A Honeywell smart thermostat is a great way to better manage how you use your heating and cooling. But like any utility, you may occasionally experience a problem. With the digital display, Honeywell smart thermostats can show an error code that professional technicians will use to get a better sense of what's happening. Here are some of the most likely error codes you could see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You may encounter this error code when your home’s Wi-Fi internet did not supply an IP address for the thermostat to connect with. This can take place if the router doesn't execute the Dynamic Host Configuration Protocol, or DHCP. This process automatically supplies the required IP address for your thermostat to connect to the Wi-Fi.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by confirming that your router is enabled for DHCP. Assuming it does, you usually also have to power cycle the router and repeat the initial setup process with your thermostat. Doing so should ensure the DHCP is delivered and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs whenever the password for accessing 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 attempt to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you'll need to do to resolve error e02 is make sure you’re entering the correct Wi-Fi password when setting up 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 recognized a malfunction. Most commonly, this appears once the compressor isn’t turning on despite being directed to. But this error code could also show up if power is shut off from the outdoor unit for an extended period of time. A “High Pressure Fault” error, caused by blocked airflow, can render this error code. Lastly, you could encounter error code 40 if there’s something wrong 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 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 your 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 around 30 seconds. The thermostat could also be disconnected if you have recently updated the password or the Wi-Fi’s SSID, which is the name you give it.
Honeywell Thermostat Error e1
Thermostats use sensors to determine 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 change out the sensor and reset the thermostat, which should resolve error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear if the thermostat can’t recognize a heating or cooling unit. This might mean that the equipment itself is defective and unable to communicate with the thermostat. This can happen when the wiring is damaged or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can utilize a voltmeter to assess if there’s a bad electrical connection. In situations where the wiring on your existing HVAC equipment is bad, the technician can replace it. When the thermostat itself is the issue, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you notice error code e2 pop up on your Honeywell smart thermostat, it could mean a few different things. For example, one of the sensors responsible for detecting the temperature isn’t working correctly. Other times, it means the router was disconnected from the outlet before the thermostat could complete the setup process.
How to Fix Honeywell Thermostat Error e2
When the error code is a result of sensor failure, a technician should troubleshoot and switch out the damaged sensor. Any time the problem comes from disconnected power, all you’ll have to do is verify the router stays on throughout the setup process.
