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Whole Home Tankless Water Heaters

Whole-home tankless water heaters deliver endless hot water with compact, energy-smart designs. Shop natural gas/propane and high-output electric models, in indoor or outdoor versions, with options for built-in recirculation, Wi-Fi/app control, and clean concentric or twin-pipe venting. Finish installs with vent kits, isolation/flush valves, filters, and maintenance parts.

Shop by need

  • Fuel & power: Natural Gas (NG), Propane (LP), or 240V electric
  • Location: Indoor (vented) or Outdoor (climate/permitted)
  • Type: Condensing (highest efficiency) or Non-condensing
  • Recirculation: built-in pump models, recirc-ready units, or add-on kits
  • Venting: concentric or 2-pipe (PVC/CPVC/PP as specified) with terminations and pipe covers
  • Kits & parts: isolation/flush valves, condensate neutralizers, controllers/Wi-Fi modules, filters, and service parts

Quick choosing guide

  1. Size by demand: total your peak fixtures and calculate required GPM at your winter temperature rise. Whole-home gas units typically cover multi-bath demand; electric whole-home requires adequate amperage and is climate-dependent.
  2. Pick fuel & service: verify gas meter/line capacity and regulator for NG/LP models, or panel amperage/breaker space for electric.
  3. Choose location: Indoor where you can vent; Outdoor where climate/clearances allow and venting is impractical.
  4. Efficiency & condensate: condensing units save energy—plan a drain and consider a condensate neutralizer.
  5. Faster hot water: select a built-in recirc model or add a recirc kit/crossover; set schedules to cut wait time.
  6. Complete the kit: vent kit/terminations, isolation/flush valves, controller or Wi-Fi, and inlet water filtration/scale control as needed.
  7. Maintenance: flush/descale periodically (more often with hard water) to protect the heat exchanger.


  • Sold out

    Rinnai V75iN Natural Gas Tankless Water Heater, 7.5 Gallons Per Minute , While supplies last (Replaced by RE180)

    Rinnai
    $ 1,066.99 - $ 1,066.99
    $ 1,066.99
    $ 1,066.99 - $ 1,066.99
    $ 1,066.99

    Spec Sheet  Install Manual Current RL and 4 of the V models will be discontinued and replaced with the New RE•SERIES™ Non-Condensing models includ...

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    $ 1,066.99 - $ 1,066.99
    $ 1,066.99
    $ 1,066.99 - $ 1,066.99
    $ 1,066.99
    Sold out

  • Rinnai - 229310NPP - 2inch / 4 inch Condensing Vent Pipe Extension, 39 Inches

    Rinnai
    $ 49.99 - $ 49.99
    $ 49.99
    $ 49.99 - $ 49.99
    $ 49.99

    For use with the following models: RU199i RU180i RU160i RU130i RUR199i RUR160i CU199i CU160i Material of Inner/Exhaust - Polypropylene Mater...

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    $ 49.99 - $ 49.99
    $ 49.99
    $ 49.99 - $ 49.99
    $ 49.99

  • Rinnai - RWMKT03 - Control-R Wireless Demand Recirculation Kit (Push Button+Temp Sensor)

    Rinnai
    $ 559.00 - $ 559.00
    $ 559.00
    $ 559.00 - $ 559.00
    $ 559.00

    Rinnai Control-R Wi-Fi Module and mobile app no longer are compatible w/ the RUCS/RUS Tankless Water Heaters Rinnai Control-R Kit with Push-Button ...

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    $ 559.00 - $ 559.00
    $ 559.00
    $ 559.00 - $ 559.00
    $ 559.00

  • Rinnai SENSEI RSC160iN RSC Series Super High Efficiency Plus - Natural Gas Water Heater

    Rinnai
    $ 1,369.62 - $ 1,369.62
    $ 1,369.62
    $ 1,369.62 - $ 1,369.62
    $ 1,369.62

    Rinnai SENSEI RSC160iN Super High Efficiency Natural Gas Water Heater Experience the ultimate in hot water performance with the Rinnai RSC160iN Sup...

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    $ 1,369.62 - $ 1,369.62
    $ 1,369.62
    $ 1,369.62 - $ 1,369.62
    $ 1,369.62

  • Rinnai - 229308NPP - 2 in. / 4 in. x 10 in. Plastic Condensing Vent Pipe Extension Kit

    Rinnai
    $ 33.79 - $ 33.79
    $ 33.79
    $ 33.79 - $ 33.79
    $ 33.79

    Concentric venting allows for secure connection 2 in. / 4 in. condensing vent pipe extension 10 in For use with Sensei Se+ tankless water heaters ...

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    $ 33.79 - $ 33.79
    $ 33.79
    $ 33.79 - $ 33.79
    $ 33.79

  • Rheem - RTG20270A- 6" Pipe Length for RTG-64DVL, RTG-84DVL, RTG-95DVL Tankless Models

    Rheem
    $ 44.99 - $ 44.99
    $ 44.99
    $ 44.99 - $ 44.99
    $ 44.99

    6" Pipe Length for Tankless Models: RTG-64DVL RTG-84DVL RTG-95DVL For 3 in. / 5 in. Concentric Tankless Venting

    $ 44.99 - $ 44.99
    $ 44.99
    $ 44.99 - $ 44.99
    $ 44.99

  • Rinnai - 229309NPP - 2 in. / 4 in. x 19.5in. Plastic Condensing Vent Pipe Extension Kit

    Rinnai
    $ 29.99 - $ 29.99
    $ 29.99
    $ 29.99 - $ 29.99
    $ 29.99

    Concentric venting allows for secure connection 2 in. / 4 in. condensing vent pipe extension 19.5 in For use with Sensei Se+ tankless water heater...

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    $ 29.99 - $ 29.99
    $ 29.99
    $ 29.99 - $ 29.99
    $ 29.99

  • Rinnai - RWMKT01P - Control-R Wireless Demand Recirculation Kit (Pump+Push Button)

    Rinnai
    $ 626.00 - $ 626.00
    $ 626.00
    $ 626.00 - $ 626.00
    $ 626.00

    Rinnai Control-R Wi-Fi Module and mobile app no longer are compatible w/ the RUCS/RUS Tankless Water Heaters Rinnai Control-R Kit with Push-Butto...

    View full details
    $ 626.00 - $ 626.00
    $ 626.00
    $ 626.00 - $ 626.00
    $ 626.00

  • Rheem - RTG-95DVLN-3 - Mid Efficiency 9.5 GPM Indoor Natural Gas EcoNet Included Tankless Water Heater

    Rheem
    $ 1,543.00 - $ 1,543.00
    $ 1,543.00
    $ 1,543.00 - $ 1,543.00
    $ 1,543.00

    Spec Sheet Mid Efficiency 9.5 GPM Indoor Natural Gas EcoNet Included Tankless Water Heater with 12 Year Limited Warranty Rheem RTG is a series of...

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    $ 1,543.00 - $ 1,543.00
    $ 1,543.00
    $ 1,543.00 - $ 1,543.00
    $ 1,543.00

  • Rinnai Bottom plate for Pipe Cover 109001364 Fits Sensei RX

    Rinnai
    $ 0.00 - $ 0.00
    $ 0.00
    $ 67.00
    $ 67.00 - $ 67.00
    $ 67.00

    Rinnai Bottom plate for Pipe Cover  109001364 Fits Sensei RX

    $ 0.00 - $ 0.00
    $ 0.00
    $ 67.00
    $ 67.00 - $ 67.00
    $ 67.00
  • Sold out

    Rheem - RTG20282- 3 in. x 5 in. Vertical Concentric Termination Vent Kit Stainless Steel for Mid Efficiency Tankless Gas Water Heaters

    Rheem
    $ 207.26 - $ 207.26
    $ 207.26
    $ 207.26 - $ 207.26
    $ 207.26

    3 in. x 5 in. Vertical concentric vent kit for use with the Rheem EcoSense mid efficiency indoor tankless gas units. Contains a storm collar, 6/1...

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    $ 207.26 - $ 207.26
    $ 207.26
    $ 207.26 - $ 207.26
    $ 207.26
    Sold out

  • Rinnai - 227412NPP - 2/4 Condensing Vertical Starter Adapter

    Rinnai
    $ 56.00 - $ 56.00
    $ 56.00
    $ 56.00 - $ 56.00
    $ 56.00

    Rinnai 2/4 Condensing Vertical Starter Adapter Weight: 1.39lbs Height: 5.63" Width: 5.71" Depth: 9.92"

    $ 56.00 - $ 56.00
    $ 56.00
    $ 56.00 - $ 56.00
    $ 56.00

  • Rinnai - 229012NPP - 12 Inch 2/4 Condensing Horizontal Termination Kit

    Rinnai
    $ 72.99 - $ 72.99
    $ 72.99
    $ 72.99 - $ 72.99
    $ 72.99

    2/4 Cond Horiz Termination Kit 12in Brand Model Compatibility SE+ Tankless Water Heaters and M-Series Boilers Diameter 4 in Lengt...

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    $ 72.99 - $ 72.99
    $ 72.99
    $ 72.99 - $ 72.99
    $ 72.99

  • Rheem - RTG20271- 90 Degree elbow for RTG-64DVL, RTG-84DVL, RTG-95DVL Tankless Models

    Rheem
    $ 99.90 - $ 99.90
    $ 99.90
    $ 99.90 - $ 99.90
    $ 99.90

    3 Inch / 5 Inch Concentric Venting 90 Degree elbow for tankless models: RTG-64DVL RTG-84DVL RTG-95DVL

    $ 99.90 - $ 99.90
    $ 99.90
    $ 99.90 - $ 99.90
    $ 99.90

  • Rinnai RX199iN Sensei Condensing Indoor/Outdoor Natural Gas/Propane Tankless Water Heater

    Rinnai
    $ 0.00 - $ 0.00
    $ 0.00
    $ 1,703.10
    $ 1,703.10 - $ 1,703.10
    $ 1,703.10

    Rinnai Sensei RX199iN Indoor/Outdoor Tankless Water Heater Rinnai introduces their Pro Build RX Series Tankless Water Heaters, featuring Adaptive G...

    View full details
    $ 0.00 - $ 0.00
    $ 0.00
    $ 1,703.10
    $ 1,703.10 - $ 1,703.10
    $ 1,703.10

  • Rinnai - 229013NPP - 2/4 21 Inch Condensing Horizontal Termination Kit

    Rinnai
    $ 81.00 - $ 81.00
    $ 81.00
    $ 81.00 - $ 81.00
    $ 81.00

    2 in. / 4 in. condensing horizontal termination kit 21 in. For use with Sensei Se+ tankless water heaters (condensing) and m-series boilers White ...

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    $ 81.00 - $ 81.00
    $ 81.00
    $ 81.00 - $ 81.00
    $ 81.00

  • Rinnai HVENT-2 DiversiTech Horizontal 2" Termination Vent

    Rinnai
    $ 34.97 - $ 34.97
    $ 34.97
    $ 34.97 - $ 34.97
    $ 34.97

    2 Inch Horizontal Vent Termination The DiversiTech HVENT-2 2-inch Horizontal Termination Kit is the premium solution for cleanly venting high-effic...

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    $ 34.97 - $ 34.97
    $ 34.97
    $ 34.97 - $ 34.97
    $ 34.97

  • Rinnai - 229230NPP - 10 in. 2/4 Condensing 90 Degree Elbow for Tankless Water Heaters

    Rinnai
    $ 24.25 - $ 24.25
    $ 24.25
    $ 24.25 - $ 24.25
    $ 24.25

    2/4 Condensing Vent Pipe Extension 10 in For Sensei Models Product Weight: 0.57 Height: 5.9" Width: 4.33" Depth: 6.29" Refer to the R...

    View full details
    $ 24.25 - $ 24.25
    $ 24.25
    $ 24.25 - $ 24.25
    $ 24.25
  • Rinnai - Rinnai Multi Unit Control kit REU-MSB-M - - Water Heater Controllers - Big Frog Supply

    Rinnai - REU-MSB-M - Multi Unit Control kit

    Rinnai
    $ 235.00 - $ 235.00
    $ 235.00
    $ 235.00 - $ 235.00
    $ 235.00

    Rinnai Multi Unit Control kit REU-MSB-M For use with Rinnai tankless water heaters. Electronically connects 3 tankless water heaters and allows the...

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    $ 235.00 - $ 235.00
    $ 235.00
    $ 235.00 - $ 235.00
    $ 235.00
  • Sold out

    Rheem - RTG-84XLN-3 - Mid Efficiency 8.4 GPM Outdoor Natural Gas EcoNet Enabled Tankless Water Heater

    Rheem
    $ 953.00 - $ 953.00
    $ 953.00
    $ 953.00 - $ 953.00
    $ 953.00

    Spec Sheet Mid Efficiency 8.4 GPM Outdoor Natural Gas EcoNet Enabled Tankless Water Heater with 12 Year Limited Warranty   Rheem RTG is a series ...

    View full details
    $ 953.00 - $ 953.00
    $ 953.00
    $ 953.00 - $ 953.00
    $ 953.00
    Sold out

  • Rinnai - 187595NPP - 2in x 2/4 Condensing Twin Pipe Adaptor

    Rinnai
    $ 92.00 - $ 92.00
    $ 92.00
    $ 92.00 - $ 92.00
    $ 92.00

    Features: Twin pipe adapter 2 in. x 2/4 Dimensions: 5.67 in. x 9.92 in. x 14.4 in. Water heater accessory For use with SENSEI SE+ tankless water h...

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    $ 92.00 - $ 92.00
    $ 92.00
    $ 92.00 - $ 92.00
    $ 92.00

  • Rinnai - RWMTS01 - Control-R Wi-Fi Temperature Sensor

    Rinnai
    $ 159.95 - $ 159.95
    $ 159.95
    $ 159.95 - $ 159.95
    $ 159.95

    Wireless Temperature Sensor The sensor turns off the recirculation and is available for purchase if required by local building codes.

    $ 159.95 - $ 159.95
    $ 159.95
    $ 159.95 - $ 159.95
    $ 159.95

  • Rinnai - HVENT-3 - DiversiTech Horizontal 3" Termination Vent

    Rinnai
    $ 34.97 - $ 34.97
    $ 34.97
    $ 34.97 - $ 34.97
    $ 34.97

    Horizontal 3" Termination Vent Horizontal vent kits for use in venting high efficiency fossil fuel appliances. The low profile kit hides the vent f...

    View full details
    $ 34.97 - $ 34.97
    $ 34.97
    $ 34.97 - $ 34.97
    $ 34.97
  • Sold out

    Rheem - RTG20151D-1 - 36" Pipe length for RTG-64DVL, RTG-84DVL, RTG-95DVL Tankless Models

    Rheem
    $ 110.30 - $ 110.30
    $ 110.30
    $ 110.30 - $ 110.30
    $ 110.30

    36" Pipe length for Tankless Models: RTG-64DVL RTG-84DVL RTG-95DVL For 3 in. / 5 in. Concentric Tankless Venting

    $ 110.30 - $ 110.30
    $ 110.30
    $ 110.30 - $ 110.30
    $ 110.30
    Sold out

Pro tips: Size from the coldest inlet temperature, verify gas line and meter capacity (or electrical service for electric units), and map the vent path before mounting. Neutralize condensate on condensing models, install isolation valves for easy flushing, and follow local code for gas/electrical and combustion air. Not sure which unit or kit fits? Tell us fuel type, location, and demand—we’ll build a dialed-in list.

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