A Honeywell smart thermostat is a great way to optimize how you use your HVAC system. But like any mechanical system, you may sometimes experience a problem. With a digital display, Honeywell smart thermostats can display an error code that professional technicians can use to understand what's happening. Here are a few of the most known error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You can receive this error code if your home’s Wi-Fi connection did not provide an IP address for the thermostat to hook up to. This can happen if a router fails to complete the Dynamic Host Configuration Protocol, or DHCP. This procedure automatically sends out the necessary 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 can complete the DHCP. When it does, you usually also need to power cycle the router and repeat the initial setup process with the thermostat. This should ensure the DHCP is sent and connects to the smart thermostat.
Honeywell Thermostat Error e02
Error code e02 occurs if the password for connecting to your home’s Wi-Fi router is not correct. After 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 have to do to clear error e02 is verify you’re entering the correct Wi-Fi password when configuring the thermostat.
Honeywell Thermostat Error 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. Most often, this happens once the compressor isn’t turning on despite being instructed to. But this error code can also show up if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, caused by obstructed airflow, can display this error code. And finally, you could experience error code 40 if there’s a problem 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 regular operation. If you restart the thermostat and error code 40 reappears, it's time to get in touch with an experienced technician.
Honeywell Thermostat Error e43
If your Honeywell thermostat shows error code e43, it is failing to communicate with the router, and by extension the 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 about 30 seconds. The thermostat may also be disconnected if you’ve recently changed the password or the Wi-Fi’s SSID, which is the name you give it.
Honeywell Thermostat Error e1
Thermostats employ sensors to detect the temperature outdoors and indoors. If a sensor malfunctions, you could notice error code e1 turn up 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 clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n could appear in situations where the thermostat can’t connect to a heating or cooling unit. This might 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 employ a voltmeter to find out if there’s a faulty electrical connection. In situations where the wiring on your type of HVAC equipment is bad, the technician can replace it. When the thermostat itself is the problem, it should probably be replaced.
Honeywell Thermostat Error e2
If you notice error code e2 show up on your Honeywell smart thermostat, it might mean a few different things. In some cases, one of the sensors used to detect the temperature isn’t working like it should. Other times, it means the router was disconnected from power before the thermostat finished the setup process.
How to Fix Honeywell Thermostat Error e2
If the error code stems from sensor failure, a technician can troubleshoot and switch out the impacted sensor. If the problem originates from disconnected power, all you’ll have to do is see to it that the router remains on throughout the setup process.