Whirlpool 40-Gallon Natural Gas Water Heater

The Whirlpool 40-Gallon Natural Gas Water Heater is the smaller-capacity sibling of the Whirlpool 50-Gallon Gas — sold through Lowe's as the Whirlpool-branded water heater line. Like the rest of the Whirlpool water heater range, the actual unit is built by AO Smith with Whirlpool branding applied for the Lowe's channel.

Specs: 40 gallons stored, 40,000 BTU input, UEF 0.58–0.62 depending on sub-model, 71-gallon first-hour rating, 6-year tank and parts warranty. Atmospheric vent through B-vent. Electronic ignition requires 120V outlet. Magnesium anode rod, polyurethane foam insulation, self-cleaning dip tube on premium sub-models.

The 40-gallon capacity is correctly-sized for 1–2 person households with sequential demand, or for households where closet height (52" typical for 40-gallon tanks) prevents installing a 50-gallon (60" typical). For 3+ person households, the 50-gallon Whirlpool or the upgrade to AO Smith Signature Premier (12-year warranty) is usually the better economic choice.

Right buyer: Lowe's-channel shoppers replacing an existing 40-gallon gas tank in a 1–2 person household. About $499 at Lowe's, $1,200 installed. Like-for-like atmospheric gas tank replacement.