155 Gas heat quiz 3

On a gas furnace, a(n) __________ switch in the chamber energizes the blower motor.

• auxiliary

• flame rollout

• pressure-sensing

• temperature-sensing

The 100% shutoff control system is necessary for systems that use propane or butane because these gases _______.

• are heavier than air and will accumulate in low places

• have higher combustion temperatures

• are lighter than air and will rise into the atmosphere

• have a higher burn rate

The dangerous by-product of poor combustion of gas is ____________.

• carbon monoxide

• carbon dioxide

• flue gas

• secondary air

The first step in systematically troubleshooting a furnace that has an IFC is to ________.

• remove the IFC from its static shielding bag

• obtain the electrical diagram of the furnace and the sequence of operation of the IFC

• make sure the technician is physically grounded

• Service technicians should not be troubleshooting the IFC.

The gas flame will lift off the burner and be noisy if it receives too much primary air.

• True

• False

The operation of a flame rectification system depends primarily on the flame’s ________.

• temperature

• ability to conduct electricity

• color

• height

The orifice is a precisely sized hole in the ____.

• manifold

• spud

• burner tube

• combustion chamber

The proper color of a gas flame is ____.

• sharp all blue

• lazy all blue

• blue with slight orange tips

• lazy with yellow tips

The purpose of the flame rollout switch is to monitor the _____, and, when tripped, to interrupt the _______.

• temperature of return air; fuel supply to the burner

• temperature of the draft hood; blower

• spillage of flue gas; electrical circuit

• buildup of combustion gases; fuel supply to the burner

The servo pressure regulator differs from a standard gas pressure regulator in that it measures the ________.

• outlet or working pressure of the gas valve

• inlet pressure of the gas valve

• atmospheric pressure surrounding the unit

• difference between the inlet and the outlet pressures