Manufacturing date vs installation date

A manufacture date describes when equipment was made. An installation date records when it was installed. Do not copy a decoded production date into a form that asks for installation. If the installation date is unknown, write that it is unknown and look for the original installer’s paperwork.

A. O. Smith’s service guide illustrates separate manufacture-year and manufacturing-week fields. A week number is not a printed calendar day. UnitReveal may show a year and a manufacturer production-week number without converting that week to a calendar month when the required calendar convention has not been verified.

Carrier’s FAQ says its warranty starts on installation and explains that coverage depends on product and ownership or registration conditions. That does not establish the terms of another manufacturer’s warranty. Use the certificate for the actual product or ask its manufacturer; a serial-date result is not a warranty decision.

Keep the rating-plate photograph, dated installation invoice and any registration confirmation together. Note which date each document actually supports. A later service invoice records service, not necessarily installation; a property purchase date is also not proof of equipment installation.

Prepared by UnitReveal using the references below. Manufacturer-specific examples apply only to the equipment described by that source. This guide does not add lookup coverage for an unsupported format.