InterNACHI Plumbing & HVAC Systems 4

Question 1

When should a home inspector recommend testing a sump pump during an inspection?

Accepted Answer

By pouring water into the pit to verify the float switch activates the pump

Answer

Pouring water into the sump pit is the standard method to verify the float switch activates and the pump discharges water properly without waiting for rain.

Question 2

What does a home inspector look for when evaluating a gas appliance's combustion air supply?

Accepted Answer

Whether adequate air openings exist to support complete combustion

Answer

Combustion appliances require sufficient air supply to burn fuel completely; inadequate combustion air leads to carbon monoxide production and flame rollout.

Question 3

Which type of drain trap is prohibited by most plumbing codes because it loses its water seal easily?

Accepted Answer

S-trap

Answer

S-traps are prohibited because self-siphoning action caused by rapid drainage easily pulls the water seal out, allowing sewer gases to enter the building.

Question 4

An inspector observes black ABS drain pipe that has been repaired with white PVC pipe and a standard coupling. What is the issue?

Accepted Answer

ABS and PVC require a special transition cement, not a standard coupling

Answer

ABS and PVC have different chemical compositions and require a special transition or all-purpose cement to bond; standard ABS or PVC cement will not create a lasting joint between them.

Question 5

What is the typical temperature range at which a residential water heater thermostat should be set to balance scalding prevention and Legionella control?

Accepted Answer

120–140°F

Answer

The recommended range is 120–140°F; 120°F minimizes scalding risk for most households, while 140°F is advised where Legionella is a concern — with an anti-scald mixing valve at fixtures.

(InterNACHI) International Association of Certified Home Inspectors Practice Test

(InterNACHI) International Association of Certified Home Inspectors Practice Test

InterNACHI Plumbing & HVAC Systems 4