Rinnai Tankless Water Heater Age by Serial Number
Since 2009 the first letter of a Rinnai serial number is the year (A = 2009) and the second letter is the month. Type the serial number below for the exact month and year.
About Rinnai
Rinnai is best known for tankless water heaters. Since 2009 its serial numbers start with two letters for the year and month.
Where to find the serial number
Tankless water heater: The rating label is on the side or bottom of the unit, or inside the front cover. Some models also show the serial number in the unit's service menu.
How to read a Rinnai serial number
Since 2009 the first letter of a Rinnai serial number is the year (A = 2009) and the second letter is the month.
2009 to today: 2 letters
Y M …
- Letter 1 is the year: A = 2009, B = 2010, C = 2011, D = 2012, E = 2013, F = 2014, G = 2015, H = 2016, J = 2017, K = 2018, L = 2019, M = 2020, N = 2021, P = 2022, R = 2023, S = 2024, T = 2025, W = 2026.
- Letter 2 is the month.
Example: BL.CA-051306
Before 2009: digits with a full stop
YY.MM-######
- The digits before the full stop are the year.
- The two digits after it are the month.
Example: 04.03-102521
Month letters: A = January, B = February, C = March, D = April, E = May, F = June, G = July, H = August, J = September, K = October, L = November, M = December (there is no I).
How long does a tankless water heater last?
Most tankless water heaters last 15 to 20 years. Yearly servicing, the local climate and how hard it works all move it within that range. Past 15 years, it is worth getting a replacement price before the unit fails, so you aren't forced into a rushed decision.
Questions
How do I tell how old my Rinnai tankless water heater is?
Find the serial number on the data plate and read it with the Rinnai code: Since 2009 the first letter of a Rinnai serial number is the year (A = 2009) and the second letter is the month. Or type it into the decoder on this page.
Is the manufacture date printed on the label?
Often, yes, especially on newer units and water heaters. Look for "Mfg. date", "MFD" or "Date of manufacture". If there is a printed date, it is more reliable than decoding the serial number.
Who makes Rinnai?
Rinnai is made by Rinnai Corporation.
How sure are these dates? Based on a single published source. Treat the date as an estimate and check the label for a printed date. How we test the decoder.
Keeping an older tankless water heater going
- Tankless water heater flush kit: Descaling once a year keeps a tankless heater efficient.
- Water heater leak detector alarm: Cheap insurance against a slow leak.