5 Best Rinnai Tankless Water Heater Reviews



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Tankless water heaters use a new type of technology that does not require the use or installation of a large tank that takes up valuable space in your home.
These models use coils that the water moves through to reach the high temperature that you want before reaching your appliances or applications. Rinnai makes solid products that you can trust in your home like the Rinnai RUC98iN Ultra Series (view on amazon.com).

This model works with natural gas systems and has a maximum BTU output of 199,000. Rinnai guarantees that this can handle multiple applications and that it will meet emissions standards in your area.



RUC98iN Ultra Series


RUC98iN Ultra Series (View on Amazon.com)


How to Choose the Ultimate One


Gallon Per Minute

The gallon per minute (GPM) of a hot water tells you exactly how much hot water it can heat and provide you with in a minute. If you live in a home by yourself or with one other person, you need a GPM of at least one. A GPM of three can supply larger appliances with hot water or run two sinks or tubs at the same time.


Temperature Rise

Temperature rise is a term that refers to the difference in the temperature of the groundwater or the water outside and the temperature that you want. The higher this rise is, the more powerful of a model you need. Those living in the south can usually get by with a smaller model because the groundwater temperature is already so high.


Efficiency Rating

Energy Star uses efficiency ratings to show shoppers how efficient different appliances and products are. You want a hot water heater with a rating of at least 0.90 or 90%. This will help you save more on your water heating bills.


Utility Models

If you need hot water for a single use like washing your hands in the bathroom sink or using hot water in your dishwasher, you can look for a utility heater. Also called a point of use water heater, manufacturers design these to attach directly to your water line and sit close to a sink or appliance.



One of the best features is that there is no tank, which means that it takes up less space. You still want to look at the overall size of the hot water heater though. This ensures that it will fit where you want to install it.


Indoor vs. Outdoor Use

You also need to decide between installing a hot water heater  inside or outside. When you decide to install it outside, you need to look for one with some type of freeze protection. Freeze protection keeps the water lines from freezing and busting.



When you use it inside that uses natural gas or propane, you must check out the type of venting required. Though some models will work with your existing vents, others will require that you install new venting.


Built-in Alarm

Though not commonly found on all tankless models, many come with a built-in alarm system. This system will alert you when or if the water line busts to keep the water from damaging your floors and any nearby belongings.


Temperature Range

The minimum temperature a tankless heater should have is around 80 degrees Fahrenheit, but the maximum can range from 120 to 140 degrees Fahrenheit. Commercial models and those with a commercial setting can reach much higher temperatures.


Operational Speed

Unless you want to stand in front of your shower for a few minutes as the water heats up, you should look for a heater from Rinnai that operates at a faster speed. Many of its tankless models will come up to temperature in 20 seconds or less.



Which Stands Out Best?


1.  RUC98iN Ultra Series (View on Amazon.com)

RUC98iN Ultra Series

The Rinnai RUC98iN Ultra Series Natural Gas is the highest rated model from the company and one of the top rated options from all companies. It comes with two connections on the top for installing the water heater and for hooking it up to both your vent and your natural gas supply.

You can use it with either PVC or concentric vents too. Though the energy efficiency rating on the RUC98iN varies based on factors like your natural gas system and the groundwater temperature, it has a maximum efficiency rating of 0.98, which makes it one of the most efficient of all models.

This model comes with a metal case that surrounds and protects all the working components inside. Those components use materials like copper and stainless steel that will last for the life of the water heater.

Rinnai knows that you may hate how much space a traditional model requires, which is why it designed this one to use a fraction of the space, and you can even install this model inside a cabinet or on a wall. With a maximum 199,000 BTU output, this brand is strong enough for use with multiple applications.

Rinnai includes a long warranty on this model that goes beyond the industry standard. You get protection on most parts for one year, but you get five year’s protection on the heat exchanger and 12 years on the digital controls. Those controls are accessible on the front of the water heater.




2.  RL94iN  (View on Amazon.com)


With a variable BTU output, this Rinnai RL94iN Natural Gas is great for homes in regions where the climate frequently changes. It can change its output based on weather conditions that change the groundwater temperature like rain or snow.

This range starts at 9,900 and can hit a maximum output of 199,000 BTU. The digital controller on this unit, which the company covers for up to 12 years, makes it easier to change the temperature regularly on your water supply.

Not only can you use the convenient buttons that use arrows for increasing and decreasing the temperature, but you can view the actual temperature on the nearby screen.

This is a great way to see how weather conditions outside or the temperature of your groundwater can change the temp of the water that comes through your pipes.

Designed for use in residential homes that have existing natural gas lines, this model has a temperature range of 98 to 140 degrees Fahrenheit. If you want to increase the temperature even higher, you can purchase a separate commercial controller and install it with this machine.

That will adjust your maximum temperature up to 185 degrees Fahrenheit. Energy Star rated this model and gave it a maximum energy efficiency rating of 0.98, and it can cut your water heating bills by up to 40%.

It also has a larger capacity and a higher flow rate that lets you enjoy up to 9.8 gallons of perfectly heated water every minute.




3.  V65EP 6.6 GPM Outdoor (View on Amazon.com)


V65EP 6.6 GPM OutdoorDo you live in a state like California or Texas that has strong rules regarding emissions standards? When you install the Rinnai V65EP 6.6 GPM Outdoor Low NOx, you’ll never worry about violating those standards or getting a fine in your mailbox ever again.

This model meets all the emissions standards found in different regions and will keep your family and pets safe. Suitable for use in residential homes of different sizes, this is one of the only Rinnai that is certified and ready for installation in mobile homes.

Though it has a maximum BTU output of 150,000, it runs so efficiently that you might notice a reduction in your heating bills within a few weeks. This tankless model has Energy Star approval and an efficiency rating of 82%.

The Rinnai V65EP 6.6 GPM Outdoor Low NOx is one of the products that come with built-in protection when installed outside to keep both it and the water lines from freezing.

Additional features protect against the scale build up caused by hard water, and it even has a detection system that alerts you of scale build up to let you know when it needs routine maintenance. Rinnai added a temperature lock to this outdoor model too, which will keep unauthorized users from changing the temperature or accessing the settings.




4.  RUR98iN 9.8 Max GPM (View on Amazon.com)

With a maximum flow rate of 9.8 gallons, this Rinnai RUR98iN 9.8 Max RUR98iN 9.8 Max GPMGPM Ultra Series Condensing Indoor Natural Gas with Recirculation gives you hot water quickly without an extended wait time. Once you select the temperature that you prefer, the water heater will remember that setting and take steps to keep the water coming out at that same temp.

It also uses new technology that heats the groundwater faster. As an indoor model, the RUR98iN does not come with freeze protection and cannot work in an outdoor location.

It uses recirculation technology that allows the water flowing through your pipes to keep moving around the heated coils inside. This not only ensures that the water comes out at high temperature but also ensures that the water never cools down.

Rinnai claims that this model will take up much less space than a traditional model and that it will still provide you with an endless source of hot water for all your needs. Whether you want to install new vents or use your existing vents, you can use this device because it will work with both concentric vents as well as those made from PVC.

The temperature of the groundwater can slightly change the efficiency of this Rinnai Model, but it has a maximum energy efficiency rating of up to 98%.






5.  V65IN 6.6 GPM Indoor (View on Amazon.com)

 V65IN 6.6 GPM Indoor Though this Rinnai V65IN 6.6 GPM Indoor Low NOx looks pretty similar to the outdoor water heaters from the company, this is an indoor model.

It is so compact and small in shape that you can install it inside a closet in your laundry room, near the floor or even inside a nearby cabinet. As long as it has access to your water and natural gas systems, it will deliver plenty of hot water for you and your family.

Rinnai guarantees that it will meet the emissions standards in Texas and California, and its low emissions standards will keep your family from inhaling any potentially dangerous fumes or gases too. This Model is so lightweight that you can grab the box off your front porch and carry it to the installation point without any hassles or problems.

The maximum BTU output of 150,000 found on this model lets you know that it will never run out of hot water, as long as it still has access to your natural gas. Despite having a high BTU rating, the V65IN has a maximum energy factor of .82 too. It comes with a digital temperature display as well as buttons for doing a diagnostic scan, checking the settings or adjusting the temperature.



Our Winning Model is.. 


RUC98iN Ultra Series


 RUC98iN Ultra Series (View on Amazon.com)


The best Rinnai Model is the Rinnai RUC98iN Ultra Series Natural Gas, which works with natural gas homes and systems. Designed to work with PVC vents, you can also use this model with the concentric vents your home already has. This model is smaller in size than other Rinnai models and comes with everything needed for installation and connecting to your vents.

Rinnai put all the buttons that you need on the front of the water heater and added a small screen that takes the guesswork out of setting the temperature. As it is a low emissions hot water heater, it will meet the harshest and strictest of state and local emissions standards.