Troubleshooting Trane Furnace Error Codes: A DIY Guide for the Homeowner

There are many reasons why an air conditioning unit won’t turn on. Trane furnaces have error codes that activate when a problem is detected. These codes alert the user to investigate potential issues with the system. A failure to turn it on doesn’t necessarily mean you need a new AC unit. In most cases, it could be as simple as resetting a breaker or replacing a tripped sensor switch. Trane error codes can help you troubleshoot your Trane furnace and determine which of its components might need repairs or replacement. This article will tell you what those error codes mean and how to address the issue by following some troubleshooting tips specific to your model of furnace.

What Does a Trane Furnace Error Code Mean?

Error codes are used by most major brands of furnaces and air conditioners to help troubleshoot and repair issues with the equipment. They are used as an onboard diagnostic tool to let the user know they have a problem. Trane error codes are listed in a table that can be located on the furnace’s control board. The table is broken down into columns, each with a different code number that corresponds to a specific problem. The code is usually displayed on the control board as a three-digit number, as well as a word description of the code. There are a few different components that can cause an error code to appear on your unit. It could be as simple as needing to reset a tripped breaker. However, it could also be a sign of a bigger problem that needs to be addressed by a professional. You can use the error code table to help you determine what the issue may be and how to address it.

Resetting the Electronic Control Module

Most furnaces and air conditioners have an electronic control module that is used to manage and facilitate the operation of the unit. If it malfunctions, it could cause one or more of the error codes listed on the error code table. The first step in troubleshooting is to reset the control module. You can do this with an ohmmeter. First, unplug the unit and shut off the power at the circuit breaker. Next, you will use the ohmmeter to test the control board. There are three pairs of wires on the control board, each pair connected to a different part of the board. The top wire of each pair is positive, while the bottom wire is negative. When you are testing the control board, touch the negative lead of the ohmmeter to the negative terminal on the board and the positive lead to the middle wire of the pair. If the error code disappears, the problem is with the control board.

Checking the Air Filters

An air filter that is clogged can cause pressure differential problems in your system and lead to a trip that activates the error code. If you have a two-stage system, the filter in the first stage is what’s responsible for removing the majority of the dirt, dust, and other contaminants. In order to operate properly and keep your system operating efficiently, the first-stage filter has to be clean. If not, then there is too much resistance in the system, and the blower motor of the first stage will trip. Once you’ve reset the error code, you can check the air filters to see if they need to be cleaned or replaced. If the filter needs to be replaced, make sure you get the right one for your unit. In some cases, the two-stage filter may need to be cleaned more often than once a year. This can depend on several factors, including the size of your home and the number of occupants.

Resetting the Electronic Motor Controller

As the name indicates, an electronic motor controller is responsible for managing the operation of the motor in a system. If the controller is faulty, it can cause an error code to appear. To reset the controller, you will need to unplug the unit and shut off the power to the circuit breaker. Next, you will place an ohmmeter across the wires connected to the controller. Touch the positive lead of the ohmmeter to the positive terminal on the controller and the negative lead to the negative terminal on the controller. If the error code disappears, the problem is with the motor controller.

Turning on the Condenser and Residual Valve

The problem may be with the condenser and residual pressure valve. These two components make up the outdoor portion of the system. The condenser is responsible for removing heat from the refrigerant gas that is circulating through the system. The outdoor unit also has a pressure switch that acts as a pressure gauge. This is used to monitor the pressure in the refrigerant lines. When the pressure drops below the manufacturer’s recommended amount, the pressure switch will trip and activate the error code. If the pressure switch is tripped, you can reset it by turning on the circuit breaker, disconnecting the wires, and then reconnecting them. Next, you will turn the circuit breaker back on. The residual pressure valve is used to protect the compressor from overheating. It works by releasing the excess heat that is produced by the compressor through an outside drain pipe. When the valve is tripped, it closes and stops the flow of heat out of the system.

Resetting the Combustion Safety Controls

The combustion safety controls are used to monitor the operation of the burner. They will trip if the burner isn’t functioning properly or there is a problem with the burner or the combustion chamber. To reset the combustion safety controls, you will need to turn off the circuit breaker, unplug the unit and then remove the control board. When it’s unplugged, there will be two wires coming from the control board. One will be black and the other will be red. You will need to unplug the red wire and then turn the breaker back on. When you plug the red wire back in, the error code will disappear.


A Trane furnace won’t turn on if you have an error code. What you need to do is find the error code and then read the troubleshooting guide to identify the problem. From there, you can solve the problem by replacing the component or cleaning the filter. If you have questions about resetting the error code or can’t identify the error code, a professional technician can help you troubleshoot the problem.