Error Code RED 4 FLASHES

Goodman GMEC960803BN Error Code RED 4 FLASHES: Open limit circuit (main limit, auxiliary limit, or rollout switch)

TL;DR

Open limit circuit (main limit, auxiliary limit, or rollout switch)

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 RED 4 FLASHES Mean?

Open limit circuit (main limit, auxiliary limit, or rollout switch)

Common Causes

Cause	Likelihood	DIY?
High temperature rise	Most common	✗ Call a pro →
High duct static pressure	Common	✗ Call a pro →
Incorrect gas pressure	Common	✗ Call a pro →
Burner misalignment	Uncommon	✗ Call a pro →
Orifice plate position issue	Uncommon	✗ Call a pro →
Wiring issue to limits	Uncommon	✗ Call a pro →

When to Call a Professional

Contact a licensed HVAC technician if:

Basic troubleshooting did not resolve the error
You smell gas at any point during the process
You are not comfortable working around gas lines or electrical components
The unit needs a gas valve, control board, or motor replacement

Sources

Goodman GMEC96 Service Instructions Manual - Two Stage Furnace with Multi-Speed ECM Motor