Rinnai Ultra Series Review


The Ultra Series by Rinnai is their high-end model offering that is ideal for medium – large sized homes, or homes with heavy demand needs. The Ultra Series is powerful to meet heavy demand and super high efficiency – this is due to its condensing & recirculation technology; thus it has a whopping uniform energy factor of 0.92 which is one of the most efficient units you can get. It also features Energy Star certification and two heat exchangers for maximum performance. If you’re having a hard time deciding on which unit to get, our post here on can help you out.

The Ultra Series also comes many configurations, as seen below

View Price – 9.8 GPM / View Price – 8.0 GPM


  • Some important specifications to consider:
  • Temperature 120 F factory default up to 140 F
  • Direct electronic ignition (goodbye pilot light!)
  • Water supply pressure min-max 50-150 PSI (recommended 60-80 PSI for best performance)
  • 3 / 4 inch gas supply line connection
  • Water inlet & outlet are both 3 / 4 inch
  • Minimum activation flow is 0.4 GPM


The Ultra Series comes with a 12 year warranty on the heat exchanger, a 5 year warranty on parts and a 1 year warranty on labor.

Advantages & Disadvantages


  • Condensing & recirculation technology
  • 2 heat exchangers
  • Energy factor of 0.92
  • Energy Star Certified
  • Extensive warranty
  • Ideal for medium to larger sized homes / heavy demand


  • None


Rinnai’s Ultra series is their high-end offering made specifically for heavy use in larger homes. This is the perfect tankless hot water heater for you if you need someone heavy duty while getting extra features like recirculation technology for extra efficiency.

What people have to say

“We love this water heater! It is actually saving us so much money on electricity that it is paying for it self! I wish I would have made the change along time ago.”
“We love not being limited in our hot water, and we love the efficiency.”
“Very quiet which is great for a finished basement. Heats up quickly. Stays hot (very well insulated).”
“We have owned this on-demand water heater product for about 7 months and have never run out of hot water, a very good thing. The settings to increase or decrease the temp is outside the unit and very easy to adjust with the touch of a button.”
“This is our first experience with an online water heater. For the most part, we are pleased, as the pros out weigh the cons. Pros: Has a small footprint and is off the floor of my garage. You won’t run out of hot water!! Is energy efficient, you are not heating water all the time, just when needed. Low maintenance. Cons: It takes a while for hot water to reach the tap. Overall worth it though.”
“We are using it for 9 months. Like it so far. Works well in cold winter and hot summer. Switching from a tank, now we can take shower back-to-back. Saves 20 min waiting between the showers.”
“We had it installed by a certified plumber so I can’t comment on ease of installation. But I like the ease of use. Changing the temperature at the push of a button. My wife took an hour long shower and was running the dishwasher the whole time and never lost the temperature. I like with the showers I can just turn it on and the temperature never changes. It’s lack of taking up space is awesome. We’ve only had it for about 4 months now.”