A Honeywell smart thermostat is an easy way to fine-tune how you use your HVAC system. But like any utility, you may sometimes experience a problem. With a digital display, Honeywell smart thermostats can show an error code that certified technicians can use to understand what's wrong. Here are several of the most common error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You can see this error code when your home’s Wi-Fi internet did not provide an IP address for the thermostat to connect to. This can occur if a router doesn't execute the Dynamic Host Configuration Protocol, or DHCP. This process automatically transmits the required IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can clear error code e42 by making sure that your router is enabled for DHCP. If it does, you may 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 occurs if the password for accessing your home’s Wi-Fi router was 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 need to do to solve error e02 is ensure you’re entering the correct Wi-Fi password when configuring the thermostat.
Honeywell Thermostat Error 40
Error code 40 can show up when the thermostat is alerted that a heat pump or air conditioner’s monitoring system has detected a malfunction. Most commonly, this occurs once the compressor isn’t running despite being instructed to. But this error code could also appear if power is disconnected from the outdoor unit for a lengthy period of time. A “High Pressure Fault” error, induced by blocked airflow, can render this error code. Lastly, you might see 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 ordinary operation. If you reset the thermostat and error code 40 reappears, it’s best to contact an experienced technician.
Honeywell Thermostat Error e43
If a Honeywell thermostat presents error code e43, it is failing to communicate with the router, and by extension the 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
Restart the router by unplugging it and leaving it that way for around 30 seconds. The thermostat may also be disconnected if you have 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 detect the temperature outdoors and indoors. If a sensor fails, you may 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 reboot the thermostat, which should clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear when the thermostat is unable to connect to a heating or cooling unit. This may mean that the equipment itself is malfunctioning and unable to communicate with the thermostat. This sometimes happens when the wiring is defective or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A professional technician can use a voltmeter to find out if there’s a poor electrical connection. When the wiring on your existing HVAC system is bad, the technician can replace it. In situations where the thermostat itself is the source of the error code, 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 can mean a couple of different things. In some cases, one of the sensors used to detect the temperature isn’t working correctly. In other instances, it means the router was disconnected from the outlet before the thermostat finished the setup process.
How to Fix Honeywell Thermostat Error e2
If the error code stems from sensor failure, a technician should troubleshoot and switch out the impacted sensor. Any time the problem comes from disconnected power, all you’ll have to do is verify the router stays on during the setup process.