Modern furnaces are incredibly safe appliances with numerous components explicitly designed to enhance their safety and prevent dangerous malfunctions. However, this high degree of security means that many homeowners can take them for granted. While your furnace is unlikely to fail in a way that can cause harm, it's still crucial to recognize the issues that can be potentially hazardous.

With gas appliances, these hazards typically take two forms: gas leaks and carbon monoxide leaks. The latter occurs as a result of dangerous combustion byproducts escaping the furnace and entering the home. Carbon monoxide leaks produce no detectable signs and can be potentially deadly, so it's critical to understand how furnace issues can lead to this problem.

Understanding Flame Rollout

Flame rollout is a relatively generic term for a fairly significant issue. A normally operating furnace burns natural gas in a combustion chamber and directs the heat and exhaust byproducts into a heat exchanger. The heat exchanger is essentially a radiator that keeps harmful exhaust gases contained while safely transferring their heat energy to your home's air.

If you watch your furnace as it operates, you should notice several blue flames extending from each burner. These scorching flames flow into your heat exchanger, where they consume oxygen and natural gas to provide heat. Issues with the oxygen supply can cause the flames to expand and extend back towards the burners, creating the situation known as "rollout."

As the name implies, flame rollout means that your burner's flames are no longer where they should be. Flame rollout can damage components in your furnace and, more significantly, allow combustion to occur outside of the sealed exhaust path. As a result, a furnace with flame rollout can spread dangerous carbon monoxide gases into your home.

Recognizing and Repairing Rollout

Your furnace should have one or more rollout sensors that will shut the unit down in the event of a flame rollout. It's crucial never to override or remove these sensors. If your furnace repeatedly triggers a safety switch, stop using your heat and contact an HVAC professional immediately. You can also recognize rollout by looking for red or orange flames pushing back toward the burners.

Rollout can occur for many reasons, including cracked heat exchangers, clogged exhaust systems, or other issues that restrict the supply of combustible oxygen. Since rollout is a severe problem with significant health consequences, it's not something you should attempt to resolve on your own. Once you know you have a problem, you'll need an expert technician to help you diagnose and repair it. Contact a company that offers furnace repair services to learn more.