InterNACHI Plumbing & HVAC Systems 5

Question 1

What condition does an inspector suspect when they find the area around a toilet base is soft, stained, or the flooring feels spongy?

Accepted Answer

A failed wax ring seal causing chronic leakage

Answer

A failed wax ring allows sewage and water to leak at the base of the toilet with each flush, leading to floor rot, mold, and structural damage over time.

Question 2

When inspecting a heat pump, what does it mean when the outdoor unit is running but the indoor air handler is blowing cool — not warm — air in heating mode?

Accepted Answer

The reversing valve may be stuck in cooling mode

Answer

The reversing valve switches refrigerant flow direction to provide heating; if stuck in the cooling position, the system cools rather than heats even with the thermostat calling for heat.

Question 3

What is the purpose of a trap primer on a floor drain in a seldom-used area?

Accepted Answer

To add water periodically to keep the trap seal from evaporating

Answer

Floor drain traps in low-use areas can evaporate dry over time, allowing sewer gas entry; a trap primer automatically introduces small amounts of water to maintain the seal.

Question 4

An inspector observes white mineral deposits (scale) heavily coating the inside of a removed water heater anode rod. What does this indicate?

Accepted Answer

The water supply has high mineral content (hard water) and the anode may be depleted

Answer

Heavy scale buildup on an anode rod indicates hard water conditions and signals the rod may be near or at end of life, leaving the tank vulnerable to corrosion.

Question 5

Which HVAC filter MERV rating provides the best balance of particle removal and adequate airflow for most residential forced-air systems?

Accepted Answer

MERV 8–11

Answer

MERV 8–11 filters capture most common household particles including dust mite debris, mold spores, and pet dander without excessively restricting airflow in residential systems.

(InterNACHI) International Association of Certified Home Inspectors Practice Test

(InterNACHI) International Association of Certified Home Inspectors Practice Test

InterNACHI Plumbing & HVAC Systems 5