NATE Oil Heating 3

Question 1

What does a barometric draft control (draft regulator) do in an oil heating system?

Accepted Answer

Maintain constant flue draft by admitting dilution air when draft exceeds setpoint

Answer

The barometric damper swings open to admit room air when draft is too strong, maintaining a stable negative pressure in the flue.

Question 2

What is the minimum recommended flue gas temperature for an oil furnace to prevent condensation in the flue?

Accepted Answer

350°F

Answer

Flue gas temperatures above 350°F prevent sulfuric acid condensation from oil combustion products, which would corrode the flue system.

Question 3

What is the purpose of the oil filter installed in the oil supply line before the pump?

Accepted Answer

Filter sediment and particulates that could clog the nozzle or damage the pump

Answer

The oil filter traps rust, sediment, and debris from the tank that could plug the fine nozzle orifice or damage pump components.

Question 4

What annual efficiency rating measures the seasonal performance of an oil furnace?

Accepted Answer

AFUE

Answer

AFUE (Annual Fuel Utilization Efficiency) measures the percentage of fuel converted to heat over the heating season for oil furnaces.

Question 5

What causes water in the oil tank and what is its effect on the burner?

Accepted Answer

Condensation inside the tank accumulates water at the bottom; water can be drawn into the burner causing flame-outs and pump damage

Answer

Condensation inside the tank introduces water that sinks to the bottom and can be drawn to the burner, causing hard lockouts and corrosion.

NATE - North American Technician Excellence Practice Test