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Tankless Water Heaters

Tankless water heaters deliver endless hot water with compact, energy-smart designs. Shop gas (natural gas or LP) and electric models from Rinnai, Rheem, Stiebel Eltron, Eemax, and Chronomite—plus venting, recirculation, controls, and repair parts to finish the job.

Shop by need

  • Fuel & power: Natural Gas and Propane; Electric 120V or 240V point-of-use and whole-home
  • Model type: Condensing and Non-condensing; Indoor or Outdoor; Combination units
  • Recirculation: built-in recirc pump models, add-on pumps, pump hardware, controllers, and WiFi control accessories
  • Venting: concentric and twin-pipe kits, terminations, pipe covers, and heater guards
  • Kits & parts: NG/LP conversion kits, descaler/flush kits, repair parts, cables, and accessories
  • Series callouts: Rinnai Sensei CX and Sensei RX series options
  • Rinnai - 229308NPP - 2 in. / 4 in. x 10 in. Plastic Condensing Vent Pipe Extension Kit

    Rinnai
    Original price $ 33.79 - Original price $ 33.79
    Original price
    $ 33.79
    $ 33.79 - $ 33.79
    Current price $ 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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    Original price $ 33.79 - Original price $ 33.79
    Original price
    $ 33.79
    $ 33.79 - $ 33.79
    Current price $ 33.79
  • Rinnai - CVENT3 - DiversiTech Concentric 3" Vent Termination

    Rinnai
    Original price $ 49.58 - Original price $ 49.58
    Original price
    $ 49.58
    $ 49.58 - $ 49.58
    Current price $ 49.58

    Concentric 3" Vent Termination  The DiversiTech 3-inch Concentric Vent Kit is the solution for simplifying high-efficiency furnace installations. T...

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    Original price $ 49.58 - Original price $ 49.58
    Original price
    $ 49.58
    $ 49.58 - $ 49.58
    Current price $ 49.58
  • Rinnai HVENT-2 DiversiTech Horizontal 2" Termination Vent

    Rinnai
    Original price $ 34.97 - Original price $ 34.97
    Original price
    $ 34.97
    $ 34.97 - $ 34.97
    Current price $ 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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    Original price $ 34.97 - Original price $ 34.97
    Original price
    $ 34.97
    $ 34.97 - $ 34.97
    Current price $ 34.97
  • Rinnai - 229205NPP - Condensing 2/4 45 Degree Elbow (2 Pack) for Tankless Water Heaters 229205NPP

    Rinnai
    Original price $ 50.75 - Original price $ 50.75
    Original price
    $ 50.75
    $ 50.75 - $ 50.75
    Current price $ 50.75

    For use with Sensei Se+ tankless water heaters (condensing) and m-series boilers. Refer to the Rinnai Water Heater Installation and Operation man...

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    Original price $ 50.75 - Original price $ 50.75
    Original price
    $ 50.75
    $ 50.75 - $ 50.75
    Current price $ 50.75
  • Rinnai - 189952 - Shingle Roof Flashing (8/12 to 16/12 pitch)

    Rinnai
    Original price $ 87.00 - Original price $ 87.00
    Original price
    $ 87.00
    $ 87.00 - $ 87.00
    Current price $ 87.00

    Precisely engineered accessories can add even more reliability, convenience and flexibility to Rinnai Tankless Water Heaters. With Rinnai Common Ve...

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    Original price $ 87.00 - Original price $ 87.00
    Original price
    $ 87.00
    $ 87.00 - $ 87.00
    Current price $ 87.00
    Sold out
  • Rinnai - 187595NPP - 2in x 2/4 Condensing Twin Pipe Adaptor

    Rinnai
    Original price $ 92.00 - Original price $ 92.00
    Original price
    $ 92.00
    $ 92.00 - $ 92.00
    Current price $ 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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    Original price $ 92.00 - Original price $ 92.00
    Original price
    $ 92.00
    $ 92.00 - $ 92.00
    Current price $ 92.00
  • Rheem - RTG20282- 3 in. x 5 in. Vertical Concentric Termination Vent Kit Stainless Steel for Mid Efficiency Tankless Gas Water Heaters

    Rheem
    Original price $ 207.26 - Original price $ 207.26
    Original price
    $ 207.26
    $ 207.26 - $ 207.26
    Current price $ 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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    Original price $ 207.26 - Original price $ 207.26
    Original price
    $ 207.26
    $ 207.26 - $ 207.26
    Current price $ 207.26
    Sold out
  • Rheem - RTG20151D-1 - 36" Pipe length for RTG-64DVL, RTG-84DVL, RTG-95DVL Tankless Models

    Rheem
    Original price $ 110.30 - Original price $ 110.30
    Original price
    $ 110.30
    $ 110.30 - $ 110.30
    Current price $ 110.30

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

    Original price $ 110.30 - Original price $ 110.30
    Original price
    $ 110.30
    $ 110.30 - $ 110.30
    Current price $ 110.30
    Sold out
  • Rinnai - 229013NPP - 2/4 21 Inch Condensing Horizontal Termination Kit

    Rinnai
    Original price $ 81.00 - Original price $ 81.00
    Original price
    $ 81.00
    $ 81.00 - $ 81.00
    Current price $ 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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    Original price $ 81.00 - Original price $ 81.00
    Original price
    $ 81.00
    $ 81.00 - $ 81.00
    Current price $ 81.00
  • Rinnai - 229012NPP - 12 Inch 2/4 Condensing Horizontal Termination Kit

    Rinnai
    Original price $ 72.99 - Original price $ 72.99
    Original price
    $ 72.99
    $ 72.99 - $ 72.99
    Current price $ 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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    Original price $ 72.99 - Original price $ 72.99
    Original price
    $ 72.99
    $ 72.99 - $ 72.99
    Current price $ 72.99
  • Rinnai - 224097 - Metal Pass Through Venting Plate

    Rinnai
    Original price $ 32.50 - Original price $ 32.50
    Original price
    $ 32.50
    $ 32.50 - $ 32.50
    Current price $ 32.50

    Rinnai has the best metal pass through plate for your venting needs. The Rinnai 224097 is suitable for use with plastic and metal components. Actua...

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    Original price $ 32.50 - Original price $ 32.50
    Original price
    $ 32.50
    $ 32.50 - $ 32.50
    Current price $ 32.50
    Sold out
  • Rheem - RTG20270A- 6" Pipe Length for RTG-64DVL, RTG-84DVL, RTG-95DVL Tankless Models

    Rheem
    Original price $ 44.99 - Original price $ 44.99
    Original price
    $ 44.99
    $ 44.99 - $ 44.99
    Current price $ 44.99

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

    Original price $ 44.99 - Original price $ 44.99
    Original price
    $ 44.99
    $ 44.99 - $ 44.99
    Current price $ 44.99
  • Rheem - RTG20270B- 12" Pipe length for RTG-64DVL, RTG-84DVL, RTG-95DVL Tankless Models

    Rheem
    Original price $ 44.99 - Original price $ 44.99
    Original price
    $ 44.99
    $ 44.99 - $ 44.99
    Current price $ 44.99

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

    Original price $ 44.99 - Original price $ 44.99
    Original price
    $ 44.99
    $ 44.99 - $ 44.99
    Current price $ 44.99
  • Rheem - RTG20270C- 24" Pipe length for RTG-64DVL, RTG-84DVL, RTG-95DVL Tankless Models

    Rheem
    Original price $ 55.99 - Original price $ 55.99
    Original price
    $ 55.99
    $ 55.99 - $ 55.99
    Current price $ 55.99

    24" Pipe length for Tankless Models: RTG-64DVL RTG-84DVL RTG-95DVL 23.66 in. overall length For 3 in. / 5 in. Concentric Tankless Venting

    Original price $ 55.99 - Original price $ 55.99
    Original price
    $ 55.99
    $ 55.99 - $ 55.99
    Current price $ 55.99
  • Rheem - RTG20271- 90 Degree elbow for RTG-64DVL, RTG-84DVL, RTG-95DVL Tankless Models

    Rheem
    Original price $ 99.90 - Original price $ 99.90
    Original price
    $ 99.90
    $ 99.90 - $ 99.90
    Current price $ 99.90

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

    Original price $ 99.90 - Original price $ 99.90
    Original price
    $ 99.90
    $ 99.90 - $ 99.90
    Current price $ 99.90
  • Rinnai - 242141 - Flashing for Metal Roof - Plastic

    Rinnai
    Original price $ 108.98 - Original price $ 108.98
    Original price
    $ 108.98
    $ 108.98 - $ 108.98
    Current price $ 108.98

    Flashing for Metal Roof For metal roof installations. Zero clearance to combustibles. Material: Plastic UPC: 8713645120461 Height: 2.5" Width...

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    Original price $ 108.98 - Original price $ 108.98
    Original price
    $ 108.98
    $ 108.98 - $ 108.98
    Current price $ 108.98
  • Rinnai - HVENT-3 - DiversiTech Horizontal 3" Termination Vent

    Rinnai
    Original price $ 34.97 - Original price $ 34.97
    Original price
    $ 34.97
    $ 34.97 - $ 34.97
    Current price $ 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...

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    Original price $ 34.97 - Original price $ 34.97
    Original price
    $ 34.97
    $ 34.97 - $ 34.97
    Current price $ 34.97
  • Rinnai - 223159 - All-Weather Wall Discharge

    Rinnai
    Original price $ 79.99 - Original price $ 79.99
    Original price
    $ 79.99
    $ 79.99 - $ 79.99
    Current price $ 79.99

    Rinnai's all-weather wall discharge 223159. Product color may vary from displayed image.

    Original price $ 79.99 - Original price $ 79.99
    Original price
    $ 79.99
    $ 79.99 - $ 79.99
    Current price $ 79.99
  • Rheem - SP20286 - Horizontal Vent Termination Kit 3 In.

    Rheem
    Original price $ 30.88 - Original price $ 30.88
    Original price
    $ 30.88
    $ 30.88 - $ 30.88
    Current price $ 30.88

    Rheem SP20286 3" Low Profile Horizontal Termination Kit 3" Low Profile Horizontal Termination. 3 in. horizontal vent termination kit for high effi...

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    Original price $ 30.88 - Original price $ 30.88
    Original price
    $ 30.88
    $ 30.88 - $ 30.88
    Current price $ 30.88
  • Rheem - RTG20321- Concentric 45 Degree elbow for RTG-64DVL, RTG-84DVL, RTG-95DVL Tankless Models

    Rheem
    Original price $ 85.99 - Original price $ 85.99
    Original price
    $ 85.99
    $ 85.99 - $ 85.99
    Current price $ 85.99

    Stainless Steel Concentric 45° elbow for use with a mid efficiency tankless gas unit installation. Perfect for making offsets in the vent run from ...

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    Original price $ 85.99 - Original price $ 85.99
    Original price
    $ 85.99
    $ 85.99 - $ 85.99
    Current price $ 85.99
  • Rinnai - 223184 - 21" Universal Non-Cond Horizontal Termination

    Rinnai
    Original price $ 84.00 - Original price $ 84.00
    Original price
    $ 84.00
    $ 84.00 - $ 84.00
    Current price $ 84.00

    Rinnai's 223184 21" universal non-condensing horizontal termination kit is compatible with all Rinnai tankless water heater models except the 98 se...

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    Original price $ 84.00 - Original price $ 84.00
    Original price
    $ 84.00
    $ 84.00 - $ 84.00
    Current price $ 84.00
  • Rinnai - 223187 - Horizontal Termination Diverter Kit 21"

    Rinnai
    Original price $ 117.00 - Original price $ 117.00
    Original price
    $ 117.00
    $ 117.00 - $ 117.00
    Current price $ 117.00

    Raised 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...

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    Original price $ 117.00 - Original price $ 117.00
    Original price
    $ 117.00
    $ 117.00 - $ 117.00
    Current price $ 117.00
    Sold out
  • Rinnai - 710342 - 3/5 Rubber Wall Plate White

    Rinnai
    Original price $ 9.00 - Original price $ 9.00
    Original price
    $ 9.00
    $ 9.00 - $ 9.00
    Current price $ 9.00

    Rubber Wall Plate (White) Wall Plate for Rinnai's unique Ubbink concentric venting system provides ease of installation. Compatible with all indoo...

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    Original price $ 9.00 - Original price $ 9.00
    Original price
    $ 9.00
    $ 9.00 - $ 9.00
    Current price $ 9.00
  • Rinnai - 790146 - Check Valve PPTL to PVC Direct Vent

    Rinnai
    Original price $ 0.00 - Original price $ 0.00
    Original price $ 0.00
    $ 212.19
    $ 212.19 - $ 212.19
    Current price $ 212.19

    PVC AND CPVC COMMON VENTING IN 3" AND 4" SIZING INCREASES SAVINGS AND FLEXIBILITY AVAILABLE WITH RINNAI INLINE TANKLESS RACK SYSTEMS (TRS) AND CORN...

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    Original price $ 0.00 - Original price $ 0.00
    Original price $ 0.00
    $ 212.19
    $ 212.19 - $ 212.19
    Current price $ 212.19
    Sold out

Quick choosing guide

  1. Size by flow: estimate peak demand in GPM at your winter inlet temperature rise. Whole-home gas units often cover 5–11+ GPM; electric point-of-use fits sinks and small loads.
  2. Pick fuel & placement: Gas for highest flow; choose indoor with proper venting or outdoor where climate allows. Electric units need the correct amperage and breakers.
  3. Efficiency: select condensing for higher efficiency and cooler exhaust; plan condensate drain where required.
  4. Faster hot water: choose a model with a built-in recirc pump or add a recirc kit and controller.
  5. Complete the install: vent kit and terminations for gas models; isolation/service valves; pipe covers; WiFi or wall controllers. Use NG/LP conversion kits only as specified.
  6. Maintenance: add a descaler/flush kit and schedule periodic cleaning to protect the heat exchanger.

Pro tips: Size for the coldest inlet temperature, verify gas line BTU capacity and vent route for NG/LP models, or breaker/wire size for electric units. Install isolation valves for easy flushing, set recirc schedules to cut wait time, and winterize outdoor units where required.

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