A Honeywell smart thermostat is a great way to better manage how you use your heating and cooling. But like any utility, you may occasionally run into a problem. With its digital display, Honeywell smart thermostats can provide an error code that trained technicians will use to figure out what's wrong. Here are a few of the most likely error codes you could see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You can see this error code if your home’s Wi-Fi internet did not provide an IP address for the thermostat to connect with. This can take place if the router doesn't complete the Dynamic Host Configuration Protocol, or DHCP. This process automatically sends out the needed IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by verifying that your router can complete the DHCP. If it does, you might also need to power cycle the router and complete the initial setup process again with your thermostat. Doing so should see to it that the DHCP is delivered and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 appears if the password for connecting to your home’s Wi-Fi router was incorrect. When this error code appears for 30 seconds, the thermostat’s digital display automatically transitions to the Wi-Fi setup screen so you can try the password again.
How to Fix Honeywell Thermostat Error e02
All you'll need to do to clear error e02 is ensure 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 informed that a heat pump or air conditioner’s monitoring system has identified a malfunction. Most commonly, this happens when the compressor isn’t working despite being directed to. But this error code may also surface if power is disconnected from the outdoor unit for a long period of time. A “High Pressure Fault” error, caused by obstructed airflow, can lead to this error code. And finally, you may experience 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, you should try to get a hold of an experienced technician.
Honeywell Thermostat Error e43
If the Honeywell thermostat presents error code e43, it is unable to communicate with the router, and by extension your Wi-Fi. This might 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
Reset the router by unplugging it and leaving it that way for about 30 seconds. The thermostat might also be disconnected if you’ve 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 identify the temperature outdoors and indoors. If a sensor breaks down, you might see error code e1 turn up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can swap out the sensor and reset the thermostat, which should take care of error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear in situations where the thermostat is failing to detect a heating or cooling unit. This might mean that the equipment itself is defective and unable to maintain a connection to the thermostat. This sometimes happens when the wiring is defective or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A qualified technician can employ a voltmeter to assess if there’s a poor electrical connection. In situations where the wiring on your existing HVAC system is bad, the technician can replace it. In situations where the thermostat itself is the problem, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you’ve noticed error code e2 show up on your Honeywell smart thermostat, it can mean several different things. In some cases, one of the sensors responsible for detecting the temperature isn’t functioning like it should. Other times, it means the router was disconnected from the outlet before the thermostat could complete the setup process.
How to Fix Honeywell Thermostat Error e2
In situations where the error code is caused by sensor failure, a technician should troubleshoot and swap out the damaged sensor. If the problem originates from disconnected power, all you have to do is verify the router stays on throughout the setup process.