A Honeywell smart thermostat is an easy way to optimize how you use your HVAC system. But like any technology, you could occasionally run into a problem. With the digital display, Honeywell smart thermostats can display an error code that certified technicians use to get a better sense of what's going on. Here are a few of the most likely error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You might encounter this error code if your home’s Wi-Fi internet did not present an IP address for the thermostat to connect with. This can happen if your router does not perform 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 fix error code e42 by confirming that your router has enabled DHCP. If it does, you may also have to power cycle the router and perform the setup process again with the thermostat. Completing this task should see to it that the DHCP is sent and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs whenever the password for accessing your home’s Wi-Fi router is not correct. After this error code has appeared for 30 seconds, the thermostat’s digital display automatically transitions 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 solve error e02 is verify you’re entering the correct Wi-Fi password when configuring the thermostat.
Honeywell Thermostat Error 40
Error code 40 can show up when the thermostat is notified that a heat pump or air conditioner’s monitoring system has recognized a malfunction. Most often, this occurs when the compressor isn’t running despite being directed to. But this error code may also show up if power is disconnected from the outdoor unit for a long period of time. A “High Pressure Fault” error, caused by poor airflow, can display this error code. Lastly, you might 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 contact an experienced technician.
Honeywell Thermostat Error e43
If your Honeywell thermostat shows error code e43, it is failing to 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 about 30 seconds. The thermostat may also be disconnected if you have recently updated the password or the Wi-Fi’s SSID, which is the name you create for it.
Honeywell Thermostat Error e1
Thermostats employ sensors to detect the temperature outdoors and indoors. If a sensor fails, you might see error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A trained technician can change out the sensor and restart the thermostat, which should clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n could appear in situations where the thermostat is unable to detect a heating or cooling unit. This may mean that the equipment itself is defective and unable to maintain a connection to the thermostat. This sometimes happens when the wiring is defective or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A qualified technician can utilize a voltmeter to find out if there’s a faulty electrical connection. In situations where the wiring on your type of HVAC system is bad, the technician can replace it. In situations where the thermostat itself is the issue, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you notice error code e2 show up on your Honeywell smart thermostat, it can mean several different things. In some cases, one of the sensors responsible for detecting the temperature isn’t functioning like it should. 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 stems from sensor failure, a technician will troubleshoot and swap out the impacted sensor. If the problem originates from disconnected power, all you have to do is make sure the router stays on throughout the setup process.