Carrier Furnace Error Codes

One of the largest HVAC manufacturers in the United States, founded in 1915.

Disclaimer
This site is not affiliated with or endorsed by Carrier Global Corporation.

How Carrier Furnaces Display Error Codes

Carrier furnaces use a two-digit LED blink code on the control board. An amber LED flashes a short-then-long pattern: count the short flashes for the first digit, then the long flashes for the second digit. For example, three short flashes followed by four long flashes means code 34. The board stores recent fault codes for retrieval.

This site covers 4 Carrier furnace models and a total of 72 error code entries. Select your model below to see the full code list with causes and repair guidance.

Carrier Furnace Models

Model Type
58MVC Variable Speed Gas Furnace →
58MVP Variable Speed Gas Furnace →
59SC2B Single Stage Gas Furnace →
59SC5A Single Stage Gas Furnace →

DIY-Friendly Carrier Error Codes

These error codes on Carrier furnaces are commonly resolved by a careful homeowner without a service call — typically by cleaning the flame sensor, checking filters, or inspecting the exhaust vent. Always turn off power and gas before attempting any repair.

Code Fault Models
14 Ignition Lockout 4 models
13 Limit Circuit Lockout 4 models
Continuous OFF No Power / Control Failure 4 models

High-Severity Carrier Error Codes

These codes indicate conditions that prevent normal furnace operation or involve safety-relevant components such as the gas valve, heat exchanger, or inducer motor. Most require a licensed HVAC technician to diagnose and repair safely.

Code Fault Models
22 Abnormal Flame-Proving Signal 4 models
45 Control Circuitry Lockout 4 models
21 Gas Heating Lockout 4 models
14 Ignition Lockout 4 models
34 Ignition Proving Failure 4 models
33 Limit Circuit Fault 4 models
13 Limit Circuit Lockout 4 models
31 Medium-Heat Pressure Switch or HPSR Relay Did Not Close or Reopened 4 models

About Carrier

Carrier traces its origins to 1902, when Willis Carrier, a mechanical engineer, invented modern air conditioning. In 1908, the Carrier Air Conditioner Company of America was established as a subsidiary of Buffalo Forge Company. In 1915, Carrier and six colleagues pooled resources to establish the independent Carrier Engineering Corporation, marking the formal founding of the modern company.

Carrier remained independent until 1979, when United Technologies Corporation acquired it. Following decades as a UTC subsidiary, Carrier was spun off as an independent publicly traded company in April 2020, listing on the New York Stock Exchange under the ticker symbol CARR with headquarters in Palm Beach Gardens, Florida.

Carrier in the Furnace Market

Carrier Global serves customers across 160 countries and reported revenues of approximately $21.7 billion in 2025 with a workforce of around 47,000 employees. The company operates through three primary business units: Carrier Residential, Carrier Commercial, and Carrier Cold Chain. Its residential furnace lineup spans three tiers — the premium Infinity System with modulating gas valves, the mid-market Performance Series, and the value-oriented Comfort Series — allowing Carrier to address a wide range of customer needs and price points.