A Honeywell smart thermostat is a great way to optimize how you use your home comfort system. But like any technology, you could occasionally experience a problem. With a digital display, Honeywell smart thermostats can provide an error code that certified technicians will use to get a better sense of what's going on. Here are several of the most known error codes you could see on your Honeywell smart thermostat.
Honeywell Error Code e42
You might receive this error code in the event that your home’s Wi-Fi internet did not present an IP address for the thermostat to connect to. This can occur if a router fails to perform the Dynamic Host Configuration Protocol, or DHCP. This process automatically transmits the required IP address for your thermostat to connect to the Wi-Fi.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by making sure that your router can complete the DHCP. When it does, you may also have to power cycle the router and complete the initial setup process again with the thermostat. Doing so should ensure the DHCP is transmitted and connects to the smart thermostat.
Honeywell Error Code e02
Error code e02 appears if the password for accessing your home’s Wi-Fi router is incorrect. When this error code has appeared for 30 seconds, the thermostat’s digital display automatically transitions 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 entering 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 often, this happens once the compressor isn’t running despite being directed to. But this error code can also surface if power is disconnected from the outdoor unit for a long period of time. A “High Pressure Fault” error, caused by poor airflow, can render this error code. Finally, you could 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 examine the air filter for signs of a clog, as well as the breakers and indoor unit’s blower for normal operation. If you reset the thermostat and error code 40 reappears, it's time to contact an experienced technician.
Honeywell Error Code e43
If the Honeywell thermostat presents error code e43, it can’t communicate with the router, and by extension the 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 around 30 seconds. The thermostat might also be disconnected if you’ve recently changed the password or the Wi-Fi’s SSID, which is the name you give it.
Honeywell Error Code e1
Thermostats use sensors to determine the temperature outdoors and indoors. If a sensor fails, you could see error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A trained technician can change out the sensor and reset the thermostat, which should resolve error code e1.
Error Code 11n for Honeywell Thermostats
Error code 11n can appear when the thermostat is unable to recognize a heating or cooling unit. This can mean that the equipment itself is malfunctioning and unable to connect with the thermostat. This sometimes happens when the wiring is bad or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can utilize a voltmeter to find out if there’s a poor 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 should probably be replaced.
Error Code e2 for Honeywell Thermostats
If you’ve noticed error code e2 show up on your Honeywell smart thermostat, it might mean a few different things. For example, one of the sensors responsible for detecting the temperature isn’t operating properly. In other cases, it means the router was disconnected from power before the thermostat finished the setup process.
How to Fix Honeywell Thermostat Error e2
If the error code is a result of sensor failure, a technician should troubleshoot and swap out the damaged sensor. Any time the problem comes from disconnected power, all you’ll have to do is see to it that the router remains on during the setup process.