#1 Home Improvement Retailer

Super High Efficiency Plus 11 GPM Residential 199,000 BTU Natural Gas Interior Tankless Water Heater

Apply Now
$undefined.00 /mo† suggested payments with months† financingApply Now
  • Enjoy endless hot water
  • Less space for heating gives you more space for living
  • Includes isolation and PRV valves; no additional purchase needed
  • View More Details
Free & Easy Returns In Store or Online
Return this item within 90 days of purchase. Read Return Policy
Product Details

About This Product

Welcome to ultimate efficiency. With technology that operates only when hot water is needed, super-efficient heating coils, no pilot light and no storage tank to heat and reheat water, you save on energy and utility costs. In fact, Rinnai Tankless Water Heaters use up to 40% less energy than a traditional tank water heater. Plus, with premium technology, increased energy efficiency, an improved Home Energy Rating System (HERS) Index Score and optimized LEED eligibility, our tankless solutions can increase your home's value. You can even qualify for energy efficiency rebates and tax credits. It's a smart investment for now and the future.


  • ENERGY STAR qualified with Uniform Energy Factor of 0.95
  • Equipped with Rinnai Circ-Logic - pair with an external pump to reduce wait time for hot water via scheduled or on-demand recirculation
  • Save time with hot water whenever and wherever you need it, any size home, even for simultaneous uses at multiple fixtures
  • Save energy and reduce utility costs by operating only when hot water is needed
  • Temperature lock function prevents accidental or unauthorized changes to water temperature
  • Complies with South Coast Air Quality Management District 14 ng/J or 20 ppm NOx emission levels
  • Wi-fi ready
  • Residential warranty: limited 15-year or 12,000 hours on heat exchanger, 5-year on parts, 1-year on labor (5-year optional on labor); commercial warranty: limited 8-year or 12,000 hours on heat exchanger, 5-year on parts, 1-year on labor (2-year optional on labor)
  • *Note. Rinnai is changing the language in its warranty terms and conditions found in the current User Installation manuals. The existing statement will be replaced by the following: "This Limited Warranty applies only to products that are installed in the United States and Canada. Improper installation may void this Limited Warranty. It is recommended that a trained and qualified professional who has attended a Rinnai installation training class complete your installation." All warranties (old or new manual) will be honored as written above.
  • You can be confident in choosing to install Rinnai tankless technology in your home; our commitment to quality has made us the #1 selling tankless water heating brand in North America; your family deserves nothing less
  • Professional installation recommended; please call 833-746-6210
  • Rinnai branded accessories will ensure optimal performance of your Rinnai Tankless Water Heater.
  • Click here for more information on Electronic Recycling Programs
  • Return Policy
  • California residents
     see Prop 65 WARNINGS

Product Information

Internet # 306655613

Model # RU199iN


Dimensions: H 26.4 in, W 18.5 in, D 11.5 in


Product Depth (in.)

11.5 in

Product Height (in.)

26.4 in

Product Width (in.)

18.5 in

Vent diameter (in.)

2 in

Water Connection Size (in.)

3/4 in


Application Type


BTU Rating


Efficiency Level

Super High

Finish Family

Silver Metallic

First Hour of Delivery (gallons/hr)


Flow Rate @ 35°F Rise (gallons/min)

9.8 gal (US)/min

Flow Rate @ 45° Rise (gallons/min)

8.5 gal (US)/min

Flow Rate @ 55° Rise (gallons/min)

7 gal (US)/min

Flow Rate @ 65° Rise (gallons/min)

5.9 gal (US)/min

Fuel Type


Gas Connection Size

3/4" MNPT

Gas Type

Natural Gas

Heat Exchanger Warranty

15 Year



Maximum Temperature (F)

185 F

Minimum Activation Rate (gpm)


Minimum Temperature (F)

98 F

Number of Showers


Pack Size


Product Weight (lb.)

64 lb

Required Volt Connection

120 volt



Total BTU (Btu)

199000 Btu

Uniform Energy Factor


Vent Type

Single Wall

Water Heater Features

Digital Display, Freeze Protection, Overheat Protection, Ultra LoNox, Wall Mounted, WiFi

Warranty / Certifications

Certifications and Listings

AHRI Certified, CSA Certified

Labor Warranty

1 Year

Part Warranty

5 Year

Questions & Answers

Typical questions asked about products:

  • Is the product durable?
  • Is the product easy to use?
  • What are the dimensions of the product?

Customer Reviews

4.6 out of 5

  • 4.6 out of 373 reviews
  • 81% recommend this product
Filter by:
Showing 1-10 of 373 reviews
get it
Man this thing is gr8 continuous hot water very quiet pretty big needs 2 ppl to mount but not hard at all
    • Recommended
    Has it weaknesses but unlimited hot water is nice
    Works well louder than I expected. Just a humming sound almost like a condensate pump. Only been using it for about 3 weeks. It is nice not running out of hot water. The only issue in my house is it turns on and off like 40 or 50 times a day a few seconds at a time between washing hands, cleaning dishes, and everything else hot water is used for. It takes a little longer for hot water but nothing crazy. Time will tell how it holds up.
    • Verified Purchase
    • Recommended
    1 found this review helpful
    Best Upgrade Ever
    Have always had a tank water heater and just made the switch to tankless. Paid a professional to install this and I couldn’t be happier. Family of 5 so no more running out of hot water or paying to heat a tank of water that isn’t being used. We are not in what is considered a “hard-water” zone, but to help ensure the life I went ahead and had the Rinnai scale cutter installed as well. Highly recommend this tankless water heater and I could’t be happier with my purchase
      • Recommended
      2 found this review helpful
      Energy efficient with plenty of hot water.
      Leaking water heater replacement, excellent product.
      • Verified Purchase
      Quality Tankless Water Heater
      Our 14 year-old Rheem tankless water heater recently failed due to the control board failing. Because of its age, the control board was no longer available and therefore the unit could not be repaired. A friend, who is a builder, said, "I didn't realize Rheem was in the tankless water heater market. We always put Rinnain tankless heaters in our new builds." Hmm. I looked into this and learned that Rinnai is a leading brand in tankless water heaters so I was fortunate to be able to order the RU 100iN from Home Depot. It shipped to the store and was available within a few days. I installed it myself today and I am very pleased with the result. It is very quiet, compared to the previous unit. I can barely hear it running when standing next to it. The installation instructions were excellent and after committing them to memory, I felt comfortable doing the job. I used the Sharkbite water heater kit for the water lines connected to copper lines and they worked perfectly--no leaking. You'll need 3/4" male unions to connect them to the Rinnai isolation valves. The condensate drain was easy-I used a 1/2" female fitting coupled to a 3/8" barbed fitting for 3/8" vinyl tubing running to a floor drain. I was able to reuse the Pressure Relieve Valve downspout from the previous unit. Be sure to use a new 3/4" yellow flex gas hose for your natural gas connection. Venting was easy with 2" PVC. I did the non-direct combustion vent, which pulls air from the room and this required a short piece of 2" PVC and a 90 degree elbow. The entire job took 6 hours and I only used a second person for lifting the unit on the mounting bracket and feeding the exhaust PVC from the outside. I saved $2,300 compared to the cost quoted for installation of a new Rheem unit and feel that I have a superior unit that is high efficiency and has a better GPM output and warranty. Based on the reputation of this brand, I'm assuming it's going to be trouble free for many years.
        • Recommended
        25 found this review helpful
        Installation was easy and the performance is great. The heater delivers hot water much faster tha...
        Installation was easy and the performance is great. The heater delivers hot water much faster than my old tankless hot water heater. Love the fact that Schedule 40 PVC can be used for venting. Dealing with condensation was a bit tricky because I do not have a drain nearby the heater, so I installed an automatic condensate removal pump (see picture) - it is also working great.
          • Recommended
          5 found this review helpful
          Fairly easy to install. Good quality and works well.
          Fairly easy to install. Good quality and works well.
          • Verified Purchase
          • Recommended
          2 found this review helpful
          Took out hot water heater replaced with the tankless perfect....
          Took out hot water heater replaced with the tankless perfect. I would recommend over hot water heater..Energy Efficient
          • Verified Purchase
          6 found this review helpful
          This is the model to get if you want maximum hot water flow capacity in a single unit at an effic...
          This is the model to get if you want maximum hot water flow capacity in a single unit at an efficient energy rate. Some pointers that may save you some time: You likely need to upgrade to at least a 3/4" gas line, you need 3/4" PVC fittings purchased separately to run the pressure relief valve drainage, 1/2" tubing or PVC for the condensate drain. If you intend to run a hot water recirculation line I would recommend against trying to link the pump via the "Circ-logic" connection to the water heater. Not only did this require me to purchase a separate connector cable but then I found out the pump marketed for this purpose would not work as designed unless you purchase even more accessories. I ended up scrapping the whole connection and simply have the pump controlled by a smart plug. The water heater works fantastic and the manual is fairly thorough, just a couple minor annoyances along the way.
          Response from Product ExpertApr 23, 2020
          We are so glad this unit worked well for you! Thank you for providing the detailed description as this will be useful to other buyers.
            • Recommended
            36 found this review helpful
            Nice quick delivery. So far the water heater is working perfectly.
            • Verified Purchase
            Showing 1-10 of 373 reviews

            Compare Similar Items

            current item

            Gas Type

            Natural Gas

            Natural Gas


            Natural Gas






            Number of Showers


            Application Type





            Efficiency Level

            Super High

            Super High

            Super High

            Super High