Thinking about replacing your water heater? Tankless models deliver instant hot water, save energy, and free up valuable space—without the risk of running out. In this guide, you'll explore the five biggest benefits of going tankless and see six of the top models that homeowners and plumbing pros trust.
1. Lower Energy Use and Reduced Utility Bills
Energy Savings with High-Efficiency Tankless Water Heaters
Tankless water heaters turn on only when hot water is needed. According to the U.S. Department of Energy, they're 24%–34% more efficient for households that use about 41 gallons per day, and 8%–14% more efficient for homes using around 86 gallons per day. That means savings on your utility bills, month after month.
For even higher savings, look for an ENERGY STAR® certified gas tankless water heater. ENERGY STAR says a family of four can save about $95 per year (or about $1,800 over the unit's life) compared to a standard gas storage water heater.
Because a tankless system only fires when you need hot water, you waste less energy than you would keeping 40–60 gallons hot at all times. Some of the top high-efficiency "condensing" tankless water heaters even reclaim extra heat from exhaust gases for increased performance.
Top Models for Maximum Efficiency
- Rinnai RX Series RXP199IN
11.1 GPM, 199,000 BTU, condensing, and an integrated recirculation pump for rapid hot water—even at distant fixtures. - Noritz GQ-C3261WZ-FF-US-NG
Up to 11.1 GPM with condensing efficiency, engineered for large households and colder climates where a higher temperature rise is needed.
2. Endless Hot Water When Sized Correctly
Choosing the Right Flow Rate for Your Home
On-demand heating means your hot water will never "run out" like it can with a storage tank. The key is choosing the right flow rate. Some small electric point-of-use models deliver about 2–5 gallons per minute (GPM), but larger homes need high-flow gas tankless or even multiple units for showers and appliances that run at the same time. Premium models like the Rinnai RX Series RXP199IN and Noritz NRCB199DV-NG have flow rates around 11 GPM.
For sizing, add up the GPM of the fixtures you'll use simultaneously. Typical showers use about 1–2 GPM, faucets about 0.5–1.5 GPM. Choose a tankless unit that meets your total demand at your home's coldest winter temperature rise.
Top Whole-Home and Point-of-Use Models
- Rinnai RE199iN (indoor)
Up to 9.8 GPM, 199,000 BTU, indoor, non-condensing, whole-home. - Noritz NR98ODNG (outdoor)
Outdoor-rated, 9.8 GPM, 199,900 BTU, saves indoor space, easy venting. - Eemax HA027240 HomeAdvantage II (electric point-of-use)
Compact, no venting needed, delivers instant hot water at the tap, ideal for low/moderate flow or warm climates.
3. Space-Saving, Flexible Installation Options
Tankless water heaters are compact, often returning a closet's worth of space to your home. Many are installed on a wall, and some are designed for outdoors, which frees up even more room in the basement, utility room, or closet.
Indoor Wall-Mount Solutions for Compact Spaces
Rinnai RE199iN
Strong GPM in a tight footprint, perfect for families.
Outdoor Installations to Free Up Indoor Space
Noritz NR98ODNG
Outdoor, durable, keeps equipment out of living spaces.
4. Longer Lifespan and Reduced Risk of Leaks
Built to Last: Why Tankless Water Heaters Outperform Storage Tanks
Most tankless water heaters are built to last. A typical lifespan is 20+ years (with replaceable parts), while storage tanks usually last 10–15 years. And with no large water reservoir, the risk of a tank leak is gone, so you're much less likely to have water damage.
Protect Your Investment from Hard Water
Tip: If you have hard water, use American Valve Scale RX to protect your investment from scale buildup.
Top Models for Longevity and Efficiency
- Noritz GQ-C3261WZ-FF-US-NG
Condensing design for long-term reliability and energy efficiency. - Rinnai RX Series RXP199IN
Integrated recirculation pump reduces wait time and water waste, combining comfort with durability.
5. Cleaner, Faster, More Efficient Hot Water
Smart Recirculation for Quick Comfort
Because tankless water heaters don't have "standby losses" from storing hot water, you're not wasting energy. Modern models use smart recirculation or small buffer tanks to reduce the "cold-water sandwich" and shorten the wait for hot water at far fixtures—features that help cut water waste and improve comfort.
Top Models for Rapid Hot Water Delivery
- Rinnai RX Series RXP199IN
Built-in recirculation pump provides near-instant hot water to every tap. - Eemax EMT6 6-Gallon Electric Mini-Tank
Not tankless, but a point-of-use add-on ideal for distant sinks or guest suites where full recirculation isn't possible.
What to Consider Before Switching to Tankless
Upfront Costs and Installation Requirements
Tankless units generally cost more and may require a gas line, venting, or electrical upgrades, plus possible replumbing.
Sizing, Temperature Rise, and Maintenance Tips
Descale and flush annually to keep things running efficiently. If your home has frequent, multiple simultaneous hot water uses, go for a higher-output unit or zoned system. Check the GPM and temperature rise with a qualified contractor.
Quick Sizing Checklist for Your Home
- List all at-once hot water uses.
- Add up the GPM for those fixtures (check the manufacturer specs).
- Determine your local "temperature rise"—subtract your coldest incoming water temp from your target hot water temp.
- Pick a unit that meets your required GPM at your needed temperature rise (gas usually handles larger rises than electric).
- If you're close to max capacity, size up or consider a secondary unit for high-traffic bathrooms.
Our Shortlist: Which Tankless Water Heater Fits Your Home?
Highest Output for Large Families
Rinnai RX Series RXP199IN – 11.1 GPM, condensing, integrated pump
Ultra-Efficient Condensing Models
Noritz GQ-C3261WZ-FF-US-NG – 11.1 GPM, condensing
All-Around Indoor Options
Rinnai RE199iN – 9.8 GPM, non-condensing, indoor
Outdoor-Ready Units
Noritz NR98ODNG – 9.8 GPM, outdoor install
Electric Tankless and Mini-Tank Add-Ons
Eemax HA027240 HomeAdvantage II – compact, no venting
Eemax EMT6 – 6-gallon mini-tank for remote taps
Bottom Line: Is a Tankless Water Heater Right for You?
If you want energy savings, continuous hot water, space savings, and longer unit life, a tankless water heater is a great upgrade, especially if your home's hot water use fits its strengths and you size it right.
At Plumbing Deals, we carry all the top tankless brands and the accessories you need—from recirculation kits to scale reducers and venting. We'll help you choose the right size and type, and we can even coordinate with your installer on specs and parts to make swap day smooth. Ready to upgrade? Start your journey to efficient, on-demand hot water today!
Products You May Need
Noritz NR98ODNG 9.8 GPM 199900 BTU 120 Volt Residential Natural Gas Tankless Water Heater for Outdoor Installation
