A Honeywell smart thermostat is an easy way to better manage how you use your home comfort system. But like any technology, you might sometimes experience a problem. With the digital display, Honeywell smart thermostats can provide an error code that certified technicians can use to understand what's wrong. Here are some of the most likely 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 provide an IP address for the thermostat to connect with. This can occur if the router fails to execute the Dynamic Host Configuration Protocol, or DHCP. This function automatically sends out the necessary 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 verifying that your router has enabled DHCP. If it does, you usually also need to power cycle the router and perform the setup process again with your thermostat. Completing this task should see to it that the DHCP is sent and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs if the password for communicating with your home’s Wi-Fi router is incorrect. After this error code appears 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 resolve error e02 is ensure you’re putting in the correct Wi-Fi password when setting up 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 identified a malfunction. For the most part, this occurs if the compressor isn’t running despite being directed to. But this error code may also surface if power is disconnected from the outdoor unit for a long period of time. A “High Pressure Fault” error, induced by obstructed airflow, can render this error code. Lastly, you might see 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 ordinary operation. If you restart the thermostat and error code 40 reappears, it's time to get in touch with an experienced technician.
Honeywell Thermostat Error e43
If the Honeywell thermostat shows error code e43, it is unable to communicate with the router, and by extension the Wi-Fi. This might 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
Restart the router by unplugging it and leaving it that way for around 30 seconds. The thermostat might also be disconnected if you recently updated the password or the Wi-Fi’s SSID, which is the name you provide it.
Honeywell Thermostat Error e1
Thermostats use sensors to determine 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 skilled technician can change out the sensor and restart the thermostat, which should resolve error code e1.
Honeywell Thermostat Error 11n
Error code 11n could appear when the thermostat is failing to recognize a heating or cooling unit. This may mean that the equipment itself is faulty and unable to communicate with the thermostat. This sometimes happens 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. If the wiring on your specific 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 appear on your Honeywell smart thermostat, it might mean several different things. In some cases, one of the sensors that detects the temperature isn’t working properly. 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
When the error code stems from sensor failure, a technician will troubleshoot and replace the damaged sensor. If the problem comes from disconnected power, all you'll need to do is see to it that the router stays on during the setup process.