean?

Eight flashes on the Goodman GMSS920803BN diagnostic LED indicate a problem in the igniter circuit. The Integrated Control Module has detected an electrical fault that prevents it from properly powering the hot surface igniter, so it will not open the gas valve or attempt ignition.

The most common cause is a failed hot surface igniter. These silicon-carbide or silicon-nitride elements are wear items that degrade with every heating cycle. When the element cracks or breaks, its circuit goes open and the board can no longer drive current through it, which produces this code. Loose or damaged igniter wiring, a poor unit or burner ground, or a faulty control module can create the same fault. If the igniter was recently replaced, a loose connector at the igniter plug is the most likely culprit.

This code is distinct from a 1-flash lockout on the same board. Eight flashes means the board never gets a healthy igniter circuit to begin the trial for ignition, so it stops before trying. A 1-flash lockout means the igniter energized and the furnace ran a full trial three times but failed to prove flame. Reading the count tells a technician whether to focus on the igniter circuit itself or on the broader gas-and-flame-sensing chain.

What You'll Notice

• The furnace will not attempt to light and the LED repeats an eight-flash pattern
• The hot surface igniter does not glow orange during what should be the warm-up stage
• You may hear the inducer run and then the sequence stall before ignition
• No burner flame and no heat are produced
• The fault may appear suddenly at startup, sometimes after years of normal service as the igniter wears out

Common Causes

How This Is Diagnosed

A technician isolates whether the fault is the igniter, its wiring, or the board. With power removed, they measure the hot surface igniter's resistance — an open or out-of-range reading confirms a cracked or failed element — and inspect the igniter leads and connector for looseness or damage, which is the first thing checked if the igniter was recently replaced.

If the igniter and its wiring are good, the unit and burner ground connections are verified, since a poor ground can disrupt the igniter circuit, and the control module's igniter output is evaluated as the last step. The repair is typically an igniter replacement, occasionally a wiring or ground correction or a board replacement — all professional service tasks.

When to Call a Professional

This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:

• The LED shows eight flashes and the furnace will not attempt to ignite
• The igniter never glows orange during startup
• A new igniter was just installed but the eight-flash code persists
• The igniter glows but the code still appears, suggesting a wiring or ground issue
• You are not equipped to test igniter resistance or ground continuity safely

✓ Verified against manufacturer service manual — March 2026