Choosing the best electric tankless water heater depends on your home’s size, hot water needs, and energy efficiency goals. After years of installing and troubleshooting various units, I’ve narrowed down the top contenders for electric tankless water heaters. These units offer quick hot water, are energy efficient, and can save space. Here’s a deep dive into the best electric tankless water heaters in 2024:
1. Stiebel Eltron Tempra 29 Plus – Best Overall Electric Tankless Water Heater
The Stiebel Eltron Tempra 29 Plus stands out for its advanced technology, energy efficiency, and consistent hot water flow. I’ve installed this unit in several homes, and its performance is impressive, especially in larger homes with high hot water demand. It’s equipped with Advanced Flow Control, a feature that automatically adjusts the water flow to ensure a steady temperature, even when multiple fixtures are running.
Key Features:
- Flow Rate: Up to 7.5 GPM (depending on inlet water temperature)
- Power: 28.8 kW at 240V
- Temperature Range: 68°F – 140°F
- Best For: Homes with 2-3 bathrooms or high hot water demand
- Efficiency: 99% energy efficiency
- Advanced Flow Control: Automatically regulates water flow to maintain a constant temperature
- Digital temperature control for precision
Pros:
- Excellent for large households with multiple hot water outlets
- High efficiency with very little energy loss
- Quiet operation
- Long-lasting with minimal maintenance
- Compact design, easy to install
Cons:
- Requires 3 x 40 amp breakers, so may need electrical upgrades
- Higher upfront cost compared to smaller units
2. EcoSmart ECO 27 – Best for Budget-Conscious Buyers
The EcoSmart ECO 27 is a great choice for anyone looking to save on both initial cost and long-term energy bills. This unit offers self-modulating technology, meaning it only uses the amount of energy needed to heat the water you’re using. I’ve seen this unit perform well in mid-sized homes or larger homes where simultaneous hot water usage isn’t constant.
Key Features:
- Flow Rate: Up to 6.5 GPM
- Power: 27 kW at 240V
- Temperature Range: 80°F – 140°F
- Best For: Mid-sized homes (2-3 bathrooms) in warmer climates
- Efficiency: 99.8%
- Self-modulating technology for energy savings
Pros:
- Affordable upfront cost
- Compact and lightweight design
- High energy efficiency with adjustable power usage
- Digital temperature control for precise water temperature
- Lifetime warranty on the heating elements
Cons:
- Performance drops in colder climates with lower inlet water temperatures
- May struggle with very large homes or high simultaneous usage
3. Rheem RTEX-18 – Best for Smaller Homes or Apartments
For smaller homes, apartments, or point-of-use installations, the Rheem RTEX-18 is a top performer. I installed this unit in a guesthouse, and it provided consistent hot water for showers and a kitchen sink without any issues. It’s a compact, easy-to-install unit, ideal for spaces with limited hot water demand.
Key Features:
- Flow Rate: Up to 4.4 GPM
- Power: 18 kW at 240V
- Temperature Range: Adjustable from 80°F to 140°F
- Best For: Apartments, small homes, or point-of-use applications
- Efficiency: 99.8%
- External adjustable digital thermostatic control with LED display
Pros:
- Great for smaller households or individual fixtures
- Instant, consistent hot water at a lower price point
- Easy installation and maintenance
- Compact size saves space
- Highly energy-efficient
Cons:
- Not suitable for large homes or high water demand
- Performance drops in colder climates with low inlet water temperatures
4. Bosch Tronic 3000 – Best for Point-of-Use
The Bosch Tronic 3000 is a fantastic choice for those needing an on-demand point-of-use water heater. I’ve installed this unit under kitchen sinks and in bathroom vanities, where it delivers hot water instantly. It’s compact, affordable, and perfect for single fixture installations in places like an office, garage, or small vacation home.
Key Features:
- Flow Rate: 0.5 to 2.5 GPM (depending on model size)
- Power: 7.2 to 12 kW (depending on the model)
- Best For: Point-of-use (sinks, small appliances, etc.)
- Efficiency: 98%
- Compact and easy to install directly under sinks
Pros:
- Perfect for point-of-use applications like under sinks
- Provides instant hot water for individual fixtures
- Small, lightweight, and easy to install
- Affordable, ideal for budget-conscious buyers
- Minimal maintenance
Cons:
- Not suitable for whole-house installations
- Limited flow rate means only one fixture can be used at a time
5. Titan SCR2 N-120 – Best for Warm Climates
The Titan SCR2 N-120 performs exceptionally well in warmer climates where inlet water temperatures are higher. I’ve recommended this unit to homeowners in Florida and Texas, where the water doesn’t need as much heating. It’s compact, affordable, and offers impressive efficiency for smaller homes or condos.
Key Features:
- Flow Rate: 4 GPM
- Power: 11.8 kW at 220V
- Best For: Small homes or condos in warmer climates
- Efficiency: 99.5%
- Space-saving design that fits in tight places
Pros:
- Ideal for warm climates where water temperatures are naturally higher
- Compact, wall-mounted design
- Quick and consistent hot water
- Affordable and easy to install
Cons:
- Lower flow rate compared to other models, so not suited for larger homes
- Not ideal for colder climates
Comparison of the Best Electric Tankless Water Heaters
| Model | Best For | Flow Rate (GPM) | Power (kW) | Efficiency | Key Features |
|---|---|---|---|---|---|
| Stiebel Eltron Tempra 29 Plus | Large homes or high demand | Up to 7.5 GPM | 28.8 kW | 99% | Advanced Flow Control, digital control |
| EcoSmart ECO 27 | Budget-friendly option | Up to 6.5 GPM | 27 kW | 99.8% | Self-modulating tech, lifetime warranty |
| Rheem RTEX-18 | Small homes or apartments | Up to 4.4 GPM | 18 kW | 99.8% | External thermostatic control, easy installation |
| Bosch Tronic 3000 | Point-of-use (sinks, etc.) | 0.5 to 2.5 GPM | 7.2 to 12 kW | 98% | Compact design, ideal for under-sink installs |
| Titan SCR2 N-120 | Small homes in warm climates | 4 GPM | 11.8 kW | 99.5% | Affordable, compact, good for warm climates |
What to Look for When Choosing an Electric Tankless Water Heater
- Flow Rate (GPM): The flow rate determines how many fixtures (e.g., showers, sinks) the unit can supply with hot water at once. Larger homes need higher GPM (around 7+), while smaller homes or point-of-use installations can get by with 2-4 GPM.
- Power (kW): More powerful units (27-30 kW) heat water faster and are better for colder climates. Lower-powered models (7-18 kW) are suitable for smaller homes or warmer regions where incoming water temperatures are higher.
- Efficiency: Look for models with 99% or higher efficiency to maximize energy savings and lower your utility bills.
- Climate Considerations: If you live in a colder climate, you’ll need a more powerful unit to compensate for lower incoming water temperatures. Warmer climates can get by with lower-powered models.
- Installation Requirements: Some units may require significant electrical upgrades, such as additional breakers or higher amperage. Ensure your home’s electrical system can support the unit you choose.
Final Recommendation
For large households with high water demand, the Stiebel Eltron Tempra 29 Plus is unbeatable in terms of performance, efficiency, and reliability. For budget-conscious buyers, the EcoSmart ECO 27 offers excellent value and high efficiency without breaking the bank. For smaller homes or point-of-use needs, the Rheem RTEX-18 or Bosch Tronic 3000 are excellent choices.
By understanding your home’s water usage and climate, you can choose the best electric tankless water heater to meet your needs, ensuring years of reliable hot water with maximum energy savings!