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How old is my Rinnai water heater?

Type the serial number from the Rinnai label to see when it was built.

Scan insteadWhere is the label?

Example

BLCA051306
  • BYear: B = 2010
  • LMonth: L = November

Built November 2010

15 years, 11 months old

Past typical life. Past the usual 10 year lifespan. Watch for error codes, water that swings between hot and cold, and scale buildup if it has not been flushed.

Plan the replacement

  • Plan the replacement. Repairs to the heat exchanger on an older unit often cost close to a new one.
  • Have a technician check the venting and combustion if it is a gas unit.
How this was read
  1. First letter B is the year. Rinnai started at A for 2009, so B is 2010.
  2. Second letter L is the month: November.
  3. The letters and digits after that are a plant code and production number.

Format: Rinnai year and month letters. Sources: Building Intelligence Center: Rinnai, Parts Town: Rinnai serial number lookup.

Reading a Rinnai serial number

Since 2009 Rinnai serials start with a year letter and a month letter. A is 2009, B is 2010, and so on.

Before 2009 the serial starts with the year and month as digits, like 04.03 for March 2004.

About Rinnai

  • Rinnai’s parent, Rinnai Corp., is based in Nagoya, Japan.
  • Rinnai America’s North American headquarters is in Peachtree City, Georgia.
  • Rinnai planned to start building tankless water heaters in Griffin, Georgia, in April 2018, the first tankless gas water heater production in North America.

Source: Water Heater Manufacturer Building First North American Plant (Plumber Magazine, 2017)

Rinnai year and month letters

Used 2009 to today. Example: BLCA051306

The first letter is the year (A = 2009) and the second letter is the month (A = January, skipping I). Two more letters and a number follow, like BL.CA-051306.

Worked example: BL.CA-051306 was built November 2010, so it is 15 years, 11 months old as of October 2026.

Year letter (first letter)
LetterYear
A2009
B2010
C2011
D2012
E2013
F2014
G2015
H2016
J2017
K2018
L2019
M2020
N2021
O2022
P2022
R2023
S2024
T2025
W2026
Month letter (second letter)
LetterMonth
AJanuary
BFebruary
CMarch
DApril
EMay
FJune
GJuly
HAugust
JSeptember
KOctober
LNovember
MDecember

Sources: Building Intelligence Center: Rinnai, Parts Town: Rinnai serial number lookup

Older Rinnai year and month digits

Used 1999 to 2008. Example: 0403102521

Before 2009, Rinnai printed the year then the month as digits, like 04.03-102521 for March 2004.

Worked example: 04.03-102521 was built March 2004, so it is 22 years, 7 months old as of October 2026.

Sources: Building Intelligence Center: Rinnai, Parts Town: Rinnai serial number lookup