5 Best Tankless Water Heater for Family of 4 Reviews & Guides

Do you own a large family and have trouble fighting for hot water in hundreds of busy morning? If so, you need to get the best tankless water heater for a family of 4. The large family heater requires a large flow rate and accordingly large power. Besides, the technology should be advanced in balancing the water temperature. All these requirements determine the searching for the best type a difficult task.

In this post, we have selected multiple large flow rate best tankless water heater for family of 4 or even 5 uses. Based on your own needs and demand, you can choose the ideal type through expert reviews and buying guides.

Now, let’s begin!

Top 5 Best Tankless Water Heater for Family of 4

what size tankless water heater for family of 4Rinnai RUC98iN Ultra Series Gas Water Heater4.8
best tankless water heater for family of 4Rinnai RL Series HE+ Tankless Hot Water Heater4.8
natural gas tankless water heater for family of 4Rheem 95XLN Outdoor Heater4.6
large family tankless water heaterTakagi T-H3J-DV-N Condensing Heater4.5
tankless water heater for family of 4Noritz NRC66DVNG Hot Water Heater4.5

Best Tankless Water Heater for Family of 4 Reviews

1. Overall Best Pick – Rinnai RUC98iN Ultra Series Gas Water Heater

what size tankless water heater for family of 4



【Condensing technology】

The natural gas tankless water heater uses condensing technology, delivering more efficiency and reducing the unnecessary loss of heat than ever before. Apart from saving much money on electricity and energy bills, it also creates an eco-friendly using experience.

【High energy efficiency】

The maximum efficiency of the heater reaches as high as 95%, which means there is less standby loss in the use of the heater. The BTU of it is between 15,200 and 199,000, meeting the standard of California and Texas low NOx emission.

【Stable water temperature】

The large flow rate of the heater enables it to support hot water for multiple showers and a couple of faucets at the same time, meeting the demand of family of 4 use. No matter how many devices run at the same time, the water temperature stays stable. Plus, the whole working process is super quiet and no large noise can be heard in use.

2. Runner Up – Rinnai RL Series HE+ Tankless Hot Water Heater

best tankless water heater for family of 4



【Outdoor installation】

Natural gas tankless water heater requires venting facilities on emitting the waste gas for indoor installation. The outdoor installation design of this unit saves your money on buying the venting devices, and at the same time spares more space if you do not have enough room to place the unit.

【9.4 gallons per minute of hot water supply】

With the large flow rate of 9.4 gallons per minute, this unit is capable of offering constant hot water for many home appliances at the same time; whether you need to use two showers and two sinks simultaneously or in need of hot water for 4 sinks at the same time, you can never run out of hot water with it.

【High technology】

To ease your way of using the heater, this model adds Wi-Fi monitoring and recirculation technology. Through the Circ-Logic technology, you can set recirculation patterns based on your typical habits, which shortens your waiting time for hot water when you are in urgent needs.


3. Direct Vent Natural Gas Tankless Water Heater – Rheem 95XLN Outdoor Heater

natural gas tankless water heater for family of 4



【2 pipe direct vent】

It offers 2 pipe direct vent system to choose the ideal one based on your needs. One reaches 35 feet of 3 feet PVC pipe while the other being 5 feet of 2 feet PVC pipe. The low NOx design enables it to save much energy and reduces the standby loss of heat as much as possible.

【Advanced technology】

This machine adopts several technologies to promise brilliant working performance. The self-diagnostic system senses the error part of the machine and adjusts automatically; intelligent electronic control used to increase both the using safety and energy efficiency.

【Easy to operate】

It comes with digital remote control to adjust the water temperature, as well as the water flow easily and conveniently. The total steel design on the covers prolong the service life of the machine and protects the unit from corrosion of the outdoor environment. With the large flow rate, you can use multiple faucets simultaneously without obstruction.

4. Commercial Tankless Water Heater – Takagi T-H3J-DV-N Condensing Heater

large family tankless water heater



【6.6 GPM flow rate】

Compound several of such units together and you can use it commercially for supplying constant hot water. The maximum 6.6 gallons per minute flow rate allows you to open up two showers and 1.5 sinks at the same time in the warm regions, and still keep the water temperature stable and smooth.

【Quiet working condition】

During the whole using time, you can hardly hear the working noise except for very low hum. And when you stay in the other room, nothing can be heard at all. The size of which shapes no larger than a computer, sparing much floor or wall space than a stored tank water heater.

【Energy efficiency】

This unit is proved to be 95% more energy-efficient, saving much unused gas and making it more environmentally friendly. According to the investigation, the life span of this unit reaches as long as 15-20 years, which is far longer than normal types sold on the market.

5. Indoor Condensing Tankless Water Heater for Family of 4 – Noritz NRC66DVNG Hot Water Heater

tankless water heater for family of 4



【6.5 gallons per minute】

The flow rate of this unit reaches 6.5 gallons per minute, able to meet the demand on hot water for 4 sinks at the same time. In warm regions, it provides you with constant hot water for two showers and 2 faucets simultaneously.

【Protective devices】

Good protection of a heater is the key to the life span, for most of which go down from the stage because of severe corrosion. This unit comes with a rain cap and atmospheric conversion kit to prolong the service life and guarantee safety in use.

【Energy efficiency】

The direct venting condensing system design saves much energy and unused gas, leading to the narrowing of energy costs for each month reflected on your bill. The dual option with Schedule 40 PVC pipe and fitting meet your different demands.

What Size Tankless Water Heater for Family of 4 Should I Choose?

Why the size of the tankless water heater so important? Well, it determines whether the heater you get is ideal for your daily use. For large family, you need those with large flow rate; for a small apartment use, the compact type supporting one shower and one sink at the same time is enough; as for the under sink use, you may as well choose the under sink or point of use type to save energy and reduce the unnecessary costs on electricity and heating costs.

So, what is the suitable water heater size for a family of 4?

First of all, you need to make clear the two elements in the size of a heater, which includes the flow rate and temperature rise. The water flow rate, to put it simply, refers to the amount of hot water it supplies. The calculation of the desired flow rate should be the total numbers of the flow rate of each needed devices.

For example, the flow rate of one shower is 3 gallons per minute, for sink it is 1.5 gallons per minute. If you intend to get a heater on supplying hot water for 2 showers and 2 sinks at the same time, then the desired flow rate should be at least 9 gallons per minute.

The other factor that affecting the size is the temperature rise, which means the difference between the set of the unit temperature and the output groundwater.

Let’s say the set of the unit temperature is 120 degrees F, the output one being 60 degrees F, then the desired temperature rise should be 60 degrees F.

The following chart is a reference on sizing that you can calculate before buying:

size tankless water heaters

Measuring the flow rate and temperature rise is a must-to-do-step in picking the best tankless water heater for a large family. However, blindly choosing the large flow rate and power type is also not a wise decision, for the over-large heater leads to the waste of heat and results in the waste of money on electricity and energy costs.



David: Penn State-educated Mechanical Engineer and Business-savvy Fluid Dynamics Specialist. Balances family plumbing business support with a thriving engineering career at a top, undisclosed company. (they want it that way) I help Will with plumbing and HVAC needs on his Real Estate.

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