Water heaters

How old is my Lochinvar water heater?

Lochinvar water heaters carry the build date inside the serial number. We know 2 serial formats for this brand; the decoder tries each one and shows every reading that fits.

How to read a Lochinvar serial number

Year and week (2011 to today (A.O. Smith era))

The first two digits are the year and the next two are the week of that year. An S in front is a factory code and is ignored.

1142N012345 reads as week 42 of 2011.

One source Building Intelligence Center

Two letters, then digits (1970s to 2011)

On older Lochinvar serials the first letter is the year and the second is the month, but two published year tables disagree by nine years. We can't give a reliable year from this serial. Lochinvar can date it from the full serial number.

One source Building Intelligence Center, Energy Trust of Oregon serial charts, InterNACHI inspector forum

Where to find the serial number

Water heater: the rating label on the side of the tank, near the EnergyGuide sticker. On a tankless unit it is on the side or bottom of the cabinet.
Use the line marked Serial No. or S/N, not the model number. If the plate prints a manufacture date, use that.

How long should it last?

Typical life of a tank water heater: 8 to 12 years

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

Should I replace it?

Should I replace my water heater?

Other brands in this group

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) · GSW / John Wood · Paloma · HTP / Westinghouse / American Standard (water heaters) · Giant · EcoSmart / Eemax · Stiebel Eltron

Parts that help it last

Anode rod The sacrificial rod that rusts instead of the tank. Checking it every few years is the cheapest way to add life.
Flush kit A hose and fittings for draining sediment from the bottom of the tank once a year.
Expansion tank Soaks up pressure swings in a closed plumbing system. Ask a plumber whether yours needs one.
Leak alarm A small alarm that goes on the floor beside the heater and warns you before a slow leak becomes a flood.

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Keep a record of your home

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.

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