A Honeywell smart thermostat is a great way to better manage how you use your heating and cooling. But like any mechanical system, you might sometimes run across a problem. With the 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 common error codes you might see on your Honeywell smart thermostat.
Error Code e42 for Honeywell Thermostats
You might see this error code in the event that your home’s Wi-Fi internet did not supply an IP address for the thermostat to connect with. This can happen if a router doesn't complete the Dynamic Host Configuration Protocol, or DHCP. This procedure automatically transmits the needed IP address for your thermostat to link up.
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 need to power cycle the router and repeat the initial setup process with the thermostat. Completing this task should see to it that the DHCP is delivered and connects to your smart thermostat.
Honeywell Error Code e02
Error code e02 is displayed if the password for communicating with your home’s Wi-Fi router is 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 to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you need to do to clear error e02 is make sure you’re typing the correct Wi-Fi password when setting up the thermostat.
Honeywell Error Code 40
Error code 40 can pop up when the thermostat is informed that a heat pump or air conditioner’s monitoring system has identified a malfunction. Most often, this appears when the compressor isn’t working despite being instructed to. But this error code can also surface if power is disconnected from the outdoor unit for a lengthy period of time. A “High Pressure Fault” error, caused by obstructed airflow, can render 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 regular operation. If you restart the thermostat and error code 40 reappears, you should try to get in touch with an experienced technician.
Honeywell Thermostat Error e43
If the Honeywell thermostat displays error code e43, it is unable to 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 about 30 seconds. The thermostat might also be disconnected if you recently updated the password or the Wi-Fi’s SSID, which is the name you provide it.
Honeywell Error Code e1
Thermostats use sensors to determine the temperature outdoors and indoors. If a sensor malfunctions, you may notice error code e1 turn up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A qualified technician can change out the sensor and restart the thermostat, which should clear error code e1.
Error Code 11n for Honeywell Thermostats
Error code 11n can appear when the thermostat can’t detect a heating or cooling unit. This can mean that the equipment itself is faulty and unable to maintain a connection to the thermostat. This can happen when the wiring is bad or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A professional technician can employ a voltmeter to assess if there’s a bad electrical connection. If the wiring on your type of HVAC system is bad, the technician can replace it. In situations where the thermostat itself is the problem, it will likely have to be replaced.
Honeywell Error Code e2
If you’ve noticed error code e2 show up on your Honeywell smart thermostat, it can mean a couple of different things. For example, one of the sensors responsible for detecting the temperature isn’t working like it should. Other times, it means the router was disconnected from its power source before the thermostat completed 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 affected sensor. Any time the problem comes from disconnected power, all you'll need to do is make sure the router remains on throughout the setup process.
