A Honeywell smart thermostat is an easy way to fine-tune how you use your HVAC system. But like any technology, you could sometimes run into a problem. With its digital display, Honeywell smart thermostats can show an error code that professional technicians will use to figure out what's happening. Here are a few of the most known error codes you could see on your Honeywell smart thermostat.
Honeywell Error Code e42
You can encounter this error code when your home’s Wi-Fi internet did not provide an IP address for the thermostat to connect to. This can occur if the router fails to execute the Dynamic Host Configuration Protocol, or DHCP. This procedure automatically supplies the needed IP address for your thermostat to connect.
How to Fix Honeywell Thermostat Error e42
You can clear error code e42 by verifying that your router can complete the DHCP. If it does, you usually also have to power cycle the router and complete the initial setup process again with your thermostat. Completing this task should see to it that the DHCP is sent and connects to your smart thermostat.
Error Code e02 for Honeywell Thermostats
Error code e02 appears whenever the password for connecting to your home’s Wi-Fi router was incorrect. 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 to enter the password again.
How to Fix Honeywell Thermostat Error e02
All you need to do to clear error e02 is make sure you’re entering the correct Wi-Fi password when setting up the thermostat.
Honeywell Thermostat Error 40
Error code 40 can pop up when the thermostat is notified that a heat pump or air conditioner’s monitoring system has identified a malfunction. Most commonly, this happens when the compressor isn’t turning on despite being directed to. But this error code may also surface if power is disconnected from the outdoor unit for an extended period of time. A “High Pressure Fault” error, induced by poor airflow, can lead to this error code. Finally, you could encounter 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 examine the air filter for signs of a clog, as well as the breakers and indoor unit’s blower for regular operation. If you reset the thermostat and error code 40 reappears, you should try to get a hold of an experienced technician.
Honeywell Error Code e43
If your Honeywell thermostat displays error code e43, it is unable 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 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 may also be disconnected if you recently changed the password or the Wi-Fi’s SSID, which is the name you create for it.
Honeywell Error Code e1
Thermostats use sensors to identify the temperature outdoors and indoors. If a sensor malfunctions, you might see error code e1 appear 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 resolve error code e1.
Honeywell Error Code 11n
Error code 11n can appear in situations where the thermostat is unable to connect to a heating or cooling unit. This can mean that the equipment itself is malfunctioning and unable to communicate with the thermostat. This sometimes happens when the wiring is damaged or even if the thermostat is faulty.
How to Fix Honeywell Thermostat Error 11n
A professional technician can employ a voltmeter to determine if there’s a faulty electrical connection. In situations where the wiring on your existing HVAC equipment is bad, the technician can replace it. If the thermostat itself is the source of the error code, it will likely have to be replaced.
Honeywell Error Code e2
If you see error code e2 appear on your Honeywell smart thermostat, it might mean a few different things. Sometimes, one of the sensors responsible for detecting the temperature isn’t functioning correctly. In other instances, it means the router was disconnected from power 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 should troubleshoot and swap out the impacted sensor. If the problem stems from disconnected power, all you’ll have to do is make sure the router stays on over the course of the setup process.