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EcoSmart ECO-18 Electric Tankless Water Heater 18KW 2+ Bath

$ 475.00

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Call us at 305-823-6991

Perfect for a large apartment or townhome with 2 bathrooms

Ideal for a large apartment/townhome with up to 3 people. The Eco Smart ECO 18 is the mid-range model that can heat over 2.5 gallons per minute. So it can handle a shower and a sink in cool climates. In warmer climates, it can handle two showers and two sinks. 

  • Savings of up to 50% on water heating costs
  • The most advanced, self-modulating technology available, meaning the ECO 18 will adjust how much energy needs to be input based on how much hot water is needed
  • Stylish and advanced design that is pleasing to the eye
  • Digital temperature control in 1-degree increments allows control of hot water
  • Copper and stainless components designed for efficiency, durability and easy replacement
  • Compact size saves valuable storage space
Dimensions (in.) 18" x 14" x 3.75"
Weight 11.25 lbs.
Exchanger Copper
Protection Thermal Auto
Temperature Control Digital
Activation flow: .25 GPM
Energy efficiency: 99.8 %
Certification: ETL Listed to UL 499 & CSA
Warranty Lifetime*
Tech Specs
Voltage 240
Phase Single
KW 18 kW
Elements 2 x 9 KW @ 240
Amperage Draw 75.0 Amps
Required Breaker 2 x 40 DP
Required Wire 2 x 8 AWG
Electrical Panel 150 Amps
HZ 50/60
Pipes fittings 3/4" NPT

Full color installation diagram for EcoSmart ECO-18 Tankless Water Heater


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

    All EcoSmart water heaters feature a limited lifetime warranty on electronic components as well as heat exchangers.

  • What size fittings does this unit have?

    The EcoSmart Eco-18 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 EcoSmart Eco-18 tankless water heater runs on 240 volts, and is a two-line heater. It pulls 150 amps, calling for 2 Double Pole 40 amp breakers, and 8/2 wire (8 gauge).

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

    The EcoSmart Eco-18 tankless water heater is a large capacity unit, with 18KW of heating power, this unit is ideal for 2.5 baths in warm climates, and up to 1.5 bathrooms in colder climates.

  • How many GPM

    Approx. 10 GPM @ 60 psi.

  • Is a pressure relief valve required

    Yes highly recommended.

  • Power is off why

    We can help you diagnose the issue with Ecosmart 18kw. Please call us at 305-823-6991.

  • Noticed - your answer below said unit pulls 150 amps with (2) 40 amp breakers that is not good! Think you have a typo. My question is how often does the unit (ECO 18) pull maximum amps (80 amps) Does this happen when max flow is being required? does the max amps stay continuous as the flow continues? Thanks John @Green Valley Electric

    Ecosmart 18 Kw:
    Here are the electrical requirements:
    18 KW @ 220 to 240 vac
    75 amp peak draw
    2- double pole 40 amp breakers 
    6 gauge wire with ground. 
    The reference we make on our site is that you'll require a load center at minimum 150 Amps. This is your breaker box (in layman terms) total amp capacity.  Not 150 amps dedicated to the heater.
    Therefore our advertized electrical requirements are dead one. Regarding load calculation, heater modulation and power draw would require for you to call our tech dept. for an indepth explanation. 305-823-6991 and we make simple for our customers to undestand. Give us a call.