Carrier Furnace Error Codes: How to Diagnose and Fix Common Problems

Keeping your HVAC system running smoothly is a constant battle. Even the best systems will break down now and again. The biggest challenge with any furnace is diagnosing problems when they occur. Several different error codes can appear on your thermostat or in other diagnostic software, alerting you to potential problems in your system. The specific error codes will vary depending on the brand and model of your furnace, but they all serve the same basic purpose: to let you know something has gone wrong and needs fixing before it gets worse. That being said, not all error codes indicate something is broken or about to break. Some of these errors are a result of user error (such as forgetting to set the thermostat), while others are expected events that merely need adjusting settings to function optimally again (such as CO2 filters needing changing). Here are some of the most common carrier furnace error codes, what they mean, and how to fix them:

FAN Error Codes

Fan-related issues account for about 30% of all furnace problems. This is most commonly caused by a lack of power to the blower motor. If the furnace cannot send power to the fan, it will not be able to move air through the system. If there is a power outage and the furnace continues to run, the van could break down, causing this error code. Another possibility is a broken or detached belt that connects the motor to the fan. If the belt snaps, the fan will not be able to spin, and the furnace will detect it. The most common Fan error codes are Fan motor overload/Too much current, Fan motor/blower wheel broken, Fan not turning, and Fan speed too high.

Glow Wire Error Codes

The CO sensor is the device that detects carbon monoxide (CO) in the exhaust. If a CO sensor error code appears, it means the sensor is not reading CO properly. There are two different ways this can happen. First, the sensor might be malfunctioning and need to be replaced. If the CO sensor is broken, the furnace will try to run, but it will shut down as soon as it detects CO in the exhaust. The other possibility for a CO sensor error code is that the sensor is blocked. This can happen if the sensor is dirty. Sometimes, a CO sensor error can be fixed by simply resetting the furnace. If the sensor is dirty, the furnace will detect it again when it tries to start up again.

CO Sensor Error Codes

The CO sensor is the device that detects carbon monoxide (CO) in the exhaust. If a CO sensor error code appears, it means the sensor is not reading CO properly. There are two different ways this can happen. First, the sensor might be malfunctioning and need to be replaced. If the CO sensor is broken, the furnace will try to run, but it will shut down as soon as it detects CO in the exhaust. The other possibility for a CO sensor error code is that the sensor is blocked. This can happen if the sensor is dirty. Sometimes, a CO sensor error can be fixed by simply resetting the furnace. If the sensor is dirty, the furnace will detect it again when it tries to start up again.

Electronic Module Error Codes

The electronic control module is the brain of the furnace. If the sensor detects an error in the module, it will display an error code. Some of the most common errors are: The sensor does not recognize the module, the module does not recognize the sensor or the sensor does not recognize the other components of the furnace. If the sensor is malfunctioning, the error will appear when you try to run the system. If the sensor is dirty, the error might show up after running the system for a while. If the sensor is misaligned, it might not be able to read the inputs from the other components.

Pressure Switch Error Codes

The pressure switch is designed to turn off the furnace if it detects low pressure in the system. If the pressure switch error code appears, the sensor detected a problem. Once again, there are two ways this can happen. First, the pressure switch might be broken and need to be replaced. If the pressure switch is dirty, it will not be able to detect the system pressure properly. Sometimes, a dirty pressure switch can be cleaned and fixed. If the pressure switch is broken, it will need to be replaced.

Safety Switch Error Codes

The safety switch is designed to turn off the furnace if it senses something is wrong with the system. If the safety switch error code appears, there is a problem with the sensor. There are two ways this can happen. First, the sensor might be broken and need to be replaced. If the sensor is dirty, it will not be able to detect problems in the system. Sometimes, a dirty sensor can be cleaned and fixed. If the sensor is broken, it will need to be replaced.

Conclusion

As you can see, every furnace has its errors, and dealing with them can be confusing. The best thing you can do to minimize frustration and get your system fixed quickly is to keep a maintenance log for your unit. If you know when something broke last time, you can keep an eye out for it happening again and make sure to get it fixed as soon as possible. This way, you can minimize the number of times you encounter error codes and make sure they do not become more serious issues.