A Honeywell smart thermostat is an easy way to fine-tune how you use your HVAC system. But like any mechanical system, you might sometimes run across a problem. With a digital display, Honeywell smart thermostats can display an error code that trained technicians can use to figure out what's happening. Here are some of the most likely error codes you could see on your Honeywell smart thermostat.
Honeywell Error Code e42
You might receive this error code when your home’s Wi-Fi internet did not present an IP address for the thermostat to hook up to. This can happen if the router fails to execute the Dynamic Host Configuration Protocol, or DHCP. This function automatically supplies the necessary IP address for your thermostat to connect to the Wi-Fi.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by verifying that your router is enabled for DHCP. If it does, you may also have to power cycle the router and perform the setup process again with the thermostat. This should see to it that the DHCP is sent and connects to the smart thermostat.
Honeywell Error Code e02
Error code e02 appears when the password for accessing your home’s Wi-Fi router was incorrect. Once this error code is displayed 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 need to do to solve error e02 is ensure you’re putting in the correct Wi-Fi password when configuring the thermostat.
Honeywell Error Code 40
Error code 40 can pop up when the thermostat is notified that a heat pump or air conditioner’s monitoring system has identified a malfunction. For the most part, this appears 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, caused by blocked airflow, can lead to this error code. 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 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, it's time to get a hold of an experienced technician.
Error Code e43 for Honeywell Thermostats
If the Honeywell thermostat presents error code e43, it is failing to communicate with the router, and by extension your Wi-Fi. This can 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 around 30 seconds. The thermostat may also be disconnected if you’ve recently changed the password or the Wi-Fi’s SSID, which is the name you create for it.
Error Code e1 for Honeywell Thermostats
Thermostats employ sensors to identify the temperature outdoors and indoors. If a sensor fails, you might see 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 resolve error code e1.
Honeywell Error Code 11n
Error code 11n may appear in situations where the thermostat is failing to connect to a heating or cooling unit. This can mean that the equipment itself is defective and unable to connect with 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 employ a voltmeter to determine if there’s a bad electrical connection. When the wiring on your type of HVAC equipment is bad, the technician can replace it. In situations where 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 several different things. For example, one of the sensors responsible for detecting the temperature isn’t functioning properly. In other cases, it means the router was disconnected from power before the thermostat finished 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 damaged sensor. Any time the problem stems from disconnected power, all you’ll have to do is make sure the router stays on over the course of the setup process.