A Honeywell smart thermostat is an excellent way to better manage how you use your home comfort system. But like any mechanical system, you might sometimes run into a problem. With its digital display, Honeywell smart thermostats can show an error code that trained technicians use to understand what's going on. Here are a few of the most likely error codes you may see on your Honeywell smart thermostat.
Error Code e42 for Honeywell Thermostats
You might encounter this error code if your home’s Wi-Fi connection did not supply an IP address for the thermostat to connect with. This can occur if your router fails to execute the Dynamic Host Configuration Protocol, or DHCP. This process automatically transmits the required IP address for your thermostat to connect to the Wi-Fi.
How to Fix Honeywell Thermostat Error e42
You can clear error code e42 by confirming that your router can complete the DHCP. If it does, you usually also need to power cycle the router and perform the setup process again with your thermostat. Completing this task should see to it that the DHCP is transmitted and connects to your smart thermostat.
Honeywell Error Code e02
Error code e02 occurs if the password for communicating with your home’s Wi-Fi router was incorrect. When this error code has appeared for 30 seconds, the thermostat’s digital display should automatically transition to the Wi-Fi setup screen so you can try the password again.
How to Fix Honeywell Thermostat Error e02
All you'll need to do to clear error e02 is make sure you’re entering the correct Wi-Fi password when setting up the thermostat.
Error Code 40 for Honeywell Thermostats
Error code 40 can appear when the thermostat is notified that a heat pump or air conditioner’s monitoring system has detected a malfunction. For the most part, this appears when the compressor isn’t turning on despite being instructed to. But this error code may also appear if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, caused by poor airflow, can display this error code. Lastly, you could see error code 40 if there’s a problem with the refrigerant, the outdoor unit’s fan motor or the motor’s starting capacitor.
How to Fix Honeywell Thermostat Error 40
You can inspect the air filter for signs of a clog, as well as the breakers and indoor unit’s blower for normal operation. If you restart the thermostat and error code 40 reappears, it’s best to get in touch with an experienced technician.
Honeywell Error Code e43
If a Honeywell thermostat presents error code e43, it is unable to communicate with the router, and by extension the Wi-Fi. This can happen if the router’s ethernet cable isn’t plugged in or it isn’t communicating with the wide area network (WAN).
How to Fix Honeywell Thermostat Error e43
Reboot the router by unplugging it and leaving it that way for a short period. The thermostat might also be disconnected if you’ve recently changed the password or the Wi-Fi’s SSID, which is the name you provide it.
Error Code e1 for Honeywell Thermostats
Thermostats use sensors to detect the temperature outdoors and indoors. If a sensor malfunctions, you could notice error code e1 appear on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can swap out the sensor and reset the thermostat, which should resolve error code e1.
Honeywell Error Code 11n
Error code 11n can appear if the thermostat is unable to connect to a heating or cooling unit. This might mean that the equipment itself is faulty and unable to maintain a connection to the thermostat. This sometimes happens when the wiring is bad or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A qualified technician can employ a voltmeter to determine if there’s a poor electrical connection. If the wiring on your specific HVAC equipment is bad, the technician can replace it. When the thermostat itself is the problem, it should probably be replaced.
Error Code e2 for Honeywell Thermostats
If you see error code e2 show up on your Honeywell smart thermostat, it might mean several different things. For example, one of the sensors used to detect the temperature isn’t functioning like it should. Other times, it means the router was disconnected from its power source before the thermostat finished the setup process.
How to Fix Honeywell Thermostat Error e2
If the error code is a result of sensor failure, a technician can troubleshoot and swap out the impacted sensor. When the problem originates from disconnected power, all you have to do is make sure the router remains on over the course of the setup process.