Determining the age of HVAC systems and water heaters is generally a bit more complicated than simply looking at the equipment data plate and finding a manufacturing date. Most manufacturers use a date code that is represented in the serial number. Because each manufacturer has a different date code system, you will need to reference the Building Intelligence Center HVAC and Water Heater Index. This is a great tool and resource to have bookmarked for quick reference as needed. We have provided a link below for your reference.
https://www.building-center.org/
AS A REMINDER, THE EXPECTED SERVICE LIFE FOR THE MOST COMMON HOME SYSTEMS ARE LISTED BELOW:
FURNACE - 25 years
A/C - 15 years
BOILER - 30 years
WATER HEATER - 12 years
These estimated service lives are per industry standards. Actual equipment service life may vary