Home Inspector Test Home Inspector Forced-Air Furnace Inspection 2

Question 1

What is the minimum recommended clearance between a gas furnace and combustible materials in a typical residential installation?

Accepted Answer

Varies by manufacturer — always check the nameplate

Answer

Clearance requirements vary by furnace model and must be verified on the manufacturer's nameplate or installation manual.

Question 2

A home inspector notices the furnace flue pipe has a downward slope toward the furnace. What is the concern?

Accepted Answer

Combustion gases may backdraft into the living space

Answer

Flue pipes must slope upward (minimum 1/4 inch per foot) toward the chimney so combustion gases draft properly and do not back-flow into the home.

Question 3

During a forced-air furnace inspection, the inspector observes soot deposits around the burner compartment. What does this most likely indicate?

Accepted Answer

Improper combustion or a cracked heat exchanger

Answer

Soot accumulation around burners is a red flag for incomplete combustion or a cracked heat exchanger allowing combustion gases to escape.

Question 4

What is the purpose of the blower door on a furnace cabinet?

Accepted Answer

To prevent air from the blower compartment from mixing with combustion air and maintain proper airflow

Answer

The blower door separates the blower compartment from the burner/heat exchanger and must be installed for safe and efficient operation.

Question 5

A furnace draft inducer motor is found on which type of furnace?

Accepted Answer

Mid-efficiency or high-efficiency induced-draft furnaces

Answer

Induced-draft furnaces use a draft inducer (vent blower) to mechanically pull combustion gases through the heat exchanger and out the flue.

Home Inspector Test Practice Test