A Honeywell smart thermostat is an excellent way to better manage how you use your home comfort system. But like any technology, you could occasionally run into a problem. With its digital display, Honeywell smart thermostats can display an error code that certified technicians use to figure out what's going on. Here are a few 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 hook up to. This can take place if a router fails to execute the Dynamic Host Configuration Protocol, or DHCP. This function 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 verifying that your router is enabled for DHCP. If it does, you usually also need to power cycle the router and perform the setup process again with your thermostat. This should ensure the DHCP is transmitted and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs if the password for communicating with your home’s Wi-Fi router is not correct. When this error code appears for 30 seconds, the thermostat’s digital display will automatically progress to the Wi-Fi setup screen so you can try to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you'll need to do to solve error e02 is verify 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 notified that a heat pump or air conditioner’s monitoring system has identified a malfunction. For the most part, this happens when the compressor isn’t running despite being instructed to. But this error code could also show up if power is disconnected from the outdoor unit for a long period of time. A “High Pressure Fault” error, triggered by poor airflow, can lead to this error code. Finally, you could encounter 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 check the air filter for signs of a clog, as well as the breakers and indoor unit’s blower for regular operation. If you reset the thermostat and error code 40 reappears, it’s best to get in touch with an experienced technician.
Honeywell Thermostat Error e43
If a Honeywell thermostat shows error code e43, it can’t communicate with the router, and by extension the Wi-Fi. This may 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 around 30 seconds. The thermostat could also be disconnected if you have recently changed the password or the Wi-Fi’s SSID, which is the name you give it.
Honeywell Thermostat Error e1
Thermostats utilize 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 qualified technician can swap out the sensor and reset the thermostat, which should clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n may appear when the thermostat is unable to recognize a heating or cooling unit. This might mean that the equipment itself is malfunctioning and unable to communicate with the thermostat. This can happen when the wiring is defective or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A professional 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 should probably be replaced.
Honeywell Thermostat Error e2
If you’ve noticed error code e2 appear on your Honeywell smart thermostat, it can mean several different things. In some cases, 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
In situations where the error code is caused by sensor failure, a technician should troubleshoot and swap out the damaged sensor. If the problem originates from disconnected power, all you'll need to do is verify the router stays on during the setup process.