A Honeywell smart thermostat is an excellent way to optimize how you use your HVAC system. But like any mechanical system, you could occasionally experience a problem. With the digital display, Honeywell smart thermostats can display an error code that trained technicians will use to get a better sense of what's going on. Here are several of the most common error codes you may see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You may receive this error code when your home’s Wi-Fi internet did not provide an IP address for the thermostat to connect to. This can happen if a router doesn't complete the Dynamic Host Configuration Protocol, or DHCP. This function automatically supplies the needed 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 can complete the DHCP. Assuming it does, you might also need to power cycle the router and perform the setup process again with the thermostat. This should ensure the DHCP is sent and connects to your smart thermostat.
Error Code e02 for Honeywell Thermostats
Error code e02 appears if 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 to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you'll need to do to resolve error e02 is make sure you’re putting in the correct Wi-Fi password when setting up the thermostat.
Error Code 40 for Honeywell Thermostats
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 often, this appears when the compressor isn’t working despite being directed to. But this error code can also show up if power is shut off from the outdoor unit for an extended period of time. A “High Pressure Fault” error, caused by blocked airflow, can display this error code. Finally, you might see error code 40 if there’s something wrong 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 ordinary operation. If you turn the thermostat off and on again and error code 40 reappears, you should try to contact an experienced technician.
Honeywell Thermostat Error e43
If a Honeywell thermostat presents error code e43, it is unable 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 around 30 seconds. The thermostat could also be disconnected if you recently switched the password or the Wi-Fi’s SSID, which is the name you provide it.
Honeywell Thermostat Error e1
Thermostats use sensors to identify 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 skilled technician can replace the sensor and reset the thermostat, which should clear error code e1.
Error Code 11n for Honeywell Thermostats
Error code 11n may appear when the thermostat is failing to recognize a heating or cooling unit. This may mean that the equipment itself is defective 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 professional technician can utilize a voltmeter to assess if there’s a poor electrical connection. If the wiring on your type of HVAC equipment is bad, the technician can replace it. In situations where the thermostat itself is the problem, it should probably be replaced.
Honeywell Error Code e2
If you’ve noticed error code e2 show up on your Honeywell smart thermostat, it can mean several different things. Sometimes, one of the sensors that detects the temperature isn’t working properly. Other times, 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 stems from sensor failure, a technician can troubleshoot and swap out the affected sensor. If the problem comes from disconnected power, all you'll need to do is make sure the router remains on over the course of the setup process.