A Honeywell smart thermostat is an excellent way to fine-tune how you use your heating and cooling. But like any technology, you might sometimes run across a problem. With the digital display, Honeywell smart thermostats can show an error code that certified technicians use to get a better sense of what's going on. Here are a few of the most common error codes you may see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You can receive this error code in the event that your home’s Wi-Fi connection did not supply an IP address for the thermostat to connect with. This can happen if your router fails to complete the Dynamic Host Configuration Protocol, or DHCP. This function automatically transmits the necessary IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can resolve error code e42 by making sure that your router has enabled DHCP. If it does, you may also need to power cycle the router and complete the initial setup process again with your thermostat. Doing so should see to it that the DHCP is sent and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears if the password for accessing your home’s Wi-Fi router is incorrect. Once this error code has appeared 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 clear error e02 is make sure you’re entering the correct Wi-Fi password when setting up the thermostat.
Honeywell Thermostat Error 40
Error code 40 can appear when the thermostat is informed that a heat pump or air conditioner’s monitoring system has identified a malfunction. Most often, this occurs if the compressor isn’t running despite being instructed to. But this error code can also surface if power is shut off 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 may encounter 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 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 a Honeywell thermostat presents error code e43, it is unable to communicate with the router, and by extension your Wi-Fi. This may 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 might also be disconnected if you’ve recently updated the password or the Wi-Fi’s SSID, which is the name you give it.
Honeywell Thermostat Error e1
Thermostats utilize sensors to determine the temperature outdoors and indoors. If a sensor breaks down, you might see 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.
Honeywell Thermostat Error 11n
Error code 11n can appear if the thermostat is unable to recognize a heating or cooling unit. This can mean that the equipment itself is malfunctioning and unable to communicate with the thermostat. This sometimes happens when the wiring is damaged or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can employ a voltmeter to assess if there’s a bad electrical connection. If the wiring on your specific HVAC system is bad, the technician can replace it. If the thermostat itself is the source of the error code, 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 several different things. In some cases, one of the sensors used to detect the temperature isn’t operating like it should. In other cases, it means the router was disconnected from power 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 replace the affected sensor. When the problem stems from disconnected power, all you have to do is make sure the router remains on throughout the setup process.