Bryant Furnace

Bryant Furnace Error Code 12

Troubleshooting guide for the Bryant Furnace system fault 12.

What It Means

Blower runs for 90 seconds following a power-up during a call for heat.

Possible Causes

  • Unit powered up mid-call for heat.
  • Heat call opened during blower on-delay.

Not sure which one it is — or if it's none of these? Try ACLogics today.

Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.
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Full Diagnosis

Blower On After Power Up. Blower runs for 90 seconds if the furnace is powered during a call for heat or if the heat call opens during blower on-delay.

All Recorded Causes

Normal operation status. The unit was powered up mid-call-for-heat or the heat call dropped during blower on-delay. No corrective action required unless the blower runs continuously.

Verify Before Replacing Parts

  1. Confirm the exact Bryant model family and furnaces context before acting on a generic code description.
  2. Confirm filter condition, blower operation, and coil cleanliness before replacing any controls — start by ruling out whether normal operation status.
  3. Measure airflow-related readings that match the symptom, such as temperature split or static pressure, and check whether the unit was powered up mid-call-for-heat or the heat call dropped during blower on-delay.
  4. After the correction, run the system long enough to confirm the furnaces fault does not return under normal load.

Still unsure about this fault?

ACLogics walks you through Bryant Furnace diagnostics step-by-step — so you confirm the cause before swapping parts.

See how ACLogics handles Furnace faults →