HTP / Westinghouse / American Standard (water heaters) water heaters carry the build date inside the serial number. We know 3 serial formats for this brand; the decoder tries each one and shows every reading that fits.
The first six digits are the month, day and year, followed by a letter and a production number.
112116E205445 reads as November 21, 2016.
One source Building Intelligence Center
Skip the first two digits. The next six are the month, day and year.
2103302238194208 reads as March 30, 2022.
One source Building Intelligence Center
Characters 10 and 11 are the year and the next three are the day of the year (1 to 366).
327402702223130000027 reads as November 9, 2022.
Two sources agree Building Intelligence Center, City of Mountain View
A standard tank water heater usually lasts 8 to 12 years. Some make it to 15 with soft water and a replaced anode rod; some fail at 7.
How long does a tank water heater last? · Should I replace my water heater? · DC Dept. of Energy & Environment, InterNACHI
A gas tankless water heater usually lasts 15 to 20 years, and sometimes longer, because there is no tank to rust through. Scale buildup in the heat exchanger is what shortens its life.
How long does a tankless water heater last? · Should I replace my water heater? · DC Dept. of Energy & Environment, U.S. DOE Building America
A heat pump (hybrid) water heater is expected to last 10 to 15 years. ENERGY STAR bases its savings math on 13 years.
How long does a heat pump water heater last? · Should I replace my water heater? · DC Dept. of Energy & Environment, ENERGY STAR (13-year basis)
A.O. Smith · American Water Heater · U.S. Craftmaster · Bradford White · State · Reliance · Kenmore · Whirlpool · Rheem · Ruud · Richmond · GE · Marathon · Rinnai · Navien · Noritz · Takagi · Bosch (tankless water heater) · Lochinvar · GSW / John Wood · Paloma · Giant · EcoSmart / Eemax · Stiebel Eltron
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The age you just looked up is the kind of fact that gets lost. A written record of serial numbers, install dates, repairs and who did the work saves the next owner, inspector or insurer from guessing.
A lifetime logbook for the house, organized by system, with room for serial numbers, install dates, repairs and contractors. It stays with the house for the next owner.
Galvanized, polybutylene, cast iron and the sewer line: what fails, what it costs, what insurance won't cover and how to decide.
A buyer's guide to older homes: wiring, pipes, lead, asbestos, insurance refusals and what the repairs actually cost.
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