There’s nothing better than stepping into a hot shower after a long day. But if your current water heater takes forever to warm up, runs cold halfway through, or wastes energy keeping a huge tank hot all day, it’s time to consider a tankless water heater. These systems heat water instantly, giving you endless hot showers without the bulk of a storage tank.
This guide focuses on the best tankless water heaters for showers in 2025. You’ll see top models, understand how to pick the right size, and learn a few maintenance tips to keep your showers steamy and worry-free.
Why a Tankless Water Heater is Ideal for Showers
- Endless hot water: Perfect for long showers or multiple showers back-to-back
- Space-saving design: Wall-mounted units free up floor space
- Energy efficiency: Heats water only when needed
- Consistent temperature: No more hot-cold spikes mid-shower
Quick Tips Before Choosing
Before jumping into product recommendations, keep these quick points in mind:
- Showerheads typically use 1.5–2.5 gallons per minute (GPM)
- In colder climates, you’ll need a higher GPM rating due to lower incoming water temperatures
- Gas models tend to offer higher flow rates, but electric units are easier to install
Top Tankless Water Heater Picks for Showers
1. Rinnai V65iN (Natural Gas)
This natural gas model delivers up to 6.5 GPM, which is more than enough for a shower plus another fixture at the same time. It’s known for reliability and consistent performance, making it one of the most popular choices for residential showers.
- Best for: Homes with gas service and high shower use
- Pros: High flow, dependable, long lifespan
- Cons: Requires venting and professional installation
2. EcoSmart ECO 18 Electric
The Eco 18 is a mid-size electric tankless heater that works well for showers in warm to moderate climates. It delivers 2.5–3.5 GPM depending on incoming water temperature, enough for a shower and small sink simultaneously.
- Best for: Electric-only households
- Pros: Affordable, easy to install, digital temperature control
- Cons: Lower flow in cold climates
3. Stiebel Eltron Tempra 24 Plus Electric
Known for precision temperature control, the Tempra 24 Plus provides steady hot water without fluctuations. It’s suitable for showers even in cooler regions thanks to its higher capacity compared to entry-level electric models.
- Best for: Consistent, luxury shower experience
- Pros: Quiet, compact, long-lasting
- Cons: Higher initial cost
4. Rheem RTGH-95DVLN (Natural Gas, Condensing)
This high-efficiency gas model can deliver over 9 GPM, making it ideal for households that often have multiple showers running. While it’s more power than a single shower needs, it ensures zero compromise in performance.
- Best for: Large families or high-demand situations
- Pros: Extremely high flow, ENERGY STAR rated
- Cons: Higher cost, requires venting
5. Camplux 2.64 GPM Portable Propane Tankless
For outdoor showers or cabins, the Camplux is portable and propane-powered. It delivers enough flow for a shower anywhere you can hook up a propane tank and water source.
- Best for: Outdoor or seasonal showers
- Pros: Lightweight, portable, affordable
- Cons: Not designed for permanent indoor use
How to Size Your Tankless Water Heater for Showers
To size correctly, consider the flow rate of your showerhead and any other fixtures you might use at the same time. For example:
- 1 shower: 2.0–2.5 GPM
- 1 shower + sink: 2.5–3.5 GPM
- 2 showers: 4–5 GPM
In colder climates, increase capacity by at least 25% to compensate for lower incoming water temperatures.
Electric vs. Gas for Shower Use
Electric tankless heaters are easier to install and maintain, and they’re ideal for single showers or smaller households. Gas-powered heaters can deliver higher flow rates, making them better for multiple showers or colder regions.
Installation Tips
- Place the heater as close to the shower as possible to reduce wait time
- Ensure correct wiring or gas line sizing before installation
- Hire a licensed plumber or electrician for safety and warranty compliance
Maintenance for Long-Lasting Performance
Even the best tankless water heater needs care:
- Flush the unit annually to prevent scale buildup
- Clean inlet filters as recommended
- Inspect connections for wear or leaks
Final Thoughts
For most shower setups, the EcoSmart ECO 18 or Stiebel Eltron Tempra 24 Plus will be perfect for electric households, while the Rinnai V65iN and Rheem RTGH-95DVLN shine in gas-powered homes. For outdoor or temporary setups, the Camplux Portable offers affordable convenience.
Choose a model that matches your climate, shower flow rate, and fuel availability, and you’ll enjoy endless hot showers every day.