A tiny house is all about smart use of space, energy efficiency, and comfort. Every appliance you choose needs to work hard without taking up too much room — and that includes your water heater. A tankless water heater can be one of the most practical upgrades for a tiny home. It heats water only when you need it, saving energy and giving you an endless supply without a bulky storage tank.
In this guide, we will start with the top tankless water heaters that work beautifully in tiny homes, then cover buying tips, installation advice, and maintenance so you can make the right choice the first time.
Top Tankless Water Heater Picks for Tiny Houses
1. Rinnai V65iN Indoor Tankless Water Heater (Natural Gas)
The Rinnai V65iN is a compact yet powerful natural gas model that can deliver up to 6.5 gallons per minute (GPM). That’s more than enough for a tiny house with one bathroom and kitchen use at the same time. It’s designed for efficiency and fits neatly in small utility areas.
- Best for: Tiny houses with natural gas supply
- Pros: High flow rate, long-lasting build, compact
- Cons: Requires professional gas installation
2. EcoSmart ECO 11 Electric Tankless Water Heater
If your tiny home runs on electricity, the EcoSmart ECO 11 is an excellent low-cost option. It provides up to 3.1 GPM in warmer climates, which is enough for a shower and a sink simultaneously. Its wall-mounted design saves precious floor space.
- Best for: Electric tiny homes in mild climates
- Pros: Affordable, easy to install, small size
- Cons: Limited performance in very cold climates
3. Stiebel Eltron Tempra Plus 15
The Tempra Plus 15 offers advanced features like automatic flow control to keep water temperature steady even when multiple fixtures are used. It’s quiet, reliable, and perfect for tiny homes with modest but steady hot water demand.
- Best for: Consistent hot water temperature
- Pros: Quiet, precise control, premium build
- Cons: More expensive than basic models
4. Rheem RTEX-13 Electric Tankless Water Heater
The Rheem RTEX-13 is a space-saving, budget-friendly electric unit that works well for one-bathroom tiny homes. It delivers up to 3.17 GPM in warm regions and has an easy-to-use digital temperature display.
- Best for: Small households with low simultaneous demand
- Pros: Affordable, compact, reliable brand
- Cons: Not for very high demand setups
5. Camplux 2.64 GPM Outdoor Tankless Water Heater (Propane)
For off-grid tiny homes, the Camplux 2.64 GPM is a great choice. It’s propane-powered, mounts outdoors, and provides instant hot water for showers and sinks. It’s also portable, making it useful for mobile setups.
- Best for: Off-grid or seasonal tiny homes
- Pros: Portable, low-cost, easy to set up
- Cons: Lower flow rate, needs weather protection
Why Tankless Water Heaters Are Ideal for Tiny Homes
A tiny house needs appliances that are efficient and space-conscious. Tankless heaters deliver on both fronts:
- Space savings: Mounts on a wall or outdoors, freeing up valuable square footage
- Energy efficiency: Only heats water when you turn on the tap
- Endless hot water: Perfect for back-to-back showers or long dishwashing sessions
- Longevity: Often lasts longer than traditional tank models
- Fuel flexibility: Available in electric, propane, or natural gas
How to Choose the Right Tankless Water Heater for a Tiny House
1. Fuel Type
Electric models are the simplest to install but require sufficient electrical capacity. Gas and propane models heat water faster but require venting and professional setup.
2. Flow Rate (GPM)
Match the GPM to your household needs. One shower and one sink may need around 3–4 GPM. If you plan to run more than that at once, look for higher capacity.
3. Climate
In colder climates, incoming water is cooler, which can lower performance. Choose a stronger unit if you live in a cold region.
4. Space & Location
Measure where you plan to install the unit. For tiny homes, compact and wall-mounted designs are preferred. Outdoor units can save indoor space but must be weather-protected.
5. Noise Level
Since tiny homes have less sound insulation, opt for models known for quiet operation, like the Stiebel Eltron Tempra Plus series.
Installation Tips
- Confirm your home’s power or gas supply can handle the chosen model
- Follow clearance requirements for safe operation
- Hire a professional for high-capacity electric or gas models
- For off-grid setups, pair with solar panels and propane for efficiency
Maintenance for Long Life
Tankless units need minimal but regular care:
- Flush annually to prevent scale buildup
- Clean inlet filters every few months
- Inspect connections and vents
- Follow the manufacturer’s maintenance guide
Conclusion
The right tankless water heater can make life in a tiny house more comfortable and efficient. If you have natural gas, the Rinnai V65iN is a strong performer. For electric setups, the EcoSmart ECO 11 offers great value, while the Stiebel Eltron Tempra Plus 15 delivers premium comfort. The Rheem RTEX-13 is a reliable budget option, and the Camplux 2.64 GPM is perfect for off-grid living.
Choosing based on your fuel type, climate, and water usage will help you get the most from your tiny house hot water system — without giving up the space and energy efficiency that tiny living is all about.