A Honeywell smart thermostat is a great way to better manage how you use your HVAC system. But like any technology, you may sometimes experience a problem. With a digital display, Honeywell smart thermostats can display an error code that trained technicians use to get a better sense of what's going on. Here are several of the most known error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You may encounter this error code in the event that your home’s Wi-Fi internet did not present an IP address for the thermostat to hook up to. This can take place if the router does not perform the Dynamic Host Configuration Protocol, or DHCP. This function automatically transmits the required IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by confirming that your router has enabled DHCP. When it does, you usually also have to power cycle the router and perform the setup process again with your thermostat. Completing this task should ensure the DHCP is delivered and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs whenever the password for communicating with your home’s Wi-Fi router is incorrect. After this error code is displayed for 30 seconds, the thermostat’s digital display should automatically transition to the Wi-Fi setup screen so you can try to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you 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 detected a malfunction. Most commonly, this happens when the compressor isn’t running despite being directed to. But this error code could also surface if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, triggered by poor airflow, can display this error code. Finally, you may encounter 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 check the air filter for signs of a clog, as well as the breakers and indoor unit’s blower for regular operation. If you turn the thermostat off and on again and error code 40 reappears, you should try 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 the Wi-Fi. This may 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 about 30 seconds. The thermostat may also be disconnected if you’ve recently updated the password or the Wi-Fi’s SSID, which is the name you create for it.
Honeywell Thermostat Error e1
Thermostats use sensors to detect the temperature outdoors and indoors. If a sensor malfunctions, you could see error code e1 turn up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A qualified technician can change out the sensor and reboot the thermostat, which should resolve error code e1.
Honeywell Thermostat Error 11n
Error code 11n may appear in situations where the thermostat can’t connect to a heating or cooling unit. This can mean that the equipment itself is defective and unable to maintain a connection to the thermostat. This sometimes happens when the wiring is defective 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 bad electrical connection. If the wiring on your existing HVAC system is bad, the technician can replace it. In situations where the thermostat itself is the source of the error code, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you see error code e2 appear on your Honeywell smart thermostat, it might mean a few different things. In some cases, one of the sensors responsible for detecting the temperature isn’t functioning like it should. 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 caused by sensor failure, a technician will troubleshoot and switch out the impacted sensor. When the problem originates from disconnected power, all you’ll have to do is verify the router stays on during the setup process.