A Honeywell smart thermostat is an excellent way to better manage how you use your HVAC system. But like any technology, you could occasionally run into a problem. With the digital display, Honeywell smart thermostats can provide an error code that certified technicians use to get a better sense of 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 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 take place if the router does not execute the Dynamic Host Configuration Protocol, or DHCP. This function automatically supplies the necessary IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by making sure that your router has enabled DHCP. If 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 transmitted and connects to your smart thermostat.
Error Code e02 for Honeywell Thermostats
Error code e02 appears if the password for accessing your home’s Wi-Fi router is not correct. Once this error code has appeared 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 need to do to clear error e02 is ensure you’re putting in the correct Wi-Fi password when configuring the thermostat.
Error Code 40 for Honeywell Thermostats
Error code 40 can show up when the thermostat is notified that a heat pump or air conditioner’s monitoring system has recognized a malfunction. Most often, this appears once the compressor isn’t running despite being instructed to. But this error code may also surface if power is disconnected from the outdoor unit for a lengthy period of time. A “High Pressure Fault” error, induced by poor airflow, can display this error code. Finally, you could encounter 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 check the air filter for signs of a clog, as well as the breakers and indoor unit’s blower for normal operation. If you turn the thermostat off and on again and error code 40 reappears, you should try to contact an experienced technician.
Honeywell Error Code e43
If a Honeywell thermostat shows error code e43, it is failing to communicate with the router, and by extension your Wi-Fi. This may 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
Reboot the router by unplugging it and leaving it that way for a short period. The thermostat may also be disconnected if you have recently updated the password or the Wi-Fi’s SSID, which is the name you give it.
Error Code e1 for Honeywell Thermostats
Thermostats employ sensors to detect the temperature outdoors and indoors. If a sensor breaks down, you could 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 restart the thermostat, which should clear error code e1.
Honeywell Error Code 11n
Error code 11n could appear if the thermostat is failing to recognize a heating or cooling unit. This may mean that the equipment itself is defective and unable to connect with the thermostat. This can happen when the wiring is damaged or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A qualified technician can use a voltmeter to find out if there’s a faulty electrical connection. When the wiring on your specific HVAC equipment is bad, the technician can replace it. If the thermostat itself is the issue, it should probably be replaced.
Honeywell Error Code e2
If you see error code e2 show up on your Honeywell smart thermostat, it could mean a couple of different things. Sometimes, one of the sensors used to detect the temperature isn’t functioning correctly. In other cases, it means the router was disconnected from power before the thermostat could complete the setup process.
How to Fix Honeywell Thermostat Error e2
In situations where the error code stems from sensor failure, a technician will troubleshoot and switch out the impacted sensor. Any time the problem stems from disconnected power, all you have to do is make sure the router remains on during the setup process.