Troubleshooting Tips for Carrier Furnace Error Codes

You may think that your Carrier furnace is just another appliance in your home and you probably don’t need to know how it works. However, if something goes wrong with your furnace, you’ll want to know how to troubleshoot the problem before calling a technician. If you find yourself facing a problem with your Carrier furnace, these troubleshooting tips will help you identify the problem and solve it quickly. In most cases, these tips will resolve any issues with the furnace and get it working again. Even if they don’t, they should give you enough information to call an expert for assistance. Regardless of what model or series of Carrier gas furnaces you have, certain error codes can appear on its control panel at some point in its lifespan. These error codes indicate a specific issue has occurred with your unit and require further diagnostics to be performed before it can be fixed correctly.

Error Code 17: Electronic Rotary Speed Control (ERSC) Problem

Erratic or unexpected noises from your furnace are often caused by a problem with its rotary speed control. This control is responsible for regulating the burn rate and speed of your furnace’s blower fan, as well as its burner’s speed. Faulty rotary speed control can send your furnace into an “err’’ state, where it will display Error Code 17 on its digital display. You can easily determine if this is the issue by listening to the furnace’s blower fan. If it is running too fast, too slow, or unevenly, it could be due to a problem with the rotary speed control. While some of these issues could also be caused by a clogged air filter, overheated blower motor, or faulty blower wheel, these issues are usually intermittent and not as consistent. To correct any issues with your rotary speed control, you’ll need to remove the furnace’s access panel and check its wiring connections. You should also clean or replace your furnace’s air filter to see if that resolves the issue. If the problem persists, you’ll need to order and replace the rotary speed control.

Error Code 19: Electronic Rotary Speed Control (ERSC) and Burner Problem

Another common problem with your Carrier furnace is a miscommunication between its burner and rotary speed control. The burner is responsible for igniting the natural gas that powers your furnace while the rotary speed control regulates the fan speed and burner speed. This combination allows both the blower and burner to operate at the same time. When the burner and rotary speed control aren’t in sync, your furnace will display Error Code 19 and shut down. This error code is also accompanied by an “ERSC” or “NOISE” message on the digital display. This type of problem could be caused by a variety of issues, such as a faulty burner, loose wiring connections, or a dirty air filter. If you notice the burner is not lighting or is taking too long to ignite, it may be due to a dirty gas line. If the burner shuts down prematurely, it could have been tripped by a safety device, low gas pressure, or a faulty pressure regulator. In most cases, you’ll need to clean or replace your furnace’s air filter to fix this problem. If that doesn’t work, you may need to replace the rotary speed control or the burner.

Error Code 21: Electronic Air and Burner Management (EABM) Problem

Another common problem with Carrier furnaces is a miscommunication between the EABM and the ERSC. The EABM is responsible for regulating the blower speed and burner speed and is often accompanied by a “WEAK” message on the digital display. This combination can be problematic because the EABM is designed to regulate the blower speed based on the furnace’s current load, or the amount of heat being produced. This means that the blower speed could change during operation without warning. One of the most common issues with the EABM is miscommunication with the ERSC. If the burner is requesting more gas, but the EABM is unable to provide more air, the furnace’s blower will slow down as a result. This will indicate a problem with the EABM and display an “ERROR” message on the digital display. Depending on the severity of the problem, you may notice the furnace running more slowly. If the EABM is unable to provide more air to the burner, the furnace will shut down prematurely. You may also notice a reduction in the furnace’s overall output due to the reduced blower speed. To correct this problem, you’ll need to check the wiring connections between the ERSC and EABM. You may also need to clean or replace your furnace’s air filter to resolve the issue. If the problem persists, you’ll need to order and replace the EABM.

Error Code 23: Electronic Air and Burner Management (EABM) and Fan Speed Problem

A problem with your furnace’s fan speed is often indicative of an issue with the EABM. As mentioned above, the EABM is responsible for regulating the blower speed, burner speed, and fan speed. This combination allows all three components to operate at the same time. When the fan speed drops below normal, your furnace will display Error Code 23 on its digital display accompanied by an “R”, “L”, or “B” next to the fan speed. There are a few reasons your fan speed could be dropping below normal, including a clogged air filter, a bad fan motor, or a dirty or faulty EABM. If you notice your furnace’s fan speed is dropping below normal, you should clean or replace your air filter as soon as possible. If the problem persists, you may need to replace the fan motor and/or the EABM.

Error Code 25: Electronic Air and Flame Management (EAFM) Problem

Another common problem with Carrier furnaces is a miscommunication between the EAFM and the ERSC. The EAFM is responsible for regulating the blower speed and burner speed, as well as the flame safety device. A miscommunication between the EAFM and the ERSC will shut down the furnace with an “ERROR” message displayed on the digital display. One of the most common issues with the EAFM is miscommunication with the ERSC. If the burner is requesting more gas, but the EAFM is unable to provide more air, the furnace’s blower will slow down as a result. Depending on the severity of the problem, you may notice the furnace running more slowly. If the EAFM is unable to provide more air to the burner, the furnace will shut down prematurely. You may also notice a reduction in the furnace’s overall output due to the reduced blower speed. To correct this problem, you’ll need to check the wiring connections between the ERSC and EAFM. You may also need to clean or replace your furnace’s air filter to resolve the issue. If the problem persists, you’ll need to order and replace the EAFM.

Error Code 31: Boiler Limit/Boiler Shutdown Problem

The boiler limit/boiler shutdown problem is most commonly caused by a faulty pressure switch. If the pressure switch detects a drop in the furnace’s pressure, the furnace will shut down and display the “PRESSURE” message on the digital display. If the pressure switch is faulty, it may falsely detect a pressure drop. This may be due to a buildup of mineral deposits or a faulty pressure switch. A faulty pressure switch can also prevent the furnace from igniting or from reaching the proper operating temperature. If you notice the “PRESSURE” message on your furnace’s display, you should clean or replace your furnace’s pressure switch. In some cases, you may need to call a technician to test the pressure switch for you before you can clean it. If the pressure switch is faulty, you’ll need to replace it to resolve the issue.