How old is my GE water heater?

Why GE needs its own page

Most brands have one rule. GE has four formats, and two of them use the same four digits to mean different things. A page that gives you a single GE rule is giving you a coin flip.

All four are from InspectApedia's GE page.

The example that proves the method

This is the strongest evidence on any of our decoder pages, because the plate confirms itself.

InspectApedia formats serial GE A511315388 as GE A WWYY nnnnn, giving week 51 and year 2013. Their note on the same tag: "The enlarged view of this data tag given below confirms this guess as it tells us explicitly that the Manufacture Date for this water heater was 18 Dec 2013."

Week 51 of 2013 is indeed mid to late December. The decoded date and the printed date agree.

Telling a month code from a week code

The arithmetic does most of the work, because there is no month 51.

1. First pair 13 to 53. It is a week. The second pair is the year.
2. First pair 01 to 12. Ambiguous on its own. It could be a month under GE MMYY, or a week under GE A WWYY if the heater is from a January to March build.
3. A letter sits between GE and the digits. That points at the GE A WWYY form, so read week then year.
4. The prefix spells something. GENG marks natural gas and GERN is a prefix; in both the digits that follow are month then year.

InspectApedia's moderator sums up the default: "common encoding is WWYY for week number and year's last 2 digits, found in the first four numeric digits of the serial number; of course there can be other formats."

Our reading, marked as ours: start with the week assumption when a letter precedes the digits, and with the month assumption when the prefix is GENG or GERN. Neither source states this as a decision order; it is how the four documented formats sort out in practice.

Where GE sits in the industry

Fast Water Heater groups "Rheem, Ruud, Richmond & GE" and says all of them read month first, then year, and that prefixes such as RH, RN or GE should be stripped before counting. InspectApedia's brand index files Hotpoint under GE.

So GE is a badge, not a factory, and its most common plate does follow the Rheem convention. The qualification matters though, and it is the reason this page exists: InspectApedia documents a GE week-code form that the Rheem family rule does not cover. If your plate fits GE MMYY, our Rheem page applies in full.

When the serial will not decode

InspectApedia gives a method rather than a guess, and it is worth repeating because it costs nothing:

• Start with the age of the building. That sets a floor under how old the heater can be.
• Read every sticker on the unit. The newest year on any of them, an energy rating label for instance, sets another floor.
• Look for an installer's handwritten date, often on the jacket or the manual.
• Check work receipts for the plumbing. If the unit was moved at some point, a relocation invoice dates that work too.
• Then test each candidate format and keep the reading that survives all of the above.

What the age tells you

Once you have a year, the repair or replace page turns it into a decision, the expected life page gives the bands by type, and the age decoder covers the other brands. Sister badges are on the Rheem page.