Co Leak From Furnace: Causes, Dangers, And Prevention

Carbon Monoxide Alarm Household Clean Smokeless Gas Furnace
Carbon Monoxide Alarm Household Clean Smokeless Gas Furnace from


In the winter months, we rely heavily on our furnaces to keep our homes warm and comfortable. However, did you know that a malfunctioning furnace can potentially leak carbon monoxide (CO)? In this article, we will explore the causes, dangers, and prevention measures associated with CO leaks from furnaces.

The Dangers of Carbon Monoxide

Carbon monoxide, often referred to as the silent killer, is a colorless, odorless, and tasteless gas. When inhaled, it can be extremely harmful and even fatal. CO binds to hemoglobin in our blood, reducing its ability to carry oxygen throughout the body. Symptoms of CO poisoning include headaches, dizziness, nausea, confusion, and in severe cases, loss of consciousness or death.

Causes of CO Leaks

CO leaks from furnaces can occur due to various reasons. Some common causes include:

1. Malfunctioning or damaged heat exchanger: The heat exchanger in a furnace is responsible for transferring heat from the combustion process to the air. If it cracks or develops holes, it can allow CO to escape into the air circulated in your home.

2. Poor ventilation: Inadequate ventilation can lead to a buildup of CO. Blocked chimneys, vents, or flues can prevent the proper expulsion of combustion gases, increasing the risk of CO leaks.

3. Improper installation: A poorly installed furnace may not be properly sealed, allowing CO to escape from gaps or cracks.

Detecting a CO Leak

It is crucial to be able to detect a CO leak to protect yourself and your family. Signs that may indicate a CO leak include:

1. Yellow or flickering burner flames: A properly functioning furnace should have a steady blue flame. If you notice a change in color or flickering flames, it could indicate incomplete combustion and the presence of CO.

2. Soot or rust around the furnace: Dark soot or rust on or around the furnace can be a sign of a CO leak.

3. Physical symptoms: If you or your family members experience unexplained symptoms such as headaches, dizziness, or nausea, especially when the furnace is running, it could be a sign of CO poisoning.

Preventing CO Leaks

Prevention is key when it comes to CO leaks from furnaces. Here are some important preventive measures:

1. Regular maintenance: Schedule annual inspections and tune-ups for your furnace by a qualified technician. They will check for any potential issues, clean the system, and ensure proper ventilation.

2. Install CO detectors: Place CO detectors on each floor of your home, especially near bedrooms. These detectors will sound an alarm if they detect high levels of CO, giving you valuable time to evacuate and seek help.

3. Maintain proper ventilation: Keep chimneys, vents, and flues clear of debris or obstructions. Ensure there is adequate airflow for proper ventilation.


CO leaks from furnaces pose a serious health risk. Understanding the causes, recognizing the signs, and implementing preventive measures can help keep you and your loved ones safe. Remember, regular maintenance and the installation of CO detectors are essential in protecting your home from the dangers of CO leaks. Stay vigilant and prioritize the well-being of your family.