The Best Tankless Hot Water of 2024 - Review and Top Picks

CONTINUOUS FLOW – Advanced Flow Control patented technology invented by Stiebel Eltron, automatically maintains water temperature for constant comfort. It’ll reduce flow slightly if hot water demand exceeds capacity. Hot showers will never be interrupted again

SPACE & ENERGY SAVER – Its small, sleek white design saves space yet still provides endless hot water for your whole house, and no venting is required. Eco friendly unit saves energy with auto-modulation and the ability to electronically control water flow. Savings monitor even shows how much you save on energy costs

EASY OPERATION – Electronic switch activates the hot water heater and it’s noise free while in use. Has a digital temperature display and preset temperature and memory buttons, while the interior solid copper heating system does all the power work

TEMPRA 24 PLUS – This specific model is 24kW, 240V, requires a min recommended electric service of 150 A, and offers an output water temperature of 68° to 140°F. Check our guides below to compare features of our various Trend and Plus models, each available in different kW levels, Tempra Plus tankless water heaters can be set to limit the maximum hot water temperature to 109°F. This can be important in some installations to prevent the possibility of scalding.

WARRANTIES INCLUDED – Stiebel Eltron’s top-rated electric tankless water heaters perform with the highest standards for comfort and reliability. Our 7-Year Leakage and 3-Year Parts Warranties are included with purchase

Original Design: Tankless hot water heater only heats when necessary to conserve energy; For the latest in non-condensing technology and a cleaner layout that speeds up service and installation, check out our new RE160eN model

Never Run Out of Hot Water with this Compact Tankless Gas Water Heater: Non-condensing tankless hot water heater from Rinnai is only the size of a small suitcase and fits in a wide variety of spaces, but provides up to 6.5 GPM (5 fixtures at once)

Smart, Durable Design: Enhanced scale detection helps prevent serious, long-term damage to unit; Includes 15-, 5-, and 1-year residential guarantee for heat exchanger, labor, and parts, respectively; See Controlr module for WiFi control (not included)

Professional Installation Recommended: Visit the Find a Rinnai PRO page on our website to locate a qualified technician in your area to install your tankless water heater; We do not recommend installing a water heater without a technician

Find Your Rinnai: See our product guides, manuals, energy guide, warranty information, videos, and tables to find the right tankless water heater for your home; Check our Ground Water Temperature Map to see if this heater is optimal for your region

No more waiting for the water tank to warm up or running out of warm water halfway through your shower. With this amazing machine, you can have a steady stream of hot water flowing to your faucets or shower without waiting for the tank to warm up.

There is a forced exhaust structure that keeps the air safe and clean while and after entering the combustion chamber. There is also a dust net to make sure no dirt gets into the tankless water heater.

There is a low water pressure startup, which helps to protect the heater and make it easier to use.

Endless On-Demand Hot Water; Consistent hot water when you need it that never runs out; Continuously monitored water temperature and controlled flow rates ensure efficiency and consistent performance within 1 degree of selected temperature

Save Space; EcoSmart tankless electric water heaters are 90% smaller than traditional tank heaters; may be installed on wall or at point of use; Dimensions 11.5 x 8 x 3.75 inches

Save Energy; EcoSmart tankless electric water heaters are 99% thermal energy efficient; Only heats water when called unlike a tank heater that maintains water temperature even when not being used.

EcoSmart ECO 11 Sizing; 13-kilowatt tankless electric water heater ideal for providing hot water for a bathroom, small sink, office breakroom and other point-of-use or low-flow applications; provides between 1.3 and 3.1 gallons-per-minute depending on the inlet water temperature; refer to the sizing guide to select the proper solution

ON/OFF Dial Control with adjustable digital temperature display

Self-modulating power control

24kW Model Flow Rate: up to 5.9 GPM for RTEX-24

Bottom 3/4" NPT water connections

On demand, consistent and continuous hot water

External adjustable digital thermostatic control with LED display (+/1 degree accuracy

Durable Copper immersion two heating elements, field Serviceable.Self-modulating power control

Simple installation – 1/2 NPT adapters included; side 1/2 inch Compression water connections

99.8% energy efficient. External controls to adjust temperature in increments of 1°f. Water-Saver Shower Head – 1.5 GPM

Threaded for easy replacement, simple installation, digital temperature display 54 A. 13kW Model Flow Rate: up to 3.17 GPM

54 A

Compact,Light Weight Portable Design-12.8 (L)*6.1(W)*21.65(H) inch ,Weight-23.85 lb. Compact and portable design perfect for barns,cabins,outdoor instant hot shower and road trips.

Easy Installation for Instant Hot Water-It only takes you a few minutes to get 2.64 gallons per minute of instant hot water. The camplux portable water heater lights when water pressure between 3.6-110 PSI, low water pressure is perfect for campings and remote cabins.

Multiple Protection Ensure Your Safety-Flame failure device, anti-freezing protection, over heating protection to ensure the family safety. The anti-freezing drain plug discharges the residual water to avoid freezing in cold areas for long-time maintenance. Gas supply automatically shut off when high water temperature protection over 167 °F.

Power Efficient & Energey Saving -Maximum power output 68,000btu/hour, you will get instant endless hot water easily wherever you are. Compact and lightweight structure with 11.5% energy saving technology. The propane water heater exchanger and main burner are desinged with advanced combustion technology to decrease gas consumption and burning noise.

Important Tips -To avoid gas leakage caused by improper sealing of the water heater, DO NOT TWINE TEFLON TAPE between gas regulator and gas inlet pipe. The tankless water heater will "caught on fire "with improper operation. Always check gas leakage before operation.

【INSTANT & SUFFICIENT HOT WATER】 With real powerful 18kW smart heating system, the tankless hot water heater electric ECO180B supplies sufficient instant and endless hot water of 120℉ or higher in seconds, no waiting for preheating nor terrible temp fluctuation during shower time any more and no worry of running out of it. Perfect companion for whole house use, including shower, sink faucets, dishwasher, washing machine, etc.

【SELF MODULATION INSTANT WATER HEATER】The electric on demand tankless hot water heater ECO180B adjusts exact power input based on current flowrate and temp setting. For example, less power will be consumed by the smart water heater when you reduce water flow, thus, you get ideal temperature instead of scalding hot, which ensures comfortable experience and excellent energy efficiency. Also, optimal energy efficiency of 98% saves considerable electric charge for you.

【CONVENIENT USE】The electric tankless water heater 18kW comes with digital display & touch control panel so temp setting is easy job. Best of all, useful information on the screen helps you get full understanding of the working status of the 240v water heater tankless, you needn’t go through hard lesson of temp setting. Now turn on the faucet and let the smart instant hot water heater do the rest.

【SAFE and DURABLE】Newly updated and applied with multiple protections, such as leakage protection, over heating protection and auto stop. Every piece electric tankless water heater ECO180B goes through strict tests to ensure 100% safety and it is listed by ETL and qualifies for UL. Inner water and electricity lines are designed to run separately so as to avoid leakage risk and scale build up. You can expect outstanding performance for years to come.

【POINT of USE WATER HEATER】The sleek tankless water heater ECO180B is compact as shoes box, making it possible to install anywhere point of use to avoid waste, ideal for shower, kitchen, bar, school and hair salon. Please verify it is the right size for you: 18kW at 240V(only); dimensions 12.22" (W) x 17.25" (H) x 4.02" (D); plumbing connections :3/4" NPT. In order to install 18kW Tankless Water Heater it would requires 240V, 2X40AMP Double Pole Breaker and 2X8AWG/2 wires with Grounding.

☼ Endless Hot Water: Imagine you are the last one in your family to take a shower before heading out for the day. You turn on the faucet and the water is freezing cold. Too bad you don’t have an Airthereal Electric Tankless Water to provide endless hot water on demand with no preheating, temperature fluctuations, or running out of hot water in the tank.

☼ Save Space: That water heater in the basement or utility closet takes up a ton of space. This wall-mounted water heater uses 90% less space than a traditional hot water heater with a tank.

☼ Save Energy: Water is only heated when you need it, not stored in a hot water tank. The self-modulating temperature technology only uses energy to heat up water while you are using it to save up to 50% on water heating costs compared to a typical tank water heater.

☼ Important Note: In order to install 18kW Electric Tankless Water Heater it requires 240 Voltage, 2 x 40 AMP Circuit Breaker Size and a set of 2 x (8AWG/2) wires. Please check to confirm that your breaker panel meet these specifications.

☼ Safe To Use: With high temp protection, dry heating protection, and electrical leakage protection you can rest easily knowing you have safe, on-demand hot water to use on your schedule. The electric and fluid systems are completely separated to prevent electric leakage and water pipe corrosion.

Note: Please download and read the installation manual and product manual carefully when purchasing the product to ensure that your installation environment is consistent with this product. When installing, please strictly follow the installation manual and installation instruction video, otherwise it may not work. If you have any questions about the product, please contact us by email. We have a professional technical support team.

【Tankless Instant Hot Water Heater】No need to preheat before using the tankless water heater. As soon as you turn on the tap, the water flows with your desired temperature.

【High Sensitive Touch Led Display】Comes with smart digital LED display high-definition large screen, freely adjustable the temperature between 30℃-65℃.

【Multiple Security Protection】The natural gas water heater is upgraded with 12 protection methods to ensure your safety. Such as dry burning protection, over 65℃(149 °F) protection, leakage protection, etc.

【Energy and Money Saving】The hot water heater adjusts power input based on flow rate and temp setting in real time. Summer/winter 2 modes to save up to 60% on your natural gas costs.

【Quality Material】Made with brushed stainless steel material, the natural gas water heater has the function of high temperature resistance, corrosion resistance. Built-in oxygen-free copper water tank, long service time.Note: This product must be installed with a ventilation and smoke exhaust pipe for normal use.