A Honeywell smart thermostat is an easy way to fine-tune how you use your home comfort system. But like any mechanical system, you might sometimes run across a problem. With its digital display, Honeywell smart thermostats can display an error code that professional technicians can use to understand what's wrong. Here are some of the most known error codes you could see on your Honeywell smart thermostat.
Error Code e42 for Honeywell Thermostats
You may encounter this error code in the event that your home’s Wi-Fi connection did not provide an IP address for the thermostat to hook up to. This can happen if a router does not execute the Dynamic Host Configuration Protocol, or DHCP. This procedure automatically sends out the required 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 verifying 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 the thermostat. Doing so should ensure the DHCP is delivered and connects to your smart thermostat.
Honeywell Error Code e02
Error code e02 appears when the password for accessing your home’s Wi-Fi router was incorrect. Once 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 need to do to resolve error e02 is ensure you’re putting in the correct Wi-Fi password when setting up the thermostat.
Honeywell Thermostat Error 40
Error code 40 can pop up when the thermostat is alerted that a heat pump or air conditioner’s monitoring system has recognized a malfunction. Most commonly, this occurs once 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 a lengthy period of time. A “High Pressure Fault” error, triggered by poor airflow, can display this error code. Finally, you may encounter error code 40 if there’s something wrong 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 ordinary operation. If you turn the thermostat off and on again and error code 40 reappears, it’s best to contact an experienced technician.
Honeywell Error Code e43
If your Honeywell thermostat shows error code e43, it can’t 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 about 30 seconds. The thermostat may also be disconnected if you recently updated 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 determine the temperature outdoors and indoors. If a sensor breaks down, you may notice error code e1 turn up on your Honeywell smart thermostat.
How to Fix Honeywell Thermostat Error e1
A skilled technician can change out the sensor and restart the thermostat, which should take care of error code e1.
Honeywell Thermostat Error 11n
Error code 11n could appear when the thermostat can’t 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 professional technician can employ a voltmeter to determine if there’s a poor electrical connection. When the wiring on your type of HVAC system is bad, the technician can replace it. If the thermostat itself is the problem, it will likely have to be replaced.
Error Code e2 for Honeywell Thermostats
If you notice error code e2 show up on your Honeywell smart thermostat, it could mean a couple of different things. For example, one of the sensors used to detect 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 should troubleshoot and swap out the damaged sensor. Any time the problem originates from disconnected power, all you'll need to do is verify the router stays on throughout the setup process.