Your Guide to Home Heating and Cooling Systems

Rinnai RUC98iN Tankless Water Heater Review

Endless hot water for your entire home

Are you tired of watching your family wastewater every time they need to shower? With a tankless water heater, you limit the amount of water that is available, which keeps your family from wasting it and keeps your bills from skyrocketing. The Rinnai RUC98iN Ultra Series Natural Gas is a smart choice for homes that use natural gas because it comes with most of the accessories and parts that you need for installation. With a 9.8 gallon per minute flow rating, it provides you with lots of supply too.


Product Summary

Product Specification

  • Has a maximum flow rate of 9.8 gallons per minute
  • Measures 26 inches long by 18.5 inches wide and 10 inches deep
  • Has a residential warranty that covers the heat exchanger for 12 years and all other parts for five years
  • Comes with a one-year warranty on labor that you can increase to five years
  • Energy Star rating lets you know that the device will use less power to lower your bills
  • Weighs 82 pounds when removed from the box and slightly more when shipped to your home
  • Has a maximum BTU rating of 199,000 units
  • Requires a concentric or twin pipe installation
  • Meets all emissions standards in both Texas and California

Detailed Review & Breakdown


  • Requires concentric venting for installing it but can also work with twin PVC pipes
  • Energy Star rated with an energy efficiency rating of 0.96 to help you save on heating costs
  • Space-saving design gives you access to all the features you need while also helping you save on space
  • Lets you select a maximum temperature of between 98 and 140 degrees Fahrenheit
  • Will work in both commercial buildings and residential homes
  • Can be even more effective when used with one of the controllers available from the manufacturer
  • Improves the overall heating efficiency of your home
  • Includes a power button, temperature control buttons and other buttons as well as a digital screen on the front


  • Past customers experienced some failures and other problems within one to three years of installing it
  • Some models have a poor ignition system that can make it fail

Our Winner

Our final verdict is that the RUC98iN Ultra Series Natural Gas is a good model for most homes, especially those living in Texas and California. It meets all emissions standards and regulations used by those states. You can also install this machine in a commercial building.

The Rinnai has an energy efficiency rating of .96 and a 9.8 gallon per minute rating to provide you with more hot water while preventing your family from wasting it. is a participant in the Amazon Services LLC Affiliate Program, an affiliate program designed to provide a means for sites to earn advertising fees by advertising and linking to