A Honeywell smart thermostat is a great way to better manage how you use your home comfort system. But like any utility, you could occasionally run into a problem. With its digital display, Honeywell smart thermostats can provide an error code that certified technicians can use to figure out what's going on. Here are several of the most common error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You might receive this error code in the event that your home’s Wi-Fi connection did not present an IP address for the thermostat to connect to. This can take place if a router does not perform the Dynamic Host Configuration Protocol, or DHCP. This process automatically sends out the necessary IP address for your thermostat to link up.
How to Fix Honeywell Thermostat Error e42
You can resolve error code e42 by verifying that your router can complete the DHCP. When it does, you might also need to power cycle the router and perform the setup process again with the thermostat. Doing so should see to it that the DHCP is transmitted and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears when the password for accessing your home’s Wi-Fi router is incorrect. When this error code has appeared for 30 seconds, the thermostat’s digital display should automatically transition 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 verify 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 informed that a heat pump or air conditioner’s monitoring system has identified a malfunction. Most often, this appears once the compressor isn’t working despite being directed 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, caused by poor airflow, can display this error code. And finally, you might encounter error code 40 if there’s an issue with the refrigerant, 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 reset the thermostat and error code 40 reappears, you should try to get in touch with 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 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
Restart the router by unplugging it and leaving it that way for a short period. The thermostat might also be disconnected if you recently updated the password or the Wi-Fi’s SSID, which is the name you provide it.
Honeywell Thermostat Error e1
Thermostats utilize sensors to determine the temperature outdoors and indoors. If a sensor fails, you might notice error code e1 appear on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can replace the sensor and reboot the thermostat, which should resolve error code e1.
Honeywell Thermostat Error 11n
Error code 11n could appear if the thermostat can’t 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 damaged or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can utilize a voltmeter to assess if there’s a poor electrical connection. When the wiring on your existing HVAC system is bad, the technician can replace it. When the thermostat itself is the issue, it should probably be replaced.
Honeywell Thermostat Error e2
If you notice error code e2 show up on your Honeywell smart thermostat, it can mean a couple of different things. Sometimes, one of the sensors responsible for detecting the temperature isn’t operating properly. 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
When the error code stems from sensor failure, a technician should troubleshoot and swap out the impacted sensor. When the problem stems from disconnected power, all you'll need to do is make sure the router remains on over the course of the setup process.