A Honeywell smart thermostat is an easy way to optimize how you use your HVAC system. But like any mechanical system, you could occasionally experience a problem. With a digital display, Honeywell smart thermostats can provide an error code that trained technicians can use to understand what's going on. Here are a few of the most common error codes you could see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You might encounter 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 occur if your router fails to perform the Dynamic Host Configuration Protocol, or DHCP. This function automatically sends out the needed 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 has enabled DHCP. When it does, you might also have to power cycle the router and perform the setup process again with your thermostat. Doing so should ensure the DHCP is delivered and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears if the password for connecting to your home’s Wi-Fi router is not correct. Once this error code is displayed 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 solve error e02 is make sure you’re entering the correct Wi-Fi password when setting up the thermostat.
Honeywell Error Code 40
Error code 40 can pop up when the thermostat is notified that a heat pump or air conditioner’s monitoring system has detected a malfunction. Most commonly, this appears if the compressor isn’t turning on despite being instructed to. But this error code may also show up if power is disconnected from the outdoor unit for an extended period of time. A “High Pressure Fault” error, triggered by blocked airflow, can display this error code. Lastly, you might see 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 ordinary operation. If you turn the thermostat off and on again and error code 40 reappears, it’s best to get in touch with an experienced technician.
Honeywell Error Code e43
If a Honeywell thermostat presents error code e43, it can’t communicate with the router, and by extension your Wi-Fi. This could 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 a short period. The thermostat may also be disconnected if you recently updated the password or the Wi-Fi’s SSID, which is the name you create for it.
Honeywell Thermostat Error e1
Thermostats utilize sensors to identify the temperature outdoors and indoors. If a sensor malfunctions, you may 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 clear error code e1.
Honeywell Error Code 11n
Error code 11n may appear when the thermostat is failing to recognize a heating or cooling unit. This might mean that the equipment itself is malfunctioning 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 utilize a voltmeter to determine if there’s a faulty electrical connection. When the wiring on your existing HVAC equipment is bad, the technician can replace it. In situations where the thermostat itself is the issue, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you see error code e2 pop up on your Honeywell smart thermostat, it could mean a couple of different things. Sometimes, one of the sensors that detects the temperature isn’t working like it should. In other cases, it means the router was disconnected from power before the thermostat could complete the setup process.
How to Fix Honeywell Thermostat Error e2
If the error code stems from sensor failure, a technician will troubleshoot and switch out the impacted sensor. If the problem comes from disconnected power, all you'll need to do is verify the router remains on throughout the setup process.