Furnace Fault Codes

Carrier, Bryant and Payne furnace status codes

Carrier status codes are two digits, shown as short flashes for the first digit and long flashes for the second. Bryant and Payne furnaces of the same generation use the same control and the same codes.

Also covers: Bryant, Payne — same manufacturer, same controls, same codes.

Carrier's integrated furnace controls report faults as two-digit status codes rather than a simple count. The first digit is the number of short flashes and the second is the number of long flashes, so code 33 is three short flashes followed by three long ones. Bryant and Payne are the same manufacturer and use the same control, so these codes apply across all three brands.

Worth knowing before you count

On red LED Carrier boards, stored codes are erased whenever power to the control is interrupted. Switching a faulted furnace off and on before reading the display destroys the information you were about to look up. Amber LED boards keep the code through a power cut — but their retrieval procedure has a four second limit that will overwrite the stored code with a false one if exceeded.

How Carrier furnaces signal codes

The status LED sits on the integrated furnace control, and on most models it can be read through the sight glass in the blower access door without opening anything — which matters, because removing the blower door trips the door switch and cuts power to the light you were trying to read. A code is one repeating pattern: short flashes for the first digit, a pause, long flashes for the second, then a longer pause before the whole thing repeats. Count several full cycles before trusting the number, and note the two patterns that are not two-digit codes at all — an LED that never lights, meaning no power is reaching the control, and rapid continuous flashing, meaning reversed line polarity.

Which LED colour your board carries decides how careful to be with the power switch. Red LED boards lose the stored code on any power interruption. Amber LED boards, fitted to the 58SC0A and 58SC1A, keep it through a power cut and support a stored-code retrieval procedure — but that procedure involves briefly disconnecting a wire near live terminals and has a four-second limit that fabricates a false limit-circuit code 33 if overrun, which is why it is technician work rather than a homeowner step.

The Carrier codes people look up most

Three fault families produce most Carrier status-code lookups. Ignition: code 14 is an ignition lockout after failed attempts, and code 34 is the ignition proving failure that usually precedes it — the furnace tried to light and could not prove flame. Draft: code 31 means the pressure switch did not close or reopened, and its mirror, code 23, means it did not open; both point at the inducer and the venting before they point at the switch itself. Airflow and overheating: code 13 is a limit circuit lockout and code 33 the underlying limit trip — and Carrier folds the flame rollout switch into that same limit circuit rather than giving it a code of its own, so 33 covers both. Code 24, a blown secondary voltage fuse, is worth knowing because a popped fuse can also present as a furnace that has simply gone dark.

Which Carrier furnaces these pages cover

The status code meanings on these pages are documented from the Carrier 58MCB service manual, and the amber LED retrieval procedure from the 58SC0A and 58SC1A installation, start-up and service instructions. Bryant and Payne are the same manufacturer using the same integrated controls, so the codes apply to equivalent Bryant and Payne furnaces of the same generation. If your furnace shows a code these pages do not list, the code legend printed inside the furnace access panel is authoritative for your specific model in a way a general table cannot be.

What the common Carrier fixes cost

Ignition codes 14 and 34 most often end at the hot surface igniter: $150–350 installed on a standard visit, with the part itself $20–60 universal or $40–120 OEM. Pressure switch codes 23 and 31 run $150–400 — with a blocked flue checked first, since the switch is usually reporting a draft problem rather than failing. A limit trip behind 13 or 33 is $150–350, and the useful money goes to finding why it tripped, not just swapping the switch. Code 24 can be a $5–150 low-voltage fuse rather than the $400–900 board it impersonates, and code 45 is legitimate board territory. A diagnostic visit runs $75–150 and is often credited against the repair — full ranges in the furnace repair cost guide.

Carrier and Bryant

Other manufacturers

This site is a reference, not a substitute for a licensed HVAC technician. Gas appliances can leak carbon monoxide and cause fire. Anything involving gas lines, the heat exchanger, or the flame sensing circuit should be handled by a licensed professional. Pages are written with AI assistance from the sources listed on each page and checked against them before publishing.