Skip to content
Enjoy fast and free shipping on all orders over $89! Contact us (855) 424-4376
Enjoy fast and free shipping on all orders over $89! Contact us (855) 424-4376

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

    Rheem - SP10869MM - Element, 4500W

    Rheem
    $ 22.91 - $ 22.91
    $ 22.91
    $ 22.91 - $ 22.91
    $ 22.91

    240-Volt, 4500-Watt Stainless Steel Heating Element for Electric Water Heaters Rheem PROTECH screw-in water heater elements feature true OEM perfor...

    View full details
    $ 22.91 - $ 22.91
    $ 22.91
    $ 22.91 - $ 22.91
    $ 22.91
    Sold out
  • Sold out

    Rheem - SP20075 - Pilot Assembly Replacement Kit

    Rheem
    $ 47.89 - $ 47.89
    $ 47.89
    $ 47.89 - $ 47.89
    $ 47.89

    The Rheem PROTECH Pilot Assembly Replacement Kit contains everything that you need to replace the Pilot Assembly on your Rheem water heater. This k...

    View full details
    $ 47.89 - $ 47.89
    $ 47.89
    $ 47.89 - $ 47.89
    $ 47.89
    Sold out
  • Sold out

    Rheem - SP11526C - 0.900 in. Dia Magnesium Anode Rod

    Rheem
    $ 23.61 - $ 23.61
    $ 23.61
    $ 23.61 - $ 23.61
    $ 23.61

    Rheem PROTECH anode rods are an important line of defense in preventing corrosion and leaks in your water heater. These devices work because the me...

    View full details
    $ 23.61 - $ 23.61
    $ 23.61
    $ 23.61 - $ 23.61
    $ 23.61
    Sold out
  • Sold out

    Rheem - SP20172 - Flammable Vapor FV Sensor Kit

    Rheem
    $ 23.61 - $ 23.61
    $ 23.61
    $ 23.61 - $ 23.61
    $ 23.61

    The Rheem PROTECH FV Sensor Replacement Kit contains everything that you need to replace the FV Sensor Assembly on your Rheem water heater. This ki...

    View full details
    $ 23.61 - $ 23.61
    $ 23.61
    $ 23.61 - $ 23.61
    $ 23.61
    Sold out
  • Sold out

    Rheem - SP11309C - Anode Rod

    Rheem
    $ 24.71 - $ 24.71
    $ 24.71
    $ 24.71 - $ 24.71
    $ 24.71

    Rheem PROTECH anode rods are an important line of defense in preventing corrosion and leaks in your water heater. These devices work because the me...

    View full details
    $ 24.71 - $ 24.71
    $ 24.71
    $ 24.71 - $ 24.71
    $ 24.71
    Sold out
  • Sold out

    Rheem - SP20060 - Electric Water Heater Tune-Up Kit

    Rheem
    $ 34.92 - $ 34.92
    $ 34.92
    $ 34.92 - $ 34.92
    $ 34.92

    Repair your water heater rather than replace it with the Rheem PROTECH Electric Water Heater Tune-Up Kit. This OEM quality Electric Water Heater Tu...

    View full details
    $ 34.92 - $ 34.92
    $ 34.92
    $ 34.92 - $ 34.92
    $ 34.92
    Sold out
  • Sold out

    Rheem - SP10552ML - Water Heater Element, Small

    Rheem
    $ 12.75 - $ 12.75
    $ 12.75
    $ 12.75 - $ 12.75
    $ 12.75

    Rheem PROTECH screw-in water heater elements feature true OEM performance. These are the same elements that are used in the production of every Rhe...

    View full details
    $ 12.75 - $ 12.75
    $ 12.75
    $ 12.75 - $ 12.75
    $ 12.75
    Sold out
  • Sold out

    Rheem - SP10874DL - 1" 1000W Copper Resistored Screw-in Element MWD (120V)

    Rheem
    $ 36.62 - $ 36.62
    $ 36.62
    $ 36.62 - $ 36.62
    $ 36.62

    1" 1000W Copper Resistored Screw-in Element MWD (120V) Watt Density Classification: LWD Input Voltage (V): 120 Wattage at 120V (W): 1000 Watt Dens...

    View full details
    $ 36.62 - $ 36.62
    $ 36.62
    $ 36.62 - $ 36.62
    $ 36.62
    Sold out
  • Sold out

    Rheem - SP20832E - OEM Upgraded Replacement for Rheem Water Heater Natural Gas Valve

    Rheem
    $ 187.99 - $ 187.99
    $ 187.99
    $ 187.99 - $ 187.99
    $ 187.99

    Rheem Water Heater SP20832E GAS CONTROL (THERMOSTAT)

    $ 187.99 - $ 187.99
    $ 187.99
    $ 187.99 - $ 187.99
    $ 187.99
    Sold out
  • Rinnai - Rinnai 21" Universal Non-Cond Horizontal Termination 223184 - - Water Heater Venting - Big Frog Supply

    Rinnai - 223184 - 21" Universal Non-Cond Horizontal Termination

    Rinnai
    $ 84.00 - $ 84.00
    $ 84.00
    $ 84.00 - $ 84.00
    $ 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...

    View full details
    $ 84.00 - $ 84.00
    $ 84.00
    $ 84.00 - $ 84.00
    $ 84.00
  • Sold out

    Scratch and Dent Rheem - RTG-70XLP-1 - Tankless Water Heater, Grey -SD1

    Rheem
    $ 0.00 - $ 0.00
    $ 0.00
    $ 959.99
    $ 959.99 - $ 959.99
    $ 959.99

    ITEM IS LIKE NEW. SIGNS OF COSMETIC DAMAGE CAN INCLUDE SCRATCHES, DENTS, AND WORN CORNERS. ITEM MAY ARRIVE WITH DAMAGED PACKAGING OR BE REPACKAGED....

    View full details
    $ 0.00 - $ 0.00
    $ 0.00
    $ 959.99
    $ 959.99 - $ 959.99
    $ 959.99
    Sold out
  • Sold out

    Rheem - RTG-84XLP-3 - Tankless Water Heater

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

    Spec Sheet Rheem RTG is a series of mid-efficiency condensing tank less gas water heaters designed for continuous hot water. Industry leading low ...

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

  • Rheem - RTG-70XLP-3 - Tankless Water Heater, Grey

    Rheem
    $ 999.00 - $ 999.00
    $ 999.00
    $ 999.00 - $ 999.00
    $ 999.00

    Spec Sheet Rheem RTG is a series of mid-efficiency condensing tank less gas water heaters designed for continuous hot water. Industry leading low ...

    View full details
    $ 999.00 - $ 999.00
    $ 999.00
    $ 999.00 - $ 999.00
    $ 999.00
  • Sold out

    Rinnai - CXP199iN- SENSEI CX Series Built for the PRO Commercial INDOOR with Pump NATURAL GAS/PROPANE

    Rinnai
    $ 0.00 - $ 0.00
    $ 0.00
    $ 2,228.10
    $ 2,228.10 - $ 2,228.10
    $ 2,228.10

    SUPER-HIGH-EFFICIENCY (CONDENSING) with Pump TANKLESS WATER HEATER SENSEI CX Series is the Built for the PRO, by the PRO with a new, more compact c...

    View full details
    $ 0.00 - $ 0.00
    $ 0.00
    $ 2,228.10
    $ 2,228.10 - $ 2,228.10
    $ 2,228.10
    Sold out
  • Sold out

    Rinnai - CXP160iN- SENSEI CX Series Built for the PRO Commercial INDOOR with Pump NATURAL GAS/PROPANE

    Rinnai
    $ 0.00 - $ 0.00
    $ 0.00
    $ 1,787.10
    $ 1,787.10 - $ 1,787.10
    $ 1,787.10

    SUPER-HIGH-EFFICIENCY (CONDENSING) with Pump TANKLESS WATER HEATER SENSEI™ CX Series is the Built for the PRO, by the PRO with a new, more compact ...

    View full details
    $ 0.00 - $ 0.00
    $ 0.00
    $ 1,787.10
    $ 1,787.10 - $ 1,787.10
    $ 1,787.10
    Sold out
  • Sold out

    Rinnai - CX160iN - SENSEI CX Series Built for the PRO Commercial INDOOR without Pump NATURAL GAS/PROPANE

    Rinnai
    $ 0.00 - $ 0.00
    $ 0.00
    $ 1,505.70
    $ 1,505.70 - $ 1,505.70
    $ 1,505.70

    SUPER-HIGH-EFFICIENCY (CONDENSING) without Pump TANKLESS WATER HEATER SENSEI™ CX Series is the Built for the PRO, by the PRO with a new, more compa...

    View full details
    $ 0.00 - $ 0.00
    $ 0.00
    $ 1,505.70
    $ 1,505.70 - $ 1,505.70
    $ 1,505.70
    Sold out

  • Rinnai REP160eN High Efficiency Non Condensing Natural Gas Tankless Water Heater With Built-in Recirculation Pump.

    Rinnai
    $ 1,016.19 - $ 1,016.19
    $ 1,016.19
    $ 1,016.19 - $ 1,016.19
    $ 1,016.19

    Rinnai REP160eN High Efficiency Tankless Water Heater With Recirculation Pump Enjoy the freedom of endless hot water installed right outside your h...

    View full details
    $ 1,016.19 - $ 1,016.19
    $ 1,016.19
    $ 1,016.19 - $ 1,016.19
    $ 1,016.19

  • Rinnai - RE140iN - RE Model Series High Efficiency Non Condensing

    Rinnai
    $ 795.69 - $ 795.69
    $ 795.69
    $ 795.69 - $ 795.69
    $ 795.69

    Spec Sheet  Install Manual Learn More RE140iN is the perfect combination of high efficiency, comfort and value in a natural gas non- condensing tan...

    View full details
    $ 795.69 - $ 795.69
    $ 795.69
    $ 795.69 - $ 795.69
    $ 795.69

  • Rinnai REP199iP High Efficiency Non Condensing Tankless Water Heater with Built-in Recirculation Pump.

    Rinnai
    $ 1,381.59 - $ 1,381.59
    $ 1,381.59
    $ 1,381.59 - $ 1,381.59
    $ 1,381.59

    Rinnai REP199iP Non Condensing Tankless Water Heater The Rinnai REP199iP Non Condensing Tankless Water Heater delivers the perfect blend of high ef...

    View full details
    $ 1,381.59 - $ 1,381.59
    $ 1,381.59
    $ 1,381.59 - $ 1,381.59
    $ 1,381.59

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.

Related Articles

How Tankless Water Heaters Work

A tankless Rinnai water heater works by heating water on demand as it flows through the unit, rather than storing...

Properly Sizing a Tankless Water Heater

Tankless hot water heaters are an excellent choice for homeowners who want to save money on their energy bills while...

Why Every Home Needs a Wireless Controller for their Tankless Water Heater

Imagine having full control over your water heating system. Now, think about being able to monitor your tankless water heater...

5 Powerful Benefits of Upgrading to a Rinnai Tankless Water Heater

If your water heater’s age is kicking into the double digits, it’s time to consider replacing it. Rusty water and...

Preventing Scale Build up in your Tankless Hot Water Heater

Scale build-up occurs when minerals and other impurities in the water accumulate on the heating element surfaces, impeding heat transfer...

Rinnai SENSEI RX: How to Set the Gas Type (NG - LP) – Quick Installer Guide

Learn how to set Natural Gas or Propane on a Rinnai SENSEI RX tankless water heater: enter Parameter 10, save,...

Rinnai Error Codes and Troubleshooting Tips

Rinnai is a popular brand of tankless water heaters that provides efficient and reliable heating solutions for homes and businesses....

How to fix the Rinnai Error Code LC or 00 Scale Build-Up Problem?

Rinnai Error Code LC Scale Build-Up can cause your water heater to malfunction. Read on to learn how to fix...

How to Properly Install Rinnai Concentric Vent Kits: A Step-by-Step Guide

Learn how to properly install Rinnai concentric vent kits to ensure safe and efficient operation of your tankless water heater....

Top Reasons to Install a Rinnai RWM101 Control-R WiFi

Have you ever considered improving your water heater experience? The Rinnai RWM101 Control-R WiFi is a tankless water heater integrated...

Rinnai Introduces Their Pro Build Sensi RX Series

Rinnai Introduces their Pro Build RX Series Tankless Water Heaters, featuring Adaptive Gas Valve Technology that allows for seamless switching...

How to set up your Rinnai Central Wifi App

Smart Connect Allows you to connect your smart phone or tablet to the SENSEI® RX Series via Bluetooth®. Use the...

Compare products

{"one"=>"Select 2 or 3 items to compare", "other"=>"{{ count }} of 3 items selected"}

Select first item to compare

Select second item to compare

Select third item to compare

Compare