A Honeywell smart thermostat is a great way to optimize how you use your HVAC system. But like any utility, you might occasionally run across a problem. With a digital display, Honeywell smart thermostats can display an error code that trained technicians can use to get a better sense of what's happening. Here are some of the most known error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You may see this error code in the event that your home’s Wi-Fi internet did not present an IP address for the thermostat to connect to. This can happen if the router does not execute the Dynamic Host Configuration Protocol, or DHCP. This function 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 confirming that your router can complete the DHCP. Assuming it does, you usually also need to power cycle the router and complete the initial setup process again with your thermostat. This should ensure the DHCP is delivered and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs whenever the password for connecting to your home’s Wi-Fi router is incorrect. After 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 try the password again.
How to Fix Honeywell Thermostat Error e02
All you 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 alerted that a heat pump or air conditioner’s monitoring system has identified a malfunction. Most commonly, this appears if the compressor isn’t turning on despite being instructed to. But this error code could also surface if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, induced by blocked airflow, can lead to this error code. Lastly, you could 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 examine 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, you should try to get in touch with an experienced technician.
Honeywell Thermostat Error e43
If your Honeywell thermostat presents error code e43, it is unable to communicate with the router, and by extension your 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
Reset the router by unplugging it and leaving it that way for a short period. The thermostat may also be disconnected if you have recently switched the password or the Wi-Fi’s SSID, which is the name you provide it.
Honeywell Thermostat Error e1
Thermostats employ sensors to determine the temperature outdoors and indoors. If a sensor breaks down, you may see error code e1 turn up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can swap out the sensor and reset the thermostat, which should resolve error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear if the thermostat is unable to detect a heating or cooling unit. This may mean that the equipment itself is defective and unable to connect 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 professional technician can utilize a voltmeter to determine if there’s a poor electrical connection. When the wiring on your existing HVAC system is bad, the technician can replace it. When the thermostat itself is the issue, it should probably be replaced.
Honeywell Thermostat Error e2
If you notice error code e2 show up on your Honeywell smart thermostat, it might mean several different things. In some cases, one of the sensors used to detect 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
If the error code is a result of sensor failure, a technician should troubleshoot and switch out the damaged sensor. When the problem comes from disconnected power, all you have to do is make sure the router stays on throughout the setup process.