10 Best Electric Tankless Water Heaters of 2026 for Efficient On-Demand Hot Water

Electric tankless water heaters deliver hot water on demand without the standby losses or storage space required by a traditional tank. The right model depends on your incoming water temperature, desired flow rate, electrical capacity, and installation location.

This roundup compares compact point-of-use units with higher-output whole-house options, so you can narrow the field by performance, installation demands, and household needs.

Best 10 Electric Tankless Water Heaters Picks for 2026

Best Whole-Home Capacity – Rheem RTEX-24 24kW

For shoppers comparing electric tankless water heaters for whole-home use, the Rheem RTEX-24 offers up to 5.9 GPM with 24kW of heating power. Its compact, wall-mounted design requires no venting, but the substantial electrical setup should be verified before installation.

Best For: Homes needing higher-capacity, on-demand hot water for multiple fixtures.

Pros:

• Provides up to 5.9 GPM for multiple-fixture applications.
• Digital thermostatic control adjusts in 1-degree increments from 80°F to 140°F.
• Compact design is 90% smaller than traditional tank water heaters and requires no venting.
• Reported 99.8% energy efficiency and a 5-year leak warranty.

Cons:

• Requires three 40-amp double-pole breakers and a recommended minimum 200-amp household service panel.
• Professional installation may be necessary because of the demanding electrical requirements.

The RTEX-24 is a strong electric tankless water heater option when flow capacity is the priority. Confirm your home’s electrical service and sizing needs before purchasing.

Best Compact Low-Demand Pick – EcoSmart ECO 8

The EcoSmart ECO 8 is a compact 8kW electric tankless water heater designed for lower-demand applications. With a listed 2 GPM flow rate, 240V operation, and wall-mounted design, it can suit a focused hot-water installation where space is limited.

Best For: Smaller hot-water demands and compact installations that can support 240V power.

Pros:

• Small 8-inch-wide, 11.5-inch-high wall-mounted format.
• Lists 2 GPM flow and 99.8% efficiency.
• Includes an LED display for convenient operation.
• Warranty covers the electronics, heat exchanger, and element for the product’s stated lifetime.

Cons:

• Its 8kW output and 2 GPM flow rate are more limited than higher-powered whole-home models.
• Requires 240V electrical service.
• The warranty does not cover labor or incidental damages.

The ECO 8 makes sense when a small footprint matters more than high simultaneous flow. Match its output to the intended fixtures and verify the electrical connection before installation.

Best Serviceable Midrange Model – Rheem RTEX-13

The Rheem RTEX-13 is a 13kW electric tankless water heater with self-modulating power control and an external digital thermostat. Its listed flow reaches up to 3.17 GPM in the product notes, making it a practical fit for moderate hot-water demand rather than high-volume, simultaneous use.

Best For: Moderate-demand applications needing adjustable controls and serviceable heating elements.

Pros:

• External digital control adjusts temperature in 1°F increments.
• Self-modulating power control helps match output to demand.
• Copper immersion elements are described as field serviceable.
• Includes 1/2-inch NPT adapters and a 1.5 GPM water-saving shower head.

Cons:

• The 13kW model is listed at up to 3.17 GPM, limiting high-demand simultaneous use.
• Requires 240V power and a 54A electrical connection.

The RTEX-13 balances useful control features with a smaller capacity than Rheem’s higher-powered models. It is worth considering when moderate flow and easier component servicing are more important than maximum household capacity.

Best Under-Sink Point-of-Use Option – CAMPLUX 120V 4.5kW

The CAMPLUX TE05N4 is a point-of-use electric tankless water heater for a single sink. Its 120V, 4.5kW design activates at 0.26 GPM, uses a touch control panel, and is small enough for under-sink or other space-constrained installations.

Best For: One sink in a kitchen, wet bar, boat, or other compact point-of-use location.

Pros:

• Compact 10.9-by-7.4-by-2.52-inch wall-mounted design.
• Self-modulating operation adjusts power based on flow and temperature settings.
• Touch controls and an LED display simplify temperature adjustment.
• Requires only 120V power and includes dry-combustion protection.

Cons:

• Designed for one sink rather than whole-home use.
• Must be hardwired with no plug and requires a 40A breaker with 10 AWG wire.
• The listed 1.0 GPM temperature rise is 50°F, so performance depends on incoming water temperature and flow.

For a single sink, the CAMPLUX is a space-saving alternative to running hot-water lines from a central heater. Treat it as a point-of-use solution and have the required hardwired circuit installed correctly.

Premium Whole-Home Pick – Stiebel Eltron Tempra 24 Trend

The Stiebel Eltron Tempra 24 Trend is a high-capacity option for shoppers comparing electric tankless water heaters for whole-home use. Its 24kW output, copper heating system, automatic modulation, and no-vent design provide continuous hot water in a compact, quiet wall-mounted unit.

Best For: Homeowners who want a premium whole-home heater and have the electrical service needed for its installation.

Pros:

• Provides continuous, on-demand hot water without a storage tank.
• Compact design requires no venting and uses automatic energy modulation.
• Quiet operation, readable digital temperature display, and copper heating system.
• Includes a 7-year leakage warranty and 3-year parts warranty.

Cons:

• Requires hard wiring, two 50A breakers, and a recommended minimum 150A electrical service.
• Its 24kW electrical demand may require professional installation or service upgrades.

This is a strong choice when reliability, quiet operation, and whole-home performance matter most. Confirm the electrical requirements before purchase, particularly for older or smaller homes.

High-Output Smart Pick – WINTEMP WN27 27kW

The WINTEMP WN27 is a high-output choice among electric tankless water heaters, offering up to 6.5 GPM and WiFi temperature control. Its self-modulating system adjusts power for water flow and incoming temperature, while multiple safety protections support whole-house use.

Best For: Households with two to three bathrooms in mild to moderate climates that want remote controls and high flow capacity.

Pros:

• Up to 6.5 GPM output for showers and everyday household hot water.
• Self-modulation adjusts energy use based on flow and temperature needs.
• Remote WiFi control, LED display, and child-lock feature.
• ETL certification plus leakage, overheat, and dry-fire protection.

Cons:

• Requires substantial electrical capacity: three 40A double-pole breakers and specified wiring.
• Installation guidance recommends consulting a qualified electrician and verifying household service.
• Its stated 250A recommended power supply may limit compatibility in some homes.

The WN27 stands out for buyers prioritizing flow rate and connected controls. Its electrical requirements are significant, so verify service capacity and installation requirements before ordering.

Value-Focused Rheem Pick – Rheem RTEX-18 18kW

The Rheem RTEX-18 is a practical option for shoppers seeking electric tankless water heaters with straightforward controls and a serviceable design. Its 18kW system delivers up to 4.4 GPM, while self-modulation adjusts power to match hot water demand.

Best For: Smaller households or replacement installations that need a compact 240V whole-home unit with digital temperature control.

Pros:

• Self-modulating operation adjusts power to hot water demand.
• External digital thermostat with LED display and approximately 1-degree accuracy.
• Copper immersion heating elements are field serviceable.
• Bottom 3/4-inch NPT connections support straightforward installation or replacement.

Cons:

• Its 4.4 GPM maximum flow is lower than the higher-output models in this roundup.
• It still requires 240V electrical power and appropriate installation planning.

The RTEX-18 balances useful features with a moderate 18kW output. It is best suited to applications where 4.4 GPM is sufficient, rather than homes needing simultaneous high-volume hot water.

High-Capacity Apartment Pick – NOVIEEX 18kW Electric Tankless Water Heater

For shoppers comparing electric tankless water heaters for a small-to-medium home, condo, or apartment, the NOVIEEX 18kW model combines a compact wall-mounted design with up to 4.9 GPM of flow. Its 240V setup can support multiple fixtures, but the substantial electrical requirements should be confirmed before purchase.

Best For: Apartments, condos, garages, and small-to-medium homes with two to three simultaneous hot-water needs.

Pros:

• Up to 4.9 GPM flow for multiple fixtures
• Adjustable 77°F–140°F temperature range in 1°F increments
• 99.8% thermal efficiency with no standby heat loss
• Compact wall-mounted profile and eight-layer safety system

Cons:

• Requires two 40A double-pole breakers and two sets of 8 AWG wiring
• Its 75A maximum current may exceed the capacity of some electrical systems

The NOVIEEX is a strong high-output option when space is limited and the electrical infrastructure is ready for it. Have a qualified electrician verify compatibility and installation requirements.

Established Multi-Fixture Choice – Rheem 11kW Tankless Electric Water Heater

The Rheem 11kW is a compact option among electric tankless water heaters for households seeking on-demand hot water without a storage tank. It provides up to 2.68 GPM and uses digital controls, while installation requires a dedicated 240V circuit and an appropriately sized electrical service panel.

Best For: Smaller homes or targeted multi-fixture applications where up to 2.68 GPM is sufficient.

Pros:

• Provides up to 2.68 GPM for multiple fixtures
• Digital thermostatic controls adjust in 1°F increments from 80°F to 140°F
• Compact design is 90% smaller than traditional tank water heaters
• Requires no venting and includes a five-year leak warranty

Cons:

• Requires a 50A double-pole breaker, #8 AWG copper conductors, and a recommended 100A service panel
• Lower flow capacity than the supplied 18kW alternatives

This Rheem model makes sense when compact size, no venting, and a recognized warranty structure matter more than maximum flow. Confirm household demand and electrical capacity before installation.

Simple Control Whole-House Option – Ranein 18kW Tankless Electric Water Heater

The Ranein 18kW is one of the electric tankless water heaters suited to whole-house, on-demand use when two or three outlets may run at once. It delivers up to 4.3 GPM, offers a control knob with LED temperature display, and has a slim wall-mounted format for space-conscious installations.

Best For: Households needing continuous hot water for showers, sinks, or dishwashing across two to three simultaneous outlets.

Pros:

• 18kW output and up to 4.3 GPM flow
• Temperature adjusts from 86°F to 131°F in 1°F increments
• 99% thermal efficiency and on-demand heating help eliminate standby heat loss
• CSA certified with leakage and overheat protection

Cons:

• Requires two dedicated 240V circuits with two 40A breakers and two 8 AWG cables
• Maximum flow is lower than the NOVIEEX 18kW model

The Ranein offers a practical balance of capacity, compactness, and straightforward controls. Its electrical demands are significant, so professional verification is important before installation.

How We Picked the Best Electric Tankless Water Heaters

We evaluated these Electric Tankless Water Heaters by comparing heating capacity, voltage, stated flow rates, intended installation type, control features, and practical fit. Lower-wattage models can work well for a sink or single fixture, while 18kW to 27kW units are better suited to larger demands when the home has sufficient electrical service.

We also considered whether each heater appears designed for point-of-use or whole-house operation, along with useful details such as digital temperature displays, thermostatic control, Wi-Fi connectivity, and certification claims. Always confirm current specifications and installation requirements before purchasing.

Quick Comparison

• Point-of-use applications: Compact 4.5kW to 8kW heaters are generally suitable for a hand-washing sink, small bathroom, or other single fixture.
• Small multi-fixture use: Models around 11kW to 13kW may support limited simultaneous demand, depending on groundwater temperature and flow.
• Whole-house applications: Units rated from 18kW to 27kW provide more heating capacity, but they also require substantial electrical infrastructure.
• Convenience features: LED displays, thermostatic controls, and Wi-Fi can simplify adjustment and monitoring, but they do not replace correct sizing.

Key Buying Factors for Electric Tankless Water Heaters

Heating Capacity and Flow Rate

Wattage indicates how much heating power the unit can provide, while gallons per minute describes potential water delivery. Cold incoming water requires more energy to reach a comfortable temperature, so a heater’s maximum flow may be lower in colder climates. Estimate how many fixtures may run at once rather than relying only on the advertised maximum.

Electrical Requirements

Check voltage, amperage, breaker count, wire size, and available service-panel capacity. High-output 240V heaters may require multiple dedicated circuits and can place a heavy load on a 100A or larger service. Have a qualified electrician verify compatibility before installation.

Installation Location and Plumbing

Measure the available wall space and confirm water connections, clearances, shutoff access, and code requirements. A point-of-use model can reduce pipe runs, while a whole-house unit must be positioned and piped for the home’s distribution system.

Controls, Warranty, and Support

Digital temperature controls improve precision, and thermostatic regulation can help maintain a stable outlet temperature. Compare warranty terms, replacement-part availability, certification information, and manufacturer support—not just purchase price.

Who Should Buy Which Electric Tankless Water Heaters?

Choose a compact point-of-use model for a remote sink, guest bathroom, workshop, or other low-flow application where space is limited. Choose an 11kW to 13kW unit for modest multi-fixture demand when electrical capacity and local water conditions allow it. Choose an 18kW to 27kW model for whole-house use or multiple simultaneous fixtures, provided a professional confirms the required electrical installation. If winter groundwater is especially cold or demand is high, consider a higher-capacity system or a traditional tank hybrid rather than sizing too close to the limit.