Error code

Carrier furnace error code 34

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Is 34 on a Carrier furnace an emergency?

Usually not an emergency. If you smell gas, do not touch switches or try to relight anything: leave, and call the gas utility or 911 from outside.

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What 34 means

“IGNITION PROVING FAILURE”

— Carrier (shareddocs.com, Carrier's literature host), Carrier 58MCB gas furnace Service and Maintenance Instructions (status codes). Codes vary by model: check your furnace’s own manual.

Where 34 fits

In plain words, 34 is about ignition — the burner did not light, or the control saw a flame signal it did not expect.

Carrier gives 2 other ignition and flame codes for this furnace: 14 (IGNITION LOCKOUT), 22 (ABNORMAL FLAME-PROVING SIGNAL).

Next to 34 in Carrier’s table: 33 (LIMIT CIRCUIT FAULT) and 45 (CONTROL CIRCUITRY LOCKOUT).

What to try first

  • Check the gas supply valve to the furnace is on; if it continues, call an HVAC technician.

Safety: If you smell gas, do not touch switches or try to relight anything: leave, and call the gas utility or 911 from outside.

How urgent is it?

At least THIS WEEK. fixRAgent treats this code as a this-week repair: the appliance has reported a fault, but the code alone does not point at a safety hazard. This is fixRAgent’s reading, not the manufacturer’s. A photo can raise it — water near wiring, scorch marks, a gas smell — but a code never lowers what the photo shows.

Who to call

HVAC technician. Have the model and serial numbers from the label ready — a photo of the label works.

Recalls and manuals

Check whether your model is under a safety recall on the U.S. Consumer Product Safety Commission’s site: cpsc.gov/Recalls. Your owner’s manual is on Carrier’s support site; search it with the model number from the label.