A Honeywell smart thermostat is an excellent way to fine-tune how you use your HVAC system. But like any mechanical system, you could sometimes experience a problem. With its digital display, Honeywell smart thermostats can display an error code that trained technicians can use to understand what's wrong. Here are several of the most known 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 to. This can take place if the router doesn't complete the Dynamic Host Configuration Protocol, or DHCP. This function automatically supplies the needed IP address for your thermostat to link up.
How to Fix Honeywell Thermostat Error e42
You can resolve error code e42 by verifying that your router is enabled for DHCP. Assuming it does, you might also need to power cycle the router and perform the setup process again with the thermostat. This should ensure the DHCP is transmitted and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears whenever the password for communicating with your home’s Wi-Fi router was incorrect. Once 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 typing the correct Wi-Fi password when configuring the thermostat.
Honeywell Thermostat Error 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. For the most part, this appears if the compressor isn’t turning on despite being instructed to. But this error code can also surface if power is shut off from the outdoor unit for an extended period of time. A “High Pressure Fault” error, induced by blocked airflow, can lead to this error code. Lastly, you may see error code 40 if there’s a problem with the refrigerant, the outdoor unit’s fan motor or the motor’s starting capacitor.
How to Fix Honeywell Thermostat Error 40
You can inspect the air filter for signs of a clog, as well as the breakers and indoor unit’s blower for regular 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 your Honeywell thermostat shows error code e43, it can’t communicate with the router, and by extension the 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 about 30 seconds. The thermostat could 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 use sensors to detect the temperature outdoors and indoors. If a sensor fails, you could notice error code e1 turn up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A trained technician can replace the sensor and restart the thermostat, which should take care of error code e1.
Honeywell Thermostat Error 11n
Error code 11n may appear when the thermostat is unable to detect a heating or cooling unit. This can mean that the equipment itself is defective and unable to maintain a connection to 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 qualified technician can use a voltmeter to assess if there’s a poor electrical connection. If the wiring on your specific HVAC equipment 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’ve noticed error code e2 appear on your Honeywell smart thermostat, it might mean a couple of different things. For example, one of the sensors responsible for detecting the temperature isn’t working like it should. In other instances, it means the router was disconnected from the outlet before the thermostat could complete the setup process.
How to Fix Honeywell Thermostat Error e2
If the error code is caused by sensor failure, a technician can troubleshoot and swap out the damaged sensor. Any time the problem originates from disconnected power, all you have to do is make sure the router stays on throughout the setup process.