Carrier Furnace Error Codes: What Do They Mean?

As anyone who has owned or operated a carrier system knows, their technology can be extremely reliable. However, all industrial equipment will occasionally have a performance issue. When this happens with your furnace, it’s important to understand what type of diagnostic codes you see on your controller and how to troubleshoot the error code you see. We’ll take a look at some of the most common error codes that may appear on your Carrier gas furnace and the steps necessary to correct them. Understanding these codes and how to fix them can help you get back up and running more quickly so that business operations are not impacted too significantly. In this article, we’ll explain what each code means and how to repair your system so that the error does not occur again in the future.

Error Code -1

The first code we’ll take a look at is an “Error Code -1”. The first digit of the error code is always a “-”, but an “Error Code -1” can have one of several different meanings. Generally speaking, an error code -1 is usually caused by one of the following issues: If your system is running a diagnostic and indicates an error code -1, you may want to double-check the following items: – Computer communications – Make sure your communications cable is properly connected to the furnace and the controller. If you are operating a multi-station system, the communications cable will have multiple connectors that run between the stations and the controller. If there are any errors or problems during communications, the controller will generally display a “Communications Error”. If the furnace is not communicating properly with the controller, a “Communications Error” will cause an error code -1. – Oil pressure – If your furnace requires oil or gas to complete the combustion process, the system will look for a specific pressure in the line. If the line pressure is too low, an error code -1 will generally be displayed on the controller. If the oil pressure is too low, there may be a leak in the system; however, it can also be caused by a clogged filter or a dirty oil burner.

Error Code 10

If you are running a diagnostic on your furnace and it displays an error code 10, this generally means that there is not enough air pressure in the air intake piping. If you are operating a single-staged system, an error code 10 means that there is not enough air pressure in the primary air intake line. If you are running a two-stage system, an error code 10 means that there is not enough air pressure in the secondary air intake line. Typically, you will see an error code 10 when the system is running a diagnostics test and it detects that the pressure in the primary or secondary air intake line is too low. In most cases, the pressure needs to be at or above 5 psi for the furnace to begin normal operation. If the pressure is too low, air can leak into the system through the air intake piping, reducing the combustion pressure. If there is not enough pressure in the air intake piping, the furnace will not be able to draw enough air in the combustion process.

Error Code 14

If you see an error code 14 when running a diagnostics test on your furnace, this means that the exhaust line pressure is too low. If you are running a single-stage system, an error code 14 in the exhaust line means that the pressure is too low in the primary exhaust line. If you are running a two-stage system, an error code 14 in the exhaust line means that the pressure is too low in the second exhaust line. If you see an error code 14, check the pressure in the exhaust line. In most cases, the pressure needs to be at or above 5 psi for the furnace to begin normal operation. If the pressure is too low, air can leak into the system through the exhaust piping, reducing the combustion pressure. If there is not enough pressure in the exhaust line, the furnace will not be able to draw enough air in the combustion process.

Error Code 18

An error code 18 means that the system has detected an issue with the primary temperature sensor. This sensor is located in the primary section of the furnace, and it acts as a temperature gauge. If the primary temperature sensor detects that the temperature in the furnace is too high or too low, the control will display an error code 18. If the primary temperature sensor detects that the temperature is too high, there may be a blockage or clogs in the air intake piping. In some cases, the sensor may be faulty and need to be replaced.

Error Code 19

If you see an error code 19 when running a diagnostics test on your furnace, this generally means that the second temperature sensor has detected an issue. This sensor is located in the secondary section of the furnace and serves the same purpose as the primary sensor. The secondary temperature sensor is responsible for keeping an eye on the temperature in the furnace. If it detects that the temperature is too high or too low, the control will display an error code 19. If the second temperature sensor detects that the temperature is too high, there may be a blockage or clogs in the air intake piping. In some cases, the sensor may be faulty and need to be replaced.

Summary

If you are experiencing intermittent operational issues with your carrier gas furnace, it is important to understand what type of diagnostic codes you see on your controller and how to troubleshoot the error code you see. The first digit of the error code is always a “-”, but an “Error Code -1” can have one of several different meanings. An error codes 10, 14, 18, or 19 all indicate issues with the temperature sensors in the furnace. An error code 14 also indicates a low pressure in the exhaust line. An error code 20 is an issue with the CO sensor, an error code 21 is an issue with the oxygen sensor, and an error code 22 is an issue with the airflow sensor.