A Honeywell smart thermostat is an easy way to better manage how you use your home comfort system. But like any mechanical system, you could sometimes run into a problem. With a digital display, Honeywell smart thermostats can show an error code that trained technicians use to figure out what's wrong. Here are several of the most likely error codes you may see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You can see this error code if your home’s Wi-Fi internet did not present an IP address for the thermostat to hook up to. This can happen if the router fails to complete the Dynamic Host Configuration Protocol, or DHCP. This process automatically supplies 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 is enabled for DHCP. If 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 delivered and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears whenever the password for accessing your home’s Wi-Fi router is not correct. Once this error code appears 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 clear error e02 is verify you’re typing the correct Wi-Fi password when configuring the thermostat.
Honeywell Thermostat Error 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 appears if the compressor isn’t running despite being instructed to. But this error code could also appear if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, caused by obstructed airflow, can display this error code. Lastly, you may see error code 40 if there’s an issue with the coolant, 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 normal operation. If you reset the thermostat and error code 40 reappears, it's time to get in touch with 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 the 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
Reset the router by unplugging it and leaving it that way for about 30 seconds. The thermostat might also be disconnected if you recently updated the password or the Wi-Fi’s SSID, which is the name you create for it.
Honeywell Thermostat Error e1
Thermostats use sensors to detect the temperature outdoors and indoors. If a sensor breaks down, you could see error code e1 appear on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can swap out the sensor and reset the thermostat, which should resolve error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear in situations where the thermostat is failing to detect a heating or cooling unit. This might mean that the equipment itself is faulty and unable to communicate with the thermostat. This sometimes happens when the wiring is defective or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A qualified technician can employ a voltmeter to find out if there’s a bad electrical connection. If the wiring on your specific HVAC equipment is bad, the technician can replace it. In situations where the thermostat itself is the source of the error code, it will likely have to be replaced.
Honeywell Thermostat Error e2
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 used to detect the temperature isn’t working correctly. Other times, 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 caused by sensor failure, a technician will troubleshoot and swap out the impacted sensor. Any time the problem originates from disconnected power, all you'll need to do is see to it that the router remains on throughout the setup process.
