A Honeywell smart thermostat is an excellent way to better manage how you use your HVAC system. But like any utility, you may sometimes run into a problem. With its digital display, Honeywell smart thermostats can show an error code that trained technicians will use to get a better sense of what's going on. Here are several of the most common error codes you could see on your Honeywell smart thermostat.
Honeywell Error Code e42
You might encounter this error code if your home’s Wi-Fi connection did not provide an IP address for the thermostat to connect to. This can occur if your router does not perform the Dynamic Host Configuration Protocol, or DHCP. This procedure automatically supplies the required IP address for your thermostat to connect to the Wi-Fi.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by making sure that your router has enabled DHCP. When it does, you may also have to power cycle the router and repeat the initial setup process with your thermostat. Completing this task should see to it that the DHCP is sent and connects to your smart thermostat.
Error Code e02 for Honeywell Thermostats
Error code e02 occurs whenever the password for connecting to your home’s Wi-Fi router is incorrect. When this error code has appeared for 30 seconds, the thermostat’s digital display will automatically progress 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 ensure you’re typing the correct Wi-Fi password when configuring the thermostat.
Error Code 40 for Honeywell Thermostats
Error code 40 can show up when the thermostat is alerted that a heat pump or air conditioner’s monitoring system has detected a malfunction. Most commonly, this happens when the compressor isn’t working despite being instructed to. But this error code can also appear if power is shut off from the outdoor unit for an extended period of time. A “High Pressure Fault” error, caused by blocked airflow, can lead to this error code. Lastly, you might experience 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 Thermostat Error e43
If your Honeywell thermostat shows error code e43, it can’t communicate with the router, and by extension your Wi-Fi. This could happen if the router’s ethernet cable isn’t plugged in or it isn’t communicating with your 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 recently switched the password or the Wi-Fi’s SSID, which is the name you give it.
Honeywell Error Code e1
Thermostats utilize sensors to identify 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 change out the sensor and reboot the thermostat, which should take care of error code e1.
Error Code 11n for Honeywell Thermostats
Error code 11n may appear if the thermostat can’t recognize a heating or cooling unit. This may mean that the equipment itself is malfunctioning and unable to communicate with the thermostat. This can happen when the wiring is damaged or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A professional technician can utilize a voltmeter to determine if there’s a poor electrical connection. If the wiring on your specific HVAC system is bad, the technician can replace it. When the thermostat itself is the problem, it will likely have to be replaced.
Error Code e2 for Honeywell Thermostats
If you see error code e2 appear on your Honeywell smart thermostat, it can mean several different things. For example, one of the sensors used to detect the temperature isn’t operating correctly. In other instances, it means the router was disconnected from power before the thermostat could complete the setup process.
How to Fix Honeywell Thermostat Error e2
If the error code is a result of sensor failure, a technician should troubleshoot and swap out the impacted sensor. Any time the problem originates from disconnected power, all you'll need to do is verify the router remains on throughout the setup process.