A Honeywell smart thermostat is an easy way to better manage how you use your HVAC system. But like any technology, you could occasionally experience a problem. With its digital display, Honeywell smart thermostats can display an error code that certified technicians use to understand what's happening. Here are some of the most common error codes you could see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You might see this error code if your home’s Wi-Fi connection did not supply an IP address for the thermostat to connect with. This can happen if your router fails to complete 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 resolve error code e42 by confirming that your router is enabled for DHCP. If it does, you usually also have to power cycle the router and perform the setup process again with your thermostat. This should ensure the DHCP is transmitted and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 is displayed if the password for accessing your home’s Wi-Fi router was incorrect. After this error code appears for 30 seconds, the thermostat’s digital display will automatically progress to the Wi-Fi setup screen so you can try the password again.
How to Fix Honeywell Thermostat Error e02
All you'll need to do to solve error e02 is make sure you’re typing the correct Wi-Fi password when setting up the thermostat.
Honeywell Thermostat Error 40
Error code 40 can pop up when the thermostat is informed that a heat pump or air conditioner’s monitoring system has detected a malfunction. Most commonly, this occurs once the compressor isn’t turning on despite being instructed to. But this error code may also surface if power is disconnected from the outdoor unit for a lengthy period of time. A “High Pressure Fault” error, induced by poor airflow, can lead to this error code. And finally, you might see error code 40 if there’s a problem with the coolant, the outdoor unit’s fan motor or the motor’s starting capacitor.
How to Fix Honeywell Thermostat Error 40
You can examine the air filter for signs of a clog, as well as the breakers and indoor unit’s blower for regular operation. If you reset the thermostat and error code 40 reappears, you should try to contact an experienced technician.
Honeywell Thermostat Error e43
If the Honeywell thermostat shows error code e43, it can’t 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 your wide area network (WAN).
How to Fix Honeywell Thermostat Error e43
Restart the router by unplugging it and leaving it that way for about 30 seconds. The thermostat could also be disconnected if you’ve recently switched the password or the Wi-Fi’s SSID, which is the name you give it.
Honeywell Thermostat Error e1
Thermostats employ sensors to determine the temperature outdoors and indoors. If a sensor malfunctions, you could see error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can change out the sensor and reboot the thermostat, which should take care of error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear if the thermostat is unable to detect a heating or cooling unit. This might mean that the equipment itself is defective and unable to maintain a connection to the thermostat. This sometimes happens 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 find out 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 source of the error code, it should probably be replaced.
Honeywell Thermostat Error e2
If you’ve noticed error code e2 appear on your Honeywell smart thermostat, it can mean a couple of different things. Sometimes, one of the sensors that detects the temperature isn’t operating like it should. Other times, it means the router was disconnected from the outlet before the thermostat finished the setup process.
How to Fix Honeywell Thermostat Error e2
If the error code stems from sensor failure, a technician can troubleshoot and replace the affected sensor. If the problem originates from disconnected power, all you’ll have to do is see to it that the router remains on throughout the setup process.