A Honeywell smart thermostat is a great way to fine-tune how you use your home comfort system. But like any technology, you could sometimes run across a problem. With the digital display, Honeywell smart thermostats can display an error code that trained technicians use to understand what's happening. Here are several of the most common error codes you could see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You can receive this error code in the event that your home’s Wi-Fi connection did not provide an IP address for the thermostat to connect to. This can happen if a router fails to perform the Dynamic Host Configuration Protocol, or DHCP. This process automatically transmits 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 has enabled DHCP. If it does, you usually also need to power cycle the router and repeat the initial setup process with your thermostat. This should see to it that the DHCP is delivered and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears when the password for connecting to your home’s Wi-Fi router was incorrect. Once this error code is displayed for 30 seconds, the thermostat’s digital display automatically transitions to the Wi-Fi setup screen so you can try to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you have to do to solve error e02 is ensure you’re entering 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 identified a malfunction. Most often, this happens if the compressor isn’t turning on despite being directed to. But this error code can also show up if power is disconnected from the outdoor unit for a long period of time. A “High Pressure Fault” error, induced by poor airflow, can render this error code. Lastly, you might experience 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 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 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 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 may also be disconnected if you recently changed the password or the Wi-Fi’s SSID, which is the name you create for it.
Honeywell Thermostat Error e1
Thermostats utilize sensors to identify the temperature outdoors and indoors. If a sensor fails, you could see error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A qualified technician can replace the sensor and reboot the thermostat, which should clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n may appear if the thermostat is failing to recognize a heating or cooling unit. This can mean that the equipment itself is defective and unable to communicate with the thermostat. This can happen when the wiring is bad or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A professional technician can use a voltmeter to determine if there’s a poor electrical connection. When the wiring on your type of HVAC equipment is bad, the technician can replace it. When the thermostat itself is the source of the error code, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you’ve noticed error code e2 pop up on your Honeywell smart thermostat, it can mean a couple of different things. Sometimes, one of the sensors responsible for detecting the temperature isn’t working 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 should troubleshoot and switch out the impacted sensor. When the problem originates from disconnected power, all you'll need to do is make sure the router remains on throughout the setup process.