A Honeywell smart thermostat is a great way to better manage how you use your HVAC system. But like any mechanical system, you might sometimes run into a problem. With its digital display, Honeywell smart thermostats can show an error code that certified technicians 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 may encounter this error code in the event that your home’s Wi-Fi connection did not present an IP address for the thermostat to connect with. This can occur if the router fails to complete the Dynamic Host Configuration Protocol, or DHCP. This process automatically sends out the necessary IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by making sure that your router can complete the DHCP. If it does, you may also need to power cycle the router and perform the setup process again with the thermostat. Completing this task should see to it that the DHCP is transmitted and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears when the password for communicating with your home’s Wi-Fi router was incorrect. When this error code appears for 30 seconds, the thermostat’s digital display will automatically progress to the Wi-Fi setup screen so you can attempt to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you'll need to do to clear 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 identified a malfunction. For the most part, this happens once the compressor isn’t running despite being directed to. But this error code could also appear if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, triggered by blocked airflow, can render this error code. And finally, you might see error code 40 if there’s something wrong 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 regular operation. If you turn the thermostat off and on again and error code 40 reappears, it's time to get in touch with 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 might 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
Reboot the router by unplugging it and leaving it that way for about 30 seconds. The thermostat might also be disconnected if you recently switched 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 malfunctions, you might notice error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A trained technician can replace the sensor and reboot the thermostat, which should take care of error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear in situations where the thermostat is unable to connect to a heating or cooling unit. This might mean that the equipment itself is malfunctioning and unable to communicate 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 poor electrical connection. If the wiring on your type of HVAC equipment is bad, the technician can replace it. If the thermostat itself is the issue, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you’ve noticed error code e2 appear on your Honeywell smart thermostat, it might mean a couple of different things. For example, one of the sensors responsible for detecting the temperature isn’t operating like it should. In other instances, it means the router was disconnected from its power source before the thermostat finished the setup process.
How to Fix Honeywell Thermostat Error e2
In situations where the error code is a result of sensor failure, a technician can troubleshoot and replace the impacted sensor. If the problem comes from disconnected power, all you have to do is verify the router remains on throughout the setup process.