A Honeywell smart thermostat is a great way to better manage how you use your HVAC system. But like any technology, you could occasionally experience a problem. With the digital display, Honeywell smart thermostats can show an error code that trained technicians will use to understand what's happening. Here are a few of the most common error codes you may see on your Honeywell smart thermostat.
Error Code e42 for Honeywell Thermostats
You might receive this error code if your home’s Wi-Fi connection did not supply an IP address for the thermostat to connect to. This can happen if a router does not perform the Dynamic Host Configuration Protocol, or DHCP. This process automatically sends out the required IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by verifying that your router has enabled DHCP. Assuming it does, you might also need to power cycle the router and complete the initial setup process again with your thermostat. Completing this task should ensure the DHCP is sent and connects to your smart thermostat.
Honeywell Error Code e02
Error code e02 appears whenever the password for connecting to your home’s Wi-Fi router is not correct. Once this error code appears for 30 seconds, the thermostat’s digital display will automatically progress to the Wi-Fi setup screen so you can try to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you have to do to resolve error e02 is ensure you’re typing the correct Wi-Fi password when configuring the thermostat.
Honeywell Thermostat Error 40
Error code 40 can pop up when the thermostat is alerted that a heat pump or air conditioner’s monitoring system has detected a malfunction. For the most part, this occurs if the compressor isn’t turning on despite being directed to. But this error code can also show up if power is disconnected from the outdoor unit for an extended period of time. A “High Pressure Fault” error, induced by obstructed airflow, can lead to this error code. And finally, you may see error code 40 if there’s something wrong 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 regular operation. If you restart the thermostat and error code 40 reappears, it's time to contact an experienced technician.
Honeywell Error Code e43
If the Honeywell thermostat presents error code e43, it is failing to communicate with the router, and by extension your Wi-Fi. This may 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 around 30 seconds. The thermostat might also be disconnected if you’ve recently updated the password or the Wi-Fi’s SSID, which is the name you provide it.
Error Code e1 for Honeywell Thermostats
Thermostats utilize sensors to detect the temperature outdoors and indoors. If a sensor malfunctions, you may notice error code e1 appear on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A trained technician can swap out the sensor and restart the thermostat, which should resolve error code e1.
Honeywell Error Code 11n
Error code 11n can appear if the thermostat is unable to recognize a heating or cooling unit. This may mean that the equipment itself is defective 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 professional technician can utilize a voltmeter to find out if there’s a faulty electrical connection. When the wiring on your type of HVAC system is bad, the technician can replace it. When the thermostat itself is the problem, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you notice error code e2 appear on your Honeywell smart thermostat, it could mean a few different things. In some cases, one of the sensors used to detect the temperature isn’t functioning correctly. In other cases, 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 caused by sensor failure, a technician should troubleshoot and switch out the damaged sensor. If the problem comes from disconnected power, all you have to do is see to it that the router stays on during the setup process.