Electric Water Heaters

Electric water heaters serve approximately 41% of US residential installs — primarily in homes without natural gas service or in jurisdictions pursuing electrification. The electric water heater category splits into three distinct sub-types: resistance tank (the volume legacy product), hybrid heat pump (the modern efficiency winner, 3x lower operating cost), and electric tankless (point-of-use and warm-climate whole-house).

The three electric water heater categories

1. Resistance electric tank (the volume baseline)

Standard 240V electric tanks with upper and lower 4500W heating elements. UEF ~0.93. Available in 30/40/50/80 gallon capacities and short-form variants for low-clearance installs. The Rheem and AO Smith lineups are the volume picks:

• Rheem Performance Platinum 50G Electric (XE50T10HE45U1) — 12-year warranty, EcoNet WiFi, leak detection
• Rheem Performance 50G Electric (XE50M06ST45U1) — 6-year warranty, volume entry tier
• AO Smith Signature 100 50G Electric (EJC-50) — 6-year, Lowe's primary channel
• Rheem Marathon 50G (MR50245) — limited-lifetime polybutene tank

2. Hybrid heat pump (the modern efficiency winner)

Heat pump technology cuts operating cost to one-third of resistance electric. UEF 3.45+. Eligible for $2,000 federal IRA tax credit. See the full heat pump water heater category.

• Rheem ProTerra 50G — Performance Platinum heat pump tier
• AO Smith Voltex 50G — direct competitor
• Bradford White AeroTherm Plus 50G — plumber-channel heat pump

3. Electric tankless (point-of-use and warm-climate whole-house)

On-demand electric heating. Caps at ~6 GPM at cold inlet, ~8 GPM at warm inlet for the largest residential units. See the full tankless category.

• Stiebel Eltron Tempra 36 Plus — flagship 36kW whole-house electric tankless
• EcoSmart ECO 27 — value pick at 27kW
• Rheem RTEX-18 — 18kW Rheem electric tankless flagship

Electric tank by capacity

• 30G electric — 1–2 person households, ADUs, vacation cabins
• 40G electric — 2–3 person households
• 50G electric — 3–4 person households (volume size)
• 80G electric — 4–6 person households or high simultaneous demand
• 100G electric — light-commercial / estate-class
• Short-form variants for low-clearance installs — Rheem 30G short, 38G short
• Point-of-use — 6G, 10G, 20G mini-tanks for remote fixtures

Electric vs gas operating cost

For a 4-person household at $0.14/kWh electric / $1.20/therm gas:

• Electric resistance tank: $580–$720/year
• Heat pump tank (ProTerra/Voltex): $170–$240/year — best in class
• Natural gas tank: $280–$380/year
• Condensing gas tankless: $180–$260/year

Electric resistance is the highest operating-cost category — but it's also the simplest install (no gas line, no venting). For homes where electrification is the goal, switching from resistance electric to heat pump is the highest-ROI upgrade.

Electric water heater warranty by tier

Install considerations

• 30-amp 240V dedicated circuit for tank installs
• 40–50 amp circuit for higher-capacity tanks or heat pump units
• 2× 30-amp or 1× 50-amp for RTEX-11+ electric tankless
• 3× 40-amp circuits + 200-amp service for Stiebel Tempra 36 Plus whole-house electric tankless
• Drain pan required by most jurisdictions for indoor installs
• Heat pump install requirements — see heat pump category for the 1,000+ cu ft + condensate drain specifics

Bottom line on electric water heaters

For all-electric households on long ownership horizons, the modern answer is heat pump — operating cost is one-third of resistance electric, $2,000 IRA tax credit closes the upfront gap, and 10-year warranty is competitive. For homes where heat pump install doesn't fit (no basement, no condensate drain, low ceiling), resistance electric remains a workable fallback — Rheem Marathon for lifetime tank coverage, Rheem Performance Platinum 50G Electric for 12-year warranty + EcoNet. For warm-climate whole-house electric tankless, Stiebel Tempra 36 Plus or EcoSmart ECO 27 are the picks. For point-of-use, the point-of-use mini-tank and tankless category covers ADU, RV, and remote-fixture applications.