A Honeywell smart thermostat is a great way to fine-tune how you use your HVAC system. But like any technology, you could occasionally run across a problem. With the digital display, Honeywell smart thermostats can provide an error code that trained technicians can use to understand what's happening. Here are some of the most likely error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You can encounter this error code if your home’s Wi-Fi connection did not supply an IP address for the thermostat to connect with. This can occur if a router doesn't perform the Dynamic Host Configuration Protocol, or DHCP. This function automatically sends out the necessary IP address for your thermostat to connect to the Wi-Fi.
How to Fix Honeywell Thermostat Error e42
You can clear error code e42 by making sure that your router is enabled for DHCP. If it does, you usually also have to power cycle the router and perform the setup process again with your thermostat. Completing this task should ensure the DHCP is delivered and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs when the password for communicating with your home’s Wi-Fi router is not correct. 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 attempt to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you need to do to clear 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 informed that a heat pump or air conditioner’s monitoring system has recognized a malfunction. Most commonly, this happens if the compressor isn’t turning on despite being instructed to. But this error code can also appear if power is disconnected from the outdoor unit for an extended period of time. A “High Pressure Fault” error, caused by blocked airflow, can lead to this error code. Finally, you may encounter error code 40 if there’s a problem 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 best to get a hold of 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 the Wi-Fi. This might happen if the router’s ethernet cable isn’t plugged in or it isn’t communicating with the 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 might also be disconnected if you have recently changed the password or the Wi-Fi’s SSID, which is the name you give it.
Honeywell Thermostat Error e1
Thermostats utilize sensors to determine the temperature outdoors and indoors. If a sensor fails, you might notice error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A qualified technician can change out the sensor and restart the thermostat, which should resolve error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear when the thermostat is failing to detect a heating or cooling unit. This can mean that the equipment itself is faulty and unable to communicate with the thermostat. This sometimes happens when the wiring is damaged 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 faulty electrical connection. When the wiring on your specific HVAC system is bad, the technician can replace it. If the thermostat itself is the issue, it should probably be replaced.
Honeywell Thermostat Error e2
If you notice error code e2 pop up on your Honeywell smart thermostat, it could mean a couple of different things. In some cases, one of the sensors used to detect the temperature isn’t working correctly. Other times, it means the router was disconnected from its power source before the thermostat finished 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 swap out the damaged sensor. Any time the problem stems from disconnected power, all you have to do is verify the router stays on over the course of the setup process.
