A Honeywell smart thermostat is an easy way to optimize how you use your HVAC system. But like any mechanical system, you could sometimes run into a problem. With the digital display, Honeywell smart thermostats can display an error code that professional technicians can use to figure out what's happening. Here are a few of the most known error codes you could 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 present an IP address for the thermostat to connect to. This can occur if your router doesn't execute the Dynamic Host Configuration Protocol, or DHCP. This process automatically supplies the required IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can clear error code e42 by verifying that your router has enabled DHCP. Assuming it does, you usually also need to power cycle the router and perform the setup process again with your thermostat. Completing this task should ensure the DHCP is transmitted and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears whenever 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 will automatically progress to the Wi-Fi setup screen so you can try the password again.
How to Fix Honeywell Thermostat Error e02
All you have to do to solve error e02 is ensure you’re putting in the correct Wi-Fi password when configuring the thermostat.
Honeywell Thermostat Error 40
Error code 40 can show up when the thermostat is notified that a heat pump or air conditioner’s monitoring system has identified a malfunction. For the most part, this occurs once the compressor isn’t running despite being instructed to. But this error code can also appear if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, induced by obstructed airflow, can render this error code. And finally, you might see error code 40 if there’s an issue 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 normal operation. If you restart the thermostat and error code 40 reappears, it’s best to get a hold of an experienced technician.
Honeywell Thermostat Error e43
If your Honeywell thermostat shows error code e43, it is failing 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
Reboot the router by unplugging it and leaving it that way for about 30 seconds. The thermostat may also be disconnected if you 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 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 reboot the thermostat, which should resolve error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear if the thermostat can’t recognize a heating or cooling unit. This might mean that the equipment itself is malfunctioning and unable to communicate with the thermostat. This sometimes happens when the wiring is damaged or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can use a voltmeter to assess if there’s a bad electrical connection. When the wiring on your type of HVAC equipment is bad, the technician can replace it. If the thermostat itself is the problem, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you’ve noticed error code e2 appear on your Honeywell smart thermostat, it can mean a few different things. In some cases, 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
In situations where the error code is a result of sensor failure, a technician can troubleshoot and swap out the impacted sensor. Any time the problem originates from disconnected power, all you’ll have to do is make sure the router remains on throughout the setup process.