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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.


  •

    Whitlam - Flow-Aide System Descaler Kit

    Whitlam
    $ 174.99 - $ 174.99
    $ 174.99
    $ 174.99 - $ 174.99
    $ 174.99

    Install Manual Complete Descaler Kit, Includes: 3.5 Gallon Bucket, 800 GPH Pump, 2 Rubber Hoses, 1 Quart FLOW-AIDE® (FLOW32). FLOW AIDE® System Des...

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    $ 174.99 - $ 174.99
    $ 174.99
    $ 174.99 - $ 174.99
    $ 174.99
  • EWS - Filter Cartridge Replacement for EWS-HEATER-GUARD-3/4 - - Mechanical - Big Frog Supply
    BB-Guard-Filter with small white balls on a white background

    EWS - BB-GUARD-FILTER-3/4 – Replacement Filter Cartridge for EWS Heater Guard ¾″

    EWS
    $ 111.75 - $ 111.75
    $ 111.75
    $ 111.75 - $ 111.75
    $ 111.75

    The BB-GUARD-FILTER-3/4 is the official replacement filter cartridge for the EWS Heater Guard ¾″ system. Built with a 5-micron pre-sediment cartrid...

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    $ 111.75 - $ 111.75
    $ 111.75
    $ 111.75 - $ 111.75
    $ 111.75

  • Whitlam - FLOW AIDE System Descaler (1 Gallon)

    Whitlam
    $ 51.80 - $ 51.80
    $ 51.80
    $ 51.80 - $ 51.80
    $ 51.80

    Install Manual FLOW AIDE® System Descaler quickly dissolves water scale, lime, rust, and other water formed deposits, restoring efficiency to most ...

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    $ 51.80 - $ 51.80
    $ 51.80
    $ 51.80 - $ 51.80
    $ 51.80

  • Whitlam - FLOW AIDE System Descaler (1 Qt)

    Whitlam
    $ 21.49 - $ 21.49
    $ 21.49
    $ 21.49 - $ 21.49
    $ 21.49

    Install Manual FLOW AIDE® System Descaler quickly dissolves water scale, lime, rust, and other water formed deposits, restoring efficiency to most ...

    View full details
    $ 21.49 - $ 21.49
    $ 21.49
    $ 21.49 - $ 21.49
    $ 21.49
  • Rinnai - Rinnai Digial Recirculation Controller MC-195T-US - - Water Heater Controllers - Big Frog Supply

    Rinnai MC-195T-US Digital Recirculation Controller

    Rinnai
    $ 275.30 - $ 275.30
    $ 275.30
    $ 275.30 - $ 275.30
    $ 275.30

    Rinnai Recirculation Controller Rinnai MC-195T-US Digital Recirculation Controller brings added convenience and flexibility to your compatible Rinn...

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    $ 275.30 - $ 275.30
    $ 275.30
    $ 275.30 - $ 275.30
    $ 275.30

  • Rinnai RWM200 Wireless Wifi Module

    Rinnai
    $ 0.00 - $ 0.00
    $ 0.00
    $ 150.00
    $ 150.00 - $ 150.00
    $ 150.00

    Rinnai RWM200 WiFi Module The Rinnai RWM200 Wireless Module connects you to your Rinnai tankless water heater from virtually anywhere, giving you c...

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    $ 0.00 - $ 0.00
    $ 0.00
    $ 150.00
    $ 150.00 - $ 150.00
    $ 150.00

  • Rinnai - MIVK-T-LW - Matsui Plumbing Isolation Valve Kit

    Rinnai
    $ 93.00 - $ 93.00
    $ 93.00
    $ 93.00 - $ 93.00
    $ 93.00

    Rinnai Isolation Valve Kit The Rinnai MVIK-T-LW tankless water heater valve kit facilitates a streamlined, two-step installation process for your ...

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    $ 93.00 - $ 93.00
    $ 93.00
    $ 93.00 - $ 93.00
    $ 93.00
  • Rinnai - Rinnai Universal Horizontal Termination Kit 11.5" 223181 - - Water Heater Venting - Big Frog Supply - 2
    Rinnai - Rinnai Universal Horizontal Termination Kit 11.5" 223181 - - Water Heater Venting - Big Frog Supply - 1

    Rinnai 223181 Non-Condensing Universal Horizontal Termination Kit 11.5"

    Rinnai
    $ 96.19 - $ 96.19
    $ 96.19
    $ 96.19 - $ 96.19
    $ 96.19

    Rinnai Universal Horizontal Termination Kit The Rinnai 223181 Non-Condensing Horizontal Termination Kit is an 11-1/2” universal venting solution th...

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    $ 96.19 - $ 96.19
    $ 96.19
    $ 96.19 - $ 96.19
    $ 96.19

  • Rinnai - 223176PP - 12", 3"/5" Condensing Horizontal Termination Kit

    Rinnai
    $ 110.00 - $ 110.00
    $ 110.00
    $ 110.00 - $ 110.00
    $ 110.00

    Rinnai's 12 inch horizontal termination kit finishes the route for your venting on a Rinnai tankless water heater. The 223176PP pipe is made specif...

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    $ 110.00 - $ 110.00
    $ 110.00
    $ 110.00 - $ 110.00
    $ 110.00
  • Rinnai - Rinnai 21" Horizontal Termination Kit for Condensing Units 223177PP - - Water Heater Venting - Big Frog Supply

    Rinnai - 223177PP - 21" Horizontal Termination Kit for Condensing Units

    Rinnai
    $ 114.00 - $ 114.00
    $ 114.00
    $ 114.00 - $ 114.00
    $ 114.00

    Rinnai's 21 inch horizontal termination kit finishes the route for your venting on a Rinnai tankless water heater. The 223177PP pipe is made specif...

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    $ 114.00 - $ 114.00
    $ 114.00
    $ 114.00 - $ 114.00
    $ 114.00

  • Rinnai MC-601-W Temperature Controller MC-601, White

    Rinnai
    $ 139.00 - $ 139.00
    $ 139.00
    $ 139.00 - $ 139.00
    $ 139.00

    The MC-601-W Temperature Controller is made from premium materials, and offers great function and value for your home. The MC-601-W is part of Rinn...

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    $ 139.00 - $ 139.00
    $ 139.00
    $ 139.00 - $ 139.00
    $ 139.00

  • Rinnai RPB200 On-Demand Recirculation via Push Button

    Rinnai
    $ 0.00 - $ 0.00
    $ 0.00
    $ 45.00
    $ 45.00 - $ 45.00
    $ 45.00

    The Rinnai RWM200 Wireless Module lets homeowners experience the ultimate in accessibility, convenience, and control. Using the Rinnai Central app ...

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    $ 0.00 - $ 0.00
    $ 0.00
    $ 45.00
    $ 45.00 - $ 45.00
    $ 45.00
  • Rinnai - Rinnai Vent Pipe Extension 39" for Condensing Units 224080PP - - Water Heater Venting - Big Frog Supply

    Rinnai - 224080PP - Vent Pipe Extension 39" for Condensing Units

    Rinnai
    $ 58.00 - $ 58.00
    $ 58.00
    $ 58.00 - $ 58.00
    $ 58.00

    Rinnai's 39 inch vent pipe extension helps route venting for your Rinnai tankless water heater. The 224080PP pipe is made specifically for Condensi...

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    $ 58.00 - $ 58.00
    $ 58.00
    $ 58.00 - $ 58.00
    $ 58.00

  • Rinnai - RWMMS01 - Control-R Motion Sensor

    Rinnai
    $ 312.00 - $ 312.00
    $ 312.00
    $ 312.00 - $ 312.00
    $ 312.00

    The Rinnai Control-R motion sensor is mounted near a main point of use such as a kitchen faucet or bathroom sink, and operates the recirculation sy...

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    $ 312.00 - $ 312.00
    $ 312.00
    $ 312.00 - $ 312.00
    $ 312.00

  • Rinnai - RWMKT01 - Control-R Wireless Demand Recirculation Kit (Push Button)

    Rinnai
    $ 439.00 - $ 439.00
    $ 439.00
    $ 439.00 - $ 439.00
    $ 439.00

    Rinnai Control-R Wi-Fi Module and mobile app no longer are compatible w/ the RUCS/RUS Tankless Water Heaters Control Your Rinnai Tankless Water Hea...

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    $ 439.00 - $ 439.00
    $ 439.00
    $ 439.00 - $ 439.00
    $ 439.00

  • Rinnai - RX2RXPCK - Internal Add-On Recirculation Conversion KIT

    Rinnai
    $ 0.00 - $ 0.00
    $ 0.00
    $ 509.90
    $ 509.90 - $ 509.90
    $ 509.90

    Rinnai Internal Add-On Recirculation Conversion Kit designed for their Sensei RX Series tankless water heaters, allowing models without a built-in ...

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    $ 0.00 - $ 0.00
    $ 0.00
    $ 509.90
    $ 509.90 - $ 509.90
    $ 509.90
  • Rinnai - Rinnai Universal Horizontal Termination Kit 21" 223182 - - Water Heater Venting - Big Frog Supply

    Rinnai - 223182 - Universal Horizontal Termination Kit 21"

    Rinnai
    $ 114.99 - $ 114.99
    $ 114.99
    $ 114.99 - $ 114.99
    $ 114.99

    Long termination kit for Rinnai tankless water heater venting in the shape of an L to go outside of side wall. Inner exhaust material is aluminum a...

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    $ 114.99 - $ 114.99
    $ 114.99
    $ 114.99 - $ 114.99
    $ 114.99
  • Two white metal covers on a white background
    Metallic rectangular object on a white background

    Rinnai PCD09-SHS Pipe Cover Enclosure

    Rinnai
    $ 153.79 - $ 153.79
    $ 153.79
    $ 153.79 - $ 153.79
    $ 153.79

    Rinnai Pipe Cover Tidy up the look of your Rinnai tankless water heater installation with the PCD09-SHS water heater pipe cover. This sleek, silver...

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    $ 153.79 - $ 153.79
    $ 153.79
    $ 153.79 - $ 153.79
    $ 153.79
  • Rinnai - Rinnai 38" Roof Discharge for Condensing Units 184162PP - - Water Heater Venting - Big Frog Supply

    Rinnai - 184162PP - 38" Roof Discharge for Condensing Units

    Rinnai
    $ 110.00 - $ 110.00
    $ 110.00
    $ 110.00 - $ 110.00
    $ 110.00

    Rinnai roof discharge 38" for condensing ultra series tankless water heaters. SKU: 184162PP Color of product may differ from image. This Venting ...

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    $ 110.00 - $ 110.00
    $ 110.00
    $ 110.00 - $ 110.00
    $ 110.00
  • Rinnai - Rinnai Vent Pipe Extension 39" 224053 - - Water Heater Venting - Big Frog Supply

    Rinnai - 224053 - Vent Pipe Extension 39"

    Rinnai
    $ 78.00 - $ 78.00
    $ 78.00
    $ 78.00 - $ 78.00
    $ 78.00

    39" vent pipe extension for your Rinnai tankless water heater venting. Inner exhaust material is aluminum and outer intake material is plastic. Pa...

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    $ 78.00 - $ 78.00
    $ 78.00
    $ 78.00 - $ 78.00
    $ 78.00

  • Rinnai - MC-601-BK - Controller MC-601, Black

    Rinnai
    $ 139.00 - $ 139.00
    $ 139.00
    $ 139.00 - $ 139.00
    $ 139.00

    Instruction The MC-601-BK is made from premium materials, this Item offers great function and value for your home. This fixture is part of Rinnai...

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    $ 139.00 - $ 139.00
    $ 139.00
    $ 139.00 - $ 139.00
    $ 139.00

  • Rinnai - 105000250 - Sensei External Pump Harness

    Rinnai
    $ 15.00 - $ 15.00
    $ 15.00
    $ 15.00 - $ 15.00
    $ 15.00

    Rinnai Sensei Pump Harness External Recirculation Pump Wire Harness (Part Number 105000250) is the essential accessory you need when adding an exte...

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    $ 15.00 - $ 15.00
    $ 15.00
    $ 15.00 - $ 15.00
    $ 15.00

  • Rinnai - 107000450 - Sensei Dedicated Return Valve

    Rinnai
    $ 114.00 - $ 114.00
    $ 114.00
    $ 114.00 - $ 114.00
    $ 114.00

    Dedicated Recirculation Valve for RUR, replaces Cold Isolation ValveIncludes: Tee Check valve Drain valve Isolation valve for return line

    $ 114.00 - $ 114.00
    $ 114.00
    $ 114.00 - $ 114.00
    $ 114.00

  • Rinnai - 107000284 - Isolation Valve Kit Next Gen Replacement for Sensei Models

    Rinnai
    $ 99.99 - $ 99.99
    $ 99.99
    $ 99.99 - $ 99.99
    $ 99.99

    Rinnai Isolation Valve Kit Next Gen Replacement for Sensei Models 107000284

    $ 99.99 - $ 99.99
    $ 99.99
    $ 99.99 - $ 99.99
    $ 99.99

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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