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Rinnai SENSEI SE+ Series 18" 199k BTU 11 GPM Commercial Gas Tankless Water Heater

Rinnai SENSEI SE+ Series 18" 199k BTU 11 GPM Commercial Gas Tankless Water Heater

Regular price $2,546.00
Regular price Sale price $2,546.00
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The Rinnai Sensei Commercial CU199 is a super high efficiency, Commercial Energy Star Certified, tankless hot water heater. The commercial line offers 97% Thermal Efficiency with a heat exchanger built for commercial demands. The CU199 is designed specifically for commercial use with precision engineering to give you an endless supply of hot water. Restaurants and hotels, as well as multi-family dwellings and schools, are perfect applications for a commercial tankless water heater.

Cascade Logic and Cable Assembly are available for the CU199 tanks. With Cascade Cables used to connect up to 24 water heaters together, Cascade Logic rotates water heater operation to ensure the entire system gets equal usage and functions as a single hot water source. In a commercial installation where you may need to use more than one unit, Rinnai offers many Tankless Rack Systems for installation flexibility as well. The Tankless Rack system is available for wall-mounted or freestanding installation for two or more units.

The commercial line of tankless water heaters is also available in either Natural Gas or Liquid Propane. The CU199 must be purchased for indoor or outdoor use*. Indoor versus outdoor installation is not interchangeable and must be decided at the time of purchase. Indoor installation of the CU199 offers both concentric and PVC/CPVC venting. The dual venting option on the top of the unit allows for maximum installation flexibility - one concentric vent or two PVC/CPVC/PP pipes can be used for venting. With concentric venting, one pipe allows for fresh outside air in, while the other allows for the exhaust to go out. Outdoor installation does not require venting. This item, the CU199i, is for indoor installation and requires venting.

The Rinnai Sensei Series with condensing technology offers built-in freeze protection down to -22°F on the indoor units. The unit features an integrated check valve located between the turbofan and the combustion chamber to prevent cold air from entering the venting system and backflow of exhaust in common vent applications. The Fiber Mesh Premix Burner helps to provide even flame distribution for optimal performance for any demand.

It features 199,000 BTUs and hot water delivery with a flow rate that ranges from 0.26 - 9.8 GPM. The minimum GPMs is perfect for low demand uses such as shaving, where warm water is needed but not at a high rate! The MCC-91-2US controller is included with the water heater as part of the front panel. The default minimum temperature setting is 98° with a maximum of 140°F. The unit offers a maximum setting of 185°F with parameter adjustment. A parameter adjustment on the CU199 unit can be made for greater hot water flow - up to 11 GPM - as well.

In a condensing tankless water heater, such as the CU199, once you turn on the tap, cold water goes into the tankless heater and the flame is activated. Water is pre-heated as it passes through the primary stainless steel heat exchanger then continues to be heated as it passes through the coils in the secondary heat exchanger, exits the water heater, into your pipes, and up to the fixture calling for the hot water. Depending on the amount of hot water called for, the flame adjusts accordingly to heat more or less water.

Benefits of a Tankless Hot Water Heater:

  • Endless hot water - Heats water as it goes through the pipes, offering endless hot water for your business

  • Hot water on demand - Once you turn the water on, hot water runs through your pipes and out the faucet! Virtually no time or water is wasted waiting for the water to heat up

  • Highly Efficient - Gallon for gallon, you will spend less money heating your hot water. With a tankless system, the water is heated on demand rather than sitting in a storage tank. A storage tank typically heats the water intermittently throughout the day and night not only when it is needed. This unit is Energy Star Qualified and features an Energy Factor of 0.93 (the closer to 1.0 the better)

  • Long-lasting - Unlike a storage tank in which the water sits in the tank all the time creating sediment and rust, a tankless water heater will last longer



  • 97% thermal efficiency, commercial Energy Star certified
  • Ultra-low NOx compliant
  • Approved for high altitude up to 10,200 ft. (3,109 m)
  • Integrated temperature controller that provides 98°F to 185°F, no external controller required
  • Isolation valves included
  • Increase savings with commercial Energy Star certified tankless water heaters that operate more efficiently on-demand to provide an endless supply of hot water

    What's Included

    • Tankless Water Heate
    • Pressure Relief Valve and Adapter
    • Isolation Valve Kit
    •  Integrated Controller
    • Recirculation Pump Cable

    *Note: The Rinnai RWM101 Control-R™ Wi-Fi Module is required for Wi-Fi connectivity.


    Manufacturer Trade Model Number U.S. CU199iN, CU199iP, CU199eN, CU199eP
    Product Depth 11.45 in / (290 mm)
    Product Height 26.4 in / (670.56 mm)
    Product Width 18.5 in / (470 mm)
    Product Weight 64 lb / (29 kg)
    Gas Type Natural Gas/Propane
    Installation Type Indoor/Outdoor
    Residential Energy Star Yes
    Domestic Hot Water Flow Rate (Maximum) 11 GPM 
    Wi-Fi Capable Yes
    SCAQMD Approved Ultra-Low NOx


    To connect with a Rinnai-trained installer, you can utilize the Rinnai Dealer Locator by visiting the link: Alternatively, you can directly reach out to Rinnai's dedicated customer support team via the Toll-Free Number: 1 (800) 621-9419.

    Options and Accessories

    3" Control-R Wi-Fi Module for Tankless Water Heaters

    • Works with all Rinnai Tankless Water Heater models manufactured 2006 and newer (except RH180 Hybrid Tank-Tankless Water Heaters).
    • The Lime Condition (LC) notification will not appear in the Rinnai
    • App, when the Control-R™ Wi-Fi Module is paired with the following series of Rinnai Tankless Water Heaters, manufactured prior to 2009: VA, VB, KA, and V53e.

    12" Condensing Horizontal Termination Kit

    • For indoor Installation
    • Depth: 4.8 in
    • Product Weight: 4.5 lbs.

    2/4 Condensing Horizontal Termination Kit in 12"

    • For indoor Installation
    • Product Width:  7.5 in
    • Product Depth:  25 in
    • Product Height: 7.87 in
    • Product Weight: 22 lbs

    EZConnect Cable

    • For indoor Installation
    • Connect your Rinnai water heaters conveniently with this EZ-connect cable
    • Diligently designed for smooth functionality of tankless water heaters
    • Plastic material helps withstand abrasion to make it durable

    21" Black Commercial Pipe Cover Enclosure

    • Helps to ensure that your pipes are protected from the outdoor elements.
    • Can be used for indoor installation for a more aesthetically appealing, finished look.


    Documents & Files


    8 yrs on Heat Exchanger
    5 Year Warranty on Parts

    1 Year Labor Warranty


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