Skip to content

All About Rinnai Tankless Water Heaters

rinnai tankless water heater guide

During the cold days of winter, water heaters are a godsend. And for households without the budget or room for a storage tank water heater, the tankless water heater provides a convenient way of providing hot water without the cost or space needed by their bigger tank-based brethren.

When it comes to tankless water heaters, Rinnai is one of the names that stands out in the industry. Learn all about the Rinnai brand, and why you should choose them for your tankless water heater.

What is a Tankless Water Heater?

As the name implies, a tankless water heater is one that doesn’t require a storage tank for pre-heated water, and only heats water as it is needed. They are also known as demand-type water heater, instantaneous water heater, and point of use tankless water heater.

The tankless water heater works by using a heat exchanger. The cold water first flows through a heat exchanger in the tankless unit, where a gas burner or an electric heating element is used to heat up the water. This allows tankless water heaters to provide a constant supply of hot water, without having to wait for a storage tank to get filled up with hot water.

However, their tankless design means that the output or flow rate is limited compared to their storage tank counterparts. Tankless water heaters typically have a hot water flow rate of 2–5 gallons (7.6–15.2 liters) per minute. In terms of output capacity, gas-fired tankless water heaters have higher flow rates than electric ones.

Who is Rinnai?

Based in Nagoya, Rinnai is a Japanese brand of gas appliances, manufacturing everything from tankless water heaters and home heating to kitchen appliances and clothes dryers. The company also manufactures commercial-use equipment like rice cookers, grillers and fryers used by restaurants. The brand has been around since 1920 when it was founded by Hidejiro Naito and Kanekichi Hayashi. 

One of Rinnai’s hallmarks is its world-renowned line of tankless water heaters. The company specializes in both residential and commercial-grade tankless water heaters with the industry’s best warranty. The brand has over 30 million tankless water heaters installed worldwide.

The Rinnai North American distribution center can be found in Peachtree, Georgia. The brand continues to expand and innovate in the water heater field and is working to incorporate locally sourced components into their products.

Why Should You Choose Rinnai?

✓ Higher efficiency

You may have heard about some of the benefits and drawbacks of storage versus tankless water heaters. For example, they are typically higher efficiency, with advanced technology included. Rinnai tankless water heaters have a temperature controller that sets a specific output temperature and have an activation flow rate as low as 0.4 gallons per minute.

✓ Versatility

Rinnai products also set themselves apart by their versatility, with gas type convertible and replaceable parts. This flexibility allows you to adjust and update your device in accordance with your specific needs and doesn’t box you in.

In addition, Rinnai’s tankless water heaters can connect to other units if you find yourself with a sizing issue and in need of more hot water. Don’t count them out if you have commercial capacity needs!

✓ Better safety

If you are concerned about safety, Rinnai has many safety devices for your protection:

  • Function lock
  • Freeze protection
  • Scale build-up detection
  • Flame rods

You can have peace of mind knowing that they’ve built in many components for your protection.

✓ Higher longevity

Tankless water heaters last on average twice as long as their storage tank counterparts, making these options great picks for making your dollar stretch further. Because these types of water heaters work by processing and heating the water continuously, they use less energy and don’t break down as quickly.

✓ Longest warranty

Rinnai water heaters are backed up by one of the longest warranties in the industry. As a testament to their quality, Rinnai offers an additional 4 years of free labor coverage (a $250 value) when the heater is registered within 3 months of purchase. 

✓ Rebates

Rinnai also qualifies for rebates for customers in the US and Canada. In fact, more than 70 of the brand’s products may be eligible for rebate programs. Click here to check out what rebates you may qualify for.

Types of Rinnai Tankless Water Heaters

Rinnai offers several types of water heaters to suit different needs, including non-condensing, condensing, outdoor and indoor installation, commercial options, and different fuel types.

Non-condensing water heaters

A non-condensing tankless water heater works by turning on the cold water tap, allowing it to flow into the tankless heater. There, the flame is activated and the water warms as it travels through the copper coils in the heat exchanger and enters your pipes, and finally into the given appliance. The flame adjusts accordingly based on the desired temperature.

A non-condensing hot water heater will push the hot gases through the vent to the outside. Typically non-condensing water heater units have efficiencies around 80%, meaning around 20% of the heat gets wasted. For this reason, non-condensing water heaters are not as cost prohibitive.

Rinnai RE180i High Efficiency Non-Condensing, 8.5 GPM Tankless Hot Water Heater

The Rinnai RE Series is a non-condensing line of tankless hot water heaters. The RE180 is for residential use and is available in either Natural Gas or Liquid Propane. It has a 180,000 BTU capacity and a flow rate that ranges from 0.13 – 8.5 GPM. 

This compact water heater is about the size of a carry-on, measuring just 22.87″ x 14.05″ x 10.77″. It is the ideal tankless solution for a home with two bathrooms, being able to handle simultaneous use of 3 – 4 fixtures at one time. An integrated controller is included, with a minimum temperature setting of 98° and a maximum of 140°F. The unit offers maximum settings at 125°F with an option to increase to 140°F.

The RE180i is also available with remote WiFi connection (Control-R WiFi Module sold separately) for remote monitoring, management.

Rinnai RE180i High Efficiency Non-Condensing, 8.5 GPM Tankless Hot Water Heater for Indoor Installation
Price: $1,184.00 Rinnai RE180i High Efficiency Non-Condensing, 8.5 GPM Tankless Hot Water Heater for Indoor Installation

  The Rinnai RE Series is a non-condensing line of tankless hot water heaters. The RE180 is for residential use and is available in either Natural Gas o...

View Product

Condensing water heaters

Like the non-condensing water heater, condensing ones work much the same way. Cold water from the tap enters the tankless heater to activate the flame in the condensing water heater. The water pre-heats while passing through the stainless steel heat exchanger and continues to warm up throughout the rest of the process.

The differences with a Rinnai condensing unit is a condensation trap and drain built into the unit, different venting systems, and a secondary heat exchanger.

Rinnai RSC160i 9.0 GPM Sensei+ with Smart-Circ Condensing Tankless Hot Water Heater with Built-In Re-Circulation for Indoor Installation

The Rinnai RSC160 is one of the newest model additions to the Sensei Series, a line of super high efficiency, Energy Star-qualified tankless hot water heaters. The RSC160 features Rinnai’s Smart-Circ Intelligent Recirculation technology, where users set the recirculation patterns based on their hot water usage and the technology learns it. This makes sure hot water is available when needed, saving the homeowner the expense and energy of circulating the water when there is no need for hot water!

This particular model features 160,000 BTUs and hot water flow rate that ranges from 0.26 – 8.0 GPMs, with a max flow rate of 9.0 GPM. This allows it to service 2 – 3 bathrooms, or the simultaneous use of 2 – 5 fixtures at one time. It comes with an integrated check valve located between the turbo fan and the combustion chamber to prevent cold air from entering the venting system and backflow of exhaust in common vent applications. The Fiber Mesh Premix Burner helps to provide even flame distribution for optimal performance for any demand.

The RU160 ships with isolation valves for easier maintenance and service.  A Thermal Bypass Valve is included with this unit for use with the crossover recirculation mode.

DISCONTINUEDRinnai RSC160iN 9.0 GPM Sensei+ with Smart-Circ Condensing Tankless Hot Water Heater with Built-In Re-Circulation for Indoor Installation - Natural Gas
Price: $1,878.00 DISCONTINUEDRinnai RSC160iN 9.0 GPM Sensei+ with Smart-Circ Condensing Tankless Hot Water Heater with Built-In Re-Circulation for Indoor Installation - Natural Gas

The RSC160i is no longer available in Liquid Propane. It is only available in Natural Gas (RSC160iN). Check Out the RXP160iN for a multi-use installation replac...

View Product

Indoor Installation

One of the great features of tankless water heaters is their space efficiency, with many units being the approximate size of a carry-on.

For indoor installation, this feature is especially key. Indoor installation uses concentric venting, where one pipe allows for fresh outside air in, and the other allows the exhaust out for optimal performance and space saving.

Rinnai RSC199i 11.0 GPM Sensei+ with Smart-Circ Condensing Tankless Hot Water Heater with Built-In Re-Circulation for Indoor Installation

Part of the Sensei Series of super high efficiency, Energy Star-qualified tankless hot water heaters, the RSC199i features 199,000 BTUs and a flow rate that ranges from 0.26 – 11.0 GPMs, with a max flow rate of 9.0 GPM. This allows it to provide hot water for simultaneous use of 3 – 6 fixtures at one time.

Two modes are available including a Dedicated Mode (for use with a dedicated return) and Crossover Mode. The Dedicated Mode works in conjunction with a dedicated return line and the integrated pump recirculates water from the RSC199 through the return line and back to the heater. For the Crossover Mode, where a return line does not exist, Smart-Circ Intelligent technology allows for the installation of a Thermal Bypass Valve (included).

The MC-91-2US controller is included as part of the front panel. For scheduled recirculation or ON-DEMAND operation, the separate MC-195T-US or ControlR WiFi module is required.

DISCONTINUEDRinnai RSC199iN 9.8 GPM Sensei+ with Smart-Circ Condensing Tankless Hot Water Heater with Built-In Re-Circulation for Indoor Installation - Natural Gas
Price: $2,244.00 DISCONTINUEDRinnai RSC199iN 9.8 GPM Sensei+ with Smart-Circ Condensing Tankless Hot Water Heater with Built-In Re-Circulation for Indoor Installation - Natural Gas

The RSC199i is no longer available in Liquid Propane. It is only available in Natural Gas (RSC199iN). RXP199iN for a multi-use installation replacement will be ...

View Product

Outdoor Installation

In many units, the choice of indoor/outdoor installation is not interchangeable and must be chosen at purchase. The main reason that many people like outdoor installation of water heaters is that they do not require venting, which can be an added cost.

Outdoor installation is not recommended for locations with extremely hot temperatures or where they may be exposed to power lines, for safety reasons.

Rinnai RSC199e 11.0 GPM Sensei+ with Smart-Circ Condensing Tankless Hot Water Heater with Built-In Recirculation for Outdoor Installation

This model features 199,000 BTUs and hot water delivery with a flow rate that ranges from 0.26 – 11.0 GPM, good for simultaneous use of 2 – 5 fixtures at one time. It is designed for outdoor installation and boasts a built-in freeze protection down to -4°F on the outdoor / external units. The unit features an integrated check valve located between the turbo fan and the combustion chamber to prevent cold air from entering the venting system and backflow of exhaust in common vent applications.

The RSC199e is for outdoor installation does not require venting.  Because of extreme temperatures and exposed water lines, outdoor / exterior installation is not recommended in locations from Virginia and north. Also keep this in mind in mountainous regions of the country where extreme temperatures may also exist.

Rinnai RSC199e 9.8 GPM Sensei+ with Smart-Circ Condensing Tankless Hot Water Heater with Built-In Recirculation for Outdoor Installation
Price: $2,244.00 Rinnai RSC199e 9.8 GPM Sensei+ with Smart-Circ Condensing Tankless Hot Water Heater with Built-In Recirculation for Outdoor Installation

    The Rinnai RSC199 is part of the Sensei SE+ Series, a line of super high efficiency, Energy Star Qualified, tankless hot water heate...

View Product

Commercial

Do you own a business or other large space where you would like to deliver hot water efficiently to multiple spaces? There are options for you.

Rinnai commercial units for outdoor installation are a great choice for these situations. With an endless supply of water, these systems work great for multi-family homes, small businesses, schools, and other similar locations.

Rinnai CU199e 9.8 GPM Sensei Commercial Condensing Tankless Hot Water Heater for Outdoor Installation

The CU199 is built specifically for commercial use, with precision engineering to give you an endless supply of hot water. This Commercial Energy Star-certified tankless hot water heater boasts 97% Thermal Efficiency with a heat exchanger designed for commercial demands. 

It features 199,000 BTUs and hot water delivery with a flow rate that ranges from 0.26 – 9.8 GPM. Cascade Logic and Cable Assembly is available for this model, which allows up to 24 water heaters to connect together. Cascade Logic rotates water heater operation to ensure the entire system gets equal usage and functions as a single hot water source. In a commercial installation where you may need to use more than one unit, Rinnai offers many Tankless Rack Systems for installation flexibility as well. The Tankless Rack system is available for wall mounted or freestanding installation for two or more units.

Rinnai CU199eN 9.8 GPM Sensei Commercial Condensing Tankless Hot Water Heater for Outdoor Installation - Natural Gas
Price: $999.00 Rinnai CU199eN 9.8 GPM Sensei Commercial Condensing Tankless Hot Water Heater for Outdoor Installation - Natural Gas

The CU199e is only available in Natural Gas. LP is no longer available. Please see CX199. The Rinnai Sensei Commercial CU199 is a super high effici...

View Product

Things to Consider Before you Buy

One of the main things you want to think about before investing in a Rinnai water heater is what you will be using it for. Do you need it for a vacation home or for everyday use? Will multiple appliances be using hot water at the same time? Will multiple visitors be staying at your house often?

Keep the purpose and capacity specifications in mind when looking for your hot water heater. Calculate the maximum flow rate and BTU range to help you narrow down the size you should be looking for.

If you aren’t sure which one is best for your needs, consult a professional prior to purchase.

Could Rinnai be the Right Fit for You?

There are many reasons why a Rinnai on demand water heater might be exactly what you are looking for. If you have been wanting to go for a tankless option, why not choose a brand that has a century’s worth of credit and proof of its products’ capabilities?

Total Home Supply is a Rinnai dealer and we carry many of their products. You can browse them all here!

If you need a little more direction in choosing your Rinnai product, contact the customer service department here and we can advise.

Mickey Luongo

Mickey is the resident heating and air conditioning expert with over 15 years of experience in the industry.

One thought on “All About Rinnai Tankless Water Heaters”

  1. Best Water Heaters of 2019 - Tankless & Tank Units says:

    […] manufactures state-of-the-art systems and leads the way in tankless design. The brand has superior quality standards, making sure that all products meet industry standards […]

Leave a Reply

Your email address will not be published. Required fields are marked *