A Honeywell smart thermostat is an excellent way to optimize how you use your HVAC system. But like any utility, you could occasionally run across a problem. With the digital display, Honeywell smart thermostats can display an error code that professional technicians can use to get a better sense of what's wrong. Here are a few of the most known error codes you could see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You might encounter this error code if your home’s Wi-Fi connection did not provide an IP address for the thermostat to hook up to. This can happen if a router doesn't complete the Dynamic Host Configuration Protocol, or DHCP. This function automatically transmits the required IP address for your thermostat to link up.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by confirming that your router is enabled for DHCP. If it does, you may also have to power cycle the router and complete the initial setup process again with your thermostat. Completing this task should ensure the DHCP is delivered and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 is displayed whenever the password for connecting to your home’s Wi-Fi router is not correct. Once this error code appears for 30 seconds, the thermostat’s digital display will automatically progress to the Wi-Fi setup screen so you can attempt to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you need to do to solve 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 show up when the thermostat is notified that a heat pump or air conditioner’s monitoring system has recognized a malfunction. For the most part, this appears once the compressor isn’t turning on despite being directed to. But this error code can also show up if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, caused by poor airflow, can render this error code. 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 regular operation. If you reset the thermostat and error code 40 reappears, it’s best to contact an experienced technician.
Honeywell Thermostat Error e43
If a Honeywell thermostat shows error code e43, it is unable to 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 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 may also be disconnected if you recently switched the password or the Wi-Fi’s SSID, which is the name you create for it.
Honeywell Thermostat Error e1
Thermostats use sensors to determine 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 replace the sensor and restart the thermostat, which should clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n could appear if the thermostat is unable to connect to a heating or cooling unit. This might mean that the equipment itself is faulty 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 licensed technician can utilize a voltmeter to find out if there’s a bad electrical connection. If the wiring on your existing HVAC equipment is bad, the technician can replace it. In situations where the thermostat itself is the issue, it should probably be replaced.
Honeywell Thermostat Error e2
If you’ve noticed error code e2 pop up on your Honeywell smart thermostat, it could mean a few different things. In some cases, one of the sensors used to detect the temperature isn’t functioning correctly. In other instances, it means the router was disconnected from power before the thermostat completed the setup process.
How to Fix Honeywell Thermostat Error e2
If the error code is a result of sensor failure, a technician should troubleshoot and switch out the damaged sensor. Any time the problem stems from disconnected power, all you'll need to do is see to it that the router stays on during the setup process.