Why Does an Oil-Fired Boiler Fire Into a Chamber & Not Directly Into a Wall?

Function

• Oil-fired boilers heat water, but the heating process is essentially the same as oil furnaces, which heat air. The basic components of any heating system that relies on a combustion reaction are the burner, blower and heat exchanger. The burner initiates the combustion reaction, creating heat. The blower sends the heat into the home; in the case of an oil-fired boiler, a tank of water is heated rather than air. The heat exchanger isolates the combustion reaction, preventing dangerous gases from entering your home.

Heating Process

• The burner ignites the oil, heating the air within the combustion chamber. The heat energy passes through the heat exchanger to warm the air chamber. In an oil-fired boiler, the heat passes into a water tank via a heating element. Meanwhile, the air in the combustion chamber, which contains toxic gases, vents outside.

Significance

• If your boiler functions properly, the air you breathe will not contain toxic gases. But cracks and rust can break the seal created by the heat exchanger, allowing dangerous gases to pass into the air you breathe. Odors might escape, allowing you to detect a problem, but some toxic gases, such as carbon monoxide, are colorless and odorless, meaning the only way to detect a problem is with a carbon monoxide detector.

Considerations

• Metal contracts as it cools, so cracks and other damage might not be visible when you inspect the exterior of the combustion chamber. Hire a professional furnace technician to inspect your boiler at least annually -- sooner if you detect foul odors. A yearly safety check and routine cleaning will help ensure your heating system is functioning efficiently and safely.