A Honeywell smart thermostat is a great way to optimize how you use your heating and cooling. But like any utility, you could sometimes experience a problem. With its digital display, Honeywell smart thermostats can display an error code that trained technicians use to figure out what's wrong. Here are some of the most common error codes you may see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You may see this error code if your home’s Wi-Fi internet did not present 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 function automatically transmits 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. When it does, you usually also have to power cycle the router and repeat the initial setup process with your thermostat. Doing so should ensure the DHCP is delivered and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs if the password for accessing your home’s Wi-Fi router is incorrect. After this error code appears for 30 seconds, the thermostat’s digital display should automatically transition to the Wi-Fi setup screen so you can try the password again.
How to Fix Honeywell Thermostat Error e02
All you have 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 appear when the thermostat is notified that a heat pump or air conditioner’s monitoring system has recognized a malfunction. For the most part, this appears once the compressor isn’t turning on despite being instructed to. But this error code could also appear 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 lead to this error code. Finally, you may encounter error code 40 if there’s a problem with the coolant, 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 restart the thermostat and error code 40 reappears, it’s best to contact an experienced technician.
Honeywell Thermostat Error e43
If the Honeywell thermostat shows error code e43, it is unable to communicate with the router, and by extension your Wi-Fi. This could 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
Reset the router by unplugging it and leaving it that way for a short period. The thermostat could also be disconnected if you recently updated the password or the Wi-Fi’s SSID, which is the name you create for it.
Honeywell Thermostat Error e1
Thermostats employ sensors to identify the temperature outdoors and indoors. If a sensor malfunctions, you could notice error code e1 appear 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 clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear when the thermostat can’t connect to a heating or cooling unit. This might mean that the equipment itself is faulty and unable to maintain a connection to the thermostat. This can happen when the wiring is damaged or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can utilize a voltmeter to find out if there’s a poor electrical connection. In situations where the wiring on your existing HVAC equipment is bad, the technician can replace it. When the thermostat itself is the issue, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you see error code e2 pop up on your Honeywell smart thermostat, it might mean several different things. Sometimes, one of the sensors responsible for detecting the temperature isn’t operating like it should. 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
If the error code is caused by sensor failure, a technician will troubleshoot and switch out the impacted sensor. When the problem comes from disconnected power, all you have to do is make sure the router remains on over the course of the setup process.