In a townhouse, space is valuable, hot water demand can be high, and energy efficiency matters. Whether you live alone or have a full household, a tankless water heater can give you an endless supply of hot water while freeing up storage space. Unlike traditional tank heaters that store and reheat water, a tankless model heats water on demand — saving energy and ensuring you never run out mid-shower.
In this guide, you will find the best tankless water heaters for townhouses in 2025, followed by a detailed buying guide with installation tips, sizing advice, and maintenance recommendations.
Top Tankless Water Heater Picks for Townhouses
1. Rinnai RU199iN Super High Efficiency Plus
The Rinnai RU199iN is a powerful natural gas unit with an impressive 11 GPM flow rate, enough for multiple bathrooms running at once. It is designed for indoor installation with direct venting, making it ideal for larger townhouses with high water demand.
- Best for: Large townhouses with 3+ bathrooms
- Pros: Very high flow rate, durable build, energy-efficient
- Cons: Higher price and requires professional installation
2. EcoSmart ECO 27 Electric Tankless Water Heater
This electric unit is perfect for townhouses without natural gas service. It offers up to 6.5 GPM in warm climates and is compact enough to fit in a utility closet. Digital temperature control allows one-degree adjustments, making it easy to get your perfect shower temperature.
- Best for: Electric-only townhouses
- Pros: Space-saving, precise temperature control, easy maintenance
- Cons: Requires a high-amperage electrical panel
3. Stiebel Eltron Tempra Plus 29
The Stiebel Eltron Tempra Plus 29 is a quiet electric model designed for households that want consistent water temperature without sudden changes. It uses advanced flow control to automatically adjust flow rate, keeping temperature stable when multiple taps are used.
- Best for: Townhouses where quiet operation is important
- Pros: Silent performance, sleek design, stable temperature
- Cons: Higher cost compared to entry-level electric models
4. Noritz NRC66DVNG Indoor Condensing Tankless Water Heater
This natural gas model delivers up to 6.6 GPM and features condensing technology for improved efficiency. It is compact enough for indoor utility rooms and comes with direct venting, making it suitable for townhouses that allow indoor gas installations.
- Best for: Mid-size townhouses with 2–3 bathrooms
- Pros: Efficient condensing technology, reliable brand
- Cons: Not as high-flow as premium gas units
5. Rheem RTEX-27 Electric Tankless Water Heater
The Rheem RTEX-27 is a high-capacity electric model for larger households. It has a flow rate of up to 6.6 GPM in warmer climates and features an easy-to-use digital thermostat. Copper immersion heating elements provide quick, efficient heating.
- Best for: Large electric-only households
- Pros: Powerful for an electric unit, responsive heating
- Cons: Needs substantial electrical capacity
Why a Tankless Water Heater Is Ideal for Townhouses
Townhouses often have multiple bathrooms and higher-than-average hot water needs. A tankless system is well-suited because it:
- Provides hot water on demand for multiple fixtures
- Saves floor space by mounting on the wall
- Reduces energy waste compared to tank storage heaters
- Has a longer lifespan when maintained properly
Key Factors to Consider When Choosing
Fuel Type
If your townhouse has natural gas service, a gas tankless water heater is usually more powerful and efficient for high-demand households. If you do not have gas, an electric model can still meet your needs if your electrical system can handle it.
Flow Rate (GPM)
Flow rate is crucial. A townhouse with 1–2 bathrooms may need 4–6 GPM, while larger homes with multiple showers running at once should aim for 8–11 GPM for uninterrupted hot water.
Space and Installation
Consider where the unit will be installed. Indoor models need proper venting for gas, while outdoor models must be weather-protected. Electric units typically require less installation space.
Temperature Control
Digital controls help you set exact water temperatures and avoid fluctuations during use.
Energy Efficiency
Look for ENERGY STAR–rated models to save on utility bills over time.
Installation Tips for Townhouses
- Check with your HOA or property management for installation guidelines
- Hire a licensed plumber or electrician for safety and code compliance
- For gas units, ensure proper venting and carbon monoxide safeguards
- For electric units, confirm your panel can handle the amperage
- Install in a location with easy access for maintenance
Maintenance Recommendations
Proper care keeps your tankless water heater efficient and extends its lifespan:
- Flush the unit once a year to prevent scale buildup
- Clean inlet filters periodically
- Inspect venting (for gas units) annually
- Check connections for leaks regularly
Conclusion
For townhouse owners, a tankless water heater is an investment in comfort, efficiency, and space savings. The Rinnai RU199iN is perfect for large, high-demand households with gas service. The EcoSmart ECO 27 and Rheem RTEX-27 are strong electric options. For quiet operation, the Stiebel Eltron Tempra Plus 29 is a standout, and the Noritz NRC66DVNG offers efficient performance for mid-size homes.
By choosing the right model based on your townhouse’s size, fuel type, and hot water needs, you can enjoy endless hot water and a more efficient home year-round.