Furnace Operation and Components

This video tutorial explains the sequence of operation for a high-efficiency gas-fired furnace with a hot surface igniter. It covers the components involved, such as the gas line, heat exchanger, and vent motor. The video details the ignition process, including the role of the thermostat, vent pressure switch, and ignition module. Safety features like the fan limit switch and high limit switch are discussed. The tutorial also explains how the furnace heats up, activates the blower, and eventually shuts down, emphasizing efficiency and safety throughout the process.

Which component is responsible for capturing the heat of the flame in a high-efficiency gas furnace?

• Flame sensor

• Vent blower

• Heat exchanger

• Gas valve

What is the first step in the operation of a high-efficiency gas furnace?

• Ignition module activation

• Thermostat calling for heat

• Fan limit switch closing

• Vent motor spinning

What happens when the vent motor starts spinning in the furnace operation?

• The ignition module deactivates

• The gas valve opens

• The vent pressure switch closes

• The blower turns on

Why is there a delay before the ignition module is energized?

• To check the flame sensor

• To allow the gas valve to open

• To let the blower start

• To ensure the vent pressure switch is closed

At what temperature does the fan limit switch typically close to start the blower?

• 150 degrees

• 130 degrees

• 110 degrees

• 90 degrees

What is the purpose of the fan limit switch in the furnace operation?

• To open the gas valve

• To start the vent motor

• To control the blower based on temperature

• To activate the ignition module

What happens when the thermostat is satisfied in the furnace operation?

• The main burners shut off

• The fan limit switch opens

• The ignition module activates

• The vent motor starts

Why does the vent blower continue to run after the call for heat is satisfied?

• To cool down the furnace

• To remove residual heat

• To activate the ignition module

• To close the vent pressure switch

What is the effect of not removing residual heat from the furnace?

• Higher blower speed

• Lower efficiency

• Faster ignition

• Increased gas usage

At what temperature does the blower typically shut off after the furnace operation?

• 90 degrees

• 80 degrees

• 70 degrees

• 100 degrees