A Honeywell smart thermostat is a great way to optimize how you use your home comfort system. But like any mechanical system, you may occasionally experience a problem. With its digital display, Honeywell smart thermostats can display an error code that certified technicians can use to get a better sense of what's happening. Here are a few of the most known error codes you may see on your Honeywell smart thermostat.

Honeywell Thermostat Error e42

You might 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 take place if your router does not complete the Dynamic Host Configuration Protocol, or DHCP. This procedure automatically sends out the needed IP address for your thermostat to connect.

How to Fix Honeywell Thermostat Error e42

You can resolve error code e42 by confirming that your router is enabled for DHCP. Assuming it does, you usually also need to power cycle the router and repeat the initial setup process with the thermostat. This should ensure the DHCP is transmitted and connects to the smart thermostat.

Error Code e02 for Honeywell Thermostats

Error code e02 appears when the password for connecting to your home’s Wi-Fi router was incorrect. After this error code has appeared for 30 seconds, the thermostat’s digital display will automatically progress to the Wi-Fi setup screen so you can try to enter the password again.

How to Fix Honeywell Thermostat Error e02

All you have to do to clear error e02 is ensure you’re putting in the correct Wi-Fi password when configuring the thermostat.

Honeywell Thermostat Error 40

Error code 40 can appear when the thermostat is informed that a heat pump or air conditioner’s monitoring system has identified a malfunction. Most often, this happens if the compressor isn’t working despite being instructed 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 blocked