A Honeywell smart thermostat is an easy way to optimize how you use your home comfort system. But like any utility, you might occasionally run across a problem. With its digital display, Honeywell smart thermostats can provide an error code that professional technicians will use to understand what's going on. Here are a few of the most common error codes you might see on your Honeywell smart thermostat.
Error Code e42 for Honeywell Thermostats
You may encounter this error code if your home’s Wi-Fi connection did not present an IP address for the thermostat to connect to. This can occur if a router doesn't perform the Dynamic Host Configuration Protocol, or DHCP. This function automatically transmits the needed 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 can complete the DHCP. Assuming it does, you may also need to power cycle the router and complete the initial setup process again with the thermostat. Doing so should ensure the DHCP is transmitted and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears when the password for connecting to your home’s Wi-Fi router was incorrect. Once this error code appears for 30 seconds, the thermostat’s digital display should automatically transition 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 make sure 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 alerted that a heat pump or air conditioner’s monitoring system has detected a malfunction. Most often, this happens when the compressor isn’t working despite being instructed to. But this error code could also appear if power is shut off from the outdoor unit for an extended period of time. A “High Pressure Fault” error, triggered by poor airflow, can lead to this error code. Lastly, you could experience 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 regular operation. If you turn the thermostat off and on again and error code 40 reappears, it’s best to get in touch with an experienced technician.
Error Code e43 for Honeywell Thermostats
If the Honeywell thermostat shows error code e43, it is failing to communicate with the router, and by extension your 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
Reset the router by unplugging it and leaving it that way for about 30 seconds. The thermostat might also be disconnected if you have recently updated the password or the Wi-Fi’s SSID, which is the name you create for it.
Honeywell Error Code e1
Thermostats utilize sensors to determine the temperature outdoors and indoors. If a sensor malfunctions, you may notice 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 resolve error code e1.
Honeywell Error Code 11n
Error code 11n could appear when the thermostat is failing to connect to a heating or cooling unit. This may mean that the equipment itself is faulty and unable to maintain a connection to the thermostat. This sometimes happens when the wiring is bad or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A professional technician can employ a voltmeter to determine if there’s a poor electrical connection. When the wiring on your type of HVAC equipment 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 see error code e2 show up on your Honeywell smart thermostat, it might mean a couple of different things. For example, one of the sensors responsible for detecting the temperature isn’t working like it should. In other instances, it means the router was disconnected from the outlet before the thermostat finished the setup process.
How to Fix Honeywell Thermostat Error e2
In situations where the error code is a result of sensor failure, a technician can troubleshoot and swap out the impacted sensor. If the problem originates from disconnected power, all you'll need to do is see to it that the router remains on during the setup process.