When it comes to choosing the best outdoor electric tankless water heater, the main considerations include durability to withstand the elements, energy efficiency, and the ability to deliver consistent hot water even in varying climates. While electric models are generally more suited for indoor use, there are some outdoor electric units built specifically for durability and performance in exposed environments.
Here are the top outdoor electric tankless water heaters available in 2024:
1. Stiebel Eltron Tempra 24 Plus – Best for Efficiency and Performance
While typically installed indoors, the Stiebel Eltron Tempra 24 Plus can also be used in outdoor installations when housed in a weatherproof enclosure. This unit is highly efficient and perfect for homes that need a steady supply of hot water. Its Advanced Flow Control feature automatically adjusts the water flow to maintain the desired temperature, which makes it excellent for outdoor use where water temperature can fluctuate.
Key Features:
- Flow Rate: 4.5 to 5.5 GPM (depending on inlet water temperature)
- Power: 24 kW at 240V
- Best For: Medium to large homes in mild climates
- Efficiency: 99% energy efficiency
- Advanced Flow Control: Ensures consistent temperature even with multiple fixtures
- Digital temperature control for precise adjustments
- Weatherproof Enclosure Option: Can be installed outdoors with the proper enclosure
Pros:
- Excellent energy efficiency and temperature consistency
- Ideal for outdoor use in a weatherproof box
- Handles multiple showers or faucets simultaneously
- Easy-to-use digital controls
Cons:
- Requires a weatherproof enclosure to be safely installed outdoors
- May require electrical upgrades depending on your home
2. EcoSmart ECO 18 – Best for Small Homes and Point-of-Use
The EcoSmart ECO 18 is a budget-friendly, compact option for outdoor use when protected by a weatherproof enclosure. It’s best suited for smaller homes, cabins, or point-of-use installations like outdoor kitchens or pool showers. With its self-modulating technology, it only uses the necessary amount of energy, making it highly efficient.
Key Features:
- Flow Rate: 3.5 GPM
- Power: 18 kW at 240V
- Best For: Small homes, outdoor kitchens, pool showers
- Efficiency: 99.8% energy efficiency
- Self-Modulating Technology: Adjusts energy usage based on water flow
- Weatherproof Enclosure Required for outdoor use
Pros:
- Compact and lightweight, easy to install
- Very energy-efficient with minimal energy waste
- Ideal for outdoor kitchens or small homes
- Affordable and great for budget-conscious buyers
Cons:
- Lower flow rate compared to larger units
- Requires a weatherproof enclosure for outdoor installation
- May struggle in colder climates with low inlet water temperatures
3. Rheem RTEX-24 – Best for Larger Outdoor Applications
The Rheem RTEX-24 is a powerful, high-performing electric tankless water heater that can handle multiple fixtures simultaneously. Like others, it must be installed in a weatherproof enclosure to be used outdoors, but it’s built for homes with moderate to high water demand. With a flow rate of up to 5.9 GPM, this model can handle showers, sinks, and outdoor faucets running at the same time, making it perfect for outdoor applications where you need consistent hot water.
Key Features:
- Flow Rate: 5.9 GPM
- Power: 24 kW at 240V
- Best For: Medium to large homes, outdoor showers, and pool areas
- Efficiency: 99.8% energy efficiency
- External Digital Thermostatic Control with an LED display
- Weatherproof Enclosure Needed for outdoor use
Pros:
- Great flow rate for large homes or outdoor applications
- Efficient and reliable with easy temperature control
- Can handle multiple fixtures simultaneously
- Compact and easy to install
Cons:
- Requires a weatherproof enclosure for outdoor installation
- Installation may require a professional due to electrical requirements
4. Bosch Tronic 3000 US12 – Best for Point-of-Use Applications
The Bosch Tronic 3000 is a small, point-of-use tankless water heater perfect for specific outdoor installations such as poolside showers, outdoor kitchens, or workshops. It’s designed for single-use applications and can be installed in small spaces. With proper housing, it can be used outdoors, providing hot water quickly for individual tasks.
Key Features:
- Flow Rate: 1.5 to 2.5 GPM (depending on model)
- Power: 12 kW at 240V
- Best For: Outdoor kitchens, pool showers, point-of-use
- Efficiency: 98%
- Compact and easy to install under sinks or in tight spaces
- Weatherproof housing required for outdoor installation
Pros:
- Ideal for point-of-use hot water
- Compact and affordable
- Simple installation for outdoor kitchens or showers
- Reliable for small-scale use
Cons:
- Low flow rate, suitable for one fixture at a time
- Needs a weatherproof enclosure for outdoor use
- Not designed for whole-house applications
5. Kelvinator Outdoor Electric Tankless Water Heater – Built for the Outdoors
The Kelvinator Outdoor Electric Tankless Water Heater is a model designed specifically for outdoor use, meaning it doesn’t require an additional weatherproof enclosure. It’s built to withstand the elements and is ideal for outdoor kitchens, poolside showers, and guesthouses. While not as powerful as indoor electric models, it’s one of the few options built specifically for outdoor environments.
Key Features:
- Flow Rate: 3.5 GPM
- Power: 18 kW at 240V
- Best For: Outdoor kitchens, guesthouses, poolside showers
- Efficiency: 98%
- Durable Outdoor Design: No need for additional enclosures
- Corrosion-resistant exterior
Pros:
- Specifically built for outdoor use, no extra enclosure needed
- Great for outdoor applications like kitchens or showers
- Durable and weather-resistant exterior
- Simple and straightforward installation
Cons:
- Lower flow rate, so not suitable for large homes
- Less powerful compared to some indoor models
Comparison Table: Best Outdoor Electric Tankless Water Heaters
| Model | Best For | Flow Rate (GPM) | Power (kW) | Weatherproof | Key Features |
|---|---|---|---|---|---|
| Stiebel Eltron Tempra 24 Plus | Large homes, multiple fixtures | 4.5-5.5 GPM | 24 kW | Requires enclosure | Advanced Flow Control, energy-efficient, digital control |
| EcoSmart ECO 18 | Small homes, outdoor kitchens | 3.5 GPM | 18 kW | Requires enclosure | Affordable, self-modulating, compact design |
| Rheem RTEX-24 | Larger homes, outdoor applications | 5.9 GPM | 24 kW | Requires enclosure | Digital control, great for multiple fixtures |
| Bosch Tronic 3000 US12 | Point-of-use, poolside showers | 1.5-2.5 GPM | 12 kW | Requires enclosure | Compact, ideal for small outdoor tasks |
| Kelvinator Outdoor Electric | Outdoor use (no enclosure needed) | 3.5 GPM | 18 kW | Built-in | Specifically built for outdoor, durable and weather-resistant |
Key Considerations for Choosing an Outdoor Electric Tankless Water Heater
- Weatherproofing:
- Most electric tankless water heaters are designed for indoor use, so if you plan to install one outdoors, make sure it’s housed in a weatherproof enclosure unless the unit is specifically designed for outdoor use like the Kelvinator model.
- Flow Rate (GPM):
- Consider how many fixtures you plan to run simultaneously. A higher flow rate (4-6 GPM) is ideal for homes with multiple showers or outdoor setups that need more than one fixture running at once. For single-use applications, like a poolside shower or outdoor kitchen, a lower GPM (1.5-3.5) will suffice.
- Durability:
- Outdoor installations are subject to the elements. Make sure the unit or the weatherproof enclosure is durable and corrosion-resistant to handle rain, snow, and temperature fluctuations.
- Electrical Requirements:
- Larger units like the Stiebel Eltron Tempra 24 Plus or Rheem RTEX-24 may require electrical upgrades (e.g., 240V circuits, multiple breakers) depending on your home’s existing wiring.
- Installation and Maintenance:
- Outdoor installations should be easy to access for maintenance and repairs. Always consider location and ease of access when choosing a unit.
Final Recommendation
- For a larger outdoor setup or homes with multiple fixtures, the Stiebel Eltron Tempra 24 Plus or Rheem RTEX-24 are both high-performing, efficient options, though they require a weatherproof enclosure.
- For smaller outdoor installations like poolside showers or outdoor kitchens, the EcoSmart ECO 18 and Bosch Tronic 3000 are great affordable choices.
- If you want an outdoor unit without the hassle of an enclosure, the Kelvinator Outdoor Electric Tankless Water Heater is specifically built for the elements and performs well for mid-sized outdoor applications.
By choosing the right model, you can ensure reliable hot water in your outdoor spaces for years to come.