How old is my Rheem water heater? Reading the serial number

Knowing your water heater's age helps you decide whether a repair is worth it, whether the warranty still applies and when to budget for a replacement. Rheem encodes the manufacture date in the serial number on the rating label.

Where to find the serial number

Look for the rating label, a sticker on the upper part of the tank, usually near the gas valve on gas models or the upper access panel on electric models. The serial number is labeled as such and sits near the model number. On tankless and hybrid models, check the label on the side or front of the unit.

How to read it

1. Ignore the letters at the start of the serial number. They identify the plant and product line, and can be one to four letters.
2. Read the next two digits as the month, 01 to 12.
3. Read the two digits after that as the year.

If the numbers do not look like a month

Some Rheem units use a week-and-year code instead. If the first pair after the prefix is 13 or higher, it cannot be a month, so read it as the week of the year followed by the year. Some tankless labels print the date in year-and-month form, such as 19.04 for April 2019. When in doubt, check whether the rating label lists a manufacture date directly.

Ruud and Richmond

Rheem also builds water heaters sold under the Ruud and Richmond names, which use the same date format. The brand badge and model number tell you which one you have.

What the age means

Tank water heaters commonly last about 8 to 12 years. See our guide on how long water heaters last for the warning signs, and compare repair quotes with the water heater replacement cost before deciding.