The plumbing inspection

I. The inspector shall inspect (when applicable and safely accessible):

1. the main water supply shut-off valve;
2. the main fuel supply shut-off valve;
3. the water heating equipment, including the energy source, venting connections, temperature/pressure-relief (TPR) valves, Watts 210 valves, and seismic bracing;
4. interior water supply, including all fixtures and faucets, by running the water;
5. all toilets for proper operation by flushing;
6. all sinks, tubs and showers for functional drainage;
7. the drain, waste and vent system; and
8. drainage sump pumps with accessible floats.

1. whether the water supply is public or private based upon observed evidence;
2. the location of the main water supply shut-off valve;
3. the location of the main fuel supply shut-off valve; and
4. the location of any observed fuel-storage system.

1. deficiencies in the water supply by viewing the functional flow in two fixtures operated simultaneously;
2. deficiencies in the installation of hot and cold water faucets;
3. mechanical drain stops that were missing or did not operate if installed in sinks, lavatories and tubs; and
4. toilets that were damaged, had loose connections to the floor, were leaking, or had tank components that did not operate.

IV. The inspector is not required to:

1. light or ignite pilot flames.
2. determine the size, temperature, age, life expectancy or adequacy of the water heater.
3. inspect the interior of flues or chimneys, combustion air systems, water softener or filtering systems, well pumps or tanks, safety or shut-off valves, floor drains, lawn sprinkler systems, or fire sprinkler systems.
4. determine the exact flow rate, volume, pressure, temperature or adequacy of the water supply.
5. determine the water quality, potability or reliability of the water supply or source.
6. open sealed plumbing access panels.
7. inspect clothes washing machines or their connections.
8. operate any valve.
9. test shower pans, tub and shower surrounds or enclosures for leakage or functional overflow protection.
10. evaluate the compliance with conservation, energy or building standards, or the proper design or sizing of any water, waste or venting components, fixtures or piping.
11. determine the effectiveness of anti-siphon, back-flow prevention or drain-stop devices.
12. determine whether there are sufficient cleanouts for effective cleaning of drains.
13. evaluate fuel storage tanks or supply systems.
14. inspect wastewater treatment systems.
15. inspect water treatment systems or water filters.
16. inspect water storage tanks, pressure pumps, or bladder tanks.
17. evaluate wait-time to obtain hot water at fixtures, or perform testing of any kind to water heater elements.
18. evaluate or determine the adequacy of combustion air.
19. test, operate, open or close safety controls, manual stop valves and/or temperature/pressure-relief valves.
20. examine ancillary or auxiliary systems or components, such as, but not limited to, those related to solar water heating and hot water circulation.
21. determine the existence or condition of polybutylene plumbing.

From International Standards of Practice for Performing a General Home Inspection – InterNACHI http://www.nachi.org/sop.htm#ixzz2UPDK5W7H