A Honeywell smart thermostat is an easy way to fine-tune how you use your home comfort system. But like any technology, you may occasionally run across a problem. With the digital display, Honeywell smart thermostats can display an error code that trained technicians use to figure out what's going on. Here are several of the most likely error codes you could see on your Honeywell smart thermostat.
Error Code e42 for Honeywell Thermostats
You can receive this error code when your home’s Wi-Fi internet did not provide an IP address for the thermostat to connect to. This can happen if your router fails to perform the Dynamic Host Configuration Protocol, or DHCP. This procedure automatically supplies the necessary IP address for your thermostat to link up.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by verifying that your router has enabled DHCP. Assuming it does, you usually also have to power cycle the router and complete the initial setup process again with the thermostat. Doing so should see to it that the DHCP is delivered and connects to your smart thermostat.
Honeywell Error Code e02
Error code e02 occurs if the password for connecting to your home’s Wi-Fi router is incorrect. When this error code appears for 30 seconds, the thermostat’s digital display automatically transitions to the Wi-Fi setup screen so you can attempt to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you have to do to resolve error e02 is ensure you’re entering the correct Wi-Fi password when setting up the thermostat.
Error Code 40 for Honeywell Thermostats
Error code 40 can show up when the thermostat is informed that a heat pump or air conditioner’s monitoring system has recognized a malfunction. For the most part, this happens once the compressor isn’t working despite being directed to. But this error code may also show up if power is disconnected from the outdoor unit for a lengthy period of time. A “High Pressure Fault” error, caused by poor airflow, can lead to this error code. And finally, you may encounter error code 40 if there’s an issue with the coolant, 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 normal operation. If you reset the thermostat and error code 40 reappears, it's time to get in touch with an experienced technician.
Honeywell Thermostat Error e43
If the Honeywell thermostat shows error code e43, it can’t communicate with the router, and by extension your 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
Reboot the router by unplugging it and leaving it that way for about 30 seconds. The thermostat could also be disconnected if you recently switched the password or the Wi-Fi’s SSID, which is the name you give it.
Honeywell Error Code e1
Thermostats employ sensors to detect the temperature outdoors and indoors. If a sensor malfunctions, you could notice error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can change out the sensor and restart the thermostat, which should clear error code e1.
Error Code 11n for Honeywell Thermostats
Error code 11n can appear when the thermostat is unable to detect a heating or cooling unit. This may mean that the equipment itself is faulty and unable to connect with the thermostat. This can happen when the wiring is bad or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A professional technician can use a voltmeter to find out if there’s a bad electrical connection. In situations where the wiring on your existing HVAC system is bad, the technician can replace it. When the thermostat itself is the problem, it should probably be replaced.
Error Code e2 for Honeywell Thermostats
If you see error code e2 pop up on your Honeywell smart thermostat, it can mean a couple of different things. In some cases, one of the sensors that detects the temperature isn’t working properly. In other instances, it means the router was disconnected from its power source before the thermostat could complete the setup process.
How to Fix Honeywell Thermostat Error e2
When the error code is caused by sensor failure, a technician can troubleshoot and replace the affected sensor. If the problem originates from disconnected power, all you’ll have to do is see to it that the router remains on during the setup process.
