A Honeywell smart thermostat is an excellent way to better manage how you use your HVAC system. But like any technology, you could sometimes run into a problem. With a digital display, Honeywell smart thermostats can show an error code that certified technicians will use to get a better sense of what's wrong. Here are some of the most known error codes you might see on your Honeywell smart thermostat.
Error Code e42 for Honeywell Thermostats
You may receive this error code when your home’s Wi-Fi connection did not present an IP address for the thermostat to connect to. This can take place if your router fails to execute the Dynamic Host Configuration Protocol, or DHCP. This function automatically supplies the required IP address for your thermostat to link up.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by confirming that your router is enabled for DHCP. When it does, you may also have to power cycle the router and complete the initial setup process again with your thermostat. Completing this task should ensure the DHCP is delivered and connects to your smart thermostat.
Error Code e02 for Honeywell Thermostats
Error code e02 occurs whenever the password for communicating with your home’s Wi-Fi router is incorrect. When this error code has appeared 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'll need to do to resolve error e02 is ensure you’re entering the correct Wi-Fi password when setting up the thermostat.
Honeywell Error Code 40
Error code 40 can pop up when the thermostat is informed that a heat pump or air conditioner’s monitoring system has identified a malfunction. Most often, this happens if the compressor isn’t working despite being instructed to. But this error code may also appear if power is shut off from the outdoor unit for an extended period of time. A “High Pressure Fault” error, induced by blocked airflow, can display this error code. Lastly, you might 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 check the air filter for signs of a clog, as well as the breakers and indoor unit’s blower for ordinary operation. If you turn the thermostat off and on again and error code 40 reappears, it’s best to get a hold of an experienced technician.
Error Code e43 for Honeywell Thermostats
If the Honeywell thermostat displays error code e43, it can’t communicate with the router, and by extension the 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
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 updated 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 breaks down, you might see error code e1 appear on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A trained technician can replace the sensor and reboot the thermostat, which should resolve error code e1.
Error Code 11n for Honeywell Thermostats
Error code 11n may appear when the thermostat is unable to detect a heating or cooling unit. This may mean that the equipment itself is malfunctioning and unable to connect with the thermostat. This can happen when the wiring is bad or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A qualified technician can use a voltmeter to assess if there’s a bad electrical connection. If the wiring on your specific HVAC equipment is bad, the technician can replace it. When the thermostat itself is the problem, it should probably be replaced.
Honeywell Thermostat Error e2
If you’ve noticed error code e2 show up on your Honeywell smart thermostat, it might mean a few different things. In some cases, one of the sensors that detects the temperature isn’t functioning correctly. In other instances, 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 replace the affected sensor. Any time the problem comes from disconnected power, all you'll need to do is see to it that the router remains on over the course of the setup process.
