Draft regulators or barometric dampers are devices used to regulate the draft on oil-fired furnaces, boilers, and water heaters. … You adjust the weight to control the amount of the opening of this damper which in turn controls the amount of excess air that can enter the flue and chimney when the oil burner is operating.

How does a draft damper work?

The barometric damper is installed in the flue between the boiler and the chimney. … If the draft inside the chimney is greater than the setpoint, the damper will open and allow air from the boiler room inside the chimney, rather than stealing heat from the boiler.

What does a barometric damper control?

A barometric damper regulates the chimney draft. Over time pressure can build up in the chimney ducts and the barometric damper job is to regulate and release the built-up pressure. The barometric damper plays an important role in fire safety.