A Honeywell smart thermostat is a great way to optimize how you use your heating and cooling. But like any utility, you could occasionally run across a problem. With its digital display, Honeywell smart thermostats can show an error code that professional technicians can use to understand what's happening. Here are several of the most known error codes you may see on your Honeywell smart thermostat.
Error Code e42 for Honeywell Thermostats
You can see this error code when your home’s Wi-Fi internet did not provide an IP address for the thermostat to connect with. This can occur if the router doesn't complete the Dynamic Host Configuration Protocol, or DHCP. This procedure automatically sends out the necessary IP address for your thermostat to link up.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by verifying that your router has enabled DHCP. Assuming it does, you usually also need to power cycle the router and complete the initial setup process again with the thermostat. This should ensure the DHCP is delivered and connects to the smart thermostat.
Honeywell Error Code e02
Error code e02 occurs whenever the password for connecting to 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 the password again.
How to Fix Honeywell Thermostat Error e02
All you need to do to resolve error e02 is verify you’re typing the correct Wi-Fi password when setting up the thermostat.
Honeywell Error Code 40
Error code 40 can appear when the thermostat is notified that a heat pump or air conditioner’s monitoring system has recognized a malfunction. Most often, this happens when the compressor isn’t working despite being instructed to. But this error code can also appear if power is shut off from the outdoor unit for a lengthy period of time. A “High Pressure Fault” error, induced by blocked airflow, can render this error code. Lastly, 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 examine 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 a hold of an experienced technician.
Honeywell Error Code e43
If a Honeywell thermostat presents error code e43, it can’t 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 may also be disconnected if you have recently changed the password or the Wi-Fi’s SSID, which is the name you give it.
Honeywell Error Code e1
Thermostats use sensors to identify the temperature outdoors and indoors. If a sensor breaks down, you may see error code e1 turn up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A trained technician can replace the sensor and reboot the thermostat, which should take care of error code e1.
Error Code 11n for Honeywell Thermostats
Error code 11n can appear if the thermostat is unable to recognize a heating or cooling unit. This may mean that the equipment itself is defective and unable to communicate with the thermostat. This can happen when the wiring is defective 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 faulty electrical connection. When the wiring on your type of HVAC equipment is bad, the technician can replace it. When the thermostat itself is the source of the error code, it should probably be replaced.
Error Code e2 for Honeywell Thermostats
If you’ve noticed error code e2 pop up on your Honeywell smart thermostat, it can mean several different things. In some cases, one of the sensors used to detect the temperature isn’t operating like it should. Other times, it means the router was disconnected from the outlet before the thermostat completed the setup process.
How to Fix Honeywell Thermostat Error e2
When the error code stems from sensor failure, a technician should troubleshoot and switch out the affected sensor. Any time the problem comes from disconnected power, all you’ll have to do is verify the router stays on throughout the setup process.