Rinnai RUR98iP (Propane) & RUR98iN (NG) Indoor Tankless Water Heater with Recirculation Review


First things first: let's talk about the numbers you'll enjoy with the RUR98 (Propane or Natural Gas).

Check Price for Propane unit

Check Price for Natural Gas unit

  • The flow rate can reach up to 9.8 gallons per minute (GPM). This is a phenomenal number, one of the best out there, though it should be noted that it only applies to homes in mild-to-moderate climates. If you live somewhere colder where your ground water is colder and needing more effort to heat up, your flow rate might range anywhere from 5-6 GPM.
  • In terms of size, the RUR98 measures 18.5 x 10.1 x 26.4 inches and weighs 70 lbs. This is the size of a small suitcase, but it is a little heavier. You'll likely need a couple of folks to help you install. It's also less bulky than a traditional water tank, so you're coming out on top in terms of floor space.
  • The RUR98 can require up to 199,000 BTUs, but it also has an energy factor of 0.94, so keep both numbers in mind when calculating energy efficiency and what you'll pay on your bill. Remember, too, that all tankless water heaters are better than water tanks in terms of saving money.
  • RU "R": The 2nd R stands for recirculation. This means it has a built-in water recirculation capability to ensure you can have nearly instant hot water at each tap.


As a whole-house unit, you can expect the same performance from the RUR98 that you would from a regular water heating system. It'll serve multiple bathrooms at once without a problem.

Whether you're washing dishes, filling a tub or doing a load of laundry, the RUR98 will deliver.

One thing to note about this unit is that it comes with a special NOx system. Unlike some gas tankless water heaters, it doesn't have to be installed outdoors, and you don't have to worry about dangerous fumes building up in enclosed spaces.

This is because of the RUR98's internal compressing system.

You will need to install it with a series of vents, however, because no natural gas model can go without them. But we'll talk more of vents in the installation section below.

Heat Output and Flow

As previously mentioned, you'll enjoy up to 9.8 GPM with the RUR98iN. This number might fluctuate depending on the temperature outside.

The colder it is, the harder your unit will have to work to deliver the same water temperature and pressure. In other words, in colder climates you may only get 8 to 8.5 GPM, but that's still sufficient to run 4 hot showers at the same time. 

All temperatures can be adjusted with a special Rinnai remote control.


All right, let's talk about that NOx. The good news is that Rinnai has made installation as simple as possible, so in addition to a detailed instruction manual, you'll also receive special isolator valves free of charge.

The bad news is that you might need to order a few other parts too. As usual, we always suggest you contact a professional plumber to do the install if you can. That way you won't forget anything necessary for the install. Not only is it easier, but you also won't run the risk of voiding your warranty through a messy DIY installation.

Depending on what you already have at home, here are a few things you should be aware of to get the job done:

  • Water lines
  • Shutoff valves
  • Circuit breakers
  • Exhaust pipes
  • Weatherproofing equipment

General Use

As with any tankless water heater, there are pros and cons to choosing the RUR98. Let's take a closer look at both sides of the equation.


  • Powerful whole-house unit can deliver up to 9.8 GPM
  • Special NOx system makes it safer than ever
  • Built-in Recirculation to ensure you can have instant hot water
  • Can be used in both residential and commercial settings


  • Not the most affordable model on the market...but is one of the most reliable
  • Installation may require trained professional

As mentioned they have recirculation capability, with or without a dedicated recirculation line. This truly is innovative technology providing an endless supply of hot water.

As a bonus, the RUR98 offers both Concentric and PVC, providing more venting options right out of the box. Check the units out on Amazon (Propane or Natural Gas).

Enable registration in settings - general
Compare items
  • Total (0)