It seems odd that so many inspectors would go through so much trouble and expense (Preston’s Guide, etc) to research and report the age of mechanical equipment … only to say that the age is not relevant to its present working condition. Why bother reporting on the age of the equipment if it is working fine at the time of the inspection?
In 2010, I inspected a home with a pristine water heater that was installed in 1971 (when I was a senior in high school). While I was amazed at the excellent condition of the water heater in light of its age … I informed my client that this was the exception and not the rule. I explained that the manufacturer of water heaters will provide a warranty for what they believe to be the life expectancy of the device (usually 6 years) … and that the NAHB estimates the life span to be higher at 10 years. While the water heater in that home showed no outward signs of deterioration, it was older than the normal life span for a water heater and that they should plan to replace it.
In my opinion, it is a very slippery slope for a home inspector to tread when he begins to use what he believes to be the opinions of real estate salesmen in communicating to his client.
If it’s broke … say it’s broke. It it’s old … say it’s old.
With all of that said, a prudent home inspector will spend extra time (verbally) and extra language in his report to ensure that every client knows that every mechanical item in the house — new and old — can stop working the moment he drives away from the property. The inspection is only a snapshot in time and that age of people or water heaters, new or old, is only an indicator of possible continued life but is no guarantee.