NHIE Plumbing 4

Question 1

What is the minimum distance a vent pipe termination must be from an operable window or door opening?

Accepted Answer

3 feet

Answer

2 feet

Answer

6 feet

Answer

10 feet

Question 2

A home inspector observes a washing machine drain hose inserted into a standpipe that is only 18 inches tall. What is the concern?

Accepted Answer

The standpipe is too short and may allow wastewater to overflow or siphon

Answer

The hose material may be incompatible with the standpipe

Answer

Washing machine standpipes must be at least 36 inches tall

Answer

The drain hose diameter is too large for residential standpipes

Question 3

What is the most likely cause of low water pressure at a single fixture while pressure at other fixtures is normal?

Accepted Answer

A partially closed supply valve or mineral-clogged aerator at that fixture

Answer

A failing pressure-reducing valve at the main service entry

Answer

Undersized main service line

Answer

A failed expansion tank on the water heater

Question 4

During a home inspection, a gas water heater is found in a bedroom closet without any combustion air provisions. What is the primary hazard?

Accepted Answer

Insufficient combustion air can cause incomplete combustion, producing carbon monoxide

Answer

The closet walls may be too close to the flue pipe

Answer

Gas appliances are only prohibited in bathrooms, not bedrooms

Answer

The unit may void its warranty in a closet location

Question 5

Which of the following is a required safety feature on a temperature and pressure relief (TPR) valve discharge pipe?

Accepted Answer

The pipe must terminate within 6 inches of the floor or to the exterior, not be capped or reduced in size

Answer

The pipe must be insulated with fiberglass wrap

Answer

The pipe must include a shutoff valve to allow testing

Answer

The discharge pipe must be copper only

Question 6

An inspector finds gray plastic pipe used for supply lines throughout a 1990s home. What is the significance?

Accepted Answer

This is likely polybutylene (PB) pipe, which is prone to failure and was the subject of a class-action settlement

Answer

Gray plastic supply pipe is a modern improvement over copper

Answer

Gray pipe indicates the use of CPVC, which is the preferred supply material

Answer

The pipe color indicates a reclaimed water system

Question 7

What is the purpose of an air gap at a dishwasher drain connection?

Accepted Answer

To prevent contaminated wastewater from siphoning back into the dishwasher and potable water supply

Answer

To prevent hot steam from the dishwasher from entering the supply line

Answer

To reduce noise from the dishwasher pump

Answer

To allow air into the line to improve drain flow speed