Error Code 1 FLASH

Goodman GMSS920803BN Error Code 1 FLASH: System lockout - ignition failure

TL;DR

System lockout - ignition failure

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 - ignition failure

Common Causes

Cause	Likelihood	DIY?
Failure to establish flame after 3 retries	Most common	✗ Call a pro →
No gas to burners	Common	✗ Call a pro →
Front cover pressure switch stuck open	Common	✗ Call a pro →
Bad igniter or igniter alignment	Uncommon	✗ Call a pro →
Improper orifices	Uncommon	✗ Call a pro →
Coated, oxidized, or improperly connected flame sensor	Uncommon	✗ Call a pro →
Loss of flame after establishment	Uncommon	✗ Call a pro →
Interrupted gas supply	Uncommon	✗ Call a pro →
Lazy burner flames (improper gas pressure or restriction in flue/combustion air piping)	Uncommon	✗ Call a pro →
Improper induced draft blower performance	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 GMSS9 Series Service Instructions Manual