Carrier Furnace Error Codes & Fix Guides
All FixCode Guide coverage for Carrier furnace error codes: start with the complete code list, or jump to a deep-dive guide for a specific code. Everything is verified against Carrier manufacturer documentation.
Guides in this section
Most searched Carrier furnace codes
| Code | Meaning |
|---|---|
| 12 | Blower on after power-up — not a fault: the control runs the blower for ~90 seconds at start-up when a thermostat call was present during a power interruption (a status/safety behaviour). |
| 13 | Limit circuit lockout — the furnace's limit switch circuit opened repeatedly and the control locked out for safety (1 hour typical) — an overheating-protection trip. |
| 14 | Ignition lockout — the furnace tried to light three times and failed, so the control locked out (typically retrying after ~1 hour). |
| 24 | Secondary voltage fuse open — the 3-amp fuse on the control board has blown (24V circuit short/overload). |
| 31 | Pressure switch did not close (or opened) during operation — the inducer couldn't prove proper venting draft. |
| 32 | Low heat pressure switch did not close / opened (on two-stage Carrier furnaces: the low-fire pressure switch proof failed). |
| 33 | Limit circuit fault — the limit switch is open right now (the furnace is too hot or the limit circuit is broken), but the control hasn't escalated to lockout (13) yet. |