Error Code Code 12

Carrier 59SC2B Error Code Code 12: Blower On After Power Up

TL;DR
Blower runs for 90 seconds if unit is powered up during a call for heat (R-W closed) or R-W opens during blower on-delay. This is normal behavior after a power interruption during a heating cycle.
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 Code 12 Mean?

Blower runs for 90 seconds if unit is powered up during a call for heat (R-W closed) or R-W opens during blower on-delay. This is normal behavior after a power interruption during a heating cycle.

Common Causes

Cause Likelihood DIY?
Power restored while thermostat was calling for heat Most common — N/A
Thermostat call for heat removed during blower on-delay period Common — N/A
Power interruption during heating cycle Common — N/A

When to Call a Professional

Contact a licensed HVAC technician if:

Sources

  1. Carrier 59SC2B Installation & Service Manual (59SC2B-03SI), Fig. 57 - Service Label, p.66