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 across a problem. With its digital display, Honeywell smart thermostats can display an error code that certified technicians use to figure out what's happening. Here are several of the most common error codes you may see on your Honeywell smart thermostat.
Honeywell Error Code e42
You may see this error code in the event that your home’s Wi-Fi connection did not present an IP address for the thermostat to connect to. This can happen if a router doesn't execute the Dynamic Host Configuration Protocol, or DHCP. This function automatically sends out the required 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 may also need to power cycle the router and perform the setup process again with your thermostat. Doing so should see to it that the DHCP is transmitted and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs when the password for accessing your home’s Wi-Fi router is not correct. After 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 try to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you need to do to clear error e02 is make sure you’re typing the correct Wi-Fi password when setting up the thermostat.
Error Code 40 for Honeywell Thermostats
Error code 40 can appear when the thermostat is informed that a heat pump or air conditioner’s monitoring system has identified a malfunction. Most often, this happens if the compressor isn’t working despite being instructed to. But this error code can also surface if power is disconnected from the outdoor unit for a lengthy period of time. A “High Pressure Fault” error, caused by poor airflow, can lead to this error code. Lastly, you might encounter 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 check 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 a hold of an experienced technician.
Error Code e43 for Honeywell Thermostats
If your Honeywell thermostat shows error code e43, it is failing to communicate with the router, and by extension the Wi-Fi. This may 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 recently changed the password or the Wi-Fi’s SSID, which is the name you create for it.
Honeywell Error Code e1
Thermostats employ sensors to identify the temperature outdoors and indoors. If a sensor fails, you could notice error code e1 turn up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can replace the sensor and reset the thermostat, which should resolve error code e1.
Honeywell Error Code 11n
Error code 11n can appear when the thermostat is failing to detect a heating or cooling unit. This may mean that the equipment itself is faulty and unable to communicate with the thermostat. This can happen when the wiring is bad or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can use a voltmeter to assess if there’s a faulty electrical connection. In situations where the wiring on your existing HVAC system is bad, the technician can replace it. In situations where the thermostat itself is the problem, it will likely have to be replaced.
Error Code e2 for Honeywell Thermostats
If you notice error code e2 show up on your Honeywell smart thermostat, it can mean a few different things. For example, one of the sensors used to detect the temperature isn’t operating like it should. Other times, it means the router was disconnected from its power source before the thermostat finished the setup process.
How to Fix Honeywell Thermostat Error e2
When the error code is caused by sensor failure, a technician will troubleshoot and switch out the damaged sensor. If the problem originates from disconnected power, all you'll need to do is make sure the router stays on over the course of the setup process.
