Error Code 3 Blinks (2-sec pause)
Ruud UGRA-07EMAES Error Code 3 Blinks (2-sec pause): 3 Blinks (2-sec pause)
TL;DR
The high-temperature limit switch, rollout safety switch, or auxiliary limit switch has opened, indicating the furnace is overheating. This is a critical safety feature. On downflow 90+ models, also check the auxiliary limit. The IFC Status LED should be blinking Fault Code 3 when the limit or IDM wire through the auxiliary limit is open or cycling. 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, rollout safety switch, or auxiliary limit switch has opened, indicating the furnace is overheating. This is a critical safety feature. On downflow 90+ models, also check the auxiliary limit. The IFC Status LED should be blinking Fault Code 3 when the limit or IDM wire through the auxiliary limit is open or cycling.
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