A Honeywell smart thermostat is a great way to optimize how you use your home comfort system. But like any technology, you could sometimes run across a problem. With its digital display, Honeywell smart thermostats can show an error code that certified technicians can use to understand what's wrong. Here are a few of the most likely error codes you could see on your Honeywell smart thermostat.
Honeywell Error Code e42
You might see this error code if your home’s Wi-Fi connection did not present an IP address for the thermostat to hook up to. This can happen if a router doesn't execute the Dynamic Host Configuration Protocol, or DHCP. This procedure automatically sends out the needed IP address for your thermostat to link up.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by confirming that your router is enabled for DHCP. Assuming it does, you may 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 your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs if the password for connecting to your home’s Wi-Fi router was incorrect. When this error code has appeared for 30 seconds, the thermostat’s digital display automatically transitions to the Wi-Fi setup screen so you can attempt to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you'll need to do to clear error e02 is ensure 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 alerted that a heat pump or air conditioner’s monitoring system has detected a malfunction. For the most part, this appears if the compressor isn’t working despite being instructed to. But this error code could also show up if power is disconnected from the outdoor unit for an extended period of time. A “High Pressure Fault” error, induced by poor airflow, can display this error code. And finally, you may experience 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 examine the air filter for signs of a clog, as well as the breakers and indoor unit’s blower for regular 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.
Error Code e43 for Honeywell Thermostats
If a Honeywell thermostat shows error code e43, it is failing to communicate with the router, and by extension your Wi-Fi. This can 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 a short period. The thermostat may also be disconnected if you recently switched the password or the Wi-Fi’s SSID, which is the name you give it.
Error Code e1 for Honeywell Thermostats
Thermostats utilize sensors to identify the temperature outdoors and indoors. If a sensor fails, you might notice error code e1 appear on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can replace the sensor and restart the thermostat, which should take care of error code e1.
Honeywell Thermostat Error 11n
Error code 11n can appear if the thermostat is unable to detect a heating or cooling unit. This can mean that the equipment itself is faulty and unable to communicate with 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 professional technician can employ a voltmeter to find out if there’s a poor electrical connection. In situations where the wiring on your existing HVAC equipment is bad, the technician can replace it. In situations where the thermostat itself is the issue, it should probably be replaced.
Honeywell Error Code e2
If you notice error code e2 pop up on your Honeywell smart thermostat, it could mean a couple of different things. For example, one of the sensors used to detect the temperature isn’t working like it should. In other cases, it means the router was disconnected from the outlet before the thermostat could complete 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 switch out the affected sensor. When the problem comes from disconnected power, all you’ll have to do is make sure the router remains on over the course of the setup process.