A Honeywell smart thermostat is an easy way to optimize how you use your home comfort system. But like any mechanical system, you might occasionally run into a problem. With the digital display, Honeywell smart thermostats can show an error code that trained technicians will 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 in the event that your home’s Wi-Fi internet did not supply an IP address for the thermostat to hook up to. This can take place if a router doesn't complete the Dynamic Host Configuration Protocol, or DHCP. This process automatically transmits the needed IP address for your thermostat to connect to the Wi-Fi.
How to Fix Honeywell Thermostat Error e42
You can resolve error code e42 by confirming that your router has enabled DHCP. If it does, you may also need to power cycle the router and repeat the initial setup process with your thermostat. This should ensure the DHCP is sent and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears whenever the password for communicating with your home’s Wi-Fi router is not correct. When this error code is displayed for 30 seconds, the thermostat’s digital display will automatically progress to the Wi-Fi setup screen so you can try the password again.
How to Fix Honeywell Thermostat Error e02
All you'll 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 alerted that a heat pump or air conditioner’s monitoring system has recognized a malfunction. Most often, this happens once the compressor isn’t turning on despite being instructed to. But this error code could also surface if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, triggered by poor airflow, can display this error code. Finally, you might see error code 40 if there’s something wrong 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 ordinary operation. If you reset the thermostat and error code 40 reappears, you should try to get a hold of an experienced technician.
Honeywell Thermostat Error e43
If your Honeywell thermostat presents error code e43, it is unable to 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 your wide area network (WAN).
How to Fix Honeywell Thermostat Error e43
Reboot 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 provide it.
Honeywell Thermostat Error e1
Thermostats utilize sensors to detect the temperature outdoors and indoors. If a sensor malfunctions, 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 restart the thermostat, which should resolve error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear if the thermostat is unable to detect a heating or cooling unit. This may mean that the equipment itself is faulty and unable to maintain a connection to the thermostat. This sometimes happens when the wiring is defective or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can employ a voltmeter to assess if there’s a faulty electrical connection. If the wiring on your existing HVAC equipment is bad, the technician can replace it. If the thermostat itself is the issue, it should probably be replaced.
Honeywell Thermostat Error e2
If you’ve noticed error code e2 pop up on your Honeywell smart thermostat, it can mean several different things. For example, one of the sensors used to detect the temperature isn’t functioning correctly. 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
When the error code stems from sensor failure, a technician can troubleshoot and switch out the affected sensor. When the problem stems from disconnected power, all you'll need to do is verify the router remains on during the setup process.