A Honeywell smart thermostat is a great way to better manage how you use your HVAC system. But like any utility, you might sometimes run into a problem. With a digital display, Honeywell smart thermostats can provide an error code that professional technicians can use to get a better sense of what's wrong. Here are a few of the most likely error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You can see this error code when your home’s Wi-Fi internet did not provide an IP address for the thermostat to hook up to. This can occur if your router fails to complete the Dynamic Host Configuration Protocol, or DHCP. This process automatically supplies the necessary IP address for your thermostat to link up.
How to Fix Honeywell Thermostat Error e42
You can clear error code e42 by verifying that your router is enabled for 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 see to it that the DHCP is transmitted and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 is displayed when the password for communicating with your home’s Wi-Fi router was incorrect. When 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 resolve error e02 is ensure you’re typing 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 detected a malfunction. Most commonly, this happens when the compressor isn’t running despite being directed to. But this error code could also surface if power is disconnected from the outdoor unit for a lengthy period of time. A “High Pressure Fault” error, induced by blocked airflow, can lead to this error code. And finally, you might encounter error code 40 if there’s an issue with the refrigerant, 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 reset the thermostat and error code 40 reappears, you should try to contact an experienced technician.
Honeywell Thermostat Error e43
If a Honeywell thermostat displays error code e43, it is failing to 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
Restart the router by unplugging it and leaving it that way for a short period. The thermostat might 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 use sensors to detect the temperature outdoors and indoors. If a sensor fails, you might notice error code e1 turn 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 clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n could appear if the thermostat is unable to recognize a heating or cooling unit. This may mean that the equipment itself is defective and unable to communicate with the thermostat. This can happen when the wiring is defective 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 poor electrical connection. If the wiring on your existing HVAC equipment is bad, the technician can replace it. In situations where the thermostat itself is the source of the error code, it should probably be replaced.
Honeywell Thermostat Error e2
If you see error code e2 appear on your Honeywell smart thermostat, it could mean several different things. In some cases, one of the sensors that detects the temperature isn’t working correctly. In other instances, it means the router was disconnected from power before the thermostat finished the setup process.
How to Fix Honeywell Thermostat Error e2
In situations where the error code stems from sensor failure, a technician can troubleshoot and swap out the affected sensor. If the problem originates from disconnected power, all you’ll have to do is see to it that the router remains on throughout the setup process.