A Honeywell smart thermostat is a great way to optimize how you use your heating and cooling. But like any mechanical system, you might occasionally run into a problem. With its digital display, Honeywell smart thermostats can provide an error code that certified technicians use to understand what's happening. Here are several of the most likely error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You can see this error code in the event that your home’s Wi-Fi connection did not provide an IP address for the thermostat to connect to. This can take place if your router doesn't execute the Dynamic Host Configuration Protocol, or DHCP. This function automatically transmits the necessary IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by verifying that your router is enabled for DHCP. Assuming it does, you might also have to power cycle the router and complete the initial setup process again with the thermostat. Completing this task should ensure the DHCP is transmitted and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears whenever the password for accessing your home’s Wi-Fi router is incorrect. Once 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'll need to do to clear 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 appear when the thermostat is informed that a heat pump or air conditioner’s monitoring system has recognized a malfunction. Most commonly, this appears once the compressor isn’t working despite being instructed to. But this error code may also surface if power is disconnected from the outdoor unit for an extended period of time. A “High Pressure Fault” error, induced by obstructed airflow, can lead to this error code. Lastly, you may see error code 40 if there’s something wrong 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 normal operation. If you turn the thermostat off and on again and error code 40 reappears, it's time to contact an experienced technician.
Honeywell Thermostat Error e43
If the Honeywell thermostat shows error code e43, it is unable to communicate with the router, and by extension the Wi-Fi. This can 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 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 provide it.
Honeywell Thermostat Error e1
Thermostats utilize sensors to determine 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 replace the sensor and restart the thermostat, which should resolve error code e1.
Honeywell Thermostat Error 11n
Error code 11n could appear if the thermostat is unable to detect a heating or cooling unit. This may mean that the equipment itself is malfunctioning and unable to communicate with the thermostat. This can happen 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 determine if there’s a bad electrical connection. In situations where the wiring on your specific HVAC system is bad, the technician can replace it. If the thermostat itself is the issue, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you’ve noticed error code e2 show up on your Honeywell smart thermostat, it can mean a few different things. Sometimes, one of the sensors that detects the temperature isn’t functioning like it should. Other times, it means the router was disconnected from power before the thermostat completed the setup process.
How to Fix Honeywell Thermostat Error e2
If the error code stems from sensor failure, a technician can troubleshoot and swap out the damaged sensor. If the problem comes from disconnected power, all you'll need to do is verify the router stays on during the setup process.