I. The inspector shall inspect (when applicable and safely accessible):
- the main water supply shut-off valve;
- the main fuel supply shut-off valve;
- the water heating equipment, including the energy source, venting connections, temperature/pressure-relief (TPR) valves, Watts 210 valves, and seismic bracing;
- interior water supply, including all fixtures and faucets, by running the water;
- all toilets for proper operation by flushing;
- all sinks, tubs and showers for functional drainage;
- the drain, waste and vent system; and
- drainage sump pumps with accessible floats.
II. The inspector shall describe:
- whether the water supply is public or private based upon observed evidence;
- the location of the main water supply shut-off valve;
- the location of the main fuel supply shut-off valve; and
- the location of any observed fuel-storage system.
III. The inspector shall report as in need of correction:
- deficiencies in the water supply by viewing the functional flow in two fixtures operated simultaneously;
- deficiencies in the installation of hot and cold water faucets;
- mechanical drain stops that were missing or did not operate if installed in sinks, lavatories and tubs; and
- 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:
- light or ignite pilot flames.
- determine the size, temperature, age, life expectancy or adequacy of the water heater.
- 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.
- determine the exact flow rate, volume, pressure, temperature or adequacy of the water supply.
- determine the water quality, potability or reliability of the water supply or source.
- open sealed plumbing access panels.
- inspect clothes washing machines or their connections.
- operate any valve.
- test shower pans, tub and shower surrounds or enclosures for leakage or functional overflow protection.
- 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.
- determine the effectiveness of anti-siphon, back-flow prevention or drain-stop devices.
- determine whether there are sufficient cleanouts for effective cleaning of drains.
- evaluate fuel storage tanks or supply systems.
- inspect wastewater treatment systems.
- inspect water treatment systems or water filters.
- inspect water storage tanks, pressure pumps, or bladder tanks.
- evaluate wait-time to obtain hot water at fixtures, or perform testing of any kind to water heater elements.
- evaluate or determine the adequacy of combustion air.
- test, operate, open or close safety controls, manual stop valves and/or temperature/pressure-relief valves.
- examine ancillary or auxiliary systems or components, such as, but not limited to, those related to solar water heating and hot water circulation.
- 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