A Honeywell smart thermostat is an excellent way to optimize how you use your HVAC system. But like any mechanical system, you may sometimes run into a problem. With its digital display, Honeywell smart thermostats can show an error code that certified technicians can use to figure out what's happening. Here are a few of the most common error codes you may see on your Honeywell smart thermostat.
Honeywell Error Code e42
You can encounter this error code when your home’s Wi-Fi internet did not supply an IP address for the thermostat to connect to. This can happen if a router fails to perform the Dynamic Host Configuration Protocol, or DHCP. This process 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 is enabled for DHCP. If it does, you might also have to power cycle the router and repeat the initial setup process with your thermostat. This should ensure the DHCP is transmitted and connects to your smart thermostat.
Honeywell Error Code e02
Error code e02 appears if 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 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 putting in the correct Wi-Fi password when configuring the thermostat.
Error Code 40 for Honeywell Thermostats
Error code 40 can pop up when the thermostat is notified that a heat pump or air conditioner’s monitoring system has recognized a malfunction. Most often, this occurs when the compressor isn’t running despite being instructed to. But this error code may also show up if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, caused by obstructed airflow, can lead to this error code. Lastly, you could encounter 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 get in touch with an experienced technician.
Error Code e43 for Honeywell Thermostats
If your Honeywell thermostat presents error code e43, it can’t communicate with the router, and by extension your Wi-Fi. This might 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 switched the password or the Wi-Fi’s SSID, which is the name you provide it.
Honeywell Thermostat Error e1
Thermostats use sensors to identify the temperature outdoors and indoors. If a sensor breaks down, you may see error code e1 show up 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.
Honeywell Error Code 11n
Error code 11n could appear when the thermostat is unable to connect to a heating or cooling unit. This may mean that the equipment itself is malfunctioning and unable to maintain a connection to the thermostat. This can happen when the wiring is damaged or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can use a voltmeter to find out if there’s a faulty electrical connection. In situations where the wiring on your existing HVAC system is bad, the technician can replace it. If the thermostat itself is the issue, it will likely have to be replaced.
Honeywell Error Code e2
If you see error code e2 appear on your Honeywell smart thermostat, it might mean several different things. In some cases, one of the sensors responsible for detecting the temperature isn’t functioning properly. In other cases, it means the router was disconnected from its power source before the thermostat completed the setup process.
How to Fix Honeywell Thermostat Error e2
If the error code is a result of sensor failure, a technician should troubleshoot and replace the affected sensor. Any time 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.