Paloma Water Heater Age Lookup
Paloma pioneered tankless heating and built many of the early Rheem tankless units. Enter your serial number to find the manufacture date and age of your Paloma-built heater. Free and instant.
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Finding Your Paloma Serial Number
Check these four spots on your Paloma water heater
Common Locations
What to Look For
- White or metallic manufacturer sticker
- Labeled "Serial No." or "S/N"
- Typically 8–12 characters long
- Usually near the model number
Can't find it? Try removing access panels or checking behind the temperature dial.
Paloma Serial Number Examples
Don't worry if yours looks different - Paloma has multiple formats and our system can decode most variations.
About Paloma Water Heaters
Paloma Co., Ltd. began in Nagoya in 1911 making alcohol lamps, moved into gas appliances, and became one of the early developers of instantaneous gas water heating. It is also the majority owner of Rheem, which makes Paloma one of the largest forces in water heating worldwide even in markets where its own name never appears on the box.
In North America, Paloma badged equipment means gas tankless heaters, indoor and outdoor rated, roughly 120,000 to 180,000 BTU per hour, installed by licensed gas contractors. Service and parts run through the Rheem network rather than a separate Paloma one, which is the useful thing to know when a unit needs attention.
There are two serial formats, and which one you have tells you which market the unit was built for. North American units carry a Rheem style letter prefix, R, RH, RNG or RHNG, followed by two digits for the month and two for the year, in that order, so RNG0815123456 is August 2015. Units built for Japan and Australia use a dotted format, and the digits after the dot are the month, not the production week, a distinction that has been getting Paloma dates wrong for years; 17.11-56003, for example, is November 2017. Both formats use a 50 year pivot, so a year code above 50 falls in the 1900s.
Where to find the serial
Paloma tankless water heaters have the rating plate on the bottom or side of the wall-mounted unit. Paloma is the majority owner of Rheem, so service and parts in North America route through the Rheem network. The serial encodes the manufacturing month and year.
What the serial actually looks like
Why the age is worth knowing
Paloma tankless units carry warranties similar to Rheem (12-year heat exchanger on most condensing models, 5 years on parts). Annual descaling is critical for warranty maintenance - skip it and Paloma will deny claims based on scale damage in the heat exchanger.
Quick answers for this brand
Is Paloma the same as Rheem?
Paloma Co. Ltd. of Japan is the majority owner of Rheem Manufacturing in North America. Paloma-branded units sold in the US are sometimes Japanese-built and sometimes Rheem-built depending on the model. Service and warranty all route through the Rheem North American network.
Where are Paloma units sold in North America?
Paloma branded tankless units have limited distribution in North America, primarily through specialty plumbing wholesalers. Most North American consumers encounter Paloma technology rebadged as Rheem or Ruud tankless. New installations under the Paloma brand are uncommon today.
Can I use Rheem parts on my Paloma?
In many cases yes - especially for tankless units built on the shared Paloma/Rheem platform. Always verify the exact part number with Rheem tech support before ordering, as small revisions matter for heat exchangers, gas valves, and control boards.
Need a plumber?
Get free quotes from licensed local pros, no commitment required.
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Know someone with an aging water heater? Send them a free check.