Most of the tankless water heaters are indoor installation, they are more convenient in using and has a long service life. Because of the hot demand, there are many brands and many types of indoor tankless water heaters on the market of 2020. In order to better help you choose the most suitable one, we made detailed reviews of the best indoor tankless water heater for you.
Top 8 Best Indoor Tankless Water Heaters on the Market
Best Indoor Tankless Water Heaters Reviews
There are many brands and types of indoor tankless water heaters on the market of 2020, in order to help you choose the most suitable one, we have made detailed reviews for you as follow:
- 9.8 GPM flow rate
The flow rate of this unit reaches as high as 9.8 gallons, it is able to support three or four bathrooms use the same time. The high flow rate of it also enables to supply constant hot water for you. It takes up 20 seconds for the water to heat up in the units.
- 2 venting options
It offers two venting options, one is concentric PVC and the other is twin-pipe, so you can choose whichever is easy to be installed. The temperature of it can reach as high as 185 degrees F, making it possible for commercial use with the commercial remote.
- Energy efficient
The power requirements range from 15200 to 199000 BTU per hour, the higher power requirements are, more powerful as it is. The energy-efficient rating is as high as 0.95. But it needs only 2 watts to keep the machine up and running.
- 2 venting options
- High energy efficient
- Quiet working performance
- Unlimited hot water
- 5 years warranty on the part
- Multiple faucets and showers use simultaneously
Need to be installed by professional
- Low NOx design
This unit meets California and Texas NOx Emissions Standards, maximum BTU is 150000, and maximum energy factor is 0.82. Being a natural gas indoor tankless water heater, it is quite energy efficient.
- 6.6 GPM
The flow rate of this unit is 6.6 gallons per minute, it can handle two showers use the same time in warm areas. It supports constantly hot water for you.
- Special venting
One thing you need to be aware of is that it requires special venting and needs to place near an outside wall for venting, it requires the aluminum interior vent pipe with PVC outer pipe.
- Lightweight and compact design
- Quiet working condition
- One button turns on and off for vacation
- Constantly hot water supply
- 10-year warranty for heating exchanger
- Easy installation
Needs special venting
- 5 gallons per minute of water flow
The unit provides about 5 gallons of water per minute, which is a high flow rate machine. It is able to raise the water by 54 degrees F at 3 GPM. It has built-in advanced flow control modules to regulate water pressure by itself.
- Stable temperature
It has an advanced flow control system in order to control water temperature in different flow levels, it is suitable for people in demand for occasional hot water. It has high-level electronic parts and a reliable cover to promise long service life of it.
- Energy efficient
Stiebel boasts that the energy rating reaches as high as 99% and full power modulations enable large power of the machine. Also, it adopts self-modulating technology to save more energy.
- Quiet working condition
- Compact design, perfect for small studio use
- Ideal in places where supplied water is under 45 degrees F
- Full power modulation
- High technology adopt
Difficult to install, need 240v power and heavy-duty wiring
- 3.6 GPM
The flow rate of this unit is 3.5 gallons per minute, it is able to provide one shower and one low rated kitchen faucet the same time. It is said to have a high capacity, but actually, it is ideal in a studio family use.
- Digital temperature control
Temperature shows on the screen of the unit, and two buttons are set to adjust the water temperature, one is for flow rate while the other is gas settings. But it is quite difficult to adjust to the exact temperature you want.
- Stylish compact shape
It is designed to light and compact, occupying an only small piece of land of your home. It adopts safe electronic ignition system, you can plug it into standard 120v electrical outlet with UL-listed cord.
- Energy saver
- Deliver hot water in a few seconds
- Efficient power ventilation
- Perfect for small house use
- Manual water temperature control
- Digital temperature control
Hard to get the temperature you want exactly
- 150 degrees F temperature
Maximum temperature of this unit reaches as high as 150 degrees, perfectly meets the demand for residential use. It demands minimal maintenance during the whole using process.
- 6.6 GPM flow rate
The flow rate of the unit is up to 6.6 gallons per minute, it provides constant hot water no matter for the climate or season. But in the cooler region, the flow rate may drop to 3-5 GPM.
- Light compact size
It is the lightest and smallest one among all the Takagi products, you can easily install it anywhere you want. Power input of it is 140000 BTU per hour, and energy-efficient reaches 81%. But as a propane tankless water heater, it has more upfront costs in venting the gas to outdoor.
- Digital remote enabled
- Multiple bathroom use available
- Demands minimal maintenance
- Easy to be installed
The working noise can be heard
- 185 degrees F temperature
Maximum temperature of it reaches as high as 185 degrees F, able to meet the demand of both residential and commercial use. But the waiting time of the hot water may be a bit long, takes around 1 minute.
- 10 GPM large flow rate
This unit provides 10 gallons per minute of water flow, the huge flow rate provides you with constant hot water. It demands 199000 BTU per hour to perform in the best way, which is a highly powerful natural gas tankless water heater.
- Set up simply
It is easy to set up, just adding several gas line. Venting facilities are needed for venting gas to outdoor. It weights light and has compact shape, can be installed anywhere you want.
- Remote control available with a controller
- High-temperature range
- Powerful enough
- Commercial & residential use
- Lightweight and compact shape
- Huge water flow
Needs to be installed by professionals
- ComfortFlow technology equipped
This unit is regarded as high technological tankless water heater, it has built-in hot buffer tank and recirculation pump, in order to eliminate cold water sandwich and save water bills by reducing the waiting time for hot water.
- Stable water temperature
The temperature of it keeps stable all the using time, the internal technology enables it quickly correct the temperature once it draws stop suddenly. The external interface shows water temperature and error codes. You can turn the machine off easily with the button.
- Condensing technology
The condensing technology of it recovers the unused extra heat to reduce energy consumption and carbon dioxide emissions. It keeps exhausted temperature low, it provides up to 0.97 UEF, which is a highly energy-efficient type.
- Hot buffer tank and recirculation pump built-in
- Clear installation and using instructions
- Short waiting time for hot water.
- Intelligent preheating technology
- Easy operated
- Large flow rate enabled
Slight working noise can be heard
- Digital temperature control
The digital temperature control enables you set water temperature in increments of 1 degrees, temperature and error codes shows on the scree. Easy operation setting makes it easy to adjust the temperature accurately.
- Advanced ThermoPro technology
It is equipped with advanced Atmor’s ThermoPro self-modulating system, it regulates the amount of energy required to heat water. And it is able to automatically detect water flow, turn it on and off by itself, so as to eliminate wasted water flow and lower the water consumption.
- 90-135 degrees F
Temperature range of the unit reaches between 90-135 degrees F, it proves to save about 50% electricity bill each month. Durable stainless steel interior and corrosion resistance performance allow for high heat efficiency and longer life expectancy.
- set temperature in increments of 1 degree.
- Durable stainless steel interior
- Save 50% on electricity bill
- Self-modulating system regulates the amount of energy required to heat water
- Automatically detect water flow
- Small footprint
Need to install a pressure relief device, and you need to buy it from manufacturer
- 3 GPM flow rate
The flow rate of this unit is 3 gallons per minute, it activates only when hot water is demanded, no pilot light is needs and much energy consumption is reduced. It is said to use as a whole home tank, supporting two things the same time, but we still suggest it be used for a tiny or small home.
- Modern design
Sleek modern design and easy operated LED display control enables to adjust water temperature easily. Black tempered glass front panel is set to show temperature, automatic temperature controls with energy-saving mode and child lock technology are set for avoiding unintentionally adjusting.
- Safe ignition
It requires a safe electronic ignition system, you need to plug it into standard 110 v electrical outlet with UL-listed cord.
- Energy efficient
- Horizontal stainless steel vent kit
- Safe electronic ignition system
- Automatic temperature control
- Sleek modern design
- Easy operation
It needs to be plugged in
Features of Indoor Tankless Water Heater
1. Long service life
The using life of indoor tankless water heater is quite long, installed inside the home. the heating machine is not affected by bad weathers, such as wind, rain or long term erosion by complicated outdoor weathers. Thus the service life of indoor tankless water heater reaches as long as 10-15 years, some even reach 20 years.
2. Various specifications
For indoor tankless water heater, the specifications and types are various, giving you more options and choices. Large flow rate indoor tankless water heaters such as whole-house tankless water heaters can be used for a large family, and portable type can be used for a small tiny home. Different specifications will meet the different demands of yours.
3. Flexible installation spots
The installation spots of indoor tankless water heater can be quite flexible, you can either install it on point of use, or in the bathroom for shower use. If you do not have much space in the bathroom, you can also install it somewhere convenient in the kitchen.
4. Large flow rate
Not all the indoor tankless water heater have a large flow rate, for some point of use tankless water heaters, the flow rate can be so low as 2 GPM. But as most of them are used for supporting multiple bathrooms the same time, the flow rate of indoor tankless water heaters are normally large.
Types of Indoor Tankless Water Heaters
According to the using applications, indoor tankless water heaters can be divided into whole-house type and point of use type.
Whole-house tankless water heater needs to support multiple bathrooms or faucets use, thus the flow rate and power are both large, reaching 9 GPM even. It can also be used as the commercial tankless water heater. We have made detailed whole house tankless water heaters reviews for you, you can check out for more information.
Point of use tankless water heater is quite small and compact in shape, some of which are small enough to be installed right under the kitchen sink. Flow rate is normally small, reaching around 3 GPM. Of course, some large flow rate types can also be used for point of use tankless water heaters, you just need to install near the application fixture and the waiting time can be shortened to a large extent. For more information on point of use types, please have a look at our best point of use tankless water heater reviews.
Which Is Best, Propane, Gas Or Electric Tankless Water Heater?
As for indoor tankless water heaters, both natural gas and propane types need to install ventilation facilities along with the heating machine to let out wasted gas, but not for an electric one.
Indoor propane tankless water heater is quite a clean machine, it does little harm to the environment. The power and flow rate of it is a bit higher than the electric one.
Tankless gas indoor water heater, however, can sometimes adopt propane as major power too. The power is normally large and can be used as whole house tankless water heater. Using costs of gas types are much cheaper.
The electric tankless water heater is quite a flexibility on its installation spots, it can be installed anywhere you want because no ventilation facilities are required. But the using costs of it is relatively high.
There are no absolutely best indoor tankless water heaters, because the size of families, budgets, home locations, applications and also daily water use are different for each family. Each of the three types of tankless water heaters has its own advantages and shortcomings, before selecting, you need to take all the factors into consideration. If you have trouble in choosing, or want to know more information on each type, please check out more on Amazon or on our reviews we made for you.
The Best Tankless Water Heaters
- Rinnai RUC98iN Tankless Water Heater – Best whole house type
- Rinnai V65IN 6.6 GPM Tankless Water Heater – Best one for middle size home use
- Stiebel Eltron Tempra Plus 24 kW Tankless Water Heater – Best electric type
Indoor Tankless Water Heater vs. Outdoor
The indoor tankless water heater is installed at home, either on the wall of the bathroom or kitchen, so it is hardly affected by weathers. However, outdoor tankless water heaters need to stay outside after installation, it needs an enclosure to prevent the machine from being corroded by rain or sunshine for a long time. Even with the protection cover, it is affected to a large extent. Therefore, compared with indoor tankless water heaters, the service life of outdoor type can be a bit shorter.
Indoor tankless water heater installation can be more flexible than outdoor types, for outdoor tankless water heater, it needs to be installed right outside the bathroom wall for short waiting time of hot water. But as for indoor types, you can install wherever is convenient.
The other difference between the indoor tankless water heater and outdoor type is ventilation. Both natural gas and propane tankless hot water heaters need ventilation facilities to let out gas for safety when installing indoor. However, if you get it hooked outside, no ventilation is needed and much money is saved on it.
Indoor Tankless Water Heater Price
Price levels of each type of indoor tankless water heaters are different, it depends on the applications, flow rate and power of the machine. Normally the whole house types are more expensive than the point of use types. And the price of gas, propane and electric tankless water heaters are also different to a large extent.
Apart from heating machine price, you should also regard using costs as an important factor. To some of the water heaters, the using costs are even expensive than the purchasing price. It is influenced by energy-efficient and waiting time of the machine. Besides, the installation and maintenance costs are also a large sum of money.
Only after integrating the two elements of costs together can you choose the most suitable and cost-effective one. If you want to know more details about the best indoor tankless water heaters on the market, you can check it out on Amazon freely.
1. Can indoor tankless water heater be installed outdoor?
It depends, if there is a clear remark on the products for outdoor installation, then you can hook it up outside. Or it needs to be installed indoor only. You can ask the manufacturer for sure before and after buying.
2. Do all the indoor tankless water heaters need ventilation facilities?
No, only natural gas and propane tankless hot water heaters need to install venting kits, the electric tankless water heater does not need.
Indoor tankless water heaters have many types and applications, all above top 9 best indoor tankless water heaters we recommended for you have their own advantages and shortcomings, you can choose according to your basic needs and budget.
To sum up, we picked out the top 3 best indoor tankless water heaters for different needs as follow:
|Tankless Water Heater||Best Type|
|Best whole house type||Rinnai RUC98iN Tankless Water Heater|
|Best one for middle size home use||Rinnai V65IN 6.6 GPM Tankless Water Heater|
|Best electric type||Stiebel Eltron Tempra Plus 24 kW Tankless Water Heater|
If you have interest in the item and would like to get more information on the products, please check out freely on Amazon. There will always be a large discount on Amazon, so you can save a large sum of money in purchasing. If you still have any other problem in selecting the best suitable one, you can just contact us for more.