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iHeat AH21 Pro Performer Whole House Tankless Water Heater 21KW

$ 575.00

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The AH series of tankless water heaters have long been known for their durability and reliability. The AH-21 is no exception. Powerful enough to heat water for average size homes in moderate to cold climates with 21 kilowatts of electrical draw it is more powerful than the AH-18. With a max temp rise of 142.8 degrees F at 1 GPM and 71.4 degrees F at 2 GPM you can see how this tankless water heater will perform very well in most applications and climates. It is perfect for 3 bedroom 2 bath homes throughout North America where incoming water temperature is no lower that 45 degrees F. This tankless water heater also works well in applications where there are many appliances that require the use of hot water.

  • Advanced Digital Temp Control
  • Completely stainless steel housing
  • Incredible heating capacity
  • Saves as much as 60% of your electrical cost to heat water
  • Color coded inlet and outlet for easy installation
  • Small in size and very easy to install
  • Cover: Stainless Steel
  • Body/Heat Exchanger: Stainless Steel
  • Element: 3 Brass Flange/Copper
  • 3 year warranty
Tech Specs
  • 21 KW at 240V
  • Three 40 AMP Double Pole Breakers Required - 8/2 Wire
  • Pipe fittings: 3/4" NPT
  • Dimensions: 16” x 17” x 3.25”
  • Shipping Weight: 16 lbs.

Drakken iHeat AH21 installation diagram. 


    Ask a Question
    • Does this unit come with a warranty?

      All iHeat brand water heaters feature a 1-year warranty.

    • What size fittings does this unit have?

      The iHeat AH-21 tankless water heater uses 3/4” fittings on both the inlet and outlet, both located on the bottom of the unit.

    • What electrical specifications are required for this unit?

      The iHeat AH-21 tankless water heater runs on 240 volts, and is a three-line heater. It calls for 3 Double Pole 40 amp breakers, and 8/2 wire (8 gauge).

    • How many bathrooms can this unit provide hot water for?

      The iHeat AH-21 tankless water heater is a large capacity unit, with 21KW of heating power and an increased flow rate. This unit is ideal for 2.5 to 3 baths in warm climates, and up to 1.5 to 2 bathrooms in cold/moderate climates.