ESCO Institute Heating Practice Exam

A gas furnace is to be installed in a garage. The national standards require that the burners and ignition souce must be located__________above the floor.

• 6 inches

• 18 inches

• 12 inches

• 24 inches

A good description of how a bi-metal fan switch operates the blower motor on a gas furnace is:

• temperature on - time off.

• time on - temperature off.

• temperature on - temperature off

• time on - time off

Redundant gas valves used on gas furnaces have:

• two manual gas shut offs.

• no manual gas shut off.

• one gas shut off seat.

• dual gas shut off seats.

Burning one cubic foot of Liquefied Petroleum gas completely will produce approximately ______ BTUs.

• 2,000-2,500

• 1,500-2,000

• 1,200-1,500

• 900-1,100

LP gas has the spacific gravity of ? (debe ser "specific")

• 1.5-2.0

• 3.0-4.0

• 1-1.5

What is the purpose of a spoiler screw located on a burner, or adjustable-shutters?

• Mix combustion and dilution air

• Mix primary and secondary air

• Mix primary air and gas

• Mix dilution and excess air

Furnace limit switches are wired in series with the:

• low speed fan

• high speed fan

• gas valve

• heat anticipator

A technician is using an extension ladder to work on roof top unit. The top of the ladder should extend_____ beyond the support point.

• 1 foot

• 2 feet

• 3 feet

• 4 feet

A technician determines that a natural gas furnace has a defective heat exchanger. The technician should;

• inform the gas company

• turn the power to the furnace off

• turn the gas main supply gas to the home

• inform the home owner and turn the gas off

A natural gas furnace usually requires ____ gas pressure at the manifold and burners.

• 3.5 in W.C.

• 4.2 in. W.C.

• 5.0 in W.C.

• 7.0 in W.C.