Error Code 12
Bryant 355MAV Error 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/W1 closed) or if the call for heat is interrupted (R-W/W1 opens) during the blower on-delay period. If this code repeats every couple of minutes it is probably caused by a direct short in the pressure switch circuits, gas valve, wiring to gas valve, or humidifier coil. 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 12 Mean?
Blower runs for 90 seconds if unit is powered up during a call for heat (R-W/W1 closed) or if the call for heat is interrupted (R-W/W1 opens) during the blower on-delay period. If this code repeats every couple of minutes it is probably caused by a direct short in the pressure switch circuits, gas valve, wiring to gas valve, or humidifier coil.
Common Causes
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