Is the ENT-30 100 a good replacement for your home?
The A.O. Smith ENT-30 100 is a tall, relatively narrow electric storage water heater for installations where floor space is limited and the household has modest hot-water needs. At Water Heating Experts, we review how much hot water the home uses, the existing equipment, available clearances and electrical supply before recommending a replacement.
The manufacturer lists 30 gallons nominal capacity, 27 gallons rated storage and a 48-gallon first-hour rating. The first-hour rating measures delivery in a standardized test; it is not the volume stored inside the tank. For back-to-back showers and overlapping appliance use, we may recommend comparing larger equipment rather than simply matching your old heater’s gallon label.
Height, width and replacement space
This tall model measures 46½ inches high × 19 inches in diameter, with top-mounted ¾-inch water connections. It can be a useful shape in a narrow equipment space, but the tank measurements do not include all the room required for piping, electrical access, servicing, a drain pan where required, and removal of the existing unit. We review the temperature-and-pressure relief discharge and other site-specific installation details before preparing an estimate.
For a height-restricted location, compare the A.O. Smith ENLB-30 110 lowboy, which is 30 inches high and 20 inches in diameter, with 26 gallons of rated storage. For greater hot-water needs and where the space allows, our ENT-50 130 50-gallon tall electric model is another option. We confirm which form and capacity fit the installation.
Electrical supply, recovery and efficiency
In its standard configuration, the ENT-30 100 runs on 240 volts with two 4,500-watt elements, using a maximum connected input of 4,500 watts in normal non-simultaneous operation—not 9,000 watts. A.O. Smith lists 21 gallons per hour of recovery at a 90°F temperature rise. We verify the data plate, breaker, circuit, wiring and any required installation changes before specifying a unit.
The manufacturer’s technical specification sheet lists 0.89 Uniform Energy Factor (UEF). This is a conventional electric resistance tank, not a heat-pump model. If lower ongoing energy use is a priority and the installation space can accommodate it, ask WHE about hybrid heat-pump water heater options.
Tank protection and warranty
The ENT-30 100 includes a lower Incoloy stainless-steel heating element, Blue Diamond glass lining, a CoreGard anode rod, a DynaClean diffuser and a brass drain valve, according to A.O. Smith’s product documentation. These features do not eliminate routine maintenance or water-quality concerns. The model comes with a six-year limited tank and parts warranty, subject to the written terms; installation labor and replacement expenses are separate.
ENT-30 100 frequently asked questions
Is this a 30-gallon tank or a 27-gallon tank?
It is a 30-gallon nominal model with 27 gallons of rated storage. A.O. Smith separately lists a 48-gallon first-hour rating, which is a delivery measurement rather than stored volume.
Will this model fit where my old heater sits?
Possibly. The heater measures 46½ inches high by 19 inches in diameter, but we also check top connections, service and removal access, drainage and electrical requirements. A matching gallon label does not guarantee a matching installation.
How is the ENT-30 100 different from the ENLB-30 110?
The ENT-30 100 is taller and narrower, with 27 gallons rated storage and a 48-gallon first-hour rating. The lowboy ENLB-30 110 is shorter and wider, with 26 gallons of rated storage and a 43-gallon first-hour rating. WHE can compare both against your space and hot-water needs.
Can WHE install an ENT-30 100 in Palm Beach Gardens or Jupiter?
WHE serves Palm Beach Gardens, Jupiter and nearby Palm Beach County communities. Mention this model in your free installation estimate request so we can verify your address, availability, suitability and scope of work.
Does the six-year warranty include installation labor?
The manufacturer’s limited tank and parts coverage is subject to its written terms. Labor and other costs may be excluded. WHE will explain any applicable installation coverage with your estimate.
Plan your replacement with WHE
Send a clear photo of the old heater’s data label and a wider photo of its surroundings. We can compare this model with other A.O. Smith water heaters and review installation needs before confirming equipment and pricing.
Technical references: A.O. Smith ENT-30 100 product page, ProLine Standard Electric specification sheet (March 2025), and manufacturer’s limited warranty. The product page’s marketing paragraph differs from its technical table on efficiency; the UEF listed here is the 0.89 value from the technical specifications. Confirm the supplied unit and installation instructions before work begins.