Error Code Rapid Flashing LED
Carrier 58MVC Error Code Rapid Flashing LED: Line Voltage Polarity Reversed
TL;DR
Indicates line voltage polarity is reversed, furnace is not grounded, or the transformers are out of phase in twinned units. 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 Rapid Flashing LED Mean?
Indicates line voltage polarity is reversed, furnace is not grounded, or the transformers are out of phase in twinned units.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Line voltage (115 VAC) polarity is reversed | ✗ Call a pro → | |
| Furnace not properly grounded | ✗ Call a pro → | |
| Transformers out of phase in twinned units | ✗ 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