Error Code 6 Flashes
High

Goodman GMSS920803BN Error Code 6 Flashes: Rollout Limit Circuit Open / Control Board Fuse Blown

TL;DR
Your Goodman GMSS920803BN's rollout limit switch tripped or the control board fuse blew. This indicates a serious safety condition — call a technician immediately.
Disclaimer
This article is for informational purposes only and does not guarantee the accuracy or completeness of the information provided. Always turn off power and gas supply before attempting any repairs. If you smell gas, leave immediately and call your gas company. Consult a licensed HVAC technician for diagnosis and repair. Any actions taken based on this information are at your own risk.

What Does Code 6 Flashes Mean?

Six flashes on the Goodman GMSS920803BN diagnostic LED indicate that the rollout limit circuit is open or the integrated control module fuse is blown. Flame rollout means combustion gases and flames are escaping from the combustion chamber in a direction they should not go — this is a serious safety hazard.

The rollout limit switch is a safety device positioned near the burner assembly that trips when it detects excessive heat outside the combustion chamber. The most common cause is a blocked exhaust flue or intake air pipe, which forces combustion gases to find an alternate path out of the furnace. Misaligned burners and a failed inducer motor can also create rollout conditions.

The control module fuse can also blow from a short circuit in the 24-volt control wiring or safety circuits, producing the same 6-flash code. If the fuse is blown, the furnace will not operate at all. Do not attempt to replace the fuse and restart the furnace without identifying the root cause — the condition that caused the rollout or short circuit may still be present.

Common Causes

Cause Likelihood DIY?
Flame rollout due to blocked flue or inlet air pipe Most common ✗ Call a pro →
Misaligned burners Common ✗ Call a pro →
Failed induced draft blower Common ✗ Call a pro →
Blown 3A control module fuse Common ✗ Call a pro →
Short in 24V control or safety circuits Uncommon ✗ Call a pro →
Faulty rollout limit switch Uncommon ✗ Call a pro →

When to Call a Professional

Contact a licensed HVAC technician if:

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Sources

  1. Installation Instructions for *MSS9* & *CSS9* Single-Stage Gas Furnace

✓ Verified against manufacturer service manual — March 2026