Furnace Operation and Components

This video tutorial, part of the Toolbox Tuesday series, focuses on the sequence of operation for a gas-fired furnace. It highlights the importance of understanding this sequence for proper diagnostics and operation. The video details each step in the sequence, from the thermostat call for heat to the blower motor activation, and includes a live demonstration. The tutorial concludes with a recap of the sequence and its significance in ensuring efficient furnace operation.

Why is understanding the sequence of operation crucial for technicians?

• It increases the lifespan of the furnace.

• It reduces the cost of furnace maintenance.

• It helps in diagnosing furnace issues.

• It improves the aesthetic appeal of the furnace.

What is the first action in the sequence of operation for a gas-fired furnace?

• The gas valve opens.

• The thermostat sends a signal.

• The blower motor starts.

• The flame sensor activates.

What role does the inducer motor play in the furnace operation?

• It ignites the gas.

• It creates a draft for combustion.

• It measures the room temperature.

• It circulates air through the house.

What is the purpose of the pressure switch in the furnace operation?

• To ignite the gas.

• To open the gas valve.

• To start the blower motor.

• To confirm the inducer motor is working.

What happens after the hot surface igniter glows?

• The blower motor starts.

• The thermostat resets.

• The gas valve opens.

• The inducer motor stops.

How does the system confirm the presence of a flame?

• With the blower motor.

• By the gas valve.

• Through the thermostat.

• Using the flame sensor.

What is the function of the blower motor in the furnace?

• To ignite the gas.

• To circulate warm air through the house.

• To measure the temperature.

• To open the gas valve.

When does the furnace system shut down?

• When the inducer motor stops.

• When the flame sensor deactivates.

• When the thermostat reaches the set temperature.

• When the gas valve closes.

What indicates that the furnace is ready to start the blower motor?

• The gas valve opens.

• The flame sensor confirms a flame.

• The thermostat sends a signal.

• The inducer motor stops.

What happens if the thermostat does not reach the set temperature?

• The blower motor stops.

• The gas valve closes.

• The system shuts down immediately.

• The system continues to operate.