A Honeywell smart thermostat is an easy way to optimize how you use your HVAC system. But like any technology, you could occasionally experience a problem. With its digital display, Honeywell smart thermostats can display an error code that certified technicians use to figure out what's wrong. Here are some of the most known error codes you may see on your Honeywell smart thermostat.
Honeywell Error Code e42
You can receive this error code when your home’s Wi-Fi connection did not supply an IP address for the thermostat to hook up to. This can take place if your router does not execute the Dynamic Host Configuration Protocol, or DHCP. This procedure automatically sends out the needed IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can clear error code e42 by making sure that your router has enabled DHCP. When it does, you usually also have to power cycle the router and perform the setup process again with the thermostat. This should ensure the DHCP is delivered and connects to the smart thermostat.
Error Code e02 for Honeywell Thermostats
Error code e02 appears if the password for connecting to your home’s Wi-Fi router is not correct. 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 resolve error e02 is verify you’re entering the correct Wi-Fi password when configuring the thermostat.
Error Code 40 for Honeywell Thermostats
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. For the most part, this happens once the compressor isn’t running 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, induced by blocked airflow, can render this error code. And finally, you may 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 check the air filter for signs of a clog, as well as the breakers and indoor unit’s blower for regular operation. If you turn the thermostat off and on again and error code 40 reappears, you should try to get in touch with an experienced technician.
Error Code e43 for Honeywell Thermostats
If a 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
Reboot the router by unplugging it and leaving it that way for about 30 seconds. The thermostat could also be disconnected if you recently updated the password or the Wi-Fi’s SSID, which is the name you create for it.
Error Code e1 for Honeywell Thermostats
Thermostats utilize sensors to identify the temperature outdoors and indoors. If a sensor malfunctions, you may notice error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can change out the sensor and restart the thermostat, which should resolve error code e1.
Honeywell Error Code 11n
Error code 11n can appear in situations where the thermostat is unable to recognize a heating or cooling unit. This may mean that the equipment itself is faulty and unable to maintain a connection to the thermostat. This can happen when the wiring is damaged or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A qualified technician can use a voltmeter to find out if there’s a poor electrical connection. When the wiring on your existing HVAC system is bad, the technician can replace it. When the thermostat itself is the source of the error code, it will likely have to be replaced.
Error Code e2 for Honeywell Thermostats
If you’ve noticed error code e2 pop up on your Honeywell smart thermostat, it might mean several different things. In some cases, one of the sensors that detects the temperature isn’t operating correctly. Other times, it means the router was disconnected from power before the thermostat could complete the setup process.
How to Fix Honeywell Thermostat Error e2
If the error code is a result of sensor failure, a technician will troubleshoot and replace the impacted sensor. If the problem stems from disconnected power, all you'll need to do is see to it that the router remains on during the setup process.
