A Honeywell smart thermostat is a great way to better manage how you use your home comfort system. But like any mechanical system, you might occasionally run across a problem. With a digital display, Honeywell smart thermostats can display an error code that professional technicians will use to understand what's wrong. Here are a few of the most likely error codes you might see on your Honeywell smart thermostat.
Honeywell Error Code e42
You can receive this error code in the event that your home’s Wi-Fi internet did not present an IP address for the thermostat to connect with. This can take place if your router does not complete the Dynamic Host Configuration Protocol, or DHCP. This process automatically sends out the required IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can resolve error code e42 by confirming that your router can complete the DHCP. If it does, you usually also need to power cycle the router and repeat the initial setup process with your thermostat. This should ensure the DHCP is transmitted and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 is displayed if the password for accessing your home’s Wi-Fi router is not correct. Once this error code appears 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 resolve error e02 is ensure you’re typing 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 happens when the compressor isn’t turning on despite being instructed to. But this error code can also appear if power is disconnected from the outdoor unit for an extended period of time. A “High Pressure Fault” error, triggered by obstructed airflow, can display this error code. 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 examine 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, you should try to get in touch with an experienced technician.
Error Code e43 for Honeywell Thermostats
If your Honeywell thermostat displays 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
Reboot the router by unplugging it and leaving it that way for a short period. The thermostat could also be disconnected if you recently switched the password or the Wi-Fi’s SSID, which is the name you create for it.
Honeywell Error Code e1
Thermostats employ sensors to determine the temperature outdoors and indoors. If a sensor breaks down, you could see error code e1 turn up 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 resolve error code e1.
Error Code 11n for Honeywell Thermostats
Error code 11n can appear if the thermostat can’t detect a heating or cooling unit. This might mean that the equipment itself is malfunctioning 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 assess if there’s a poor electrical connection. If the wiring on your existing HVAC equipment is bad, the technician can replace it. When 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 can mean several different things. In some cases, one of the sensors used to detect the temperature isn’t operating correctly. In other instances, it means the router was disconnected from the outlet before the thermostat could complete the setup process.
How to Fix Honeywell Thermostat Error e2
When the error code is a result of sensor failure, a technician can troubleshoot and switch out the affected sensor. Any time the problem comes from disconnected power, all you have to do is verify the router remains on throughout the setup process.
