A Honeywell smart thermostat is a great way to fine-tune how you use your heating and cooling. But like any technology, you could sometimes run across a problem. With the digital display, Honeywell smart thermostats can show an error code that certified technicians can use to figure out what's going on. Here are several of the most known error codes you could see on your Honeywell smart thermostat.
Error Code e42 for Honeywell Thermostats
You might 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 a router fails to execute the Dynamic Host Configuration Protocol, or DHCP. This procedure automatically sends out the necessary IP address for your thermostat to connect to the Wi-Fi.
How to Fix Honeywell Thermostat Error e42
You can clear error code e42 by making sure that your router can complete the DHCP. When it does, you usually also need to power cycle the router and complete the initial setup process again with your thermostat. Completing this task should ensure the DHCP is delivered and connects to the smart thermostat.
Honeywell Error Code e02
Error code e02 occurs whenever the password for connecting to 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 attempt to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you need to do to solve error e02 is make sure you’re typing the correct Wi-Fi password when configuring the thermostat.
Error Code 40 for Honeywell Thermostats
Error code 40 can appear when the thermostat is notified that a heat pump or air conditioner’s monitoring system has detected a malfunction. For the most part, this happens if the compressor isn’t turning on despite being instructed to. But this error code can also surface if power is disconnected from the outdoor unit for an extended period of time. A “High Pressure Fault” error, triggered by poor airflow, can render this error code. Finally, you could see error code 40 if there’s something wrong with the coolant, the outdoor unit’s fan motor or the motor’s starting capacitor.
How to Fix Honeywell Thermostat Error 40
You can examine 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 time to contact an experienced technician.
Honeywell Error Code e43
If the Honeywell thermostat shows 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
Restart the router by unplugging it and leaving it that way for about 30 seconds. The thermostat could also be disconnected if you recently changed the password or the Wi-Fi’s SSID, which is the name you give it.
Honeywell Error Code e1
Thermostats utilize sensors to detect the temperature outdoors and indoors. If a sensor malfunctions, you may notice error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can swap out the sensor and restart the thermostat, which should take care of error code e1.
Honeywell Error Code 11n
Error code 11n may appear when the thermostat is unable to connect to a heating or cooling unit. This may mean that the equipment itself is faulty and unable to maintain a connection to 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 employ a voltmeter to find out if there’s a bad electrical connection. When the wiring on your existing HVAC system is bad, the technician can replace it. When the thermostat itself is the problem, it will likely have to be replaced.
Error Code e2 for Honeywell Thermostats
If you notice error code e2 pop up on your Honeywell smart thermostat, it can mean a few different things. Sometimes, one of the sensors used to detect the temperature isn’t operating correctly. Other times, 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 is caused by sensor failure, a technician should troubleshoot and switch out the impacted sensor. If the problem comes from disconnected power, all you have to do is make sure the router stays on during the setup process.