AO Smith Signature 100 40-Gallon Electric Water Heater

The AO Smith Signature 100 40-Gallon Electric Water Heater (EJC-40) is the Lowe's-channel volume electric pick for 1–3 person households on all-electric service. 6-year warranty, 0.92 UEF, 4500W dual-element. Same chassis as AO Smith's commodity electric platform — the Signature 100 designation is the Lowe's badge on what most plumbers know as the ProLine.

Headline specifications

• Capacity: 40 gallons
• Fuel: Electric, 240V
• Element: 4500W upper + 4500W lower (non-simultaneous)
• First Hour Delivery: 52 GPH
• Recovery: 21 GPH at 90°F rise
• UEF: 0.92
• Warranty: 6-year tank and parts
• Anode: magnesium
• Dimensions: 47" H × 20" diameter

Who this model is for

Right buyer profile: homeowner on electric service replacing a 40-gallon tank like-for-like, shopping at Lowe's, valuing AO Smith brand reliability over the heat-pump premium of a Voltex Hybrid. 1–3 person households, single bathroom. Apartments, condos, and properties without natural gas service.

If your household runs more than two simultaneous demand points or you have 3+ people, step up to the 50-gallon. If you're a long-term homeowner with 50+ amp service to spare, the Voltex Hybrid recovers its premium in 3–4 years of energy savings.

Where it beats the alternatives

Vs Rheem Performance Platinum 40 Electric ($649): AO Smith ~$100 less at Lowe's. Rheem ships 12-year warranty + EcoNet WiFi; AO Smith ships 6-year + no WiFi. For shorter-horizon ownership (5–6 years), AO Smith is the value pick.

Vs Rheem Performance 40 Electric ($499): nearly identical price and warranty (6 years). Choose AO Smith if Lowe's, Rheem if Home Depot.

Vs Whirlpool 40 Electric ($429): Whirlpool is AO Smith manufacturing at Lowe's budget tier. Same hardware, 6-year warranty, fewer comfort features. Step up only if you value the Signature badge.

Vs Voltex Hybrid 50 HP ($1,649): the Voltex uses 50–70% less electricity but costs ~3x more upfront and needs 1,000 cu ft of ambient air. For renters, short-term owners, or basements without the air volume, the Signature 100 is correct.

Where it falls short

6-year warranty is class-baseline. Rheem Performance Platinum offers 12 years at the same price tier — the AO Smith bet is brand familiarity and Lowe's availability over warranty length.

0.92 UEF is competitive for resistance electric but well below the 3.4+ UEF you'd get from a heat pump. Annual operating cost runs $400–$550 for typical 1–3 person households at $0.14/kWh — about 3x what a heat pump costs to run.

No smart-home integration. No leak detection. No remote temperature control.

Install considerations

47" height fits standard closets. 30-amp 240V dedicated circuit required. Existing 30-amp circuit from prior electric tank is reusable for direct swap.

Install cost: $300–$650 for like-for-like swap. New gas-to-electric conversion adds $400–$800 in electrical work if a 240V circuit must be run.

Maintenance

• Annual flush (especially hard water)
• Magnesium anode check year 3, replace year 5
• T&P valve test annually
• Element inspection at year 5

Bottom line

The AO Smith Signature 100 40 Electric is the Lowe's volume pick for 1–3 person all-electric households on a budget. 6-year warranty, 0.92 UEF, 4500W elements. $100 less than Rheem Platinum but with 6 years of warranty vs 12. For longer-horizon owners with heat-pump-suitable basements, the Voltex Hybrid pays back in operating savings within 4 years.