7 Shocking Facts About Tankless Water Heaters

Introduction: Why Tankless Water Heaters Are Gaining—and Losing—Attention

Tankless water heaters—also known as on-demand systems—have exploded in popularity over the last decade. Promising endless hot water, lower energy bills, and sleek space-saving design, these units have become the go-to upgrade in modern homes.

But are they really the future of home water heating, or just an overhyped investment?

At Bezruchuk Inc., we’ve worked with dozens of clients across bathroom remodels, walk-in tub installations, and custom shower conversions. And we’ve seen firsthand how tankless water heaters often fall short of expectations—especially when the fine print is ignored.

In this guide, we’ll walk you through 7 shocking facts you need to know before choosing a tankless system. From real-world performance issues to unexpected maintenance costs, you’ll get the full picture—not just what sales reps want you to hear.

If you’re planning a home remodel, adding a walk-in tub, or upgrading your heating system, read this first to avoid costly mistakes. Then get a free quote to find the right solution for your needs.

Whether you live in Puyallup, Bellevue, or the greater Seattle area, we’ll help you make the smart choice for your next project.

Let’s dive in.

Table of content

The Real Cost of Tankless Water Heater Systems

One of the biggest selling points of a tankless water heater is its energy efficiency. But what many homeowners don’t realize is that the upfront and hidden costs often outweigh the long-term savings.

Let’s break it down: a traditional 50-gallon water heater typically costs around $2,000 to $2,500, fully installed. In contrast, a tankless system often starts at $3,000 just for the unit—and installation can add another $2,000 to $4,000, especially if you need new gas lines, electrical work, or ventilation.

Tankless vs. Traditional: Installation and Unit Cost

Many homeowners are also surprised to learn that most tankless water heaters are rented through builders or service contracts—resulting in payments that can total over $10,000 across 20 years for a unit that only costs $3,000.

That’s not exactly what we’d call energy savings.

Maintenance Costs Add Up Quickly

Tankless systems aren’t “set it and forget it.” They require yearly flushing by a licensed technician to prevent scale build-up, especially in areas with hard water. Skip the service? You risk voiding the warranty and shortening the lifespan of the unit.

And unlike a simple tank replacement, many tankless heaters use proprietary parts that can take weeks to arrive from overseas. That means no hot water and long waits—often with premium service fees.

In comparison, a traditional water heater is straightforward. If it ever fails, replacement is fast, cheap, and reliable.

Want More Hot Water Without the Cost?

Our team often recommends installing a high-efficiency tank system with a recirculation pump. It delivers hot water in seconds, saves energy, and avoids the common issues of tankless systems. See how it works in this project.

💡 Pro Tip: Don’t just compare monthly energy bills. Always include installation, maintenance, and lifespan when evaluating your water heater investment.

Click here to request a free quote and compare smart water heater options for your remodel or new construction project.

Performance, Problems, and When Tankless Systems Fail

Tankless water heaters promise “endless hot water.” But in real-world use, that statement comes with major caveats. These systems can struggle to deliver consistent performance—especially in multi-bathroom homes or when paired with low-flow fixtures.

Many of our remodeling clients report delays, inconsistent water temperatures, or cold surges. These issues aren’t rare—they’re common symptoms of system mismatch, poor installation, or low water pressure.

Low Flow Fixtures = Big Tankless Headaches

Modern plumbing fixtures are designed to conserve water. But when flow rates fall below a tankless system’s minimum threshold, the heater doesn’t even turn on. That means you could be sending cold water to your shower or sink without realizing why.

This issue is especially common in homes with:

• Low-flow showerheads or faucets

• Short water runs close to the unit

• Bathroom remodels using eco fixtures

We’ve seen tankless heaters fail to fire when someone simply wanted warm water to wash their hands or rinse a dish. That’s frustrating—and unacceptable in a high-end home upgrade.

Inconsistent Temperature, Long Waits

With a tankless water heater, the water must first reach a set flow rate, then be heated as it passes through a heat exchanger. This can cause:

• Delays of 30–60+ seconds before hot water arrives

• Fluctuating temperatures when multiple taps are running

• Intermittent cold bursts during showers

Compared to a traditional tank paired with a recirculation pump, which can deliver hot water in under 2 seconds, tankless units often feel sluggish. For many homeowners, the added wait time—and wasted water—becomes a daily annoyance.

Breakdowns and Replacement Parts: A Global Problem

Unlike standard tanks with universal parts, tankless systems often use brand-specific components manufactured overseas. When something breaks, you might be waiting weeks—sometimes months—for a replacement board or sensor to ship from abroad.

This is a key reason why experienced plumbers and general contractors often prefer tanks. They’re simple, fast to fix, and less likely to leave your home without hot water for days at a time.

Why Performance Matters in Remodels

If you’re upgrading your bathroom, kitchen, or installing a walk-in tub, you need water heating that works—on demand and under pressure. If your heater can’t keep up, that sleek new fixture becomes a cold disappointment.

Make sure your water heater matches your lifestyle and your home’s layout. What works in a 1-bedroom condo may fail in a 3-bathroom home.

Is Your Tankless System Struggling Already?

Have you noticed any of these signs?

• Inconsistent shower temperatures

• Cold surges when running two fixtures

• Hot water delays in distant bathrooms

• Service calls due to error codes

If so, it might be time to reassess whether your current system is the right fit.

Request a free evaluation and let our licensed remodeling pros assess your hot water setup before your next upgrade. We’ll help you avoid future frustration and wasted money.

When Tankless Water Heaters Actually Make Sense

Despite all the downsides we’ve discussed, tankless water heaters aren’t always the wrong choice. In fact, under the right conditions, they can be an excellent solution for your hot water needs—especially when installed correctly and chosen based on proper capacity.

Smart Use Cases for Tankless Water Heaters

If you’re living in a small home, studio, or apartment without a basement, space savings alone may justify installing a tankless water heater. They can also be ideal in these scenarios:

• Homes with 10+ people who require continuous hot water use over several hours

• Properties with limited mechanical space or no basement for a traditional water heater

• Southwestern or southern homes where heaters are commonly mounted in garages

• Homeowners seeking a point-of-use heater for a guest bathroom or outdoor shower

Today’s high flow tankless water heaters can deliver up to 11 GPM (gallons per minute), making them more capable than older models that couldn’t handle multiple taps at once. Brands like Navien, Rinnai, and Noritz now offer smart systems that auto-adjust based on water demand, improving performance in real-time.

Walk-In Tubs: A Special Case for Tankless or Oversized Tanks

If you’re installing a walk-in tub, standard 40- or 50-gallon tanks may not cut it. These deep tubs often require 50–80 gallons of hot water to fill, depending on the model and size. That exceeds the capacity of most traditional water heater systems.

There are two smart options in this case:

• Install a larger 80-gallon traditional water heater with fast recovery

• Use a high-efficiency tankless water heater with a flow rate of at least 9–11 GPM

If space is limited or you want quick hot water refills between uses, tankless becomes the better fit—but only if it’s sized correctly and installed with attention to flow rate and local plumbing code.

See how our remodeling team integrates the right water heating solution into every bathroom design.

Best Tankless Water Heater Brands to Consider

Not all systems are created equal. Based on our experience with installations and client feedback, here are three of the best tankless water heaters currently available for residential use:

• Navien NPE-240A2 – Up to 11.2 GPM, Wi-Fi capable, dual stainless steel heat exchangers.
• Rinnai RU199iN – Internal recirculation, compact size, ENERGY STAR® certified.
• Noritz EZ Series – Retrofit-friendly, high-efficiency gas unit with advanced diagnostics.

These units perform well in high-demand homes when properly sized and installed by a qualified contractor. But remember, even the best tankless water heater won’t solve problems caused by poor planning or undersized plumbing.

💡 Need help choosing? Our team matches water heater capacity to the exact demands of your home—whether you’re adding a soaking tub, upgrading to multiple bathrooms, or installing radiant heat.

Click here to get a custom system recommendation tailored to your next remodeling project.

Navien NPE-240A vs. NPE-240S: Which One Should You Choose?

If you’re considering switching to a tankless water heater, Navien is one of the most trusted brands on the market. Two of its most popular models—the NPE-240A and NPE-240S—are often compared. So which one is right for your home?

Side-by-Side Comparison: NPE-240A vs. NPE-240S

Real User Experiences with Navien

Many homeowners on forums like Reddit and Houzz shared feedback after installing both models:

• “We run our recirculation pump 24/7 and get hot water instantly from every tap.”
• “Without the pump, it took 3–5 minutes to get hot water in our master bath.”
• “If your heater is more than 15 feet from the nearest fixture, the A model is worth it.”
• “Make sure you have the return plumbing or install NaviCirc under the farthest sink.”

💡 Bottom line: If your plumbing supports recirculation—or you’re building new—the Navien NPE-240A is usually worth the extra $200. For retrofit installations with short runs or tight budgets, the NPE-240S is still a reliable, high-performance choice.

Get a free estimate to find out which model fits your home best.

Rinnai Tankless Water Heaters: Recirculation Options and Performance Insights

Rinnai has earned a strong reputation in the U.S. for high-efficiency tankless water heaters, with popular models like the RU199iN and the upgraded RXP199iN. These systems are designed to deliver endless hot water with smart technology—but performance heavily depends on your plumbing layout and recirculation strategy.

Common Issue: Delayed Hot Water Without Return Line

Homeowners using the RU199iN often report long wait times—up to 3 minutes—for hot water in distant fixtures. This is common in large homes without a dedicated recirculation line. Fortunately, Rinnai offers several retrofit solutions:

• GTK15 Kit + Thermal Bypass Valve: Allows use of the cold water line as a return, bypassing the need for a dedicated loop.
• RSC199i / RXP199iN: Newer models with built-in pumps and smart scheduling features.

Keep in mind: Using the cold line as a return will cause the cold water line to run warm until purged.

Rinnai Models Compared

Things to Watch For: Maintenance and Heat Exchanger Life

While Rinnai units are known for reliability, several users have reported heat exchanger failures with the RU199iN—sometimes within the first 1–2 years. Rinnai’s warranty may be voided if your local water quality exceeds their CO₂ guidelines (15 mg/L). Be sure to check your municipal water report or install a water softener if needed.

Is Rinnai Right for You?

Rinnai remains a top-tier option, especially with newer models offering smart recirculation and WiFi control. But if you’re in an older home without a return loop, plan for added installation steps or consider whether a model with integrated pump is worth the extra upfront cost.

💡 Get a free estimate to upgrade your system or explore recirculation installation options for your Rinnai heater.

Noritz EZ Series: Warranty Power and Easy Retrofit Installation

If you’re upgrading from a traditional water heater and prefer minimal disruption, the Noritz EZ Series deserves a serious look. Models like the EZTR50 and EZ111 are purpose-built to simplify installation by aligning with existing tank-style plumbing and venting layouts. For homeowners who value convenience and longevity, Noritz provides an attractive balance of warranty coverage, reliability, and adaptability.

Top Features of Noritz EZ Models

• 25-Year Heat Exchanger Warranty: One of the longest warranties on the market—10 years longer than Navien’s standard.
• EZ Retrofit Design: Inlet and outlet water lines match standard tank heater positions, reducing plumbing work.
• Compact Wall-Mount Profile: Designed to fit tight indoor utility closets or replace existing tank heaters without major rework.

Noritz EZTR50 vs Navien NPE-240S2

DIY or Pro Install?

Many homeowners are drawn to the EZ Series due to its user-friendly installation layout. However, Reddit discussions warn that licensed plumbers typically won’t “sign off” on homeowner installs due to liability issues. It’s best to pull a permit and let your local building inspector handle final approval. Noritz includes robust documentation, but proper gas sizing, venting, and condensate drainage are still critical safety concerns.

Who Should Consider Noritz?

Noritz is ideal for:

• Retrofitting homes with standard tank water heater layouts
• Homeowners who value extended warranty coverage
• Simple installs in closets, garages, or laundry areas

💡 Get a free quote to compare Noritz vs Navien systems for your home layout and hot water demands.

Choosing the Right Size Water Heater for Your Home

One of the most common mistakes homeowners make is installing a water heater—tankless or traditional—that doesn’t match the actual water demand of their home. Whether you’re remodeling or building new, selecting the correct size is essential to avoid cold showers, poor water pressure, or wasted energy.

Understand Your Flow Rate Needs

Tankless water heaters are rated by flow rate, measured in gallons per minute (GPM). To determine what size you need, add up the GPM of all fixtures that might be used simultaneously. For example:

• Shower: 2.0–2.5 GPM

• Bathroom faucet: 0.5–1.0 GPM

• Kitchen sink: 1.5–2.0 GPM

• Washer: 2.0 GPM

• Dishwasher: 1.5 GPM

If your family often showers while the laundry runs, a water heater that supports at least 6–8 GPM is a must. Larger homes with multiple bathrooms may require 9–11 GPM systems or dual-unit configurations.

Compare GPM and Temperature Rise

The higher your incoming water temperature, the easier it is for a tankless heater to deliver warm water. In colder climates like Washington State, the system needs to work harder to heat cold groundwater. This means you’ll need a stronger unit to achieve the same result.

As a general rule:

• Warm climates (incoming water ~70°F): Lower GPM units work fine

• Cool climates (incoming water ~40–50°F): Choose higher GPM with strong BTU output

Request a free evaluation and we’ll calculate the ideal water heater size based on your home layout, climate, and lifestyle.

Final Verdict: Choose the Right Water Heater for Your Home

When it comes to choosing between a tankless water heater and a traditional water heater, the right decision comes down to your home’s layout, your hot water habits, and your long-term goals.

If you value simplicity, low maintenance, and consistent performance, a high-efficiency tank with a recirculation pump might be your best choice. These systems are affordable to install, easy to repair, and deliver instant hot water—even to distant fixtures.

But if your home requires high-capacity output, space-saving solutions, or continuous hot water use—like in homes with walk-in tubs or radiant heating—then a properly sized high flow tankless water heater may serve you better.

Tankless Systems Are Evolving

New models like the Rinnai RU199iN, Navien NPE-240A2, and Noritz EZ Series are much more advanced than earlier generations. With improved sensors, better cold weather performance, and higher GPM ratings, these options now support whole-home usage when sized and installed correctly.

Still, these systems require a solid understanding of water heater capacity, local plumbing code, and proper electrical or gas upgrades. It’s not a DIY swap—it’s a carefully engineered installation.

Let Our Experts Help You Decide

At Bezruchuk Inc., we help homeowners across Seattle, Puyallup, and Bellevue avoid costly heating mistakes by matching the right system to the right home.

Whether you’re planning a bathroom remodel, converting your shower, or upgrading your water heating system to support a curbless shower or walk-in tub, we’ll guide you every step of the way.

💬 Want to make the right investment? Let our licensed general contractors help you compare options, plan the layout, and ensure your new system meets code, flow, and warranty requirements.

Click here to request your free quote today or visit our Bathroom Remodel service page to see more projects and solutions.

Frequently Asked Questions