If you’ve ever run out of hot water halfway through a shower, you know how frustrating it can be. For decades, traditional tank-style water heaters have been the norm, but they come with plenty of downsides: limited hot water, wasted energy, and bulky storage tanks that eat up space. That’s why more and more homeowners are switching to tankless water heaters.
In this guide, we’ll explore the top tankless water heater brands in 2025, what makes them stand out, and how to pick the right one for your home. And toward the end, we’ll cover a crucial—but often overlooked—part of your plumbing system that needs attention if you want to avoid costly repairs.
Why Tankless Water Heaters Are Worth the Investment
Tankless water heaters, also called on-demand water heaters, heat water only when you need it. When you turn on a faucet or shower, cold water runs through the unit where it’s quickly heated by powerful burners or electric elements. That means:
- Endless hot water – No waiting for a tank to refill.
- Lower energy bills – You’re not constantly heating stored water.
- Longer lifespan – Many models last 20 years or more with proper care.
- More space – A wall-mounted unit frees up valuable floor space.
While the upfront cost can be higher than a traditional heater, the long-term savings and convenience often outweigh the initial investment.
Top Tankless Water Heater Brand Overall: Rinnai
In 2025, Rinnai continues to lead the pack. Known for its reliability, advanced technology, and strong warranties, Rinnai has built a reputation among both homeowners and installers for delivering high performance year after year.
Their flagship model, the Rinnai RU199iN Super High Efficiency Plus, is a standout with features like:
- Up to 11 gallons per minute (GPM) flow rate – perfect for large households.
- ENERGY STAR® certified for efficiency.
- Compact, wall-mounted design.
- Durable construction and a long warranty.
Other Leading Tankless Water Heater Brands
Stiebel Eltron
Known for precision engineering and quiet operation, Stiebel Eltron’s Tempra Plus series keeps water temperature consistent even when multiple taps are in use. A favorite for households that value performance and silence.
Rheem
One of the most recognizable names in water heating, Rheem’s tankless models offer a mix of performance and smart technology. The Performance Platinum 9.5 GPM comes with Wi-Fi controls, letting you adjust settings from your phone.
Noritz
Specializing in durable, high-efficiency gas tankless heaters, Noritz offers models that are especially easy to install when replacing old tank systems. Their EZ Series is built for cold climates and high demand.
EcoSmart
Focused on electric models, EcoSmart is a great option for smaller households and warmer regions. The ECO 27 is compact, efficient, and budget-friendly, though it requires a strong electrical panel.
How to Choose the Right Brand
When selecting the top tankless water heater brand for your home, consider:
- Fuel type: Gas heats faster and works well for larger households; electric is easier to install and maintain for smaller homes.
- Flow rate (GPM): Match the GPM to your peak hot water use.
- Climate: Cold incoming water requires more heating power.
- Budget: Factor in both the purchase price and installation cost.
Pro Tip: Check your home’s gas line capacity or electrical service before buying—upgrades can add to installation costs.
Installation and Maintenance
No matter which brand you choose, professional installation is recommended. Gas units need proper venting, while electric models may require an electrical panel upgrade. Once installed, maintenance is straightforward:
- Flush the unit annually to prevent mineral buildup.
- Check and clean filters if your model has them.
- Inspect venting and water lines periodically.
The Forgotten Side of Your Plumbing
Upgrading to the top tankless water heater brand ensures hot water flows smoothly into your home. But what about after it leaves? If you have a septic system, neglecting it can lead to slow drains, bad smells, and expensive repairs.
Many homeowners don’t think about their septic system until something goes wrong, but by then, the fix can cost thousands.
SEPTIFIX – Protect Your Septic System
This is where SEPTIFIX comes in. It’s the #1 septic tank treatment in the US, and it’s as simple as flushing a tablet down the toilet. Here’s why homeowners love it:
- Removes odors within days.
- Breaks down waste, grease, and sludge.
- Prevents costly pump-outs and backups.
- Safe for all septic systems and eco-friendly.
- No mess—just drop it in and flush.
Why Combine a Tankless Upgrade with Septic Care?
When you upgrade to a tankless heater, your home’s water use may increase slightly since you’ll never run out of hot water. Keeping your septic system healthy ensures that all that water exits your home without causing problems.
Final Thoughts
Choosing the top tankless water heater brand comes down to matching your household’s needs with the right model. For most, Rinnai offers the best combination of reliability, performance, and support. But Stiebel Eltron, Rheem, Noritz, and EcoSmart each shine in specific situations.
And remember—hot water is only part of the equation. Pair your new heater with regular septic maintenance using SEPTIFIX, and you’ll enjoy comfort and peace of mind for years.
Get SEPTIFIX Now – Keep Your Septic Tank Clean and Odor-Free
Endless hot water is great. Endless hot water without septic problems? That’s even better.