10 Best Instant Hot Water Heater of December 2025

• 【INSTANT & SUFFICIENT HOT WATER】Applied with 5.5KW heating system, the electric water heater supplies instant, consistent and endless hot water of 116℉or higher temp shortly, no waiting for preheat nor terrible temp up & down, perfect companion for sinks. Time to get rid of those "lukewarm" toys.
• 【SMART SELF ADJUSTMENT】The hot water heater adjusts power input based on flow rate and temp setting in real time. For example, less power will be applied by the system when waterflow reduced, thus you still get ideal temperature instead of scalding hot water, which means comfortable experience. Optimal energy efficiency of 98% saves considerable electric charge.
• 【CONVENIENT USE】The tankless water heater comes with digital display & touch control panel so temp setting is easy job. Now turn on the tap and let the smart unit do the rest, you needn’t go through hard lesson about temp setting by a mixer tap without any hint. The Black model comes with Remote control, useful for installation under sink.
• 【SAFE and DURABLE】Applied with multiple protection devices, every piece goes through strict tests to ensure 100% safe. Inner water and electricity lines are designed to run separately so as to avoid leakage or harm of scale build up. Approval by ETL and qualifies for UL, you can expect outstanding performance for years to come.
• 【POINT of USE】The sleek tankless water heater is compact as an oatmeal box, making it possible to install anywhere close to outlet and avoid energy waste. It can be mounted horizontally, vertically, obliquely, ideal for kitchen, bar, school, hospital, community and hair salon. Please verify it is the right size for you: 5.5kW@240V; dimensions 11" x 7.5" x 2.35"; pipes fittings :1/2" NPT.

ECOTOUCH

• CONTINUOUS FLOW – Hot showers will never be interrupted again. Enjoy continuous, on-demand hot water with an unlimited supply, when you want it without wasting any energy when not needed.
• 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.
• SILENT OPERATION – One electronic flow sensor activates the noise free water heater. Digital temperature display is easy to read, while the powerful solid copper interior heating system does the work.
• TEMPRA 15 TREND – This specific model is 14.4kW, 240V9/208V, requires a min. recommended household electric service of 100 A, and offers an output water temperature of 86˚ to 140˚F. Check our guides below to compare features of our various Trend and Plus models, each available in different kW levels.
• 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.

Stiebel Eltron

• Sleek and compact design with digital output temperature display
• ECOSMART tankless water heaters are 99.8-percent energy efficient
• Manufactured in United States
• 12 A

Ecosmart

• WATTS RECIRCULATING HOT WATER PUMP: Provides hot water at every faucet or shower when needed, eliminating wasted water, 0.5 inches bypass value.
• BEST SELLING RECIRCULATING SYSTEM: Conserve up to 15,000 gallons of water per year. Save up to 10% of your water bill. It costs only $0.05 per day to operate.
• EASY INSTALLATION: Install in less than 1 hour. This unique product easily connects to existing plumbing and is maintenance-free.
• WATTS HOT WATER RECIRCULATING SYSTEM: The kit includes a pump with timer, 2 adapters with rubber washers, valve mounting screws, sensor valve, and two 12-inch supply lines.
• RECIRCULATING PUMP WITH TIMER: 24-hour programmable timer activates pump when you need it. No vibrations: it’s extremely quiet compared to other systems in the market. Do not use with tankless water heaters. Insert the 115V plug on the line cord from the pump into a properly grounded 115V outlet.

Watts Premier

• External digital thermostatic control with LED display (+/1 degree accuracy)
• Most advanced self-modulation, adjust power to meet hot water demand
• Durable Copper immersion two heating elements, field Serviceable. Flow Rate- up to 4.4 GPM
• Simple installation – bottom 3/4 inch NPT water connections
• Threaded for easy replacement, simple installation, digital temperature display

Rheem

• Lifetime warranty
• Save up to 60-percent on your water heating cost with an ECOSMART electric tankless water heater
• Never run out of hot water with an ECOSMART tankless water heater
• Patented Self Modulating Technology and design
• ECOSMART tankless water heaters are 99.8-percent energy efficient.Uniform Energy Factor:0.98

Ecosmart

• CONVENIENT HOT WATER HEATER: 4 gallon point-of-use mini-tank fits under your sink to provide hot water right where you need it. Thermal efficiency is 98%. Dimensions : 13.75 W x 13.75 H x 13.5 D Inches
• LONG LASTING QUALITY: This electric water heater is easy to maintain and has premium glass-lined material for a long service life. (Amps 12A, Volts (VAC) 120)
• INDEPENDENT INSTALLATION: 36-37" cord plugs into a 120 volt outlet for independent installation or in-line with a large hot water source
• FAST RECOVERY RATE: Eliminates long waits for hot water at your sink, get on demand hot water at your every need (supplies up to 2 sinks at a time)
• EASILY MOUNTED: Can be shelf, wall or floor mounted (bracket included); simply tap into the cold water line and install the water heater directly at the sink to provide hot water

Bosch Thermotechnology

• Savings of up to 50% on water heating costs. Dimensions :17H x 17W x 3.625D inches ;Pipes fittings :3/4 inch NPT
• Digital temperature control in 1-degree increments allows control of hot water; Activation Flow: 0.3 GPM
• Copper and stainless components designed for efficiency, durability and easy replacement.
• Compact size saves valuable storage space, while the stylish and advanced design is pleasing to the eye and Copper and stainless components designed for efficiency, durability and easy replacement.
• Prior to purchase & installation, please verify that this model is the right size for your hot water needs and electrical requirements. Electrical requirements: 27 kW, 240 volts, (3) 40 required breakers, 112.5 maximum power (AMP), (3) 8 required wire.Amperage Draw:113 A
• Required Breaker Quantity: Three 40 Amp Double Pole
• Recommended Electrical Panel: 200 Amps
• NEVER run out of hot water with an ECOSMART tankless water heater.
• Save up to 12 cubic feet of storage space.
• Digital temperature control in 1-degree increments gives users complete control of hot water

Ecosmart

• CONVENIENT HOT WATER HEATER: 2.5 gallon point-of-use mini-tank fits under your sink to provide hot water right where you need it. Thermal efficiency is 98%. Dimensions : 13.75 W x 13.75 H x 10.75 D Inches
• LONG LASTING QUALITY: This electric water heater is easy to maintain and has premium glass-lined material for a long service life. (Amps 12A, Volts (VAC) 120)
• INDEPENDENT INSTALLATION: 36-37" cord plugs into a 120 volt outlet for independent installation or in-line with a large hot water source
• FAST RECOVERY RATE: Eliminates long waits for hot water at your sink, get on demand hot water at your every need (supplies up to 2 sinks at a time)
• EASILY MOUNTED: Can be shelf, wall or floor mounted (bracket included); simply tap into the cold water line and install the water heater directly at the sink to provide hot water

Bosch Thermotechnology

• 【ENDLESS WATER HEATER】3 seconds to get hot water without preheating. Instant consistent and endless hot water of the maximum temperature reach to 131 ℉. Tankless electric water heater on demand suits for sinks and bathroom( meet bathing needs except extremely cold winter such as 28℉).
• 【SMART INVERTER FOR ENERGY SAVING】The hot water heater built-in smart chip to scientifically calculate the minimum required power based on the water flow and temperature thus costing less energy and money. Save up to 70%. The water flow rate and temp is stable under chip's control.
• 【SAFE DURABLE & LONGEVITY】Multiple safety protection functions protect you from the risk of scald, leakage or other injury. Premium tempered glass shell is corrosion resistant, high-grade and easy to wipe. This mini hot water heater is ideal for kitchen, bathroom, bar, school, hospital, community and hair salon.
• 【EASY TO USE】 The electric tankless water heater comes with digital display & touch control panel for visual setting. Shower head, water valve, pipes and other accessories are complete for quick installation without additional expenses or preparing time of accessories.
• 【COMPACT & POINT-OF-USE】It is surprised that this electric hot water heater can be installed 360°(no matter mounted horizontally, vertically & obliquely). Dimensions: 7.4″L x2.5″W x11.0″H; 5.13lbs; 1/2″NPT NPT. 6.5 kW, 220-240 volts. One-year warranty and 24H customer service support, feel free to contact us.

BISELONG