Quick Overview: This guide reviews top electric tankless water heaters for home use, highlighting capacity, flow rate, and installation needs. The table below summarizes key specs of the selected models to help you compare at a glance.
| Model | Brand | Power / Flow Rate | Best For |
|---|---|---|---|
| Rheem 18kW 240V Tankless Electric Water Heater | Rheem | 18 kW / Up To 4.4 GPM | Whole-house light to medium demand |
| Rheem RTEX-24 24kW 240V Tankless Electric Water Heater | Rheem | 24 kW / Up To 5.9 GPM | Higher-flow whole-house applications |
| EcoSmart ECO 11 13kW Tankless Electric | EcoSmart | 13 kW / Point-of-use or small multi-point | Space-saving, energy-efficient point-of-use |
| Stiebel Eltron Tempra 24 Plus | Stiebel Eltron | 24 kW / Continuous Flow, whole-house capable | Advanced flow control and consistent temp |
| ORBEK 14kW Tankless Water Heater | Orbek | 14 kW / Up To 3.38 GPM | 2–3 points of use, ETL certified |
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Rheem 18kW 240V Tankless Electric Water Heater
This Rheem model features an external digital thermostatic control with LED display offering +/-1 degree accuracy. The unit uses self-modulation to adjust power based on hot water demand, improving energy efficiency during variable use.
The heater includes durable copper immersion heating elements that are field serviceable and a rated flow rate of up to 4.4 GPM. This makes it suitable for light whole-house applications where simultaneous fixtures are limited.
Installation requires a 240V electrical supply and appropriate breaker sizing. The combination of precise temperature control and serviceable elements targets homeowners seeking reliable, maintainable performance without venting requirements.
Rheem RTEX-24 24kW 240V Electric Tankless
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The RTEX-24 offers a higher heat output at 24 kW and a flow rate up to 5.9 GPM, suitable for larger homes or multiple simultaneous hot water demands. It includes an ON/OFF dial control with adjustable digital temperature display for straightforward operation.
Like other Rheem units, it features self-modulating power control to adjust energy usage based on demand. This model is designed for whole-house applications where higher flow and consistent temperature are required without tank storage.
Electrical capacity and breaker sizing must match the unit’s specifications. The emphasis on modulation and a clear digital interface aims to balance performance and efficiency for higher-demand households.
EcoSmart ECO 11 Electric Tankless Water Heater
The EcoSmart ECO 11 is a compact, wall-mount unit delivering 13 kW at 240V. It emphasizes space savings and energy efficiency, claiming near-instant hot water with continuous on-demand supply for point-of-use installations.
Its patented self-modulating technology continuously monitors water temperature and controls flow rates to maintain selected temperature within one degree. The unit’s small physical size makes it a candidate for under-sink or single-bath installations.
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Electrical requirements include substantial amperage draw; installation must follow local electrical codes. For homes seeking a compact solution to eliminate a tank or serve a single fixture reliably, this model focuses on efficiency and minimal footprint.
Stiebel Eltron Tempra 24 Plus
The Tempra 24 Plus uses Advanced Flow Control to maintain consistent outlet temperatures by slightly reducing flow when demand exceeds capacity. This patented technology aims to prevent temperature fluctuations during showers or multi-fixture use.
Its interior solid copper heating system and auto-modulation reduce energy waste. The unit includes a digital temperature display, preset temperature memory, and a savings monitor to track energy use.
Stiebel Eltron positions this model for whole-house use where temperature stability is a priority. The unit’s design avoids venting and emphasizes quiet operation and electronic flow control to manage simultaneous demands.
ORBEK 14kW Tankless Electric Water Heater
The ORBEK 14kW delivers up to 3.38 GPM and targets 2–3 points of use. It emphasizes fast warm-up time, ETL certification, and a design that claims to minimize scale and corrosion through water-electricity separation.
Installation notes indicate a 240V/60A two-pole breaker and 6 AWG wiring, so electrical planning is essential. The unit’s LED digital display and compact footprint make it suitable for apartments or homes seeking a mid-range point-of-use or small multi-point solution.
ORBEK highlights potential energy savings versus tanks and quick response, intended for users prioritizing rapid hot water delivery for a few fixtures simultaneously.
Buying Guide For Electric Tankless Water Heaters
This buying guide covers essential considerations to match a tankless electric water heater to your home’s needs. Use the sections below to compare capacity, installation complexity, efficiency, and maintenance requirements.
Capacity And Flow Rate
Flow rate (GPM) and temperature rise determine whether a unit can supply simultaneous fixtures. Higher kW models (e.g., 24 kW) deliver greater GPM and higher temperature rise for whole-house use. Lower kW units (8–14 kW) are best for point-of-use or limited multi-point setups.
Estimate peak simultaneous demand by adding fixture flow rates: a shower (~1.5–2.5 GPM), sink (~0.5–1.5 GPM). Match the heater’s rated flow at your required temperature rise, considering local incoming water temperature.
Electrical Requirements
Power supply is a primary constraint. Tankless electric units typically require 240V and dedicated circuit breakers sized to the unit’s amperage. Larger units (18–24 kW) may require multiple 40–60A breakers and heavier gauge wiring. Verify panel capacity before purchase.
Consult an electrician for panel upgrades, breaker configuration, and wire sizing to ensure safe installation and compliance with codes.
Installation And Space
Electric tankless heaters are wall-mounted and compact compared with tanks, saving floor space. Some models are designed for point-of-use and can be mounted under sinks. Consider access for maintenance and local codes when selecting a location.
Ventilation is typically unnecessary for electric models, simplifying placement relative to gas units. Still, allow clearance per manufacturer instructions.
Temperature Control And Consistency
Look for digital thermostats, flow control, or self-modulation features. These help maintain steady outlet temperatures during variable flow conditions. Models with patented flow control can reduce temperature swings when multiple fixtures are used.
Units that display exact setpoints and have memory/preset options offer more precise user control and easier troubleshooting.
Energy Efficiency And Operating Costs
Electric tankless heaters eliminate standby losses associated with storage tanks and use modulation to match power to demand. Efficiency depends on usage patterns—frequent short draws benefit most from on-demand systems.
Consider local electric rates and potential savings versus replacing older tank models. Energy-monitoring features help track relative savings over time.
Durability, Maintenance, And Water Quality
Heating element materials (copper, stainless steel) and the unit’s approach to scale management affect longevity. Hard water areas increase scaling risk, so models with accessible elements or descaling recommendations are favorable.
Plan periodic maintenance per manufacturer guidance, including flushing to reduce mineral buildup and inspecting electrical connections. Field-serviceable elements can reduce repair costs.
Safety Features And Certifications
Check for ETL/UL certification and built-in protections like overheat or dry-fire prevention. Certifications verify independent safety testing and compliance with electrical standards.
Comparing Models: Use Case Perspectives
- Single Bathroom / Point-of-Use: Compact 8–14 kW units with quick response are typically adequate.
- Whole-House With Multiple Fixtures: 18–24 kW models or multiple units in parallel provide higher GPM and temperature stability.
- Homes With Hard Water: Prefer units with accessible heating elements and clear descaling procedures.
- Limited Electrical Capacity: Choose lower kW point-of-use models or consult an electrician about panel upgrades if you need higher output.
Warranty And Support
Review manufacturer warranties for parts and labor coverage. Consider the availability of local service and replacement parts. Units with field-serviceable elements and clear support channels can reduce downtime and repair complexity.
Tips for Getting the Best HVAC Prices
- Prioritize Quality Over Cost
The most critical factor in any HVAC project is the quality of the installation. Don’t compromise on contractor expertise just to save money. - Check for Rebates
Always research current rebates and incentives — they can significantly reduce your overall cost. - Compare Multiple Quotes
Request at least three estimates before making your choice. You can click here to get three free quotes from local professionals. These quotes include available rebates and tax credits and automatically exclude unqualified contractors. - Negotiate Smartly
Once you've chosen a contractor, use the proven strategies from our guide — How Homeowners Can Negotiate with HVAC Dealers — to get the best possible final price.
Final Selection Checklist
- Calculate required GPM based on peak simultaneous fixtures and desired temperature rise.
- Verify your electrical panel can support the unit’s amperage and breaker configuration.
- Assess installation location for access, clearance, and proximity to hot water fixtures.
- Check certification (ETL/UL) and manufacturer maintenance recommendations for water quality.
- Confirm warranty terms and service availability in your area.