A Honeywell smart thermostat is an easy way to optimize how you use your home comfort system. But like any technology, you may sometimes run across a problem. With its digital display, Honeywell smart thermostats can provide an error code that professional technicians 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 Thermostat Error e42
You may see this error code if your home’s Wi-Fi connection did not supply an IP address for the thermostat to hook up to. This can happen if the router fails to perform the Dynamic Host Configuration Protocol, or DHCP. This function automatically sends out the required IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by confirming that your router is enabled for DHCP. When it does, you might also need to power cycle the router and complete the initial setup process again with the thermostat. Completing this task should see to it that the DHCP is sent and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears when the password for communicating with your home’s Wi-Fi router was incorrect. When this error code has appeared 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 need to do to resolve error e02 is ensure you’re typing the correct Wi-Fi password when setting up the thermostat.
Honeywell Thermostat Error 40
Error code 40 can appear when the thermostat is informed that a heat pump or air conditioner’s monitoring system has detected a malfunction. Most commonly, this appears once the compressor isn’t running despite being directed to. But this error code could also appear if power is shut off from the outdoor unit for an extended period of time. A “High Pressure Fault” error, caused by obstructed airflow, can lead to this error code. Finally, 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 ordinary operation. If you turn the thermostat off and on again and error code 40 reappears, it's time to get a hold of 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 your Wi-Fi. This might 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 might also be disconnected if you recently switched the password or the Wi-Fi’s SSID, which is the name you provide it.
Honeywell Thermostat Error e1
Thermostats employ sensors to determine 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 replace the sensor and restart the thermostat, which should clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear when the thermostat is failing to connect to a heating or cooling unit. This might mean that the equipment itself is faulty and unable to maintain a connection to the thermostat. This can happen when the wiring is defective or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A professional technician can employ a voltmeter to assess if there’s a bad electrical connection. When the wiring on your type of HVAC system is bad, the technician can replace it. When the thermostat itself is the source of the error code, it should probably be replaced.
Honeywell Thermostat Error e2
If you notice error code e2 appear on your Honeywell smart thermostat, it could mean several different things. Sometimes, one of the sensors responsible for detecting the temperature isn’t working like it should. Other times, it means the router was disconnected from its power source before the thermostat completed the setup process.
How to Fix Honeywell Thermostat Error e2
If the error code is caused by sensor failure, a technician should troubleshoot and swap out the impacted sensor. When the problem comes from disconnected power, all you have to do is make sure the router remains on during the setup process.