A Honeywell smart thermostat is an easy way to fine-tune how you use your home comfort system. But like any mechanical system, you may sometimes run across a problem. With the digital display, Honeywell smart thermostats can display an error code that trained technicians will use to figure out what's wrong. Here are some 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 connection did not provide an IP address for the thermostat to connect to. This can take place if your router does not complete the Dynamic Host Configuration Protocol, or DHCP. This procedure automatically supplies the needed IP address for your thermostat to link up.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by making sure that your router is enabled for DHCP. Assuming it does, you may also have to power cycle the router and perform the setup process again with your thermostat. This should ensure the DHCP is delivered and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 is displayed whenever the password for connecting to your home’s Wi-Fi router was incorrect. After this error code is displayed for 30 seconds, the thermostat’s digital display automatically transitions to the Wi-Fi setup screen so you can try the password again.
How to Fix Honeywell Thermostat Error e02
All you need to do to solve error e02 is ensure you’re putting in the correct Wi-Fi password when setting up 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 happens when the compressor isn’t running despite being directed to. But this error code can also appear if power is disconnected from the outdoor unit for a long period of time. A “High Pressure Fault” error, induced by poor airflow, can display this error code. Finally, you could experience error code 40 if there’s an issue with the coolant, 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 ordinary operation. If you restart the thermostat and error code 40 reappears, you should try to contact an experienced technician.
Honeywell Thermostat Error e43
If your Honeywell thermostat presents error code e43, it is failing 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 the 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 may also be disconnected if you 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 determine the temperature outdoors and indoors. If a sensor malfunctions, you may see error code e1 appear on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A qualified technician can replace the sensor and reset the thermostat, which should take care of error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear in situations where the thermostat is failing to recognize 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 defective 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 poor electrical connection. If the wiring on your existing 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 notice error code e2 show up on your Honeywell smart thermostat, it can mean a few different things. In some cases, one of the sensors responsible for detecting the temperature isn’t working correctly. In other cases, it means the router was disconnected from its power source before the thermostat completed the setup process.
How to Fix Honeywell Thermostat Error e2
When the error code stems from sensor failure, a technician will troubleshoot and swap out the affected sensor. Any time the problem originates from disconnected power, all you have to do is make sure the router stays on during the setup process.