Reliance age lookup
How to read a Reliance water heater serial number
Type the serial number from the label and the decoder shows when your Reliance water heater was made. Below that: every Reliance format the decoder knows, and a real label from one of my inspections.
Accuracy is not guaranteed.
This decoder gives an estimate based on how brands have coded serial numbers in the past. Manufacturers change their formats, and a serial can be misread, so the results may be wrong. Use them as a starting point only. Confirm with the date printed on the plate or with the manufacturer.
Reading a Reliance water heater serial number
Newer Reliance serials read like A.O. Smith's: the first two digits are the year and the next two are the week. Older Reliance serials start with a month letter that counts from October, so A is October of the year before the one in the serial, and D is January. The decoder does that math for you.
The Reliance label above prints a BUILD DATE of 06/08/2021, and the serial agrees: week 23 of 2021. Newer Reliance labels often print that date, so check for it first.
Reliance serial number formats
Each format below has a made-up example split into its parts, so you can match it to your own serial.
4 digits for the year and week, then a letter and 6 digits or 9 more digits (about 2008 and later)
Example1714A123456: Year 17, Week 14, Unit number A123456.
Reads as week 14 of 2017. Used from 2005 to today.
- The first 2 digits are the year and the next 2 are the week. Newer serials are 13 digits long and start the same way. A letter in front, if there is one, is skipped.
A month letter, 2 digits for the year, then 6 or 7 more characters (older Reliance)
ExampleK95123456: Month K, Year 95, Unit number 123456.
Reads as July 1995. Used from 1970 to 2008.
- These serials count from a business year that starts in October: A is October, B November, C December, D January, and so on to M for September. A, B and C units were made in the calendar year before the one in the serial. The decoder does that math for you.
A factory letter, a month letter, 2 digits for the year, then 6 digits (older Reliance)
ExampleAE01123456: Factory A, Month E, Year 01, Unit number 123456.
Reads as February 2001. Used from 1970 to 2008.
- Same business-year month code as the style above: A is October of the year before, D is January.
Where to find the serial number on a Reliance water heater
Look for a label marked Serial, Serial No. or S/N. The model number is usually right next to it, so check which one you're reading.
- Gas or electric tank. A rating label on the side of the tank, usually at eye level or above the gas control. If the tank sits in a closet, it may face the wall; a phone camera held at an angle often reaches it.
Brands that use the same formats
These brands share at least one serial number format with Reliance, so their serials read the same way.
Buying a home in the Portland area?
A home inspection covers the water heater along with the rest of the house, including its approximate age and visible condition. Serving the Portland metro and Southwest Washington, seven days a week.