A Honeywell smart thermostat is an excellent way to better manage how you use your home comfort system. But like any utility, you may occasionally experience a problem. With the digital display, Honeywell smart thermostats can show an error code that certified technicians will use to figure out what's happening. Here are several of the most common error codes you may see on your Honeywell smart thermostat.
Honeywell Error Code e42
You may see this error code when your home’s Wi-Fi internet did not supply an IP address for the thermostat to connect to. This can occur if your router doesn't 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 clear error code e42 by confirming that your router has enabled DHCP. If it does, you might also need to power cycle the router and repeat the initial setup process with the thermostat. This should see to it that the DHCP is transmitted and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 is displayed when the password for communicating with your home’s Wi-Fi router is incorrect. Once this error code has appeared for 30 seconds, the thermostat’s digital display automatically transitions 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 clear error e02 is make sure you’re entering the correct Wi-Fi password when configuring the thermostat.
Honeywell Thermostat Error 40
Error code 40 can appear when the thermostat is alerted that a heat pump or air conditioner’s monitoring system has recognized a malfunction. Most commonly, this occurs once the compressor isn’t running despite being instructed to. But this error code could also show up if power is disconnected from the outdoor unit for a long period of time. A “High Pressure Fault” error, caused by poor airflow, can display this error code. Lastly, you might experience 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 normal operation. If you turn the thermostat off and on again and error code 40 reappears, it’s best to get a hold of an experienced technician.
Honeywell Error Code e43
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 your wide area network (WAN).
How to Fix Honeywell Thermostat Error e43
Restart the router by unplugging it and leaving it that way for about 30 seconds. The thermostat may also be disconnected if you have recently switched the password or the Wi-Fi’s SSID, which is the name you create for it.
Honeywell Error Code e1
Thermostats use sensors to detect the temperature outdoors and indoors. If a sensor breaks down, you could notice error code e1 turn up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can change out the sensor and reset the thermostat, which should clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n could appear when the thermostat can’t recognize a heating or cooling unit. This might mean that the equipment itself is malfunctioning and unable to connect with 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 qualified technician can use a voltmeter to assess if there’s a poor electrical connection. In situations where the wiring on your existing HVAC system 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 Error Code e2
If you’ve noticed error code e2 show up on your Honeywell smart thermostat, it can mean a few different things. Sometimes, one of the sensors used to detect the temperature isn’t working like it should. In other cases, 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 affected sensor. When the problem originates from disconnected power, all you have to do is verify the router remains on during the setup process.