A Honeywell smart thermostat is an easy way to fine-tune how you use your heating and cooling. But like any mechanical system, you could sometimes experience a problem. With the digital display, Honeywell smart thermostats can provide an error code that trained technicians use to get a better sense of 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 might see this error code if your home’s Wi-Fi connection did not provide an IP address for the thermostat to hook up to. This can happen if your router fails to execute the Dynamic Host Configuration Protocol, or DHCP. This procedure automatically sends out 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 making sure that your router has enabled DHCP. Assuming it does, you might also have to power cycle the router and repeat the initial setup process with your thermostat. Completing this task should ensure the DHCP is transmitted and connects to the smart thermostat.
Honeywell Error Code e02
Error code e02 occurs when the password for communicating with your home’s Wi-Fi router is incorrect. Once 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 clear error e02 is ensure you’re entering the correct Wi-Fi password when setting up the thermostat.
Error Code 40 for Honeywell Thermostats
Error code 40 can show up when the thermostat is informed that a heat pump or air conditioner’s monitoring system has identified a malfunction. For the most part, this occurs if the compressor isn’t working despite being directed to. But this error code can also show up if power is disconnected from the outdoor unit for an extended period of time. A “High Pressure Fault” error, caused by obstructed airflow, can display this error code. And finally, you might encounter error code 40 if there’s something wrong with the coolant, 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 restart the thermostat and error code 40 reappears, it's time to contact an experienced technician.
Honeywell Error Code e43
If the Honeywell thermostat presents 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 around 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 provide it.
Honeywell Thermostat Error e1
Thermostats utilize sensors to identify the temperature outdoors and indoors. If a sensor fails, you could notice error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A trained technician can change out the sensor and reboot the thermostat, which should resolve error code e1.
Error Code 11n for Honeywell Thermostats
Error code 11n may appear when the thermostat is failing to detect a heating or cooling unit. This can mean that the equipment itself is faulty 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 qualified technician can use a voltmeter to determine if there’s a faulty electrical connection. When the wiring on your type of HVAC equipment is bad, the technician can replace it. When the thermostat itself is the source of the error code, it should probably be replaced.
Honeywell Thermostat Error e2
If you notice error code e2 pop up on your Honeywell smart thermostat, it can mean a couple of different things. For example, one of the sensors responsible for detecting the temperature isn’t operating properly. In other cases, 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 swap out the impacted sensor. If the problem originates from disconnected power, all you’ll have to do is verify the router remains on throughout the setup process.
