AO Smith Conservationist 40-Gallon Electric Water Heater (ENT-40)
AO Smith Conservationist 40-Gallon Electric Water Heater (ENT-40) Review
The AO Smith Conservationist 40-Gallon Electric (ENT-40) is the smaller-capacity sibling of the ENT-50, designed for 1-2 person households or installs where 50-gallon dimensions won't fit. Mainstream Conservationist tier between AO Smith's budget ProMax and premium Signature Premier lines.
Specs: 40 gallons stored, two 4500W heating elements, UEF 0.93, 52-gallon first-hour rating, 6-year tank and parts warranty. ENERGY STAR certified. Glass-lined steel tank with self-cleaning dip tube on sub-models. Magnesium anode rod, polyurethane foam insulation.
The 40-gallon electric capacity (52-gallon FHR) covers 1-2 person households with sequential demand. For 3+ person households, the 50-gallon Conservationist or upgrade to AO Smith Voltex heat-pump is the right choice. Like-for-like 40-gallon electric replacement is one of the simplest residential plumbing jobs.
Right buyer: Lowe's-channel shopper replacing an existing 40-gallon electric tank in a 1-2 person household with 5-8 year ownership horizon. About $549 at Lowe's, $1,100 installed. For longer ownership, the upgrade to AO Smith Voltex heat-pump (massively lower operating cost) or Rheem Marathon (lifetime warranty) usually pays back.
- No combustion, no venting required — installs anywhere with 240V electrical access
- Strong UEF 0.92 efficiency — approximately 20% lower annual operating cost vs 0.62 standard
- Discontinued model — original warranty has expired; replacement parts availability is age-dependent
- 6-year warranty — below the 8–12 year average for premium models in this class
- Resistance electric has slower recovery than gas at comparable capacity — schedule heavy use to match tank recovery