A Honeywell smart thermostat is a great way to optimize how you use your HVAC system. But like any utility, you may sometimes run into a problem. With the digital display, Honeywell smart thermostats can provide an error code that certified technicians will use to understand what's wrong. Here are some of the most known error codes you may see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You might see this error code when your home’s Wi-Fi internet did not provide an IP address for the thermostat to hook up to. This can happen if your router fails to complete the Dynamic Host Configuration Protocol, or DHCP. This function automatically supplies the required IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can clear error code e42 by verifying that your router can complete the DHCP. If it does, you usually also need to power cycle the router and complete the initial setup process again with the thermostat. Completing this task should ensure the DHCP is sent and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears if the password for accessing your home’s Wi-Fi router is incorrect. When 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 solve error e02 is ensure you’re typing the correct Wi-Fi password when configuring the thermostat.
Honeywell Thermostat Error 40
Error code 40 can pop up when the thermostat is notified that a heat pump or air conditioner’s monitoring system has detected a malfunction. Most often, this happens when the compressor isn’t running despite being instructed to. But this error code can also show up if power is shut off from the outdoor unit for a lengthy period of time. A “High Pressure Fault” error, triggered by blocked airflow, can lead to this error code. Finally, you could encounter 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 check 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 can’t 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 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 employ sensors to determine the temperature outdoors and indoors. If a sensor malfunctions, you might see error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A qualified technician can swap out the sensor and reset the thermostat, which should clear 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 might mean that the equipment itself is faulty and unable to maintain a connection to the thermostat. This sometimes happens when the wiring is damaged or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can employ a voltmeter to assess if there’s a bad electrical connection. When the wiring on your type of 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 notice error code e2 show up on your Honeywell smart thermostat, it can mean a few different things. Sometimes, 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 completed the setup process.
How to Fix Honeywell Thermostat Error e2
When the error code stems from sensor failure, a technician should troubleshoot and switch out the damaged sensor. If the problem originates from disconnected power, all you’ll have to do is verify the router remains on over the course of the setup process.