A Honeywell smart thermostat is an excellent way to fine-tune how you use your home comfort system. But like any utility, you could sometimes experience a problem. With the digital display, Honeywell smart thermostats can display an error code that trained technicians can use to understand what's happening. Here are some of the most likely error codes you could see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You can see this error code when your home’s Wi-Fi connection did not present an IP address for the thermostat to connect with. This can occur if a router does not execute the Dynamic Host Configuration Protocol, or DHCP. This process automatically transmits the needed IP address for your thermostat to connect to the Wi-Fi.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by verifying that your router is enabled for DHCP. If it does, you may also have to power cycle the router and perform the setup process again with your thermostat. Completing this task should see to it that the DHCP is delivered and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs whenever the password for accessing your home’s Wi-Fi router is incorrect. Once this error code has appeared for 30 seconds, the thermostat’s digital display will automatically progress 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 solve error e02 is verify you’re putting in 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 detected a malfunction. Most commonly, this occurs once 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, triggered by obstructed airflow, can render this error code. And finally, you might see 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 ordinary operation. If you turn the thermostat off and on again and error code 40 reappears, it's time to get in touch with an experienced technician.
Honeywell Thermostat Error e43
If the Honeywell thermostat shows error code e43, it is unable to communicate with the router, and by extension the Wi-Fi. This could 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
Reboot the router by unplugging it and leaving it that way for about 30 seconds. The thermostat might also be disconnected if you’ve recently updated the password or the Wi-Fi’s SSID, which is the name you create for it.
Honeywell Thermostat Error e1
Thermostats employ sensors to detect the temperature outdoors and indoors. If a sensor fails, you could see error code e1 appear 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 could appear in situations where the thermostat is unable to recognize a heating or cooling unit. This can 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 is faulty.
How to Fix Honeywell Thermostat Error 11n
A licensed technician can use a voltmeter to find out if there’s a bad electrical connection. If the wiring on your specific HVAC equipment is bad, the technician can replace it. When the thermostat itself is the issue, it should probably be replaced.
Honeywell Thermostat Error e2
If you’ve noticed error code e2 appear on your Honeywell smart thermostat, it might mean several different things. Sometimes, one of the sensors used to detect the temperature isn’t operating correctly. In other instances, 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 caused by sensor failure, a technician can troubleshoot and replace the damaged sensor. Any time the problem stems from disconnected power, all you have to do is see to it that the router stays on throughout the setup process.