A Honeywell smart thermostat is an excellent way to optimize how you use your heating and cooling. But like any mechanical system, you may occasionally run across a problem. With its digital display, Honeywell smart thermostats can provide an error code that professional technicians will use to figure out what's going on. Here are some of the most known error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You may see this error code when your home’s Wi-Fi internet did not present an IP address for the thermostat to hook up to. This can occur if the router fails to complete the Dynamic Host Configuration Protocol, or DHCP. This function automatically transmits the needed IP address for your thermostat to link up.
How to Fix Honeywell Thermostat Error e42
You can clear error code e42 by verifying that your router has enabled DHCP. When it does, you may also have to power cycle the router and complete the initial setup process again with your thermostat. This should see to it that the DHCP is transmitted and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears if the password for communicating with your home’s Wi-Fi router is incorrect. Once this error code is displayed for 30 seconds, the thermostat’s digital display should automatically transition to the Wi-Fi setup screen so you can try to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you have to do to resolve error e02 is make sure you’re putting in the correct Wi-Fi password when setting up 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 appears once the compressor isn’t running despite being instructed to. But this error code can also surface if power is shut off from the outdoor unit for an extended period of time. A “High Pressure Fault” error, induced by obstructed airflow, can display this error code. And finally, you might encounter 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 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, it's time to contact 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 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
Reboot the router by unplugging it and leaving it that way for around 30 seconds. The thermostat may also be disconnected if you recently switched the password or the Wi-Fi’s SSID, which is the name you give it.
Honeywell Thermostat Error e1
Thermostats use sensors to identify the temperature outdoors and indoors. If a sensor breaks down, you might notice error code e1 appear on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can swap out the sensor and restart the thermostat, which should take care of 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 malfunctioning and unable to connect with the thermostat. This can happen when the wiring is damaged or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A professional technician can utilize a voltmeter to find out if there’s a poor electrical connection. If the wiring on your type of HVAC equipment is bad, the technician can replace it. If the thermostat itself is the problem, it should probably be replaced.
Honeywell Thermostat Error e2
If you notice error code e2 appear on your Honeywell smart thermostat, it could mean a couple of different things. For example, one of the sensors used to detect the temperature isn’t working properly. In other cases, it means the router was disconnected from power before the thermostat finished 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 damaged sensor. When the problem comes from disconnected power, all you'll need to do is make sure the router stays on during the setup process.