There’s nothing worse than stepping into a shower expecting a relaxing blast of hot water, only to be greeted by a sudden rush of icy cold. If that’s been happening in your home, or you’re just tired of paying to keep 40+ gallons of water hot all day, a tankless water heater might be exactly what you need. In 2025, the technology is better than ever, and there are a handful of models that truly stand out as the best on the market.
This guide is written in plain, everyday language—no unnecessary technical talk—so you can easily decide which one is right for your home. And stick with me until the end, because I’m going to share something most water heater buyers overlook… and it could save you thousands of dollars on repairs.
Why Tankless Water Heaters Are Worth It
Traditional water heaters have one big job: keep a tank of water hot, all the time. It works, but it’s wasteful. Tankless units do things differently—they heat water only when you need it, as it flows through the system. The benefits are hard to ignore:
- Unlimited hot water – Great for families or homes with multiple bathrooms.
- Lower energy bills – No more heating water you don’t use.
- Compact size – Mounted on a wall instead of eating up floor space.
- Longer life – Many last 20 years or more with the right care.
And here’s the thing—when you install a tankless water heater, you’re not just buying convenience. You’re investing in efficiency, reliability, and home comfort for the long run.
The Best Tankless Water Heater on the Market: Rinnai RU199iN
If we had to name one standout in 2025, it would be the Rinnai RU199iN Super High Efficiency Plus. It’s gas-powered, built for high demand, and delivers hot water like few others can. Here’s why it’s a leader:
- High flow rate – Up to 11 gallons per minute, enough for several showers running at once.
- Top-tier efficiency – Helps keep energy bills low without sacrificing performance.
- Reliable build – Backed by a strong warranty and proven track record.
- Compact, wall-mounted design – Saves space in any utility area.
For larger households or anyone who hates cold-water surprises, this model is a smart choice. Yes, it’s on the higher end of the price scale, but when you factor in longevity and performance, it’s worth it.
Other Strong Contenders Worth Considering
EcoSmart ECO 27 (Electric)
This is one of the most popular electric tankless heaters on the market. It’s affordable, compact, and energy-efficient. Best for smaller households or homes in warmer climates, but keep in mind—it needs a strong electrical panel to run at full capacity.
Stiebel Eltron Tempra 36 Plus (Electric)
Quiet, powerful, and designed to keep water temperature steady even when multiple taps are running. It’s also sleek and doesn’t take up much space.
Rheem Performance Platinum 9.5 GPM (Gas)
This gas unit offers smart controls via Wi-Fi and can handle heavy usage without trouble. It’s great for families who like the idea of adjusting settings from their phone.
Noritz EZ Series (Gas)
Known for easier installation when replacing an old tank-style heater, the Noritz EZ is built to last and runs efficiently in different climates.
How to Choose the Right Model for Your Home
Before you make a choice, think about:
- How many bathrooms will use hot water at the same time?
- Do you already have a gas line, or will you need an electric model?
- What’s your climate? Colder water coming in means you’ll need more heating power.
- What’s your budget for both the unit and installation?
Tip: Gas units generally heat water faster and are better for large families, while electric units can be easier to maintain and install in smaller homes.
Installation and Ongoing Care
Most gas models need professional installation for proper venting and safety. Electric units can be easier to install, but may still require electrical upgrades. Either way, don’t skip annual maintenance—flushing the system once a year can prevent mineral buildup and keep your heater efficient.
The Overlooked Part of Your Home’s Water System
Now, let’s talk about something almost no one mentions in tankless heater guides—what happens to the water after you use it. If you have a septic tank, the health of that system is just as important as having a steady supply of hot water.
Septic problems can creep up on you: bad smells in the yard, slow drains, backups in the house, and massive repair bills. Many people don’t think about their septic system until it’s too late.
Why I Recommend SEPTIFIX for Septic Tanks
SEPTIFIX is the #1 septic tank treatment in the US, and for good reason. These small tablets dissolve in your toilet and release oxygen and beneficial bacteria that break down waste, sludge, and grease. The result? A cleaner, healthier, odor-free septic system.
Here’s why homeowners love it:
- Eliminates foul odors in just a few days.
- Breaks down waste to prevent clogs and backups.
- Reduces the need for expensive pump-outs.
- Safe for all septic systems and eco-friendly.
- Super easy—just flush one tablet each month.
Pairing the Best Water Heater with a Healthy Septic System
If you’re upgrading to a top-tier tankless water heater, it’s smart to protect the rest of your plumbing at the same time. SEPTIFIX is a low-cost, high-impact way to make sure your system works as it should for years to come.
Think of it this way: a tankless heater gives you endless hot water, and SEPTIFIX ensures the water leaves your home without causing trouble later. Together, they make your whole system more efficient and stress-free.
Final Thoughts
The Rinnai RU199iN might be the best tankless water heater on the market right now, but there are excellent alternatives depending on your budget, household size, and fuel source. No matter which one you choose, remember to also take care of your septic system—it’s an investment in your home’s comfort and safety.
Click Here to Get SEPTIFIX – Keep Your Septic Tank Clean and Odor-Free
Hot water without limits is great. Hot water without plumbing problems? That’s even better. Upgrade your heater, protect your septic system, and enjoy peace of mind every day.