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Apollo Water Heater Age by Serial Number — Free Lookup

A.O. Smith

Also works for A.O. Smith-built labels: State, Reliance, American, Whirlpool, U.S. Craftmaster, Kenmore, GSW and John Wood.

How Old Is Your Apollo Water Heater?

Apollo was a private-label brand built by the A.O. Smith manufacturing family, so the serial number carries the same date code as State, Reliance, American, and U.S. Craftmaster units: the manufacture date is in the first digits of the serial. Enter your serial number in the free decoder above for an instant answer, or follow the guide below to read it yourself.

Where to Find the Serial Number

Look for the rating plate — a silver or white sticker on the side of the tank, usually in the upper half. It lists the model number, serial number, and capacity together. The date lives in the serial, not the model number. If the sticker has faded, photograph it and boost the contrast — you only need the first four digits.

How the Apollo Serial Format Works

The date code is year, then week, in the first four digits:

Worked example — 1214A003927:

  • 12 = 2012 (year)
  • 14 = week 14 (early April)
  • A and the remaining digits = factory and production sequence
  • Result: manufactured in week 14 of 2012

Watch for letter prefixes. Some serials start with letters, or insert a letter inside the date block — these are factory codes, not part of the date. Skip leading letters and read the first four digits you find. For example, AC0815B004772 decodes to week 15 of 2008.

Because the year is two digits, a code like 04 could be 2004 or 2014 on a modern-style serial. Compare the unit's condition and model line — and when in doubt, our decoder lists every plausible year instead of guessing.

Why Your Apollo Water Heater's Age Matters

  • Lifespan. Tank water heaters average 8–12 years of service. Past that, internal corrosion makes tank failure — and a flooded floor — far more likely.
  • Warranty. Apollo tanks typically carried 6- or 12-year warranties counted from the manufacture date. Decoding the serial tells you whether a repair might still be covered.
  • Replacement planning. A unit past 10 years is on borrowed time. Knowing the date lets you shop calmly instead of during an emergency.

Sources

Brand ownership and serial format verified against the InterNACHI water heater dating chart, which groups Apollo with the A.O. Smith production-line brands, and A.O. Smith's manufacturing-date guidance.

Frequently asked questions

Who makes Apollo water heaters?
Apollo was a private-label brand produced by the A.O. Smith family of manufacturers. The InterNACHI water heater dating chart groups Apollo with the dozens of retail labels built on A.O. Smith production lines (State, Reliance, American, U.S. Craftmaster), so Apollo serials use the same date coding. Note: this is the water heater label — not the unrelated Apollo hydro-heat boiler brand from earlier decades.
How do I tell the age of an Apollo water heater from the serial number?
Read the first four digits of the serial as year and week. For example, serial 1214A003927 means week 14 of 2012 — early April 2012. Letters before or inside the serial are factory codes; skip them and read the leading digits.
Where is the serial number on an Apollo water heater?
On the rating plate — the silver or white sticker on the upper half of the tank listing the model and serial numbers together. On older tanks it can fade or get painted over; a phone photo with the contrast bumped usually makes the first four digits readable.
How long do Apollo water heaters last?
Apollo tanks are built to the same 6- and 12-year warranty tiers as other A.O. Smith-family brands. In practice most tank water heaters last 8–12 years, with regular sediment flushing and anode rod replacement pushing units toward the longer end.
My Apollo serial starts with letters. How do I read it?
Leading letters are factory or production-line codes, not part of the date. Skip them and read the first four digits you find as year and week — for example, AC0815B004772 decodes to week 15 of 2008.