Carrier Furnace Error Codes: Full List & Meanings

Every Carrier furnace error code we have verified against Carrier's own support pages, with its official meaning. This list covers weathermaker 8000 two-stage gas furnaces (58dxt/58uxt); status codes are short flashes then long flashes. Codes vary by model, so confirm in your owner's manual. Support: Carrier dealer or Carrier customer relations (carrier.com).

Smell gas? Leave the building now. Do not touch light switches, phones or appliances inside. Call your gas utility or 911 from outside. CO alarm sounding or headache, dizziness or nausea? Get everyone outside and call 911. Gas valves, burners, venting and wiring are for a licensed technician only. See our safety policy.

Codes by system

Heating

Venting / airflow

All Carrier furnace error codes

Codes marked "Reset only" or "Service" have no separate page because the manufacturer publishes no owner fix beyond a reset or a service call.

Code	Official meaning	System	Owner action
33	A limit or flame roll-out switch is open. Carrier lists a dirty filter or restricted ducts first. A flame roll-out switch needs a manual reset because combustion air is inadequate. If it stays open over 3 minutes, the code becomes 13 (lockout, auto-resets after 3 hours). Also: 13	Heating	Owner checks
34	Flame wasn't proved. Carrier lists a gas valve turned off, a manual shut-off closed, low inlet gas pressure, or a dirty flame sensor. After 4 tries it becomes 14 (ignition lockout, auto-resets after 3 hours). Also: 14	Heating	Owner checks
32	The low-heat pressure, draft safeguard or aux-limit switch didn't close. Causes include a restricted vent, excessive wind, inadequate combustion air or an inducer fault. Also: 31, 43	Venting / airflow	Owner checks
21	The manufacturer lists 21 as: gas heating lockout (does not auto-reset); mis-wired gas valve or defective control. A licensed HVAC technician must diagnose this.	Control / electronics	Service
22	The manufacturer lists 22 as: abnormal flame-proving signal (flame sensed with gas valve off); possible leaky or stuck-open gas valve, so shut off gas and call a technician. A licensed HVAC technician must diagnose this.	Heating	Service
23	The manufacturer lists 23 as: pressure switch did not open (obstructed tubing or stuck switch). A licensed HVAC technician must diagnose this.	Control / electronics	Service
24	The manufacturer lists 24 as: 24 VAC fuse open (short in low-voltage wiring). A licensed HVAC technician must diagnose this.	Power supply	Service
45	The manufacturer lists 45 as: replace control. A licensed HVAC technician must diagnose this.	Control / electronics	Service
11	No stored code. Codes erase after a power interruption or 48 hours.	Status / reminder	Service
12	The blower runs 90 seconds if power returns during a call for heat (normal).	Status / reminder	Service
Rapid flashing	Line polarity is reversed. Electrician or technician.	Power supply	Service

Symptoms

Sources

https://www.shareddocs.com/hvac/docs/1009/Public/03/58D_U-9SM.pdf (official)

Last reviewed: October 20, 2026. ErrorCodePro is not affiliated with Carrier.