The Most Common Goodman Furnace Error Codes and What They Mean

When you’re using an automated system like a furnace, you might think that it operates with perfect efficiency all the time. However, even these devices have their quirks and are prone to error codes at times. When this happens, you’ll want to be able to identify the problem as quickly as possible so that you can take action and resolve the issue before it gets worse. Knowing what the different codes mean is also essential in understanding how best to troubleshoot and fix any issues with your unit. If you are a homeowner who has installed a new gas or electric furnace recently, then sooner or later, chances are good that you will get an error code on your furnace control panel. These automatic systems often make use of diagnostic codes to indicate where a problem lies when something unexpected happens during operation.

Check the Basics First

If you’ve ruled out other more serious issues with your furnace, the first place to start is with the basics. For example, every automated system is designed for a specific setting, so if you’ve adjusted the settings on your furnace, check that the level is correct. The same applies to the wiring and connections. If you’ve recently moved your furnace, it’s also possible that the system is still set up for another house and will read an error code because it doesn’t recognize the settings in your current home. Similarly, if you’ve changed the type of fuel your furnace uses, the settings on the system might not be appropriate for the new fuel. It’s always best to make sure that these things are set up correctly before trying to troubleshoot any error codes you might receive. Just because you see an error code doesn’t necessarily mean there is something wrong with your furnace.

Check Location and Environment

The conditions in which you operate your furnace could also be to blame for an error code. For example, if you’re burning fuel like natural gas, you need to be sure that the lines leading to and from your furnace are properly vented to the outside. The same goes for your carbon dioxide lines. If there is a kink or blockage in the line, it could cause your furnace to display an error code. Similarly, make sure that your air filter is clean and your system is properly charged with refrigerant. A clogged filter could impede the flow of air through your system, and a low refrigerant charge could cause an overpressure condition in the system and trip a pressure switch.

Constant Error Codes

Certain error codes are usually consistent when the furnace is having a problem. For example, a low voltage error is usually related to a power problem and could be caused by a blown fuse, tripped circuit breaker, or a loose connection. Some systems also have a self-diagnostic feature that could kick in if the voltage is too low. As a rule of thumb, if you’re getting a low voltage error code and you’ve already checked all of the connections and fuses, you might want to get an electrician to take a look at your system. Likewise, if you see a diagnostic code that mentions an overheating furnace or an overpressure condition, you can be pretty sure that there is a problem with airflow through your system. This could be due to a clogged filter or a restricted line, or because the system has too little refrigerant in it.

One-Time Error Codes

These are the error codes that only appear once. This doesn’t necessarily mean that you can ignore them, but if they only appear once, then a single fix probably won’t resolve the issue. You might have to have your system serviced or make some adjustments to get the code to stop appearing on your furnace control panel. One-time error codes that indicate a problem with the burner system on your furnace, for example, are often resolved by cleaning the burner or adjusting the air/fuel mixture. You might also see an error code that indicates the control system is overloading. If this happens, you can usually adjust the load by lowering the fan speed or changing the number of zone settings on the system.

What Does Each Code Mean?

Depending on the system, the error codes could be different, but some are fairly common among various brands of furnaces. For example, an E0 code is often a problem related to the air intake sensor. You can also expect to see an E1 code if your system has trouble reading the thermostat. Some systems also use an E2 code to indicate a problem with the blower motor. Many systems also use an F code to indicate a problem with the flame sensor. An F2 means that the flame is weak, while an F3 means that the flame is too strong. You might also see a code like L1 or L2 that indicates a problem with the combustion blower or the exhaust blower. And if a system displays a code like P1 or P2, it means that there is a problem with the pressure switch, either too much or too little pressure in the system.


Overall, it’s important to remember that just because you see an error code on your furnace, it doesn’t necessarily mean that something is broken. Sometimes, it’s just a sign that you need to clean your system or make some minor adjustments to get it running correctly. However, if you see the same code appearing on your system over and over again and you’ve already tried to troubleshoot the issue, it’s time to call a professional to have the system inspected.