A Honeywell smart thermostat is an easy way to optimize how you use your home comfort system. But like any technology, you may occasionally run into a problem. With its digital display, Honeywell smart thermostats can display an error code that certified technicians will use to get a better sense of what's going on. Here are a few of the most known error codes you might see on your Honeywell smart thermostat.
Error Code e42 for Honeywell Thermostats
You can see this error code when your home’s Wi-Fi connection did not provide an IP address for the thermostat to connect with. This can occur if the router fails to execute the Dynamic Host Configuration Protocol, or DHCP. This process automatically transmits the necessary IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can clear error code e42 by confirming that your router is enabled for DHCP. If it does, you may also have 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 transmitted and connects to your smart thermostat.
Error Code e02 for Honeywell Thermostats
Error code e02 appears when the password for accessing your home’s Wi-Fi router was incorrect. When this error code appears 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 have to do to resolve error e02 is make sure you’re putting in the correct Wi-Fi password when setting up the thermostat.
Honeywell Error Code 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. Most commonly, this occurs when the compressor isn’t working despite being instructed to. But this error code could also show up if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, triggered by poor airflow, can render this error code. And finally, you might experience error code 40 if there’s a problem with the coolant, the outdoor unit’s fan motor or the motor’s starting capacitor.
How to Fix Honeywell Thermostat Error 40
You can examine 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 time to get in touch with an experienced technician.
Honeywell Error Code e43
If the Honeywell thermostat presents error code e43, it can’t communicate with the router, and by extension your Wi-Fi. This might 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
Reset the router by unplugging it and leaving it that way for around 30 seconds. The thermostat could also be disconnected if you recently changed the password or the Wi-Fi’s SSID, which is the name you give it.
Error Code e1 for Honeywell Thermostats
Thermostats utilize sensors to detect the temperature outdoors and indoors. If a sensor fails, you may notice error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A qualified 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 could appear in situations where the thermostat is unable to connect to a heating or cooling unit. This can mean that the equipment itself is defective and unable to connect with the thermostat. This sometimes happens when the wiring is damaged or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A qualified technician can employ a voltmeter to find out if there’s a poor electrical connection. In situations where the wiring on your specific HVAC equipment is bad, the technician can replace it. When the thermostat itself is the issue, it should probably be replaced.
Honeywell Thermostat Error e2
If you see error code e2 appear on your Honeywell smart thermostat, it could mean several different things. For example, one of the sensors used to detect the temperature isn’t operating properly. Other times, it means the router was disconnected from power before the thermostat completed the setup process.
How to Fix Honeywell Thermostat Error e2
In situations where the error code is caused by sensor failure, a technician should troubleshoot and replace the impacted sensor. Any time the problem comes from disconnected power, all you’ll have to do is verify the router stays on throughout the setup process.