A Honeywell smart thermostat is a great way to better manage how you use your HVAC system. But like any technology, you might sometimes run into a problem. With its digital display, Honeywell smart thermostats can provide an error code that trained technicians can use to understand what's wrong. Here are a few of the most likely error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You may encounter this error code when your home’s Wi-Fi connection did not present an IP address for the thermostat to connect with. This can take place if a router does not execute the Dynamic Host Configuration Protocol, or DHCP. This process automatically sends out the needed IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by verifying that your router can complete the DHCP. Assuming 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.
Honeywell Thermostat Error e02
Error code e02 is displayed if the password for accessing your home’s Wi-Fi router was 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 clear error e02 is make sure you’re typing the correct Wi-Fi password when configuring the thermostat.
Honeywell Thermostat Error 40
Error code 40 can show up when the thermostat is notified that a heat pump or air conditioner’s monitoring system has identified a malfunction. For the most part, this appears when the compressor isn’t running despite being directed to. But this error code can also appear if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, triggered by blocked airflow, can lead to this error code. Finally, you may see error code 40 if there’s an issue 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 get a hold of an experienced technician.
Honeywell Thermostat Error e43
If your 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 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 may also be disconnected if you have recently updated the password or the Wi-Fi’s SSID, which is the name you provide it.
Honeywell Thermostat Error e1
Thermostats utilize sensors to detect the temperature outdoors and indoors. If a sensor malfunctions, you may notice 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 reboot the thermostat, which should clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n could appear in situations where the thermostat is unable to detect a heating or cooling unit. This might mean that the equipment itself is defective and unable to maintain a connection to 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 professional technician can use a voltmeter to assess if there’s a faulty electrical connection. When the wiring on your specific HVAC system is bad, the technician can replace it. In situations where the thermostat itself is the issue, it should probably be replaced.
Honeywell Thermostat Error e2
If you notice error code e2 appear on your Honeywell smart thermostat, it might mean a few different things. Sometimes, one of the sensors used to detect the temperature isn’t functioning like it should. In other cases, it means the router was disconnected from the outlet before the thermostat finished the setup process.
How to Fix Honeywell Thermostat Error e2
When the error code is caused by sensor failure, a technician can troubleshoot and swap out the damaged sensor. Any time the problem stems from disconnected power, all you’ll have to do is verify the router remains on throughout the setup process.