A Honeywell smart thermostat is a great way to fine-tune how you use your HVAC system. But like any mechanical system, you might sometimes experience a problem. With the digital display, Honeywell smart thermostats can provide an error code that trained technicians will use to figure out what's happening. Here are several of the most common error codes you may see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You might receive this error code if your home’s Wi-Fi connection did not supply an IP address for the thermostat to hook up to. This can occur if your router fails to execute the Dynamic Host Configuration Protocol, or DHCP. This procedure 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 can complete the DHCP. Assuming it does, you might also need to power cycle the router and repeat the initial setup process with the thermostat. Completing this task should ensure the DHCP is delivered and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears whenever the password for accessing your home’s Wi-Fi router is incorrect. After this error code appears for 30 seconds, the thermostat’s digital display automatically transitions 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 putting in the correct Wi-Fi password when setting up 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 running despite being instructed to. But this error code can also surface if power is disconnected from the outdoor unit for a long period of time. A “High Pressure Fault” error, induced by blocked airflow, can render this error code. And finally, 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 normal operation. If you turn the thermostat off and on again and error code 40 reappears, it's time to contact an experienced technician.
Honeywell Thermostat Error e43
If your Honeywell thermostat shows error code e43, it can’t communicate with the router, and by extension your Wi-Fi. This can happen if the router’s ethernet cable isn’t plugged in or it isn’t communicating with your 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 might 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 determine the temperature outdoors and indoors. If a sensor breaks down, you may notice error code e1 appear on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A qualified technician can change out the sensor and restart the thermostat, which should take care of error code e1.
Honeywell Thermostat Error 11n
Error code 11n may appear if the thermostat can’t connect to a heating or cooling unit. This may mean that the equipment itself is faulty and unable to communicate with the thermostat. This can happen when the wiring is defective or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can use a voltmeter to assess if there’s a bad electrical connection. In situations where the wiring on your specific HVAC equipment is bad, the technician can replace it. In situations where the thermostat itself is the source of the error code, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you see error code e2 appear on your Honeywell smart thermostat, it can mean a few different things. For example, one of the sensors used to detect the temperature isn’t operating like it should. Other times, it means the router was disconnected from the outlet before the thermostat finished the setup process.
How to Fix Honeywell Thermostat Error e2
When the error code is a result of sensor failure, a technician can troubleshoot and switch out the damaged sensor. Any time the problem comes from disconnected power, all you have to do is see to it that the router remains on during the setup process.