Electric Tankless Water Heater Install Cost in 2026

Two distinct categories: point-of-use vs whole-home

Electric tankless is misleadingly marketed as one category. In practice, the install economics, the use cases, and the failure modes are completely different between point-of-use (POU) and whole-home units.

Point-of-use (POU): the easy, cheap install

A POU unit installs under a single sink, in a remote bathroom, or at a workshop wet station. Typical specs:

• 120V or 240V single-phase
• 15A to 60A breaker draw
• 0.5 to 1.5 GPM output
• Unit cost $80 to $400
• Install cost $150 to $500 (electrical hookup, water lines, wall mount)
• Total installed: $230 to $900

POU is the right answer for a remote bathroom 60 ft from the main water heater (where standing waste alone could be a gallon every time someone washes their hands), a guest cottage, a garage workshop, or any single-fixture install where running a hot-water line back to a central heater would itself be expensive.

Whole-home electric tankless: the complicated install

A whole-home electric unit replaces the central water heater for the entire house. Typical specs:

• 240V single-phase
• 80A to 150A continuous breaker draw (typically split across two or three breakers)
• 3 to 8 GPM output (climate-dependent)
• Unit cost $450 to $1,200
• Install cost $350 to $3,500 (highly variable based on panel work)
• Total installed: $800 to $4,700

The wide range is almost entirely the electrical infrastructure question. A home with 200A service and a panel with spare slots is at the low end. A home with 100A service, a full panel, and an old service drop is at the high end.

The whole-home electric tankless models worth quoting

Stiebel Eltron Tempra Plus series (24, 29, 36 kW)

The Stiebel Eltron Tempra Plus is the benchmark whole-home electric tankless. PID modulation, plus-or-minus 1F temperature stability, German engineering. The Tempra 24 Plus draws 100A, the Tempra 29 Plus draws 120A, the Tempra 36 Plus draws 150A. Unit prices $700 to $1,200. Installed cost $1,000 to $3,500 depending on panel work.

EcoSmart ECO series (18, 24, 27, 36 kW)

EcoSmart is the value play. Same kW ratings and amp draws as the Tempra equivalents, simpler bang-bang temperature control, lifetime element warranty. Unit prices $400 to $750. Installed cost $700 to $3,000.

Rheem RTEX series (13, 18, 24, 27 kW)

Rheem's electric tankless line, distributed through Home Depot. PID modulation, comparable to Stiebel. Unit prices $500 to $900. Installed cost $850 to $3,100.

Bosch Tronic 6000 series

Bosch's whole-home electric line, sized 18 to 27 kW. Slightly more capacity than the Tempra at marginally higher install cost. Unit prices $550 to $850. Installed $900 to $3,100.

Itemised installed cost: Stiebel Tempra 24 Plus, no panel upgrade

3-bath suburban home with 200A panel and a spare double-pole slot, retrofit from a 50-gallon electric tank:

Itemised installed cost with a panel upgrade

Same Tempra 24 Plus install in a home with existing 100A service requiring an upgrade to 200A:

This is the scenario where electric tankless economics break down. A $3,000 to $6,000 install is more expensive than an equivalent gas tankless install where natural gas is available. Make the panel-capacity check before the equipment choice.

Why climate is the dominant capacity variable

Electric tankless capacity is rated at a specific temperature rise (typically 50F). Cold-climate winter inlet temperatures cut effective output by 30% to 40%. A Tempra 24 Plus delivers:

• 4.0 GPM at 50F rise (75F inlet to 125F output): summer FL
• 3.3 GPM at 60F rise (65F inlet to 125F output): winter FL or summer northern US
• 2.7 GPM at 75F rise (40F inlet to 115F output): winter MN, NY, ME
• 2.4 GPM at 85F rise (32F inlet to 117F output): winter Mountain West high altitude

In a cold-climate winter, a 4 GPM rated unit delivers what a 2.5 GPM unit delivers in summer. That is the difference between adequate-for-one-shower and inadequate-for-one-shower. If you live in a cold climate, the rule of thumb is to upsize one kW tier above what the spec sheet suggests: a Tempra 29 (120A) in cold climates where the spec sheet says a Tempra 24 (100A) would suffice. The cost premium is real (a 200A panel becomes more necessary) but the alternative is cold showers in February.

25C credit on electric tankless

ENERGY STAR certifies several electric whole-home tankless models as Most Efficient. The 25C credit applies to those at 30% of installed cost capped at $600 per tax year. Check current ENERGY STAR Most Efficient list before claiming; the certification is reviewed annually. The credit is claimed on IRS Form 5695.

The cap is binding for any install at $2,000 or above, returning the full $600. On a smaller POU install at $800 total, the 30% would be $240 (the cap does not bind there).

Where heat-pump water heaters compete

Heat-pump water heaters (HPWH) deserve a mention because they compete directly with electric tankless. An HPWH uses 60% less electricity than an electric tank for the same hot-water output, qualifies for a higher 25C credit cap ($2,000 vs $600 for tankless), and works without the panel upgrade headache because they typically draw 15 to 30A continuous.

The trade-off: HPWHs are tank-style (60 to 80 gallon footprint), produce some cooling and humidity in the install space (a feature in basements, a bug in living spaces), and take 5 to 8 hours to recover a depleted tank. For a household where standby loss is the operating cost driver, HPWH usually wins on lifecycle economics; for households where unlimited on-demand hot water is the priority, electric tankless still has a use case.

Bottom line

Electric tankless is the right choice for point-of-use installs (under a remote sink, in a guest cottage, at a workshop) and for whole-home installs in warm-climate, well-electrified homes. Installed cost is $230 to $900 for POU, $800 to $2,800 for whole-home without a panel upgrade, and $2,000 to $4,500 with a panel upgrade.

In cold climates, electric tankless struggles to keep up with realistic winter demand. In any home where natural gas is available, gas tankless usually wins on installed cost, operating cost, and capacity. The honest moment of decision is the panel check: if it needs upgrading, the economics often swing toward gas (where available) or heat-pump-tank (where the 25C credit advantage matters).