A Honeywell smart thermostat is an easy way to optimize how you use your heating and cooling. But like any mechanical system, you might sometimes run into a problem. With a digital display, Honeywell smart thermostats can display an error code that certified technicians can use to understand what's going on. Here are several of the most likely error codes you could 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 present an IP address for the thermostat to hook up to. This can take place if a router doesn't execute the Dynamic Host Configuration Protocol, or DHCP. This procedure automatically supplies the required IP address for your thermostat to link up.
How to Fix Honeywell Thermostat Error e42
You can clear error code e42 by making sure that your router can complete the DHCP. If it does, you usually also need to power cycle the router and perform the setup process again with the thermostat. Doing so should ensure the DHCP is sent and connects to your smart thermostat.
Honeywell Error Code e02
Error code e02 occurs if the password for communicating with your home’s Wi-Fi router was incorrect. When this error code has appeared for 30 seconds, the thermostat’s digital display should automatically transition to the Wi-Fi setup screen so you can try to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you have 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 alerted that a heat pump or air conditioner’s monitoring system has detected a malfunction. Most commonly, this happens once the compressor isn’t turning on despite being directed to. But this error code could also show up if power is shut off from the outdoor unit for a long period of time. A “High Pressure Fault” error, induced by blocked airflow, can render this error code. Finally, you may see error code 40 if there’s an issue with the coolant, the outdoor unit’s fan motor or the motor’s starting capacitor.
How to Fix Honeywell Thermostat Error 40
You can inspect the air filter for signs of a clog, as well as the breakers and indoor unit’s blower for normal operation. If you reset the thermostat and error code 40 reappears, it's time to contact an experienced technician.
Honeywell Error Code e43
If your Honeywell thermostat displays error code e43, it is failing 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 around 30 seconds. The thermostat might also be disconnected if you recently changed the password or the Wi-Fi’s SSID, which is the name you create for it.
Error Code e1 for Honeywell Thermostats
Thermostats utilize sensors to detect the temperature outdoors and indoors. If a sensor fails, you might see error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A trained technician can swap out the sensor and reset the thermostat, which should resolve error code e1.
Honeywell Thermostat Error 11n
Error code 11n may appear if the thermostat is unable to detect a heating or cooling unit. This may mean that the equipment itself is faulty and unable to maintain a connection to the thermostat. This sometimes happens when the wiring is bad or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A qualified technician can employ a voltmeter to determine if there’s a poor electrical connection. When the wiring on your specific HVAC system is bad, the technician can replace it. When the thermostat itself is the problem, it will likely have to be replaced.
Error Code e2 for Honeywell Thermostats
If you see error code e2 pop up on your Honeywell smart thermostat, it might mean several different things. For example, one of the sensors responsible for detecting the temperature isn’t operating properly. Other times, it means the router was disconnected from its power source before the thermostat completed the setup process.
How to Fix Honeywell Thermostat Error e2
In situations where the error code is caused by sensor failure, a technician will troubleshoot and swap out the affected sensor. Any time the problem comes from disconnected power, all you'll need to do is see to it that the router remains on throughout the setup process.