Choosing the right electric tankless water heater can dramatically improve your home’s hot-water reliability while conserving energy. This guide highlights five top options, comparing flow rates, efficiency, installation needs, and notable features to help American homeowners pick a model that fits their demand, from single-family showers to multi-point use. Each product section provides concise specs and real-world considerations to support an informed purchase.
| Product | Brand | Max GPM | Voltage/Power | Why It Stands Out |
|---|---|---|---|---|
| EcoSmart ECO 11 | EcoSmart | Up to 1.3–3.0 | 13 kW, 240V | Self-modulating tech; compact; space-saving |
| Rheem RTEX-24 | Rheem | Up to ~4.0 | 24 kW, 240V | Reliable performance for whole-home usage |
| Rheem 18kW 240V | Rheem | Up to 4.4 | 18 kW, 240V | Advanced self-modulation; durable elements |
| ORBEK 14kW | Orbek | Up to 3.38 | 14 kW, 240V | LED display; cost-conscious, efficient |
| WINTEMP 27kW | WINTEMP | Up to 6.3–6.5 | 27 kW, 240V | WiFi control; high capacity for larger homes |
EcoSmart ECO 11 Electric Tankless Water Heater
The EcoSmart ECO 11 provides on-demand hot water with self-modulating technology that adjusts power based on flow and temperature. It is designed for efficiency and space-saving installation, offering continuous hot water with performance within one degree of the selected temperature. This unit draws 54 A and is marketed as 90% smaller than traditional tank heaters, suitable for wall mounting or point-of-use installation.
Rheem RTEX-24 24kW Electric Tankless Water Heater
Rheem RTEX-24 is a high-capacity tankless model designed for whole-home use. It requires three 40-amp double-pole breakers and recommends a sturdy 200-amp service. The unit features an on/off dial with a digital temperature display and 1-degree adjustment increments to fine-tune hot water output, helping maintain comfort and efficiency across multiple fixtures.
Rheem 18kW 240V Tankless Electric Water Heater
This Rheem model features external digital thermostatic control with LED display for precise 1-degree adjustments. It employs advanced self-modulation to meet hot-water demand, uses durable copper immersion heating elements, and is field-serviceable. It delivers up to 4.4 GPM, making it suitable for mid-sized homes or multiple fixtures in moderate cold-water conditions.
ORBEK 14kW Tankless Electric Water Heater
Orbek’s 14kW model requires a 240V/60A two-pole breaker and 6 AWG wiring. It can supply up to 3.38 GPM for two to three points of use concurrently. The unit emphasizes energy efficiency through water-electricity separation to reduce scale and corrosion, offering fast hot water delivery with potential electricity savings compared to tank heaters.
WINTEMP 27kW Electric Tankless Water Heater
The WINTEMP 27kW model delivers up to 6.3 GPM (or as high as 6.5 GPM depending on temperature). It requires three 40-amp double-pole breakers and three 8/2 AWG wiring with grounding, with a recommended 250A service. It supports WiFi control and includes an LED temperature display, offering robust performance for larger homes with multiple simultaneous hot-water needs.
Buying Guide: Key Considerations for Electric Tankless Heaters
- Household hot-water demand: Determine the maximum GPM you need during peak usage. Larger homes or busy families typically require higher-capacity units like 18–27 kW models.
- Electrical service and wiring: Most high-capacity units demand dedicated circuits (often multiple double-pole breakers) and appropriately sized gauge wires. Verify that your electrical panel can support the load or plan an upgrade.
- Installation location: Tankless heaters are compact but require proper ventilation-free setup and space for water connections. Consider wall mounting versus under-sink or point-of-use installations.
- Temperature control: Look for digital displays and precise 1-degree adjustments to maintain comfortable output and reduce energy waste. Self-modulating technology can further boost efficiency.
- Energy efficiency and maintenance: Self-regulating systems minimize standby energy and scale buildup. Field-serviceable elements can lower maintenance costs over time.
- Water chemistry: Hard water may increase mineral buildup. In some cases, water softening or occasional descaling is advisable to prolong unit life.
- Cost of ownership: While higher-kW units can supply more GPM, they also consume more electricity. Compare expected monthly energy use based on your local rates and water temperature.”
- Warranty and support: Review manufacturer warranties and the availability of service technicians in your region to ensure long-term reliability.
Selecting the best electric tankless heater involves balancing hot-water needs with electrical capabilities, installation constraints, and long-term efficiency goals. The models highlighted here offer a range of capacities and features to accommodate different homes and usage patterns while prioritizing reliability and energy savings.