Furnace Repairs That Might Be Needed When The Flame Rollout Switch Trips

Your gas furnace has a few safety switches built into it to protect you and your furnace from danger if something goes wrong during the combustion process. One of these switches is the flame rollout switch. Here's how this switch works, how to test it, and signs the switch needs to be replaced.

How The Flame Rollout Switch Works

Your furnace has at least one of these switches, but it might have more. The switch is located on the side of the burner box in your furnace where the flames ignite to create heat. The purpose of the switch is to detect when flames roll out of the box and enter your furnace, which is a hazardous situation. If this problem is detected, the switch activates and keeps the flames from burning or being ignited.

How To Test The Switch

A residential furnace repair technician has to determine why the flame rollout switch tripped. They may start by pushing the reset button located by the switch. Then they can watch the ignition cycle start to determine the problem. Resetting the switch is often a temporary fix, so it's not recommended to reset it frequently. Instead, the cause of the tripping should be found.

The technician can tell for sure if the switch is bad by testing it with a multimeter. Knowing if the switch is bad or if there is another problem is important since the switch might be tripping due to a safety hazard that needs to be repaired or due to a bad switch.

Signs The Switch Could Be Bad

When the flame rollout switch is bad, your furnace won't make heat. However, there are many things that cause this problem, so the furnace repair technician has to narrow down the issue. If they see the switch is tripped, they may check the heat exchanger for cracks, see if the combustion area is covered with soot that needs to be cleaned off, or make sure the flue isn't blocked.

If a reason for the tripped switch is found and repaired, the switch can be reset and then monitored to make sure the switch and furnace are functioning properly. If the switch is found to be bad, it can easily be pulled out and replaced with a new one.

A flame rollout switch isn't very expensive, and it's an easy furnace repair to replace the switch. It plays an important role in helping your furnace operate safely. Flame rollout could cause damage to the furnace that is expensive to repair, and that could even allow carbon monoxide to escape into your home.

Contact a residential furnace contractor to learn more. 

Share