5 Best Tankless Water Heaters, According To Home Experts

For homeowners looking to save space and reduce energy costs, tankless water heaters have become an increasingly popular alternative to traditional storage tanks. These compact units heat water on demand, promising endless hot showers and lower utility bills – but with dozens of models on the market ranging from $500 to over $2,000, choosing the right one can feel overwhelming. After analyzing real user experiences across the industry’s top brands, we’ve identified the best tankless water heaters for every home size and budget.

Best Tankless Water Heaters, According to Experts

1. Steibel Eltron

The Stiebel Eltron tankless water heater, a powerhouse in the industry since the 1920s, has earned its reputation as a top performer. Forbes points out the DHC 10-2 model’s impressive specs, including its ability to pump out up to six gallons of hot water per minute with 32,757 BTUs of heating capacity. The brand’s confidence shows in their warranty coverage: 10 years against leaks and three years against defects.

For those concerned about efficiency, This Old House loves the unit’s smart self-modulating technology and impressive flow rate of 1.5-4.5 GPM. The compact design eliminates the need for venting, making it an ideal choice for space-conscious homeowners looking to trim their energy bills.

Family Handyman gives a nod to the 36 Plus model’s thoughtful features, including its advanced flow control that ensures consistent shower temperatures – no more unexpected cold blasts. The digital display adds a modern touch while letting you track your energy savings in real-time. With a flow rate of seven and a half gallons per minute in warmer climates, it’s built to handle most household demands. Installation does require some electrical muscle, though – you’ll need a 240-volt connection and a 40-amp circuit breaker to power its 9,600-watt heating element.

2. Rheem Tankless RTEX-18

Rheem’s RTEX-18 electric tankless water heater delivers impressive performance in a compact package. Popular Mechanics spotlights its user-friendly design, featuring an LED display for easy temperature adjustments and flexible installation options that won’t eat up valuable wall space.

Bob Vila gives high marks to this 18kW powerhouse, which boasts an impressive 99.8 percent efficiency rating thanks to its advanced self-modulation technology. The unit can easily handle one or two simultaneous showers, making it an ideal choice for smaller households, while its precise temperature control allows adjustments in single-degree increments.

The engineering excellence shines through in the details – from the durable brass-topped heating elements to the straightforward installation process. With a flow rate of 4.4 GPM and the ability to exceed standard 110-degree temperatures, this 240V unit strikes a sweet spot between performance and practicality, though you’ll need two 40-amp breakers to power it up.

3. Rinnai Indoor Tankless

The Rinnai RL75iN natural gas tankless water heater stands out as a powerhouse for larger households. The Spruce says this Japanese manufacturer has a sterling reputation for reliability, backing it up with an impressive 12-year warranty on the heat exchanger. With 180,000 BTUs of heating power and a maximum flow rate of 7.5 GPM, it can handle multiple fixtures simultaneously in climates where groundwater ranges from 47 to 67 degrees Fahrenheit.

This Old House emphasizes the advantages of the unit’s indoor installation, which protects it from temperature fluctuations that could impact performance. The gas-powered system delivers higher flow rates than typical electric alternatives, making it an ideal fit for medium to large homes that demand consistent hot water delivery.

Family Handyman takes the enthusiasm up a notch, noting that this compact unit – roughly the size of a small suitcase – can handle up to six running water fixtures simultaneously with its nearly 10-gallon-per-minute capacity. For tech-savvy homeowners, there’s an optional Wi-Fi module that adds smart functionality. The versatile design allows for installation almost anywhere indoors, from attics to crawl spaces, giving homeowners flexibility in placement without sacrificing performance.

4. Ecosmart 11

The EcoSmart ECO 11 proves that good things come in small packages. Thomas Net appreciates how this compact electric tankless heater packs premium features into a budget-friendly unit, with 13 kilowatts of power perfectly suited for single-bathroom applications. The patented self-modulating technology helps slash energy usage by about 60%, though it’s worth noting that the lifetime warranty on elements, electronics, and exchanger is only valid with professional installation.

For smaller households of one or two people, This Old House says the 1.3-3.1 GPM flow rate hits the sweet spot. The unit’s precise temperature control keeps water within one degree of your selected setting, ensuring consistent comfort without wasteful energy consumption.

According to Bob Vila, the ECO 11 has an impressive 99.8% efficiency rating using the stringent UEF standard, estimating annual hot water cost savings around 50%. The digital interface allows for precise temperature adjustments in single-degree increments from 80 to 140 degrees Fahrenheit, making it an ideal choice for compact modern homes where you might need to run a shower and low-flow faucet simultaneously. The combination of efficiency, precision, and compact size makes this an attractive option for those in warmer climates seeking to modernize their hot water setup.

5. Bosch Tronic 3000

The Bosch Tronic 3000 tackles a common household frustration: the long wait for hot water at fixtures far from the main heater. According to Thomas Net, this battery-powered point-of-use unit can be discreetly installed anywhere near a fixture, providing up to four gallons of hot water while you wait for the central system to kick in. Its versatility shines through in multiple applications, from standalone sink service to supplementing existing systems in showers, outdoor kitchens, or private sheds.

Drinking-Water.org loves the unit’s compact 2.5-gallon tank capacity, which proves sufficient for single-fixture demands. The system comes backed by Bosch’s confidence: a six-year limited warranty on the unit and two years on components. Most impressively, users can expect hot water delivery in under 90 seconds, effectively eliminating those frustrating waits at distant faucets.

Money says this point-of-use heater addresses a key efficiency issue in home water systems. While traditional tankless heaters lurk in basements or utility rooms, the Tronic 3000 can be tucked away under sinks or inside cabinets, providing an immediate hot water bridge until the main system catches up. This strategic placement not only reduces water waste from long pipe runs but also eliminates those annoying 10-second-plus waits for hot water to reach distant fixtures.

Note: This article was not paid for nor sponsored. StudyFinds is not connected to nor partnered with any of the brands mentioned and receives no compensation for its recommendations. This article may contain affiliate links in which we receive a commission if you make a purchase.