7 Best On-Demand Water Heater Reviews

On-demand water heaters have revolutionized the way we access hot water. These heaters, available in electric, gas, and propane variants, provide hot water instantly without the need for a storage tank. Electric models are perfect for homes with easy access to power, while gas and propane versions are ideal for locations without electricity.

For those who love to travel, there are specific models designed for RVs, ensuring a warm shower even on the road. If you’re looking to heat your floors, some heaters are optimized for infloor heating.

For those who prioritize showers, certain models ensure a consistent temperature for a comfortable experience. Outdoor enthusiasts aren’t left out either, with outdoor-specific models available.

With so many options, finding the top on-demand water heater to suit your needs has never been easier.

Stiebel Eltron Tempra 29 Plus Water Heater

Top Benefits of On-Demand Water Heaters

On-demand water heaters, often referred to as tankless heaters, have revolutionized the way we use hot water. One of their standout features is the ability to provide hot water instantly.

No more waiting for the tank to heat up; it’s all about instant gratification. This immediacy is not just about comfort but also about energy conservation. Traditional water heaters keep the water hot continuously, leading to energy wastage. In contrast, on-demand heaters only heat the water as it’s needed, translating to significant cost savings on energy bills.

The design of these heaters is another notable advantage. Their compact nature means they occupy less space, making them ideal for homes with space constraints.

The absence of a storage tank minimizes the risk of water damage. Traditional tanks, over time, can corrode and leak, potentially causing property damage. With tankless systems, this risk is significantly diminished.

Top 7 On-Demand Water Heater Reviews

1. Stiebel Eltron Tempra 29 Plus Water Heater

The Stiebel Eltron Tempra 29 Plus is a state-of-the-art tankless water heater designed to provide an endless supply of hot water on demand. Its sleek design not only saves space but also eliminates the need for venting.

The heater boasts two temperature memory presets, allowing users to adjust according to their personalized needs. It requires a hard-wired 240 or 208-volt electric service and is equipped with Advanced Flow Control German patented technology.

This ensures constant comfort by automatically maintaining water temperature. Moreover, it’s energy-efficient, using 15-20% less energy compared to conventional electric tank water heaters.

  • Special Feature: LED Display
  • Capacity: 0.39 Gallons
  • Material: Copper
  • Wattage: 28.8 KW
  • Style: Tempra 29 Plus (29 kW)
  • Dimensions: 4.63 x 16.63 x 14.5 inches
  • Weight: 1 Pound

Key Features

  • Advanced Flow Control technology
  • Energy-efficient design
  • Dual temperature memory presets
  • Sleek, space-saving design
  • No venting required

Compatible For

  • Large households
  • Commercial spaces
  • Energy-saving homes

Where Need to Improve

  • Requires hard-wired electric service
  • Needs 200 amp total service to residence

The Stiebel Eltron Tempra 29 Plus is a top-tier tankless water heater, perfect for those seeking energy efficiency and an endless hot water supply. Its advanced features and sleek design make it a standout choice for on-demand water heating.

2. Camplux 1.58 GPM Propane Water Heater

Camplux’s 1.58 GPM Propane Water Heater is a versatile and portable solution for those who require hot water in off-grid and rural areas.

Powered by two size D batteries, this heater ensures you never have to endure a cold outdoor shower again. Its compact design, weighing just 14 lbs, makes it an ideal companion for camping, road trips, and RVs.

The heater offers a range of safety features, including anti-freezing protection, overheating protection, and a flame failure device. With a capacity of 1.58 gallons, it’s efficient, and energy-saving, and ensures up to 98.95% savings on water heating costs.

  • Special Feature: LED Display
  • Capacity: 1.58 Gallons
  • Material: Alloy Steel
  • Wattage: 12 KW
  • Style: 6L Water Heater
  • Dimensions: 17.3 x 11.6 x 4.3 inches
  • Weight: 13.7 Pounds

Key Features

  • Energy-saving design
  • Portable and lightweight
  • Multiple safety features
  • Ideal for off-grid areas
  • Battery-powered operation

Compatible For

  • Camping and road trips
  • RVs and mobile homes
  • Outdoor showers

Where Need to Improve

  • Requires D batteries for operation
  • Specific installation instructions

The Camplux 1.58 GPM Propane Water Heater is the ultimate on-demand solution for outdoor enthusiasts. Its portability and energy-saving features make it a must-have for those on the move, ensuring a warm shower wherever you are.

3. Thermomate Electric Tankless Water Heater

The Thermomate Electric Tankless Water Heater is a cutting-edge solution for those seeking instant hot water without the wait. This heater is designed to provide consistent hot water, ensuring efficient heating and stable performance.

Its unique design allows for significant energy savings, with self-modulating technology that adjusts energy based on demand. The heater is constructed with alloy metal housing, ensuring longevity and reduced maintenance.

Its compact wall-mounted design is perfect for any space, making it a versatile choice for modern homes.

  • Special Feature: Instant heating water, free of maintenance heating element
  • Capacity: 2.15GPM at 35°F Rise
  • Material: Alloy Steel
  • Wattage: 11 KW
  • Style: Auto
  • Dimensions: 14.75 x 11.75 x 3.13 inches
  • Weight: 14.37 pounds

Key Features

  • Endless on-demand hot water
  • Energy-saving self-modulating technology
  • Durable alloy metal housing
  • Easy and safe installation
  • Compact space-saving design

Compatible For

  • Modern homes
  • Office spaces
  • Apartments and condos

Where Need to Improve

  • Requires 2 sets of double-pole 30AMP breakers
  • Specific installation requirements

The Thermomate Electric Tankless Water Heater stands out as a top choice for on-demand water heating. Its energy-saving features and durable design ensure consistent hot water whenever you need it.

4. RUINOPAR Portable Propane Water Heater

RUINOPAR’s Portable Propane Water Heater is the ultimate solution for those seeking hot water in various settings. Whether you’re camping or in a cabin, this heater ensures you have hot water instantly.

Its design is not only compact but also packed with safety features, ensuring a comfortable and safe experience. The heater is versatile, suitable for both indoor and outdoor use, and offers a range of protections, including anti-freezing and flame-out protection.

  • Special Feature: LED Display, Anti-Freezing Protection
  • Capacity: 6 Liters
  • Material: Copper
  • Style: Portable, Automatic, Adjustable, Outdoor
  • Dimensions: 11.8 x 6.1 x 11.3 inches
  • Weight: 12.62 pounds

Key Features

  • Instant on-demand hot water
  • Multiple safety protections
  • Lightweight portable design
  • Energy-saving automatic ignition
  • Suitable for indoor and outdoor use

Compatible For

  • Camping and outdoor adventures
  • Cabins and remote locations
  • RVs and mobile homes

Where Need to Improve

  • Requires specific installation steps
  • Gas leakage precautions

RUINOPAR’s Portable Propane Water Heater is a game-changer for those on the move. Its portability combined with safety features ensures you have hot water wherever you go, making it a top pick for outdoor enthusiasts.

5. Camplux Propane Tankless Water Heater

Camplux’s Propane Tankless Water Heater is designed for those who prioritize both performance and aesthetics. This heater ensures steady temperature control, providing hot water within seconds.

Its high heating performance is complemented by its sleek black design, making it a stylish addition to any space.

The heater is not only efficient but also space-saving, making it ideal for homes, cabins, and apartments.

  • Special Feature: Instant heating water, free of maintenance heating element
  • Capacity: 3.18 Gallons
  • Material: Stainless Steel
  • Wattage: 42 watts
  • Style: Liquid Propane 3.18 GPM
  • Dimensions: 14.37 x 4.72 x 25.39 inches
  • Weight: 24.8 pounds

Key Features

  • Steady temperature control
  • High heating performance
  • Space-saving design
  • Easy to operate with LED touchscreen
  • Energy-efficient with auto ignition

Compatible For

  • Modern homes and apartments
  • Indoor installations
  • Cabins and vacation homes

Where Need to Improve

  • Requires specific installation requirements

The Camplux Propane Tankless Water Heater is the epitome of efficiency and style. Its advanced features combined with its sleek design make it an excellent choice for those seeking consistent on-demand hot water.

6. WINTEMP Electric Tankless Water Heater

The WINTEMP Electric Tankless Water Heater is a modern marvel in the world of water heating. Designed to provide instant hot water without the need for a storage tank, this heater is both efficient and space-saving.

Its unique rotatable digital display ensures easy temperature monitoring, even in tight spaces. The heater is constructed with a fire-retardant ABS casing, ensuring safety and durability.

Its energy-saving feature adjusts power input based on real-time demand, ensuring you only use what you need.

  • Special Feature: Fire-retardant ABS casing
  • Material: Acrylonitrile Butadiene Styrene
  • Wattage: 3500 watts
  • Style: 3.5 KW
  • Dimensions: 9 x 2.6 x 8.5 inches
  • Weight: 5.04 pounds

Key Features

  • Instant and endless hot water
  • Rotatable digital display
  • Energy-saving adjustments
  • Compact and versatile design
  • Multiple safety protections

Compatible For

  • Modern kitchens
  • Small apartments
  • Office spaces

Where Need to Improve

  • Limited to 120V circuit

WINTEMP’s Electric Tankless Water Heater is a top-tier choice for those seeking efficient and instant hot water solutions. Its unique features and compact design make it a must-have for modern homes.

7. ECOTOUCH Electric Tankless Water Heater

ECOTOUCH’s Electric Tankless Water Heater is a blend of power and innovation. With a whopping 14kW heating system, it promises instant hot water without the wait.

Its self-modulating feature ensures optimal energy efficiency, adjusting power based on real-time demand. The heater boasts a sleek design, making it a stylish addition to any space.

Its overheating protection ensures safety, making it a reliable choice for households.

  • Special Feature: Overheat Protection
  • Capacity: 14 Kilowatts
  • Material: Aluminum
  • Wattage: 14000.00
  • Style: Indoor Installation
  • Dimensions: 11.14 x 3.46 x 15.87 inches
  • Weight: 14.11 pounds

Key Features

  • Instant and sufficient hot water
  • Smart self-modulation
  • Sleek and stylish design
  • Multiple safety features
  • Easy-to-use digital controls

Compatible For

  • Modern homes
  • Large apartments
  • Commercial spaces

Where Need to Improve

  • Limited to indoor installation

ECOTOUCH’s Electric Tankless Water Heater stands out with its powerful heating system and sleek design. It’s the perfect blend of functionality and style, making it a top choice for on-demand water heating.

Buying Guide for the Best On-Demand Water Heaters

Energy Source

Before diving into specific models, determine your preferred energy source. On-demand water heaters can be powered by electricity, gas, or propane. Your choice will influence installation requirements and operational costs.

Size and Capacity

Size matters. Ensure the unit can handle your household’s hot water demands. Larger families or homes with multiple bathrooms might require a more robust system. Check the unit’s gallons-per-minute (GPM) rating to gauge its capacity.

Efficiency and Savings

Look for models boasting high energy efficiency. These units not only reduce environmental impact but also lead to significant savings on utility bills. Energy Factor (EF) is a key metric here; higher EF indicates greater efficiency.

Installation and Maintenance

Some units might have specific installation prerequisites, especially gas-powered models that need proper ventilation. Also, consider maintenance needs. Models with self-cleaning systems or easy-to-access parts can save time and effort in the long run.

Safety Features

Safety should never be compromised. Opt for heaters with built-in safety mechanisms like overheat protection, dry-heating protection, and electricity leakage protection.

Digital Displays and Controls

Modern on-demand water heaters often come with digital displays, allowing for precise temperature control and system monitoring. This feature enhances user experience and ensures a consistent hot water supply.

Durability and Warranty

A water heater is a long-term investment. Prioritize models known for durability. Also, check the warranty terms. A more extended warranty often indicates the manufacturer’s confidence in the product’s longevity.

Read More: 7 Best Mini Tank Water Heaters


On-demand water heaters, commonly known as tankless heaters, are a modern solution for an efficient hot water supply. Here’s a detailed guide to ensure a proper installation:

Step 1: Shut off the Power Supply

Before beginning, shut off the main power supply to prevent any electrical mishaps. If you’re working with a gas unit, ensure the gas supply is turned off.

Step 2: Prepare the Area

Clear the installation space, ensuring it’s free from any obstructions. For gas units, ensure the area has adequate ventilation.

Step 3: Remove Existing Unit

If you’re replacing an old heater, disconnect and remove it. Ensure all water lines are drained.

Step 4: Mounting

Secure the mounting hardware to the wall, ensuring it’s sturdy and level.

Step 5: Position the Heater

Hang the tankless heater onto the mounting hardware, ensuring it’s stable.

Step 6: Water Line Connections

Connect the incoming cold water line to the heater’s inlet and the outgoing line to the heater’s outlet. Seal connections with Teflon tape to prevent leaks.

Step 7: Gas or Electric Connections

For electric models, connect the heater to the electrical supply following the manufacturer’s guidelines. For gas models, attach the gas line, ensuring a tight connection.

Step 8: Venting

If you’re installing a gas model, set up the venting system as per the manufacturer’s specifications to ensure the safe expulsion of gases.

Step 9: Power On

Reconnect the power supply. For gas models, ensure the pilot is ignited.

Step 10: Test Run

Activate the heater by turning on a hot water tap. Monitor for any leaks and verify that the water reaches the desired temperature.

Key Factors to Consider

Choosing the right on-demand water heater requires a bit of homework. It’s essential to select a heater that matches your household’s size and needs. A unit too small might not meet the demand, while an oversized one could lead to unnecessary energy consumption.

The energy source is another vital consideration. While electric models are popular due to their ease of installation, gas and propane options can be more energy-efficient and cost-effective in the long run.

Installation can be a significant expense, so it’s essential to factor in both the unit’s cost and the installation charges.


Like all appliances, on-demand water heaters require regular maintenance to function optimally.

One common issue with these heaters is mineral build-up, which can affect their efficiency. Periodic descaling can help prevent this.

For those using gas or propane models, ensuring proper ventilation is crucial to prevent harmful gas build-ups. Regularly inspecting the unit for leaks or malfunctions can prevent potential damage and ensure the system’s longevity.

It’s also wise to have the unit inspected by professionals periodically to ensure it’s operating at peak performance.

Smart Usage Recommendations

To get the most out of your on-demand water heater, some usage tips can come in handy. It’s essential to adjust the temperature settings to a comfortable level to prevent scalding.

Monitoring and maintaining proper water pressure ensures the unit operates efficiently.

Remember, the beauty of these systems lies in their efficiency and instant heating capability, so use them wisely to reap the maximum benefits.

Frequently Asked Questions

How Do On-Demand Water Heaters Differ from Traditional Ones?

On-demand water heaters, also known as tankless heaters, heat water directly without the use of a storage tank. Unlike traditional heaters that store and continuously heat water, on-demand units heat water only as it flows through the device, offering immediate hot water.

Is It Cost-Efficient to Switch to an On-Demand Water Heater?

Yes, while the initial investment might be higher, on-demand water heaters can be more cost-efficient in the long run. They typically last longer than traditional heaters and can reduce energy consumption by up to 30%, leading to significant savings on monthly bills.

Can One On-Demand Heater Serve an Entire Household?

It depends on the size and capacity of the heater and the household’s hot water needs. Larger homes or those with simultaneous hot water demands might require multiple units or a larger capacity model.

Are There Any Special Installation Requirements?

Installation can vary based on the energy source (electric, gas, propane). Gas models, for instance, might require a larger gas line or proper ventilation. It’s essential to consult with a professional to determine specific installation requirements.

Do On-Demand Water Heaters Provide Consistent Temperature?

Yes, advanced models come with modulating burners that adjust the flame size based on the flow rate, ensuring consistent temperature even with varying water flow rates.

In Summary

After discussing the various aspects of on-demand water heaters, it’s evident that they offer numerous advantages over traditional models. Their energy efficiency, space-saving design, and ability to provide instant hot water make them a top choice for modern households. For those considering a switch, the WINTEMP Tankless Water Heater also stands out with its unique features like the rotatable digital display, energy-saving capabilities, and safety certifications at an affordable price. Investing in such a unit can lead to long-term benefits, both in terms of comfort and savings.

Read More: 7 Best Indirect Water Heaters