A Honeywell smart thermostat is an excellent way to fine-tune how you use your heating and cooling. But like any mechanical system, you could sometimes run into a problem. With the digital display, Honeywell smart thermostats can provide an error code that professional technicians use to figure out what's happening. Here are a few of the most common error codes you could 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 connect with. This can happen if the router does not perform the Dynamic Host Configuration Protocol, or DHCP. This process automatically transmits the needed IP address for your thermostat to connect to the Wi-Fi.
How to Fix Honeywell Thermostat Error e42
You can resolve error code e42 by making sure that your router is enabled for DHCP. If it does, you may also have to power cycle the router and perform the setup process again with your thermostat. This should ensure the DHCP is transmitted and connects to your smart thermostat.
Honeywell Thermostat Error e02
Error code e02 is displayed whenever the password for accessing your home’s Wi-Fi router was incorrect. Once this error code appears for 30 seconds, the thermostat’s digital display automatically transitions to the Wi-Fi setup screen so you can attempt to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you'll need to do to solve error e02 is ensure you’re typing the correct Wi-Fi password when setting up the thermostat.
Honeywell Thermostat Error 40
Error code 40 can pop up when the thermostat is informed that a heat pump or air conditioner’s monitoring system has identified a malfunction. Most commonly, this happens if the compressor isn’t working despite being instructed to. But this error code may also show up if power is shut off from the outdoor unit for an extended period of time. A “High Pressure Fault” error, induced by blocked airflow, can display this error code. Finally, you may 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 a Honeywell thermostat presents error code e43, it is unable to communicate with the router, and by extension the 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 around 30 seconds. 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.
Honeywell Thermostat Error e1
Thermostats utilize sensors to identify the temperature outdoors and indoors. If a sensor malfunctions, you may see 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 reboot the thermostat, which should clear error code e1.
Honeywell Thermostat Error 11n
Error code 11n may appear when the thermostat is failing to detect a heating or cooling unit. This might mean that the equipment itself is malfunctioning and unable to communicate 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 use a voltmeter to assess if there’s a poor electrical connection. When the wiring on your existing HVAC equipment is bad, the technician can replace it. If the thermostat itself is the problem, it will likely have to be replaced.
Honeywell Thermostat Error e2
If you’ve noticed error code e2 show up on your Honeywell smart thermostat, it can mean a few different things. For example, one of the sensors that detects the temperature isn’t operating like it should. Other times, 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 replace the impacted sensor. Any time the problem stems from disconnected power, all you’ll have to do is make sure the router remains on throughout the setup process.