A Honeywell smart thermostat is an easy way to optimize how you use your heating and cooling. But like any mechanical system, you might occasionally experience a problem. With a digital display, Honeywell smart thermostats can show an error code that trained technicians will use to get a better sense of what's happening. Here are several of the most common error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You might receive this error code in the event that your home’s Wi-Fi connection did not present an IP address for the thermostat to connect with. This can happen if your router doesn't complete the Dynamic Host Configuration Protocol, or DHCP. This process automatically supplies the required IP address for your thermostat to connect to the Wi-Fi.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by confirming that your router can complete the DHCP. When it does, you usually also need to power cycle the router and repeat the initial setup process with your thermostat. Doing so should see to it that the DHCP is sent and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs when the password for communicating with 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 resolve error e02 is make sure you’re putting in 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. For the most part, this occurs once the compressor isn’t turning on despite being instructed to. But this error code could also surface if power is shut off from the outdoor unit for an extended period of time. A “High Pressure Fault” error, triggered by blocked airflow, can lead to this error code. Lastly, you might encounter error code 40 if there’s a problem 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, it's time to get a hold of an experienced technician.
Honeywell Thermostat Error e43
If the Honeywell thermostat presents 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 your wide area network (WAN).
How to Fix Honeywell Thermostat Error e43
Reset the router by unplugging it and leaving it that way for around 30 seconds. The thermostat might also be disconnected if you recently changed the password or the Wi-Fi’s SSID, which is the name you provide it.
Honeywell Thermostat Error e1
Thermostats utilize sensors to detect the temperature outdoors and indoors. If a sensor fails, you may see error code e1 appear on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A trained technician can swap out the sensor and reset the thermostat, which should take care of error code e1.
Honeywell Thermostat Error 11n
Error code 11n may appear when the thermostat is failing to connect to a heating or cooling unit. This can mean that the equipment itself is faulty and unable to connect with the thermostat. This can happen when the wiring is bad or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can use a voltmeter to determine if there’s a bad electrical connection. When the wiring on your existing HVAC equipment is bad, the technician can replace it. When the thermostat itself is the problem, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you see error code e2 appear on your Honeywell smart thermostat, it can mean several different things. In some cases, one of the sensors responsible for detecting the temperature isn’t functioning 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
When the error code is a result of sensor failure, a technician should troubleshoot and swap out the affected sensor. When the problem comes from disconnected power, all you'll need to do is make sure the router stays on during the setup process.