Error Code 11
Info

Carrier 59SC5A Error Code 11: No Previous Code

TL;DR
Your furnace has no stored error codes, confirming no recent faults. This is a normal diagnostic status.
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 11 Mean?

Status code 11 on the Carrier 59SC5A indicates that no fault codes are stored in the control board's diagnostic memory. The 59SC5A retains the most recent error code so that a technician can retrieve it later for troubleshooting. Code 11 means the memory is clean — either no faults have occurred, or previous codes were automatically cleared.

The system erases stored codes after 72 hours. This means if a transient issue occurred — such as a pressure switch briefly opening during a high-wind event — the code would be retained for three days and then automatically cleared. Code 11 after that period is expected behavior.

On the 59SC5A, you can trigger a code recall by briefly removing and reconnecting one main limit wire. The board will display the last stored code, then automatically run a component test. If code 11 appears during recall, it confirms no faults have been logged since the last memory clear.

Common Causes

Cause Likelihood DIY?
No faults have occurred in the last 72 hours Most common
Contact a licensed HVAC technician if any of these apply:

Sources

  1. Carrier 59SC5A Installation, Start-Up, Operating and Service and Maintenance Instructions

✓ Verified against manufacturer service manual — March 2026