A Honeywell smart thermostat is a great way to optimize how you use your home comfort system. But like any technology, you may occasionally run into a problem. With a digital display, Honeywell smart thermostats can provide an error code that certified technicians will use to get a better sense of what's going on. Here are some of the most likely error codes you could see on your Honeywell smart thermostat.
Honeywell Error Code e42
You may see this error code in the event that your home’s Wi-Fi connection did not present an IP address for the thermostat to connect to. This can occur if the router doesn't complete the Dynamic Host Configuration Protocol, or DHCP. This function automatically transmits the required IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can clear error code e42 by making sure that your router can complete the DHCP. When it does, you might also have to power cycle the router and complete the initial setup process again with the thermostat. Doing so should see to it that the DHCP is sent and connects to your smart thermostat.
Honeywell Error Code e02
Error code e02 is displayed if the password for accessing your home’s Wi-Fi router is not correct. When this error code is displayed 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 have to do to clear error e02 is verify you’re putting in the correct Wi-Fi password when configuring the thermostat.
Error Code 40 for Honeywell Thermostats
Error code 40 can pop up when the thermostat is alerted that a heat pump or air conditioner’s monitoring system has recognized a malfunction. For the most part, this happens once the compressor isn’t running despite being instructed to. But this error code can also surface if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, triggered by blocked airflow, can lead to this error code. And finally, you could 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 check the air filter for signs of a clog, as well as the breakers and indoor unit’s blower for regular operation. If you turn the thermostat off and on again and error code 40 reappears, you should try to get in touch with an experienced technician.
Error Code e43 for Honeywell Thermostats
If the Honeywell thermostat presents error code e43, it can’t 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
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.
Error Code e1 for Honeywell Thermostats
Thermostats employ sensors to identify the temperature outdoors and indoors. If a sensor fails, you could see error code e1 appear on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A trained technician can replace the sensor and reset the thermostat, which should resolve error code e1.
Error Code 11n for Honeywell Thermostats
Error code 11n may appear if the thermostat is unable to recognize a heating or cooling unit. This may 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 professional technician can employ a voltmeter to determine if there’s a bad electrical connection. When the wiring on your type of HVAC equipment is bad, the technician can replace it. If the thermostat itself is the problem, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you see error code e2 appear on your Honeywell smart thermostat, it might mean several different things. Sometimes, one of the sensors that detects the temperature isn’t working like it should. In other instances, it means the router was disconnected from power 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 swap out the damaged sensor. When the problem comes from disconnected power, all you have to do is make sure the router stays on over the course of the setup process.