Error Code RED LED1 ON (solid)

Carrier 58MVP Error Code RED LED1 ON (solid): Emergency Heat

TL;DR

Furnace is operating in emergency heat mode. The system has bypassed normal two-stage operation and is running in a backup heating configuration.

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 RED LED1 ON (solid) Mean?

Furnace is operating in emergency heat mode. The system has bypassed normal two-stage operation and is running in a backup heating configuration.

Common Causes

Cause	Likelihood	DIY?
Microprocessor detected a fault requiring emergency heat fallback	Most common	✗ Call a pro →
Repeated limit switch trips forcing high-heat-only mode	Common	✗ Call a pro →
Blower or inducer motor calibration failure causing fallback	Common	✗ 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

Carrier 58MVP Service and Maintenance Manual, p.11 – LED Codes