American Standard AS-40 40-Gallon Natural Gas Water Heater

The American Standard AS-40 40-Gallon Natural Gas is the smaller-capacity sibling of the American Standard AS-50. A.O. Smith-built with American Standard branding for hardware-store and plumbing-supply channels.

Specs: 38,000 BTU input, UEF 0.58, 71-gallon FHR, 6-year tank and parts warranty. Atmospheric vent through B-vent. Electronic ignition. Magnesium anode rod.

The 40-gallon American Standard covers 1-2 person households. Same A.O. Smith engineering as ProMax 40-gal with American Standard branding for brand-preference buyers.

About $479 unit, $1,150 installed. For longer ownership horizons, A.O. Smith Signature Premier or Rheem Performance Platinum (both 12-year warranty) is usually the better economic choice.