Error Code Fast Flash

Trane TUH1B080A9H31A Error Code Fast Flash: Normal - Call for Heat

TL;DR
The LED flashes rapidly, indicating the furnace has received a call for heat from the thermostat and is in the process of firing up or actively heating. This is normal operation.
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 Fast Flash Mean?

The LED flashes rapidly, indicating the furnace has received a call for heat from the thermostat and is in the process of firing up or actively heating. This is normal operation.

When to Call a Professional

Contact a licensed HVAC technician if:

Sources

  1. ManualsLib - Trane AUH1B040A9H21B Installation Manual (18-CD33D1-4), which covers *UH1B models where * = A or T. Explicitly lists *UH1B060A9H31B and *UH1B080A9H31C (same UH1B-H series, suffix A/B/C are revision levels). (page 36). Cross-verified with Trane *UH1B040A9241A Installer's Manual: (page 39)