A Honeywell smart thermostat is an excellent way to better manage how you use your HVAC 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 understand what's going on. Here are several of the most likely error codes you may see on your Honeywell smart thermostat.
Honeywell Error Code e42
You might encounter this error code in the event that your home’s Wi-Fi connection did not provide an IP address for the thermostat to connect with. This can occur if your router doesn't execute the Dynamic Host Configuration Protocol, or DHCP. This function automatically supplies the necessary IP address for your thermostat to link up.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by confirming that your router can complete the DHCP. Assuming it does, you might also have to power cycle the router and complete the initial setup process again with the 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 occurs when the password for communicating with your home’s Wi-Fi router was incorrect. Once this error code appears for 30 seconds, the thermostat’s digital display will automatically progress to the Wi-Fi setup screen so you can try the password again.
How to Fix Honeywell Thermostat Error e02
All you have 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 show up when the thermostat is alerted that a heat pump or air conditioner’s monitoring system has identified a malfunction. Most often, this happens when the compressor isn’t running despite being instructed to. But this error code could also show up if power is disconnected from the outdoor unit for a long period of time. A “High Pressure Fault” error, induced by obstructed airflow, can render this error code. Finally, you may encounter 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 a hold of an experienced technician.
Honeywell Thermostat Error e43
If the 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
Reset the router by unplugging it and leaving it that way for a short period. The thermostat could also be disconnected if you’ve recently changed the password or the Wi-Fi’s SSID, which is the name you give it.
Honeywell Thermostat Error e1
Thermostats utilize sensors to detect the temperature outdoors and indoors. If a sensor malfunctions, you might notice error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A qualified technician can replace the sensor and restart the thermostat, which should resolve error code e1.
Error Code 11n for Honeywell Thermostats
Error code 11n may 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 maintain a connection to the thermostat. This can happen when the wiring is bad or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can employ a voltmeter to determine if there’s a faulty electrical connection. If the wiring on your specific HVAC equipment is bad, the technician can replace it. When the thermostat itself is the problem, it will likely have to be replaced.
Honeywell Error Code e2
If you see error code e2 show up on your Honeywell smart thermostat, it could mean a few different things. Sometimes, one of the sensors that detects the temperature isn’t operating properly. Other times, it means the router was disconnected from the outlet 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 switch out the affected sensor. If the problem originates from disconnected power, all you have to do is make sure the router stays on during the setup process.