A Honeywell smart thermostat is an excellent way to fine-tune how you use your HVAC system. But like any utility, you may sometimes run into a problem. With a digital display, Honeywell smart thermostats can provide an error code that certified technicians can use to understand what's wrong. Here are several of the most common error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You can encounter this error code if your home’s Wi-Fi internet did not supply an IP address for the thermostat to connect to. This can take place if your router doesn't perform the Dynamic Host Configuration Protocol, or DHCP. This process automatically sends out the required 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. When it does, you usually also need to power cycle the router and repeat the initial setup process with your thermostat. This should ensure the DHCP is transmitted and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs if the password for connecting to your home’s Wi-Fi router was incorrect. Once this error code has appeared 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 solve error e02 is make sure you’re entering the correct Wi-Fi password when setting up 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 recognized a malfunction. Most commonly, this happens if the compressor isn’t working despite being directed to. But this error code may also surface if power is shut off from the outdoor unit for an extended period of time. A “High Pressure Fault” error, induced by poor airflow, can display this error code. Lastly, you could experience 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 inspect 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 get in touch with an experienced technician.
Honeywell Thermostat Error e43
If a Honeywell thermostat presents error code e43, it is failing to 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 a short period. The thermostat could also be disconnected if you’ve recently changed the password or the Wi-Fi’s SSID, which is the name you provide it.
Honeywell Thermostat Error e1
Thermostats employ sensors to identify the temperature outdoors and indoors. If a sensor breaks down, you could notice error code e1 turn up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can change out the sensor and restart the thermostat, which should clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear if the thermostat is failing to recognize a heating or cooling unit. This may mean that the equipment itself is malfunctioning and unable to maintain a connection to 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 professional technician can employ a voltmeter to assess if there’s a bad electrical connection. When the wiring on your existing HVAC system is bad, the technician can replace it. In situations where the thermostat itself is the issue, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you see error code e2 appear on your Honeywell smart thermostat, it could mean a few different things. Sometimes, one of the sensors responsible for detecting the temperature isn’t operating properly. Other times, it means the router was disconnected from its power source before the thermostat completed the setup process.
How to Fix Honeywell Thermostat Error e2
When the error code is caused by sensor failure, a technician should troubleshoot and swap out the damaged sensor. If the problem stems from disconnected power, all you'll need to do is verify the router remains on throughout the setup process.