NATE Oil Heating 2

Question 1

What does a #2 fuel oil supply line's two-pipe system accomplish compared to a single-pipe system?

Accepted Answer

Returns unused oil to the tank, preventing vapor lock and allowing the tank to be below the burner

Answer

Increases oil flow rate to the burner

Answer

Filters water from the oil supply

Answer

Provides redundancy if the primary supply fails

Question 2

What is the purpose of the electrodes in an oil burner?

Accepted Answer

Produce a high-voltage spark to ignite the atomized oil-air mixture

Answer

Sense the flame via rectification

Answer

Control oil pump speed

Answer

Measure flue gas temperature

Question 3

What condition does a high CO2 reading combined with a high smoke number indicate on a combustion analysis?

Accepted Answer

Too little combustion air (rich mixture causing incomplete combustion)

Answer

Too much combustion air (lean mixture)

Answer

Perfect combustion efficiency

Answer

Low oil pump pressure

Question 4

What is the function of the delayed oil valve (solenoid valve) on some oil burners?

Accepted Answer

Stop oil flow immediately on burner shutdown to prevent after-drip and after-fire

Answer

Prevent oil flow during power outages

Answer

Regulate oil pressure during high-fire mode

Answer

Allow oil to flow only on a call for heat

Question 5

What is a puffback in an oil heating system?

Accepted Answer

Small backfire explosion caused by igniting accumulated unburned oil in the combustion chamber

Answer

Reverse airflow through the flue

Answer

Oil pump pressure surge

Answer

Excessive combustion air condition

Question 6

What percentage of CO2 in flue gas typically represents near-ideal combustion for a #2 oil burner?

Accepted Answer

11–13%

Answer

5–7%

Answer

8–10%

Answer

15–17%