mrac2025_ch34_revquestions

Which of the following is not an action that an oil furnace’s primary control unit performs in response to a call for heat?

• Closing a damper in the flue to build pressure in the combustion chamber

• Opening a solenoid valve in the fuel line

• Signaling the igniter to send high-voltage electricity to the electrodes

• Turning on the oil burner motor

A fuel oil’s viscosity primarily plays a part in determining ____.

• air band adjustment

• burner nozzle orifice size

• flue pipe size

• oil tank vent pipe size

The heating value of No. 2 fuel oil ranges from ____ per gallon.

• 240 Btu to 480 Btu

• 14,000 Btu to 20,000 Btu

• 12,000 Btu to 14,000 Btu

• 137,000 Btu to 141,800 Btu

The amount of noncombustible contaminants in fuel oil is referred to as the fuel oil’s ____.

• ash content

• carbon residue

• distillation quality

• sediment

A flame that is ____ may be the result of incomplete fuel oil combustion.

• dull orange or red

• mainly yellow and luminous

• mostly blue with red or orange feathering

• white

When taking combustion efficiency measurements, ____ is the acceptable range of carbon dioxide in the flue gas.

• 0% to 5%

• 8% to 12%

• 25% to 28%

• 42% to 47%

Stack temperature is determined by subtracting the temperature of the ____ from the temperature of the flue gas in the flue pipe.

• combustion air

• combustion chamber

• flame

• oil storage tank

An oil-fired appliance may use a(n) ____ in its flue pipe to help control the amount of air drawn into the flue.

• air tube

• barometric damper

• booster pump

• combustion head

When determining an oil-fired appliance’s combustion efficiency, the test that involves drawing a sample of flue gas from the flue or combustion chamber and passing it through filter paper is the ____.

• CO2 test

• draft test

• oil filter test

• smoke test

A(n) ____ allows a one-pipe fuel delivery system to operate as a two-pipe fuel delivery system.

• booster pump

• combustion air tee

• fuel line filter

• oil deaerator