A Honeywell smart thermostat is a great way to better manage how you use your heating and cooling. But like any mechanical system, you may sometimes run into a problem. With its digital display, Honeywell smart thermostats can display an error code that certified technicians use to get a better sense of what's wrong. Here are a few of the most common error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You may encounter this error code if your home’s Wi-Fi internet did not provide an IP address for the thermostat to connect to. This can occur if your router does not complete 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 resolve error code e42 by making sure that your router has enabled DHCP. If it does, you might also need to power cycle the router and complete the initial setup process again with your thermostat. This should ensure the DHCP is sent and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 is displayed when the password for communicating with your home’s Wi-Fi router is incorrect. When this error code appears 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 ensure you’re putting in the correct Wi-Fi password when setting up the thermostat.
Honeywell Thermostat Error 40
Error code 40 can appear when the thermostat is notified that a heat pump or air conditioner’s monitoring system has identified a malfunction. Most commonly, this appears if the compressor isn’t turning on despite being instructed to. But this error code can also surface if power is shut off from the outdoor unit for a lengthy period of time. A “High Pressure Fault” error, caused by blocked airflow, can display this error code. Lastly, you may experience 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 inspect the air filter for signs of a clog, as well as the breakers and indoor unit’s blower for regular operation. If you restart the thermostat and error code 40 reappears, it's time to get in touch with 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 could 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
Reboot the router by unplugging it and leaving it that way for a short period. The thermostat could also be disconnected if you’ve recently switched 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 fails, you may see error code e1 appear on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can change out the sensor and restart the thermostat, which should take care of error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear in situations where the thermostat is failing to recognize a heating or cooling unit. This may mean that the equipment itself is defective and unable to communicate with the thermostat. This sometimes happens when the wiring is damaged or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A professional technician can utilize a voltmeter to determine if there’s a poor electrical connection. When the wiring on your type of HVAC equipment 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 pop up on your Honeywell smart thermostat, it can mean several different things. In some cases, one of the sensors that detects the temperature isn’t working like it should. In other cases, it means the router was disconnected from its power source before the thermostat could complete the setup process.
How to Fix Honeywell Thermostat Error e2
In situations where the error code is caused by sensor failure, a technician should troubleshoot and switch out the affected sensor. When the problem comes from disconnected power, all you have to do is see to it that the router stays on over the course of the setup process.