A Honeywell smart thermostat is a great way to fine-tune how you use your heating and cooling. But like any mechanical system, you could sometimes run into a problem. With the digital display, Honeywell smart thermostats can provide an error code that trained technicians use to get a better sense of what's happening. Here are a few of the most likely error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You might see this error code when your home’s Wi-Fi connection did not provide an IP address for the thermostat to connect with. This can occur if a router fails to execute the Dynamic Host Configuration Protocol, or DHCP. This process automatically supplies the needed IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can clear error code e42 by confirming that your router can complete the DHCP. Assuming it does, you usually 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 delivered and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears when the password for connecting to your home’s Wi-Fi router is not correct. When 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 need to do to resolve error e02 is ensure you’re putting in the correct Wi-Fi password when setting up the thermostat.
Honeywell Error Code 40
Error code 40 can pop up when the thermostat is notified that a heat pump or air conditioner’s monitoring system has recognized a malfunction. Most often, this appears once the compressor isn’t running despite being directed to. But this error code can also surface if power is shut off from the outdoor unit for a lengthy period of time. A “High Pressure Fault” error, caused by obstructed airflow, can display this error code. Finally, you may encounter error code 40 if there’s an issue with the coolant, 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 normal operation. If you turn the thermostat off and on again and error code 40 reappears, it’s best to get a hold of an experienced technician.
Honeywell Error Code e43
If a Honeywell thermostat displays error code e43, it can’t 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 your 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 have recently switched the password or the Wi-Fi’s SSID, which is the name you create for it.
Error Code e1 for Honeywell Thermostats
Thermostats use sensors to detect the temperature outdoors and indoors. If a sensor breaks down, you may notice error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A qualified technician can swap out the sensor and reboot the thermostat, which should resolve error code e1.
Error Code 11n for Honeywell Thermostats
Error code 11n may appear if the thermostat can’t recognize 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 damaged 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 faulty electrical connection. In situations where the wiring on your specific HVAC system is bad, the technician can replace it. If the thermostat itself is the source of the error code, it should probably be replaced.
Error Code e2 for Honeywell Thermostats
If you notice error code e2 appear on your Honeywell smart thermostat, it can mean several different things. Sometimes, one of the sensors used to detect the temperature isn’t operating properly. In other instances, it means the router was disconnected from power before the thermostat completed 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 damaged sensor. When the problem comes from disconnected power, all you have to do is see to it that the router stays on during the setup process.