There’s nothing quite as frustrating as running out of hot water—especially when you’re in the middle of a shower or have guests over. That’s why more homeowners are switching to gas tankless water heaters. These systems heat water on demand, offering high flow rates and excellent performance, even in larger households.
But here’s the question: which is the best gas tankless water heater brand in 2025? In this guide, we’ll go over the top contenders, what makes them stand out, and how to choose the right one for your home. We’ll also share a critical home maintenance tip at the end that could save you thousands of dollars in repairs.
Why Choose Gas Over Electric?
While electric tankless heaters work well for smaller homes or warmer climates, gas-powered models are the go-to choice for high-demand households. Here’s why:
- Higher flow rates: Perfect for multiple showers or appliances running at the same time.
- Better cold-weather performance: Gas heats water faster, even when the incoming water is very cold.
- Lower operating costs in many areas: Natural gas can be cheaper than electricity per BTU.
- Longer lifespan: Many gas models last 20 years or more with proper care.
Gas tankless units do cost more upfront and require proper venting, but the performance benefits make them a smart long-term investment for many homes.
Best Gas Tankless Water Heater Brand: Rinnai
When it comes to reliability, efficiency, and performance, Rinnai is the brand most homeowners and installers trust. This Japanese company has been producing high-quality water heating products for decades and consistently tops “best of” lists worldwide.
Their flagship model, the Rinnai RU199iN Super High Efficiency Plus, is a prime example of why the brand is so well-regarded:
- Up to 11 GPM flow rate – enough for multiple showers and appliances at once.
- ENERGY STAR® certified for high efficiency.
- Compact wall-mounted design saves space.
- Built with durable components and backed by a strong warranty.
For large families or anyone who values consistent hot water supply, Rinnai is hard to beat.
Other Top Gas Tankless Water Heater Brands
Noritz
Noritz is known for its durable, high-performance gas models and user-friendly installation. The EZ Series is designed to make replacing old tank heaters simpler, while offering excellent cold-weather efficiency.
Rheem
A household name in water heating, Rheem offers gas tankless models with a strong balance of performance and technology. The Performance Platinum 9.5 GPM includes Wi-Fi connectivity for remote control and monitoring.
Navien
Navien specializes in high-efficiency condensing gas units, often with built-in recirculation systems to deliver hot water faster. Their models are popular for energy savings and advanced features.
Bosch
Bosch delivers German-engineered reliability with sleek designs and efficient performance. While they may not have the highest flow rates, they excel in long-term durability and low-maintenance operation.
Choosing the Right Brand for Your Home
When selecting a gas tankless water heater, consider these key factors:
- Flow rate (GPM): Match this to your peak water usage. A household with three bathrooms likely needs 9–11 GPM.
- Climate: Colder regions require more powerful units to handle low incoming water temperatures.
- Gas type: Make sure your unit matches your fuel source—natural gas or propane.
- Budget: Higher-end brands may cost more upfront but often save money long-term with better efficiency and fewer repairs.
Pro Tip: Have your gas line inspected before installation. Some high-capacity units require larger gas lines than older water heaters.
Installation and Maintenance
Professional installation is essential for gas tankless water heaters to ensure proper venting, safety, and optimal performance. Once installed, regular maintenance is straightforward:
- Flush the heat exchanger annually to remove mineral buildup.
- Inspect venting and gas connections periodically.
- Clean intake filters if your unit includes them.
The Overlooked Part of Your Water System
Upgrading to a top gas tankless water heater brand ensures endless hot water, but what happens after that water leaves your home is equally important. If you have a septic system, neglecting it can lead to slow drains, unpleasant odors, and even costly backups.
Septic issues often build up slowly, and by the time you notice them, repairs can cost thousands. That’s why proactive septic care is crucial.
SEPTIFIX – The Easy Way to Keep Your Septic System Healthy
SEPTIFIX is the #1 septic tank treatment in the US, trusted by thousands of homeowners. Each tablet releases oxygen and beneficial bacteria into your septic tank, breaking down waste, sludge, and grease while neutralizing odors.
Benefits include:
- Eliminates foul odors in just days.
- Prevents costly pump-outs and backups.
- Safe for all septic systems and environmentally friendly.
- Simple to use—just flush one tablet per month.
It’s an easy, low-cost way to keep your septic system running smoothly, especially if your water use increases after upgrading to a gas tankless heater.
Final Thoughts
When it comes to the best gas tankless water heater brand in 2025, Rinnai takes the crown for its unmatched blend of power, efficiency, and reliability. Noritz, Rheem, Navien, and Bosch also offer excellent gas models that may be better suited to specific needs or budgets.
And remember—upgrading your water heater is only half the job. Keep your septic system in top shape with SEPTIFIX, and you’ll have a complete, worry-free water system for years to come.
Order SEPTIFIX Today – Protect Your Septic Tank
Endless hot water is great. Endless hot water without plumbing problems? That’s even better.