A Honeywell smart thermostat is an easy way to better manage how you use your HVAC system. But like any mechanical system, you might sometimes run into a problem. With a digital display, Honeywell smart thermostats can display an error code that trained technicians will use to figure out what's happening. Here are several of the most likely error codes you may see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You may see this error code if your home’s Wi-Fi connection did not provide an IP address for the thermostat to connect to. This can take place if the router fails to perform the Dynamic Host Configuration Protocol, or DHCP. This function automatically transmits the necessary IP address for your thermostat to connect to the Wi-Fi.
How to Fix Honeywell Thermostat Error e42
You can resolve error code e42 by verifying that your router is enabled for DHCP. If it does, you might also need to power cycle the router and perform the setup process again with the thermostat. This should see to it that the DHCP is delivered and connects to your smart thermostat.
Honeywell Error Code e02
Error code e02 is displayed if the password for connecting to your home’s Wi-Fi router was incorrect. After this error code appears for 30 seconds, the thermostat’s digital display automatically transitions to the Wi-Fi setup screen so you can attempt to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you need to do to solve error e02 is ensure you’re entering the correct Wi-Fi password when configuring the thermostat.
Honeywell Error Code 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. For the most part, this occurs if the compressor isn’t working despite being instructed to. But this error code can also surface if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, triggered by blocked airflow, can lead to this error code. Finally, you might 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 examine 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, you should try to contact an experienced technician.
Error Code e43 for Honeywell Thermostats
If a Honeywell thermostat shows error code e43, it is unable to communicate with the router, and by extension your Wi-Fi. This may 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 about 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.
Error Code e1 for Honeywell Thermostats
Thermostats utilize sensors to identify the temperature outdoors and indoors. If a sensor fails, you might notice error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can swap out the sensor and restart the thermostat, which should take care of error code e1.
Error Code 11n for Honeywell Thermostats
Error code 11n can appear if the thermostat is unable to detect a heating or cooling unit. This can mean that the equipment itself is defective and unable to connect with the thermostat. This can happen when the wiring is damaged or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A professional technician can use a voltmeter to find out if there’s a bad electrical connection. If the wiring on your specific HVAC system is bad, the technician can replace it. In situations where the thermostat itself is the source of the error code, it will likely have to be replaced.
Honeywell Error Code e2
If you see error code e2 show up on your Honeywell smart thermostat, it could mean several different things. In some cases, one of the sensors used to detect 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
When the error code is a result of sensor failure, a technician will troubleshoot and switch out the impacted sensor. Any time the problem stems from disconnected power, all you have to do is verify the router stays on during the setup process.