Tankless water heaters are changing the way homes access hot water by providing on-demand, endless supplies without the need for bulky storage tanks. Ideal for homeowners looking for energy efficiency and space-saving solutions, tankless water heaters offer a reliable and sustainable way to meet your household’s hot water needs.
This guide will walk you through the best tankless water heaters for indoor use. We explain how they work, highlight the benefits, and help you choose the best model for your home.
The Advantages of Indoor Tankless Water Heaters
A tankless water heater is an excellent choice for homeowners who want to establish a constant hot water supply while minimizing energy usage and reducing their utility bills. Unlike traditional storage tank water heaters, tankless models heat water only when you need it, saving space and energy.
Key Benefits:
- Endless Hot Water: Tankless water heaters provide a continuous hot water supply. You never have to worry about running out during peak times like showers or dishwashing.
- Energy Efficiency: These units only heat water when needed. They reduce standby heat loss and offer up to 34% better efficiency than conventional tank systems.
- Compact Size: Tankless water heaters are significantly smaller than traditional units. These free up valuable space in your home.
- Longer Lifespan: With proper maintenance, tankless water heaters can last over 20 years as compared to 10-15 years for traditional models.
Now that we’ve discussed the key benefits of tankless water heaters, let’s explore the top-rated models for indoor use.
Best Overall: Stiebel Eltron Electric Tankless Water Heater
The Stiebel Eltron Electric Tankless Water Heater ranks as our best overall choice for indoor use. Known for its impressive efficiency and reliability, this unit can provide up to 5 gallons per minute (GPM) with a heat capacity of 24 kW. It delivers consistent and on-demand hot water throughout your home.
Key Features:
- Flow Rate: 5 GPM
- Heat Capacity: 24 kW
- Energy-Efficient: Uses advanced self-modulating technology to adjust power usage based on demand.
- Warranty: 7 years for leaks and 3 years for parts.
- Compact Design: Fits easily into tight spaces, making it versatile for various home layouts.
Customer Review:
"The Stiebel Eltron Electric Tankless Water Heater has exceeded my expectations. Hot water is delivered quickly, and the compact size makes it a perfect fit in my utility room."
Why It’s Best:
This model's combination of strong performance, energy savings, and a reliable warranty makes it a great all-around choice for homeowners seeking reliable, instant hot water. The self-modulating technology further enhances its efficiency by adjusting power output based on real-time demand.
Best Whole-House: Rinnai Indoor Gas Tankless Hot Water Heater
For medium to large homes with higher hot water demands, the Rinnai Indoor Gas Tankless Hot Water Heater is an exceptional option. With a flow rate of 7.5 GPM and a heat capacity of 120,000 BTU, this gas-powered heater guarantees a steady supply of hot water even during peak usage times.
Key Features:
- Flow Rate: 5 GPM
- Heat Capacity: 120,000 BTU
- Energy Efficiency: Only heats water when needed. This reduces utility costs.
- No Venting Required: Easy installation without the need for complex ventilation.
- Compact Design: Fits into small spaces, saving room in your home.
Customer Review:
"This unit has been a game-changer for our family of five. We can run multiple appliances and still get hot showers without running out of hot water."
Why It’s Best for Whole-House:
With its large flow rate and powerful heating capacity, the Rinnai indoor gas model serves the entire home without compromising performance. Its energy-efficient design also means you can save on utility costs while enjoying endless hot water.
Best Propane-Powered: Rinnai Outdoor Gas Tankless Hot Water Heater
If you prefer propane as a fuel source or don’t have enough space for indoor installation, the Rinnai Outdoor Gas Tankless Hot Water Heater is an excellent choice. It boasts a flow rate of 5.3 GPM and a heat capacity of 180,000 BTU. It provides reliable hot water for homes with outdoor water heater setups.
Key Features:
- Flow Rate:3 GPM
- Heat Capacity: 180,000 BTU
- Outdoor Installation: Eliminates the need for venting and saves space indoors.
- Durable Construction: Built to withstand outdoor elements.
- Efficient Performance: Delivers consistent hot water while minimizing energy use.
Customer Review:
"The Rinnai Outdoor Gas Tankless Hot Water Heater has been a fantastic addition to our home. It was easy to install outside, and we now have endless hot water for all our needs."
Why It’s Best for Outdoor Use:
This propane-powered model is perfect for homes that prefer outdoor installation, with its high efficiency and ability to provide hot water to multiple fixtures. It eliminates indoor space constraints and removes the need for complicated venting.
Most Efficient: EcoSmart ECO 18 Electric Tankless Water Heater
For those focused on energy savings, the EcoSmart ECO 18 Electric Tankless Water Heater is a standout option. Offering up to 5 GPM with a heat capacity of 18 kW, this electric unit is designed to maximize energy efficiency without sacrificing performance.
Key Features:
- Flow Rate: 5 GPM
- Heat Capacity: 18 kW
- Energy-Efficient: Self-modulating technology adjusts power based on water flow and temperature.
- Compact Size: Ideal for homes with limited space.
- Warranty: Lifetime warranty for residential use.
Customer Review:
"The EcoSmart ECO 18 has significantly lowered our energy bills while providing endless hot water. The self-modulating feature is a big plus for energy efficiency."
Why It’s the Most Efficient:
The EcoSmart ECO 18’s advanced self-modulating technology allows it to adapt its energy use based on water demand. This helps reduce utility bills while delivering consistent hot water. The lifetime warranty is another reason homeowners choose this model for long-term value.
Best for Small Households: EcoSmart ECO 11 Electric Tankless Water Heater
If you have a smaller household or limited hot water needs, the EcoSmart ECO 11 Electric Tankless Water Heater is the perfect fit. Its compact design and efficient performance make it ideal for apartments or single bathrooms.
Key Features:
- Flow Rate: 2 GPM
- Heat Capacity: 13 kW
- Energy-Efficient: Self-modulating technology for minimal energy usage.
- Compact Design: Saves space, perfect for smaller installations.
- Warranty: Lifetime warranty for residential use.
Customer Review:
"The EcoSmart ECO 11 is a fantastic unit for our small home. It delivers hot water instantly without using too much energy, and it fits perfectly in our small utility closet."
Why It’s Best for Small Households:
With a 2 GPM flow rate and its self-modulating technology, this unit provides sufficient hot water for smaller homes while maintaining energy efficiency. It’s perfect for apartments, tiny houses, or homes with minimal hot water demands.
Best Value: Rheem Tankless Electric Water Heater
For budget-conscious homeowners, the Rheem Tankless Electric Water Heater offers excellent value. Although it has a lower flow rate than some other models, it’s still a reliable option for point-of-use applications like sinks or small appliances.
Key Features:
- Flow Rate:95 GPM
- Heat Capacity: 8 kW
- No Venting Required: Easy installation with no venting needed.
- Point-of-Use Installation: Ideal for under-sink setups.
- Compact Size: Saves space for smaller installations.
Customer Review:
"This Rheem water heater is perfect for under the sink in our bathroom. It provides instant hot water without taking up much space."
Why It’s the Best Value:
The Rheem Tankless Electric Water Heater is an affordable option that still delivers reliable hot water for smaller tasks. It’s best suited for point-of-use installations like bathrooms or kitchens, where you don’t need a whole-house system.
Important Factors When Choosing a Tankless Water Heater
Before purchasing a tankless water heater, there are several key considerations to keep in mind to make sure you choose the right model for your home:
- Power Source:
- Electric: Easy to install and maintain, but may require an electrical upgrade for larger households.
- Gas: Higher efficiency and faster water heating, but requires ventilation and can be more expensive to install.
- Flow Rate:
Consider your household’s water demand. Larger homes with multiple appliances running simultaneously will need a higher GPM (gallons per minute) rate for a consistent hot water supply.
- Condensing vs. Non-Condensing:
- Condensing Units: More energy-efficient as they extract heat from exhaust gases to further heat water. Typically more expensive but offer long-term savings.
- Non-Condensing Units: More affordable upfront but less efficient, as they vent exhaust gases directly.
- Size and Space:
Tankless water heaters are available in various sizes. Smaller models are great for under-the-sink or point-of-use applications. Whereas, larger units can supply hot water to an entire home.
- Installation Costs:
While tankless water heaters can save you money in the long run, they often come with higher upfront costs due to installation requirements. Professional installation is recommended for both electric and gas units to guarantee safety and efficiency.
- Maintenance:
Tankless water heaters require regular maintenance for optimal performance. Flushing the system and descaling are necessary to prevent mineral build-up, especially if you live in an area with hard water.
Installation Tips for Tankless Water Heaters
When installing a tankless water heater, it’s essential to follow proper procedures to ensure the unit functions correctly and safely:
- Hire a Professional: While DIY installation may seem appealing, hiring a professional ensures the installation complies with local codes and regulations. This is especially important for gas-powered units requiring proper ventilation.
- Proper Sizing: Make sure the unit is the correct size for your household’s hot water demands. A professional can help determine the right GPM and heating capacity needed.
- Regular Maintenance: Plan for annual maintenance to keep your unit in top shape. This may include flushing the system, inspecting for leaks, and checking the performance of any self-modulating features.
Choosing the right tankless indoor water heater can transform your home’s hot water supply by providing efficient, on-demand heating that never runs out. Whether you’re looking for the best overall option like the Stiebel Eltron Electric Tankless Water Heater or seeking a whole-house solution like the Rinnai Indoor Gas Tankless Hot Water Heater, there’s a model to meet every need and budget.
Before making a purchase, carefully consider your household’s hot water demands, the type of fuel available, and any additional installation requirements. Consulting with a professional installer can also help guarantee that your new system is correctly installed for optimal performance and long-term savings.
For reliable installation and professional advice, reach out to Water Heaters Now. We are your trusted partner for all your tankless water heater needs. Enjoy endless hot water, reduced energy bills, and the convenience of modern water heating technology.
