Lennox Furnaces are known for their reliability and efficiency, however, like any mechanical equipment, they can also experience issues. To make troubleshooting easy, Lennox Furnaces are designed to display error codes on the control panel when there is an issue with the system. Understanding these error codes is crucial for quickly identifying and resolving issues with your furnace. In this blog post, we'll take a look at the most common Lennox Furnace error codes, their light patterns, meanings and potential issues.
Lennox furnaces use a two-digit code system to indicate an error. These codes can be found on the furnace's control panel, usually cleared by turning the system off and then back on again. Here's a table of some common Lennox furnace error codes, their light patterns, meanings, and potential issues:
|
Code |
Meaning |
Potential Issues |
| 1 blink | Pressure switch stuck closed | The pressure switch is not able to detect proper airflow which can be due to a clogged air filter, a blocked vent or a faulty inducer motor |
| 3 blinks | Flame sensor not working | The flame sensor is not able to detect the flame and could be due to a faulty flame sensor or ignition control module |
| 4 blinks | Ignition failure | The furnace is not able to ignite due to a faulty ignitor or gas valve |
| 1 blink | Pressure switch stuck open | The pressure switch is not able to detect proper pressure, and could be caused by a blocked vent or a faulty inducer motor |
| 3 blinks | Limit switch open | The limit switch is not able to detect proper temperature and could be caused by a faulty limit switch or malfunctioning thermocouple |
| 4 blinks | Draft inducer not working | The draft inducer is responsible for drawing combustion gases out of the furnace and could be caused by a faulty draft inducer or blocked vent |
| 1 blink | Blocked vent | Blocked vents can cause pressure switch issues as well as limit switch issues |
| 3 blinks | Ignition control problem | A faulty ignition control module or a problem with the control circuit could be causing this error |
