A Honeywell smart thermostat is a great way to fine-tune how you use your heating and cooling. But like any utility, you could sometimes run into a problem. With its digital display, Honeywell smart thermostats can display an error code that certified technicians use to get a better sense of what's wrong. Here are several of the most known error codes you may 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 connection did not provide an IP address for the thermostat to hook up to. This can happen if your router does not execute the Dynamic Host Configuration Protocol, or DHCP. This process automatically supplies the required IP address for your thermostat to link up.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by making sure that your router has enabled DHCP. If it does, you usually also have to power cycle the router and perform the setup process again with the thermostat. This should ensure the DHCP is sent and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs when the password for accessing your home’s Wi-Fi router is not correct. After this error code has appeared 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 resolve error e02 is verify you’re entering the correct Wi-Fi password when setting up the thermostat.
Honeywell Thermostat Error 40
Error code 40 can show up when the thermostat is informed that a heat pump or air conditioner’s monitoring system has identified a malfunction. For the most part, this occurs if 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 a lengthy period of time. A “High Pressure Fault” error, triggered by poor airflow, can display this error code. Lastly, you could see 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 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, you should try to contact an experienced technician.
Honeywell Thermostat Error e43
If the Honeywell thermostat presents error code e43, it is failing to communicate with the router, and by extension your 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
Reboot the router by unplugging it and leaving it that way for about 30 seconds. The thermostat could also be disconnected if you’ve recently changed the password or the Wi-Fi’s SSID, which is the name you give it.
Honeywell Thermostat Error e1
Thermostats utilize sensors to determine the temperature outdoors and indoors. If a sensor fails, you may see error code e1 turn up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A trained technician can swap out the sensor and reboot the thermostat, which should clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n could appear when the thermostat is failing to connect to a heating or cooling unit. This can mean that the equipment itself is faulty and unable to connect with the thermostat. This can happen when the wiring is defective or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A qualified technician can utilize a voltmeter to find out if there’s a faulty 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 source of the error code, it should probably be replaced.
Honeywell Thermostat Error e2
If you notice error code e2 appear on your Honeywell smart thermostat, it might mean a few different things. In some cases, one of the sensors used to detect the temperature isn’t functioning like it should. In other cases, it means the router was disconnected from the outlet 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 will troubleshoot and switch out the affected sensor. When the problem comes from disconnected power, all you'll need to do is see to it that the router remains on during the setup process.