Lennox furnace error code 04

Lennox furnace error code 04 is the most common problem in heating and cooling systems. A faulty COP Sensor causes this error code.

This article will present some of the causes for Lennox furnace error code 04, solutions for this problem and what to do when you experience this issue.

An LENNOX furnace or air handler will produce a “Lennox Error Code” if an airflow sensor, also known as a COP-Sensor, detects an issue with the system’s airflow. The error codes are typically four-letter alphanumeric codes printed on a sticker near the control panel on your furnace or air handler unit. They can also be found online or in your manual or owner’s guide that came with your system.

Lennox furnace error code 04 is a relatively common error code, meaning your furnace is not responding to the control panel. Various things can cause it, but it’s usually linked to a break in power.

If you use an older Lennox furnace and haven’t updated the firmware according to Lennox’s instructions, you may have this issue.

If you are still unsure of what could be causing this issue, take your furnace to your local Lennox-certified technician.

The Lennox factory error code 04 tells you that the furnace communicates with the thermostat.

A Lennox furnace error code 04 can occur for several reasons. The most common might be that the thermostat has been unplugged or there is an issue with the gas line.