Home Inspector Forced-Air Furnace Inspection Flashcards
7 cards from real Home Inspector Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Home Inspector Forced-Air Furnace Inspection flashcards as text
What is the minimum recommended clearance between a gas furnace and combustible materials in a typical residential installation?
Answer: Varies by manufacturer — always check the nameplate
Clearance requirements vary by furnace model and must be verified on the manufacturer's nameplate or installation manual.
A home inspector notices the furnace flue pipe has a downward slope toward the furnace. What is the concern?
Answer: Combustion gases may backdraft into the living space
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.
During a forced-air furnace inspection, the inspector observes soot deposits around the burner compartment. What does this most likely indicate?
Answer: Improper combustion or a cracked heat exchanger
Soot accumulation around burners is a red flag for incomplete combustion or a cracked heat exchanger allowing combustion gases to escape.
What is the purpose of the blower door on a furnace cabinet?
Answer: To prevent air from the blower compartment from mixing with combustion air and maintain proper airflow
The blower door separates the blower compartment from the burner/heat exchanger and must be installed for safe and efficient operation.
A furnace draft inducer motor is found on which type of furnace?
Answer: Mid-efficiency or high-efficiency induced-draft furnaces
Induced-draft furnaces use a draft inducer (vent blower) to mechanically pull combustion gases through the heat exchanger and out the flue.
Which condition requires reporting as a safety defect when inspecting a gas furnace's gas supply line?
Answer: A flexible connector longer than 3 feet inside a confined space
Flexible gas connectors must not exceed the manufacturer's specified length (typically 3–6 feet) and should not pass through walls, floors, or ceilings.
What does a cracked heat exchanger most directly risk in a forced-air system?
Answer: Carbon monoxide entering the living space via supply air
A crack allows combustion gases, including carbon monoxide, to mix with the circulating air and be distributed throughout the home.