Error Code 1 FLASH

Goodman GMSS960803BN Error Code 1 FLASH: System lockout

TL;DR

System lockout

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 1 FLASH Mean?

System lockout

Common Causes

Cause	Likelihood	DIY?
Ignition failure after 3 retries	Most common	✗ Call a pro →
No gas to burners	Common	✗ Call a pro →
Bad igniter or igniter alignment	Common	✗ Call a pro →
Coated or oxidized flame sensor	Uncommon	✗ Call a pro →
Interrupted gas supply	Uncommon	✗ Call a pro →
Improper gas pressure	Uncommon	✗ Call a pro →
Restriction in flue and/or combustion air piping	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 GMSS96 Installation Instructions Manual