A Honeywell smart thermostat is an excellent way to optimize how you use your HVAC system. But like any utility, you might sometimes run across a problem. With its digital display, Honeywell smart thermostats can display an error code that certified technicians will use to figure out what's happening. Here are several of the most likely error codes you may see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You may encounter this error code if your home’s Wi-Fi connection did not present an IP address for the thermostat to connect with. This can occur if a router fails to complete the Dynamic Host Configuration Protocol, or DHCP. This function automatically transmits the required IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can clear error code e42 by confirming that your router can complete the DHCP. If it does, you might also have to power cycle the router and repeat the initial setup process with your thermostat. Doing so should ensure the DHCP is delivered and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs whenever the password for communicating with your home’s Wi-Fi router is not correct. When this error code is displayed for 30 seconds, the thermostat’s digital display automatically transitions to the Wi-Fi setup screen so you can try to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you'll need to do to solve error e02 is verify you’re typing the correct Wi-Fi password when setting up 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 identified a malfunction. Most often, this occurs when the compressor isn’t running despite being directed to. But this error code could also show up if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, induced by poor airflow, can render this error code. Finally, you may encounter error code 40 if there’s something wrong with the refrigerant, 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 restart the thermostat and error code 40 reappears, it's time to contact an experienced technician.
Honeywell Thermostat Error e43
If the Honeywell thermostat presents error code e43, it is failing 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
Restart the router by unplugging it and leaving it that way for about 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 provide it.
Honeywell Thermostat Error e1
Thermostats use sensors to determine the temperature outdoors and indoors. If a sensor fails, you could notice error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A qualified technician can replace the sensor and restart the thermostat, which should take care of error code e1.
Honeywell Thermostat Error 11n
Error code 11n could appear in situations where the thermostat can’t detect a heating or cooling unit. This can mean that the equipment itself is defective and unable to maintain a connection to the thermostat. This can happen when the wiring is bad or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can employ a voltmeter to find out if there’s a poor electrical connection. When the wiring on your specific HVAC system is bad, the technician can replace it. In situations where the thermostat itself is the issue, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you’ve noticed error code e2 pop up on your Honeywell smart thermostat, it could mean several different things. Sometimes, one of the sensors that detects the temperature isn’t operating 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
In situations where the error code is caused by sensor failure, a technician will troubleshoot and switch out the affected sensor. If the problem comes from disconnected power, all you have to do is make sure the router stays on during the setup process.