A Guide to Error Codes on Furnace Thermostats and How to Correct Them

When a thermostat is installed in your home, it can serve as an important indicator of whether there are any issues with your furnace. If the thermostat starts sending error codes and diagnostic alerts when the system is turned on, you should consider them as red flags that indicate potential problems. Reducing the risk of malfunctioning or damaged equipment is why manufacturers provide their own set of troubleshooting tips for users when a specific error code appears on the device’s display. But what if you don’t have this information? Fortunately, online communities such as FixYa have compiled databases of common error codes and their solutions for many brands and models of thermostats.

Error Code 21

The most common error code observed on thermostats is Error Code 21. It’s usually followed by numbers that indicate further details and instructions on how to correct the problem. The reason behind this error code is that the thermostat can’t detect a power source or the power source is faulty. The first step in troubleshooting is to check the circuit breaker and make sure that it is turned on. If it is, it is likely that the main power source is faulty. You should get in touch with your utility company to have it checked. If the circuit breaker is off, you have to check whether the power source is connected to the thermostat. In many cases, the thermostat is wired to an outlet that is switched on and off with the furnace. If the circuit is faulty, the entire system will stop working. In this case, you need to replace the circuit or contact the utility company again and inform them of the problem.

Error Code 24

Another frequent error code is Error Code 24. It is followed by a series of numbers that indicate the exact problem. The thermostat can’t communicate with the furnace, and the problem is with the wiring. This error code can signal that the thermostat is wired to a lower circuit than the furnace. If the circuit is higher than the thermostat, it won’t have the power to communicate with the furnace. In this case, you have to rewire the thermostat to the same circuit as the furnace. If the circuit is the same but the wiring is damaged, the system will still fail to communicate, resulting in this error code. You will have to replace the wiring or consult a professional.

Error Code 25

Error Code 25 indicates that the thermostat can’t detect a signal from the furnace. This problem is usually caused by a wiring error. In this case, you have to check the wiring and replace the damaged parts or rewire the entire system. In some cases, the furnace may be broken and isn’t sending any signals to the thermostat. If this is the case, you will have to replace the furnace.

Error Code 34

Error Code 34 is often followed by an error code that indicates the problem. In this case, the problem is with the wiring. In most cases, the wiring is connected to the wrong terminals on the thermostat. To correct this error, you have to check the wiring and make sure it is connected to the correct terminals on the thermostat. In some cases, you may have to rewire the entire system.

Error Code 38

Error Code 38 is followed by a series of numbers that indicate the reason for the error. In most cases, it is a wiring error. You may have rewired the system incorrectly or the wires may be faulty. If the wiring is incorrect, you will have to check the wiring and make sure it is connected correctly to the terminals on the thermostat. The wiring may also be damaged and have to be replaced.

Error Code 40

Error Code 40 is a common error that indicates that the thermostat can’t connect to the internet or there is a problem with the internet connection. In most cases, you will have to check the internet connection and make sure that the system is working properly. If the internet connection is faulty, you may want to contact your ISP and report the problem.

Conclusion

Thermostats are an essential part of any heating and cooling system. But what happens when something goes wrong? When your thermostat starts sending error codes, it’s time to take action. With this guide, you’ll have all the information you need to troubleshoot and fix any problems that come up. With a little bit of effort, you’ll have your system working like new in no time.