A Honeywell smart thermostat is a great way to optimize how you use your HVAC system. But like any technology, you could occasionally run into a problem. With its digital display, Honeywell smart thermostats can display an error code that trained technicians can use to understand what's going on. Here are a few of the most common error codes you could see on your Honeywell smart thermostat.
Honeywell Error Code e42
You might see this error code in the event that your home’s Wi-Fi connection did not supply an IP address for the thermostat to connect to. This can occur if the router doesn't complete the Dynamic Host Configuration Protocol, or DHCP. This procedure automatically transmits the needed IP address for your thermostat to link up.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by verifying 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. Doing so should ensure the DHCP is transmitted and connects to the smart thermostat.
Honeywell Error Code e02
Error code e02 occurs whenever the password for connecting to your home’s Wi-Fi router is not correct. When this error code has appeared 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 have to do to resolve error e02 is ensure you’re entering 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 detected a malfunction. Most often, this appears once the compressor isn’t working despite being directed to. But this error code may 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 lead to this error code. Lastly, you may experience 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 examine 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 time to contact an experienced technician.
Error Code e43 for Honeywell Thermostats
If your Honeywell thermostat displays error code e43, it is unable 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 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’ve recently switched the password or the Wi-Fi’s SSID, which is the name you give it.
Error Code e1 for Honeywell Thermostats
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 change out the sensor and reboot the thermostat, which should take care of error code e1.
Honeywell Error Code 11n
Error code 11n could appear in situations where the thermostat can’t connect to a heating or cooling unit. This can mean that the equipment itself is defective 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 professional technician can use a voltmeter to assess if there’s a poor electrical connection. In situations where the wiring on your type of HVAC system is bad, the technician can replace it. In situations where the thermostat itself is the issue, it should probably be replaced.
Honeywell Error Code e2
If you notice error code e2 pop up on your Honeywell smart thermostat, it could mean a couple of different things. Sometimes, one of the sensors responsible for detecting the temperature isn’t operating correctly. 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 is caused by sensor failure, a technician should troubleshoot and replace the damaged sensor. When the problem originates from disconnected power, all you have to do is verify the router remains on over the course of the setup process.
