A Honeywell smart thermostat is a great way to better manage how you use your heating and cooling. But like any technology, you may sometimes run into a problem. With a digital display, Honeywell smart thermostats can show an error code that certified technicians use to figure out what's wrong. Here are several of the most common error codes you could see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You can see this error code if your home’s Wi-Fi connection did not present an IP address for the thermostat to hook up to. This can take place if your router fails to complete the Dynamic Host Configuration Protocol, or DHCP. This procedure 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 confirming that your router can complete the DHCP. When it does, you usually also need to power cycle the router and perform the setup process again with your thermostat. Doing so should ensure the DHCP is transmitted and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 is displayed whenever the password for accessing your home’s Wi-Fi router was incorrect. Once 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 to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you'll need to do to solve error e02 is make sure you’re putting in the correct Wi-Fi password when setting up the thermostat.
Honeywell Thermostat Error 40
Error code 40 can pop up when the thermostat is informed that a heat pump or air conditioner’s monitoring system has detected a malfunction. For the most part, this appears once the compressor isn’t turning on despite being directed to. But this error code could also surface if power is disconnected from the outdoor unit for a long period of time. A “High Pressure Fault” error, induced by obstructed airflow, can display this error code. Lastly, you may see 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 contact an experienced technician.
Honeywell Thermostat Error e43
If a Honeywell thermostat presents error code e43, it is unable 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 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 could also be disconnected if you’ve 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 breaks down, you could see 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 reboot the thermostat, which should clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n could appear if the thermostat is unable to detect 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 bad or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A professional technician can utilize a voltmeter to find out if there’s a bad electrical connection. In situations where the wiring on your specific HVAC equipment is bad, the technician can replace it. In situations where 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 can mean a couple of different things. For example, one of the sensors used to detect the temperature isn’t functioning 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
When the error code is caused by sensor failure, a technician should troubleshoot and switch out the affected sensor. Any time the problem stems from disconnected power, all you'll need to do is see to it that the router remains on over the course of the setup process.
