A Honeywell smart thermostat is a great way to optimize how you use your heating and cooling. But like any mechanical system, you may occasionally run into a problem. With a digital display, Honeywell smart thermostats can display an error code that professional technicians use to understand what's happening. Here are a few of the most common error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You might receive this error code when your home’s Wi-Fi connection did not provide an IP address for the thermostat to connect with. This can occur if your router fails to execute the Dynamic Host Configuration Protocol, or DHCP. This procedure 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 verifying that your router can complete the DHCP. When it does, you might also have to power cycle the router and complete the initial setup process again with your thermostat. This should ensure the DHCP is transmitted and connects to your 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. When this error code appears for 30 seconds, the thermostat’s digital display automatically transitions to the Wi-Fi setup screen so you can try the password again.
How to Fix Honeywell Thermostat Error e02
All you have to do to resolve error e02 is make sure you’re typing the correct Wi-Fi password when setting up the thermostat.
Honeywell Thermostat Error 40
Error code 40 can show up when the thermostat is informed that a heat pump or air conditioner’s monitoring system has detected a malfunction. For the most part, this occurs when the compressor isn’t running despite being instructed to. But this error code could also show up if power is shut off from the outdoor unit for a lengthy period of time. A “High Pressure Fault” error, triggered by blocked airflow, can display this error code. Lastly, you might encounter 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 check the air filter for signs of a clog, as well as the breakers and indoor unit’s blower for normal operation. If you reset the thermostat and error code 40 reappears, you should try to get a hold of an experienced technician.
Honeywell Thermostat Error e43
If a Honeywell thermostat displays error code e43, it can’t communicate with the router, and by extension your 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
Reboot the router by unplugging it and leaving it that way for a short period. The thermostat could also be disconnected if you’ve recently changed the password or the Wi-Fi’s SSID, which is the name you provide it.
Honeywell Thermostat Error e1
Thermostats employ sensors to detect the temperature outdoors and indoors. If a sensor fails, you might see error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A qualified technician can swap out the sensor and reboot the thermostat, which should clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n may appear in situations where the thermostat is unable to detect a heating or cooling unit. This might mean that the equipment itself is malfunctioning and unable to maintain a connection to the thermostat. This can happen when the wiring is bad 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 faulty electrical connection. In situations where the wiring on your type of 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 notice error code e2 show up on your Honeywell smart thermostat, it might mean a few different things. In some cases, one of the sensors that detects the temperature isn’t working like it should. Other times, it means the router was disconnected from the outlet before the thermostat could complete the setup process.
How to Fix Honeywell Thermostat Error e2
In situations where the error code is a result of sensor failure, a technician should troubleshoot and switch out the damaged sensor. When the problem originates from disconnected power, all you have to do is make sure the router remains on during the setup process.