NEED PLUMBING SERVICES! GET A FREE QUOTE NOW 888-378-1710

These are the 10 Best Tankless Water Heater for Tub : Top Rated Models Reviewed & Compared!

The Best Tankless Water Heaters for Tub

If you want to fill up your bathtub with hot water then a tankless water heater is the best. Because with it you can supply your desired temperature hot water endlessly. Where other heating devices aren’t capable to supply hot water at endless and certain temperatures.

Rinnai is the best tankless water heater for tub and also for the whole house. Besides, Rheem, Stiebel & Ecosmart are best for Point-of-use and Multi-point-of-use. You can operate the Eemax device with electricity, and use natural gas for Noritz.

These are the 10 Best Tankless Water Heater for Tub

  1. Top Pick: Rinnai V75eP Propane Tankless Hot Water Heater
  2. Editor’s Choice: Ecosmart ECO Electric Tankless Water Heater
  3. Best Overall: Stiebel Eltron Tankless Water Heater
  4. Best Budget: Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater, GRAY
  5. Best Rated: Eemax EEM24027 Electric Tankless Water Heater
  6. Best Point Of Use: Rheem RTEX-24 24kW 240V Electric Tankless Water Heater
  7. Best Electric Powered: Rheem RTEX-18 18kW 240V Electric Tankless Water Heater, small, Gray
  8. Best Multi Point Use: Stiebel Tankless Electric Water Heater
  9. Best Indoor: Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater
  10. Best Gas: Noritz NRC66DVNG Tankless Hot Water

Review

1. Rinnai V75eP Propane Tankless Hot Water Heater

Top Pick
Tankless Water Heater for Tub

Rinnai V75eP

Specification

  • Activation GPM: 0.4
  • Uniform Energy Factor (UEF): 0.82
  • Water Connection: 3/4″
  • Gas Connection: 3/4″
  • Flow Rate (Max): 7.5 GPM
  • Flow Rate (Mini):  0.26 GPM
  • Gas Input BTU(Max): 180000
  • Water Pressure PSI (Max): 150
  • Water Pressure PSI (Min): 20
  • Temperature (Max): 140 Degree F
  • Temperature (Mini): 98 Degree F
  • Dimensions:  30 x 14.04 x 9.27 inches
  • Weight: 47.4 lbs.
  • Installation place: Outdoor Only
  • Fuel Type: Liquid propane
  • Vent Type: Vent-free
  • Voltage: 120V
  • Wattage: 76 watts.
  • AMP: 4A
  • AHRI Certified: Yes
  • CSA Approved:  Yes
  • Heat Exchanger Warranty: 10 years
  • Key Features: Endless Hot Water, Energy and Space Efficient, Optimal Water Pressure, Leak Detection, Temperature Lock, And Freeze Protection

You can use Rinnai V75EP as a tankless water heater for tub because it has 32% higher energy efficiency than the tank saves energy, saves your water heating cost, and also reduce your utility bill.

It is only outdoor installation, so it can be supposed to you a bad feature but to keep free you from the tension it has Freeze Protection. You can install it for mobile homes and it is Certified for it. It has a WiFi connection feature.

You can use the Rinnai V75EP instead of tank not for point-of-use. Generally, point of use tankless water heater can’t support many fixtures. But it can support more fixtures.

The ignition type is electronic, so it saves your money for fuel by removing the pilot light.

The leak detection feature reduces your property damage by shutting off the water and Temperature Lock save you and your family member from unauthorized or accidental changes in water temperature.

The manufacturer offers 5 years on parts, 10 years coverage on the heat exchanger, and 1 year on labor.

Pros

  • Leak detection limit property damage.
  • Smarter, more durable than a tank.
  • Super high efficiency.
  • Temperature lock prevents changes to water temperature.
  • Saves valuable space.
  • Enjoy energy-saving benefits

Cons

  • It is only outdoor installation.
  • Isolation valves are sold separately.

2. Ecosmart ECO Electric Tankless Water Heater

Editor’s Choice
Ecosmart ECO Electric Tankless Water Heater, 27 KW at 240 Volts, 112.5 Amps with Patented Self Modulating Technology, White

Ecosmart ECO

Specification

  • Activation GPM: 0.3
  • Energy efficiency: 99.8%
  • Water Connection: 3/4”
  • Flow Rate (Max): 2.7 GMP
  • Flow Rate (Mini):  6.5 GMP
  • Water Pressure PSI (Max): 150
  • Water Pressure PSI (Min): 25
  • Temperature (Max): 140 Degree F
  • Temperature (Mini): 80 Degree F
  • Dimensions: ‎3.63 x 17 x 17 inches
  • Weight: 10.98 pounds
  • Installation place: Indoor
  • Fuel Type: Electricity
  • Vent Type: Vent Free
  • Recirculation: No
  • Voltage: 240V
  • Wattage: 27 KW.
  • AMP: 112.5A
  • Number of breakers: 3 x 40 DP
  • CSA Approved:  Yes
  • Warranty:  Lifetime
  • Key Features: Endless on-Demand Hot Water, Save Space, Save Energy, Auto thermal protection.

EcoSmart ECO 27 has a digital temperature control panel with the control panel you can increase the temperature by 1 degree. With the digital display, you can observe the outlet water temperature.

It has a Self-modulating flow sensor, this technology control the supply of energy. When you need more hot water than you it supplies more energy. This technology reduces the waste of energy and saves utility bills.

The manufacturer offers a lifetime warranty that is amazing but it is only on electronics, elements, and exchangers.

Auto Thermal Protection saves you and your family member from accidental changes in water temperature.

It is only for indoor installation but if you want you can install it outdoor. But when will you mount it outdoor you have to keep away from debris, rain, dust, insects, splashed water, and direct sunlight. The warranty could be violated if any moisture is inside it when it freezes.

Pros

  • Saves up to 60% cost.
  • Lifetime warranty.
  • Auto thermal protection.
  • Compact design.
  • Self-modulating flow sensor technology.
  • Digital temperature control.

Cons

  • Manufacturers don’t provide any accessories.

3. Stiebel Eltron Tankless Water Heater

Best Overall
Stiebel Eltron Tankless Water Heater – Tempra 24 Plus – Electric, On Demand Hot Water, Eco, White

Stiebel

Specification

  • Activation GPM: 0.5
  • Uniform Energy Factor (UEF): 0.99
  • Water Connection: 3/4”
  • Flow Rate (Max):  8 GPM
  • Flow Rate (Mini):  0.5 GPM
  • Water Pressure PSI (Max): 150
  • Water Pressure PSI (Min): 30
  • Temperature (Max): 140 Degree F
  • Temperature (Mini): 68 Degree F
  • Dimensions:  ‎4.63 x 16.63 x 14.5 inches
  • Weight: 16.1lbs
  • Installation place: Indoor
  • Fuel Type: Electric
  • Vent Type: Vent Free
  • Recirculation: No
  • Natural Gas Thermal Efficiency:
  • Voltage: 240V
  • Wattage: ‎18000 watts.
  • AMP: 100A
  • Number of breakers: 2 x 50 A DP
  • CSA Approved:  Yes
  • Heat Exchanger Warranty: 7 years
  • Key Features: Powerful Output, Endless Water Supply On-Demand, Remarkable Energy-Saving, Compact Design, Space & Energy Saver, Easy Operation.

Stiebel Eltron Tempra 24 Plus is a vent-free and compact design that allow flexibility in installation. Since it is compact so you can use it as a tankless water heater for tub.

The efficiency of the device is 99% and it saves 15% to 20% electricity compared to a conventional electric water heater tank. 

The manufacturer offers a 7-year warranty on the heat exchanger and 3 years on parts.

Advanced Flow Control German patented technology invented by Stiebel Eltron to automatically maintain water temperature for constant comfort

The device is easy to install. It has a monitor with the energy monitor, you can calculate the cost savings.

Flow control technology, continuously observes the flow and temperature and prevents accidental change. You can also enjoy the preset temperature memory button.  

When installing it you have noticed that it must be installed vertically.

Pros

  • Easy and quick installation.
  • Compact space-saving design.
  • Two temperature memory keys.
  • Self-Modulation Energy Technology.
  • Energy monitor showing cost savings.
  • Preset temperature memory button.

Cons

  • Professional installation is recommended.

4. Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater, GRAY

Best Budget
Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater, GRAY

Rheem

Specification

  • Activation GPM: 0.3
  • Uniform Energy Factor (UEF): 0.99
  • Water Connection: 3/4”
  • Flow Rate (Max):  4 GPM
  • Flow Rate (Mini):  0.3 GPM
  • Water Pressure PSI (Max): 150
  • Water Pressure PSI (Min): 25
  • Temperature (Max): 140 Degree F
  • Temperature (Mini): 59 Degree F
  • Dimensions:  ‎12.63 x 8.25 x 3.63 inches
  • Weight: 19lbs
  • Installation place: Indoor
  • Fuel Type: Electricity
  • Vent Type: Vent Free
  • Recirculation: No
  • Voltage: 240V
  • Wattage: 13000 watts.
  • AMP: 54A
  • CSA Approved:  Yes
  • Heat Exchanger Warranty: 5 years
  • Key Feature: External digital display, Digital temperature display, On-demand water supply

Rheem RTEX 13 Residential tankless water heater energy efficiency is 99.8%. The high energy efficiency means it doesn’t waste energy.

Since this tankless water heater can supply endless hot water so you can install it for your tub and also for other bathroom and kitchen fixtures.

The activation flow rate is 0.3 GPM and the highest flow rate is 4 GPM. The temperature range is 59 to 140 degrees Fahrenheit and the water pressure range is 25 to 150 PSI.

It has an external display so you can easily watch and also it has a digital temperature display.

The device design is sleek and compact, so you can install it in less space compared to a tank water heater. The dimension is 12.63 x 8.25 x 3.63 inches.

Pros

  • Simple installation.
  • Don’t need a professional.
  • External controls to adjust the temperature.
  • 99.8% energy efficient.
  • Replaceable heating elements.

Cons

  • Sometimes unit function can be failed.

5. Eemax EEM24027 Electric Tankless Water Heater

Best Rated
Eemax EEM24027 Electric Tankless Water Heater , Blue

Eemax

Specification

  • Activation GPM: 0.3
  • Uniform Energy Factor (UEF): 0.99
  • Water Connection: 3/4”
  • Flow Rate (Max):  7 GPM
  • Flow Rate (Mini):  0.3 GPM
  • Water Pressure PSI (Max): 150
  • Water Pressure PSI (Min): 25
  • Temperature (Max): 140 Degree F
  • Temperature (Mini): 80 Degree F
  • Dimensions: 17 x 17 x 3.75 inches
  • Weight: 13.75 pounds
  • Installation place: Indoor
  • Fuel Type: Electricity
  • Vent Type: Vent Free
  • Recirculation: No
  • Voltage: 240V
  • Wattage: ‎27000 watts.
  • AMP: 112A
  • Number of breakers: 3 x 40 AMP
  • CSA Approved:  Yes
  • Heat Exchanger Warranty: 5 years
  • Key Features: Digital Display, On-demand endless hot water, Variable Temperature,  Automatic Shut Off, Compact, Corrosion Resistant.

EEMAX EEM24027 is corrosion resistant, so the lifespan is long and it has 5 years warranty on the heat exchanger and also 1 year on parts.

The manufacturer uses Copper Emerson and brass that increase the product’s durability and it is easy to replace.

The company provides 1/2” CF water connectors and 3’ electric cables. So buyers don’t need to buy separately. Users can install it yourself don’t need a plumber. During installation, notice that the water connection will be bottom.

General, do people think that Can a tankless water heater fill a tub? Yes, a tankless water heater for tub not only fills the tub but also supports other bathroom and kitchen fixtures. How many fixtures it can support depends on the maximum flow rate.

Pros

  • 99.8% energy efficient.
  • Instant, consistent, and endless hot water.
  • Corrosion Resistant.
  • Automatic shut off.
  • Sleek and compact design.
  •  Variable Temperature.

Cons

  • Heating elements have issues.

6. Rheem RTEX-24 24kW 240V Electric Tankless Water Heater

Best Point Of Use
Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray

Rheem

Specification

  • Activation GPM: 0.3
  • Uniform Energy Factor (UEF): 0.99
  • Water Connection: 3/4”
  • Flow Rate (Max): 5.9 GPM
  • Flow Rate (Mini):  0.3 GPM
  • Water Pressure PSI (Max): 150
  • Water Pressure PSI (Min): 25
  • Temperature (Max): 140 Degree F
  • Temperature (Mini): 80 Degree F
  • Dimensions:  18.25 x 14.5 x 3.5 inches
  • Weight: 17.8 pounds
  • Installation place: Indoor
  • Fuel Type: Electricity
  • Vent Type: Vent Free
  • Recirculation: No
  • Voltage: 240V
  • Wattage: 24,000 watts.
  • AMP: 100A
  • Number of breakers: 3×40 Amp
  • CSA Approved:  Yes
  • Heat Exchanger Warranty: 5 years
  • Key Feature: On-Demand Hot Water, Optimized Operation, No Venting, Energy Smart

Rheem RTEX 24 is an energy and cost-saving device because it heats the amount of water that is only needed, doesn’t heat exceed water.

As a point-of-use, it is the best tankless water heater for tub, because with this device users can save up to 50% on water heating costs if you use it as a point-of-use or if you use it for whole-home then it can save 34%.

The device ensures continuous hot water. If you use the device for other fixtures instead of tub you can run two faucets and three showers.

The product design is compact and sleek. So it can easily fit any small place like under sinks or cabinets.

The manufacturer provides a 1-year warranty on parts and 5 years on the heat exchanger.

It is easy to operate, you can increments the temperature by 1-degree from 80 to 140 degrees F. It has an external digital display. So you can easily monitor the temperature and other functionality.

Pros

  • Digital temperature display.
  • Self Modulating.
  • On-demand endless hot water.
  • Simple Installation.
  • Easy to maintain.
  • 99.8% Energy efficient.

Cons

  • It is a bit slower than the tank water heater.

7. Rheem RTEX-18 18kW 240V Electric Tankless Water Heater, small, Gray

Best Electric Powered
Rheem RTEX-18 18kW 240V Electric Tankless Water Heater, small, Gray

Rheem

Specification

  • Activation GPM: 0.25
  • Uniform Energy Factor (UEF): 0.99
  • Water Connection: 3/4”
  • Flow Rate (Max):  4.4 GPM
  • Flow Rate (Mini):  0.25 GPM
  • Water Pressure PSI (Max): 150
  • Water Pressure PSI (Min): 25
  • Temperature (Max): 140 Degree F
  • Temperature (Mini): 80 Degree F
  • Dimensions: ‎18.5 x 14.5 x 3.5 inches
  • Weight: ‎14.78 pounds
  • Installation place: Indoor
  • Fuel Type: Electric
  • Vent Type: Vent Free
  • Recirculation: No
  • Voltage: 240V
  • Wattage: 18,000 watts.
  • AMP: 75 A
  • Number of breakers: 2 x 40 AMP
  • CSA Approved:  Yes
  • Heat Exchanger Warranty: 5 years
  • Key Features: On-Demand Hot Water, Simple Maintenances, Electronic Temperature  Control, Easy Installation.

Rheem RTEX 18 tankless water heater can be used as a point-of-use or whole home. The efficiency is 99.8%. with continuous hot water. It has a digital temperature control panel with this panel you can monitor easily. The temperature range between 80 degrees F to 140 degrees F.

The Robust copper and brass mixer increase the durability of heating elements and they are easy to replace.

The minimum flow rate is 0.25 gallons per minute and the maximum flow rate is 4.4 gallons per minute. With the digital display you can control temperature and it has a self-modulating power control feature.

It is easy to install, just remember that the water connection should be bottom. The water connection is 3/4” NPT that universal size, so it can easily fit with other accessories.

Pros

  • Most advanced self-modulation.
  • Digital temperature display.
  • 99.8% Energy efficient.
  • On-demand continuous hot water.
  • Compact design.

Cons

  • Sometimes it doesn’t supply the desire water flow.

8. Stiebel Tankless Electric Water Heater

Best Multi Point Use
Stiebel Eltron Single-Multi-Point-of-Use Tankless Electric Water Heater

Stiebel Eltron

Specification

  • Activation GPM: 0.26
  • Uniform Energy Factor (UEF): 0.99
  • Water Connection: 1/2”
  • Flow Rate (Max):  2 GPM
  • Flow Rate (Mini):  0.26 GPM
  • Water Pressure PSI (Max): 150
  • Water Pressure PSI (Min): 30
  • Temperature (Max): 140 Degree F
  • Temperature (Mini): 86 Degree F
  • Dimensions:  ‎14.25 x 8 x 4.12 inches
  • Weight: ‎6.89 pounds
  • Installation place: Indoor
  • Fuel Type: Electric
  • Vent Type: Vent Free
  • Recirculation: No
  • Voltage: 240V
  • Includes Isolation Valve Kit: Yes
  • Wattage: 9600 watts.
  • AMP: 40A
  • Number of breakers: 1
  • Heat Exchanger Warranty: 7 years
  • Key Feature: No Venting Required, Seismic-proof Construction, On-demand endless water supply, No scalding, Sleek design fits in anywhere.

Stiebel Eltron 224201 DHC-E 8/10 is perfect for point-of-use or if you want you can use it for multi-point-use. The tankless water heater for a bathtub flow rate up to 2 GPM and temperature range 80 to 140 degrees F.

It has self-modulating technology, this technology saves energy by measuring incoming water temperature. It has thermal protection reset and overheats safety protection.

The wattages are 9600 watts, the voltage is 240V, and the amperage draw 40A. It needs only one breaker. The efficiency is 99.8% which means it doesn’t waste energy.

The manufacturer offers 7 years warranty heater exchanger and 3 years on parts.

Pros

  • Includes Isolation Valve Kit.
  • Lightweight.
  • Self-modulating technology.
  • No vent is required.
  • Thermal protection reset.
  • Overheat safety protection.

Cons

  • The maximum flow rate is only 2 GPM.

9. Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater

Best Indoor
Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater

Ecosmart ECO

Specification

  • Activation GPM: 0.25
  • Uniform Energy Factor (UEF): 0.99
  • Water Connection: 3/4”
  • Flow Rate (Max): 6 GPM
  • Flow Rate (Mini):  0.25 GPM
  • Temperature (Max): 140 Degree F
  • Temperature (Mini): 80 Degree F
  • Dimensions: ‎3.6 x 21 x 17 inches
  • Weight: ‎18.35 pounds
  • Installation place: Indoor
  • Fuel Type: Electric
  • Vent Type: Vent Free
  • Recirculation: No
  • Voltage: 240 Volts
  • Wattage: ‎36000 watts
  • AMP: 150A
  • Number of breakers: 4 x 40 AMP
  • CSA Approved:  Yes
  • Heat Exchanger Warranty: Limited Lifetime Warranty
  • Key Features: Endless Hot Water, Save Space, Digital temperature control, Save Energy, Self-modulating Technology.

Ecosmart ECO 36 can provide up to 8.7 gallons per minute but it depends on the inlet water temperature. With this endless hot water supplier, you can save up to 50% on water heating costs.

It has a digital temperature control system, with this you can raise or down between 80 to 140 degree F. The Self-modulating technology always monitors the inlet water temperature and adjusts with the heating chamber.

The device saves space, the device needs less space than the conventional tank water heater. If you compare ECO 36 with a traditional tank water heater, the ECO 36 is 90% smaller.

It saves valuable time because it can supply endless water hot water instantly and it is easy to install.

Pros

  • Field replaceable elements.
  • Compact design, more storage space.
  • Save up to 50% on your water heating costs.
  • It can supply up to 6 gallons per minute.

Cons

  • It needs 4 breakers.

10. Noritz NRC66DVNG Tankless Hot Water

Best Gas
Noritz NRC66DVNG Indoor Condensing Direct Tankless Hot Water Heater

Noritz

Specification

  • Activation GPM: 0.5
  • Uniform Energy Factor (UEF): 0.89
  • Water Connection: 3/4”
  • Gas Connection: 1/2”
  • Flow Rate (Max): 6.6 GPM
  • Flow Rate (Mini):  0.5 GPM
  • Gas Input BTU(Max): 1,20,000
  • Gas Input BTU(Min): 15,000
  • Temperature (Max): 60 Degree F
  • Temperature (Mini): 160 Degree F
  • Dimensions: 6.7 x 13.8 x 23.6 inches
  • Weight: 39 pounds
  • Installation place: Indoor
  • Includes Isolation Valve Kit: No
  • Fuel Type: Natural Gas
  • Vent Type: Direct Vent
  • Recirculation: Yes
  • Natural Gas Thermal Efficiency: 92%
  • Voltage: 120V
  • AHRI Certified: Yes
  • CSA Approved:  Yes
  • Heat Exchanger Warranty: 12 years
  • Key Features: Lightning Protection Device, Overheat Prevention Device, Freeze Protection, Flame Sensor, Thermostat Display included.

Nortiz NRC66DVNG is run by natural gas. Overheating protection saves the user from accidental or unauthorized changes in water temperature.

Freeze protection avoids the freezing problem and it has also a flame sensor. You can monitor the temperature with a thermostat display. Lighting protection reduces the cost.

Recirculation is available on this device. So, if supplied hot water doesn’t use then with time it will be cold. If you want you can recirculate the cold water and again heat it.

Since it has a direct vent, you can install it in a tight place. The efficiency is high with low NOx Eco-Burner reduce emissions.

You can install it only indoors. The water connection is standard size 3/4” and the gas connection is 1/2”.

The manufacturer offers 12 years on heat exchanger, 5 years on parts, and a 1-year labor warranty.

Pros

  • Compact & modern design.
  • Power Cord included.
  • Recirculation of water is available.
  • Freeze protection.
  • Flame Sensor & thermostat display included

Cons

  • Isolation valve kit not included.

How we select these products

When we are selecting products then we try to keep different types of Category, so that the user can pick up one which is more suitable. For this, in this article we include Point of Use, Multi Point Use, Indoor, Outdoor, etc. By fuel, there are two categories a. Electric Powered and b. Gas. We also take user reviews and analyzed it. After all that we make this product list.

Subscribe
Notify of
guest
0 Comments
Inline Feedbacks
View all comments