A Honeywell smart thermostat is a great way to better manage how you use your heating and cooling. But like any technology, you might sometimes run across a problem. With a digital display, Honeywell smart thermostats can show an error code that certified technicians use to understand what's happening. Here are some of the most likely error codes you could see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You may see this error code if your home’s Wi-Fi internet did not present an IP address for the thermostat to connect to. This can happen if a router does not perform the Dynamic Host Configuration Protocol, or DHCP. This process automatically supplies the needed IP address for your thermostat to link up.
How to Fix Honeywell Thermostat Error e42
You can resolve error code e42 by confirming that your router is enabled for DHCP. When it does, you might also have to power cycle the router and repeat the initial setup process with the thermostat. Doing so should see to it that the DHCP is sent and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 is displayed if the password for communicating with your home’s Wi-Fi router is not correct. After 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 try the password again.
How to Fix Honeywell Thermostat Error e02
All you'll need to do to clear error e02 is verify you’re putting in the correct Wi-Fi password when configuring the thermostat.
Honeywell Thermostat Error 40
Error code 40 can appear when the thermostat is notified that a heat pump or air conditioner’s monitoring system has recognized a malfunction. Most commonly, this appears when the compressor isn’t running despite being instructed to. But this error code may also surface if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, caused by obstructed airflow, can display this error code. Lastly, you could see 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 examine 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, you should try to get in touch with an experienced technician.
Honeywell Thermostat Error e43
If your Honeywell thermostat displays error code e43, it is unable to communicate with the router, and by extension the 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 around 30 seconds. The thermostat could also be disconnected if you’ve recently updated the password or the Wi-Fi’s SSID, which is the name you create for it.
Honeywell Thermostat Error e1
Thermostats use sensors to identify the temperature outdoors and indoors. If a sensor malfunctions, you could notice error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A trained technician can swap out the sensor and reset the thermostat, which should resolve error code e1.
Honeywell Thermostat Error 11n
Error code 11n may appear in situations where the thermostat can’t recognize 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 qualified technician can utilize a voltmeter to assess if there’s a poor electrical connection. If the wiring on your existing HVAC system is bad, the technician can replace it. When the thermostat itself is the issue, it should probably be replaced.
Honeywell Thermostat Error e2
If you notice error code e2 show up on your Honeywell smart thermostat, it can mean a couple of different things. Sometimes, one of the sensors that detects the temperature isn’t operating properly. In other cases, 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 affected sensor. When the problem originates from disconnected power, all you have to do is make sure the router remains on over the course of the setup process.