A Honeywell smart thermostat is a great way to optimize how you use your heating and cooling. But like any technology, you may sometimes run into a problem. With a digital display, Honeywell smart thermostats can show an error code that certified technicians can use to get a better sense of what's going on. Here are a few of the most likely error codes you could see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You can receive this error code if your home’s Wi-Fi connection did not provide an IP address for the thermostat to connect with. This can take place if your router fails to execute the Dynamic Host Configuration Protocol, or DHCP. This function automatically sends out the necessary 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 making sure that your router can complete the DHCP. Assuming it does, you might also need to power cycle the router and repeat the initial setup process with your thermostat. Doing so should see to it that the DHCP is sent and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs when the password for communicating with your home’s Wi-Fi router was incorrect. Once this error code is displayed 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 have to do to resolve error e02 is make sure you’re entering the correct Wi-Fi password when configuring the thermostat.
Honeywell Thermostat Error 40
Error code 40 can appear when the thermostat is alerted that a heat pump or air conditioner’s monitoring system has detected a malfunction. For the most part, this appears if the compressor isn’t running despite being directed to. But this error code may also show up if power is shut off from the outdoor unit for a lengthy period of time. A “High Pressure Fault” error, caused by blocked airflow, can render this error code. Lastly, 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 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 the Honeywell thermostat displays error code e43, it can’t communicate with the router, and by extension the Wi-Fi. This may 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
Restart 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 create for it.
Honeywell Thermostat Error e1
Thermostats utilize sensors to detect the temperature outdoors and indoors. If a sensor malfunctions, you could see error code e1 turn up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can replace the sensor and reboot the thermostat, which should clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear in situations where the thermostat can’t connect to a heating or cooling unit. This may mean that the equipment itself is faulty and unable to connect with 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 use a voltmeter to assess if there’s a bad electrical connection. In situations where the wiring on your specific HVAC equipment is bad, the technician can replace it. If the thermostat itself is the problem, it should probably be replaced.
Honeywell Thermostat Error e2
If you notice error code e2 pop up on your Honeywell smart thermostat, it can mean a couple of different things. In some cases, one of the sensors responsible for detecting the temperature isn’t operating properly. In other cases, 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 stems from sensor failure, a technician can troubleshoot and replace the damaged sensor. If the problem originates from disconnected power, all you'll need to do is make sure the router remains on over the course of the setup process.