A Honeywell smart thermostat is an easy way to fine-tune how you use your home comfort system. But like any utility, you could occasionally run into a problem. With its digital display, Honeywell smart thermostats can show an error code that trained technicians can use to get a better sense of what's wrong. Here are a few of the most likely error codes you might see on your Honeywell smart thermostat.
Honeywell Thermostat Error e42
You can encounter this error code when your home’s Wi-Fi internet did not present an IP address for the thermostat to connect to. This can occur if a router doesn't complete the Dynamic Host Configuration Protocol, or DHCP. This process automatically sends out the necessary IP address for your thermostat to link up.
How to Fix Honeywell Thermostat Error e42
You can fix error code e42 by verifying that your router can complete the DHCP. Assuming it does, you may also have to power cycle the router and complete the initial setup process again with the thermostat. This should ensure the DHCP is sent and connects to your smart thermostat.
Honeywell Error Code e02
Error code e02 appears when the password for communicating with your home’s Wi-Fi router is incorrect. When this error code appears for 30 seconds, the thermostat’s digital display will automatically progress to the Wi-Fi setup screen so you can attempt to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you have to do to solve error e02 is verify you’re putting in the correct Wi-Fi password when configuring the thermostat.
Error Code 40 for Honeywell Thermostats
Error code 40 can pop up when the thermostat is alerted that a heat pump or air conditioner’s monitoring system has identified a malfunction. Most often, this appears if the compressor isn’t turning on despite being instructed to. But this error code could also appear if power is disconnected from the outdoor unit for a long period of time. A “High Pressure Fault” error, induced by obstructed airflow, can render this error code. Lastly, you might see 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 inspect 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, it’s best to get in touch with an experienced technician.
Honeywell Thermostat Error e43
If the Honeywell thermostat presents error code e43, it is unable 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 the wide area network (WAN).
How to Fix Honeywell Thermostat Error e43
Restart the router by unplugging it and leaving it that way for a short period. The thermostat could also be disconnected if you recently changed the password or the Wi-Fi’s SSID, which is the name you provide it.
Error Code e1 for Honeywell Thermostats
Thermostats utilize sensors to identify the temperature outdoors and indoors. If a sensor fails, you may notice error code e1 show up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A qualified technician can swap out the sensor and reset the thermostat, which should resolve error code e1.
Error Code 11n for Honeywell Thermostats
Error code 11n can appear in situations where the thermostat is failing to recognize a heating or cooling unit. This might mean that the equipment itself is malfunctioning and unable to connect with the thermostat. This sometimes happens when the wiring is defective or even if the thermostat has failed.
How to Fix Honeywell Thermostat Error 11n
A qualified technician can employ a voltmeter to assess if there’s a poor electrical connection. In situations where 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.
Honeywell Error Code e2
If you’ve noticed error code e2 pop up on your Honeywell smart thermostat, it might mean a couple of different things. Sometimes, one of the sensors that detects the temperature isn’t operating correctly. In other cases, it means the router was disconnected from its power source 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 should troubleshoot and replace the affected sensor. If the problem originates from disconnected power, all you have to do is make sure the router remains on during the setup process.