A Honeywell smart thermostat is an excellent way to optimize how you use your HVAC system. But like any mechanical system, you could occasionally run into a problem. With a digital display, Honeywell smart thermostats can display an error code that certified technicians use to understand what's wrong. Here are some of the most common error codes you may see on your Honeywell smart thermostat.
Honeywell Error Code e42
You might see this error code in the event that your home’s Wi-Fi connection did not provide an IP address for the thermostat to hook up to. This can occur if your router does not complete the Dynamic Host Configuration Protocol, or DHCP. This function 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 verifying that your router is enabled for DHCP. If it does, you may also need to power cycle the router and complete the initial setup process again with your thermostat. This should see to it that the DHCP is delivered and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 is displayed when the password for accessing your home’s Wi-Fi router was incorrect. When this error code is displayed for 30 seconds, the thermostat’s digital display automatically transitions to the Wi-Fi setup screen so you can attempt 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 typing the correct Wi-Fi password when configuring the thermostat.
Honeywell Error Code 40
Error code 40 can appear when the thermostat is alerted that a heat pump or air conditioner’s monitoring system has detected a malfunction. Most commonly, this happens once the compressor isn’t working despite being instructed to. But this error code can also surface if power is shut off from the outdoor unit for an extended 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 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, it's time to get a hold of an experienced technician.
Error Code e43 for Honeywell Thermostats
If a Honeywell thermostat shows error code e43, it can’t communicate with the router, and by extension the 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
Restart the router by unplugging it and leaving it that way for a short period. The thermostat might also be disconnected if you recently changed the password or the Wi-Fi’s SSID, which is the name you give it.
Honeywell Error Code e1
Thermostats employ sensors to identify the temperature outdoors and indoors. If a sensor breaks down, you might notice error code e1 appear on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A trained technician can replace the sensor and reboot the thermostat, which should resolve error code e1.
Honeywell Thermostat Error 11n
Error code 11n may appear when the thermostat can’t detect a heating or cooling unit. This might mean that the equipment itself is defective and unable to connect with the thermostat. This can happen when the wiring is defective or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can use a voltmeter to find out if there’s a faulty electrical connection. In situations where the wiring on your specific HVAC system is bad, the technician can replace it. When the thermostat itself is the problem, it should probably be replaced.
Honeywell Error Code e2
If you see error code e2 show up on your Honeywell smart thermostat, it could mean a couple of different things. For example, one of the sensors that detects the temperature isn’t operating correctly. In other cases, it means the router was disconnected from the outlet before the thermostat completed the setup process.
How to Fix Honeywell Thermostat Error e2
When the error code is a result of sensor failure, a technician will troubleshoot and swap out the damaged sensor. Any time the problem comes from disconnected power, all you have to do is see to it that the router remains on throughout the setup process.
