A Honeywell smart thermostat is an easy way to optimize how you use your heating and cooling. But like any mechanical system, you might occasionally run across a problem. With the digital display, Honeywell smart thermostats can display an error code that professional technicians will use to understand what's going on. Here are some of the most common error codes you may see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You may encounter this error code if your home’s Wi-Fi connection did not provide an IP address for the thermostat to connect to. This can happen if your router doesn't execute the Dynamic Host Configuration Protocol, or DHCP. This function automatically supplies the needed IP address for your thermostat to connect to the Wi-Fi.
How to Fix Honeywell Thermostat Error e42
You can resolve error code e42 by making sure that your router can complete the DHCP. Assuming it does, you might also need to power cycle the router and perform the setup process again with the thermostat. Completing this task should ensure the DHCP is delivered and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears when the password for connecting to your home’s Wi-Fi router is 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 try to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you'll need to do to solve error e02 is verify you’re entering 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. Most commonly, this happens once the compressor isn’t running despite being directed to. But this error code may also show up if power is disconnected from the outdoor unit for an extended period of time. A “High Pressure Fault” error, induced by blocked airflow, can display this error code. And finally, you may see error code 40 if there’s a problem 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 restart the thermostat and error code 40 reappears, it’s best to get a hold of an experienced technician.
Honeywell Thermostat Error e43
If a Honeywell thermostat displays error code e43, it is failing to communicate with the router, and by extension your Wi-Fi. This could 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
Restart the router by unplugging it and leaving it that way for around 30 seconds. The thermostat may also be disconnected if you’ve recently changed 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 fails, you may see error code e1 turn up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A qualified technician can replace the sensor and reboot the thermostat, which should clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear if the thermostat is unable to connect to a heating or cooling unit. This can mean that the equipment itself is faulty and unable to communicate 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 determine if there’s a poor electrical connection. If the wiring on your specific HVAC system is bad, the technician can replace it. When the thermostat itself is the source of the error code, it should probably be replaced.
Honeywell Thermostat Error e2
If you’ve noticed error code e2 appear on your Honeywell smart thermostat, it might mean a few different things. For example, one of the sensors used to detect the temperature isn’t working like it should. 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
In situations where the error code stems from sensor failure, a technician can troubleshoot and swap out the impacted sensor. When the problem comes from disconnected power, all you’ll have to do is make sure the router stays on during the setup process.