Error Code 3 Blinks (2-sec pause)

Ruud UGPH-07EAMGR Error Code 3 Blinks (2-sec pause): 3 Blinks (2-sec pause)

TL;DR
The high-temperature limit switch or rollout safety switch has opened, indicating the furnace is overheating. This is a critical safety feature that shuts down the burner to prevent heat exchanger damage and fire hazard.
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 3 Blinks (2-sec pause) Mean?

The high-temperature limit switch or rollout safety switch has opened, indicating the furnace is overheating. This is a critical safety feature that shuts down the burner to prevent heat exchanger damage and fire hazard.

When to Call a Professional

Contact a licensed HVAC technician if:

Sources

  1. Rheem RGPH Installation Instructions Manual (covers Ruud UGPH)