Isotemp SPA 20 Marine Water Heater - 5.3 Gallon
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Isotemp SPA 20 Marine Water Heater - 5.3 Gallon

Isotemp SPA 20 Marine Water Heater - 5.3 Gallon

  • Capacity: 5.3 Gal., Orientation: Horizontal or Vertical, Heat Exchanger: Front
  • Select Voltage / 750 Watts, Tank Material: Stainless Steel
  • Dimensions: 23.2" L x 12.7" OD, Exterior: Polypropylene
  • Item #: 
    Model #: 
    Multiple Models Available
    Reg. Price:     From: $499.99 To: $539.99
    Sale Price:     From: $399.99 To: $431.99
    Note:  This item ships from the manufacturer.
    It typically ships within 2 business days  (more...)
    399.99 431.99
    Please enter quantity below.


    Model #
    Shipping Weight
    115 Volt AC
      27.28 Lbs.
    Reg. Price: $499.99
    Sale Price: $399.99
    230 Volt AC
      28.00 Lbs.
    Reg. Price: $539.99
    Sale Price: $431.99
    Click the "More Info" button above for specific information about that product.

    Shipping weight reflects calculated Dimensional Weight and is not actual product weight - see here for details.

    Indel Webasto Marine Product Catalog

    Isotemp Water Heaters General Features:

    • All Isotemp water heaters use two thermostats: a temperature thermostat and a safety thermostat designed to trip in the event the tank is run dry
    • All Isotemp water heaters come standard with a mixing valve
      • Every Isotemp tank features a safety mixing valve that regulates the temperature of the water coming out of the tank so that water heated to 160+ degrees will not scald boat owners or their guests
      • Temperature of the hot water coming out of the tank can be adjusted to the preference of the owner by turning the mixing valve on the water heater
      • This feature allows the thermostat to be set at a higher temperature, while keeping the user safe from scalding
      • It also extends the capacity of onboard hot water by using only a fraction of the water in the tank to produce the desired water temperature
    • Standard heating elements are 750 watts which won’t overload generators or trip dock breakers
    • All Isotemp products are CE certified and manufactured in ISO certified facilities
    • All Isotemp tanks are covered by a 5-year limited warranty against leakage due to manufacturing defect or corrosion and a 2-year warranty on all other parts
    • 750 Watt immersion heating element as standard on all Isotemp Water Heaters
      • 1200 Watt and 2000 Watt Elements are available as an option (Special Order Only)
        • Note: 2000 Watt heating element is only combatable on 230 Volt versions

    Isotemp SPA 20 Marine Water Heater Features:

    • Exterior casing / jacket made of high quality polypropylene
    • Inner tank made of AISI 316 stainless steel
    • Includes safety valve, mixing valve and plug
    • Robust design and manufactured to highest-quality marine standards for long service life
    • Immersion heating element specially designed to heat water at bottom of tank
    • Thermostat-controlled mixing valve standard on all Isotemp water heaters
    • Aluminum mounting brackets adjustable for deck or bulkhead installations
    • Extra-thick insulation for low temperature loss, high performance
    • Extra-long corrugated coils for high heat exchange efficiency
    • Five-year limited warranty on inner tank against corrosion and material stress


    Part No.
    Tank Capacity
    5.3 Gallon
    5.3 Gallon
    Power (Heating Element)
    115 Volt AC / 750 Watts
    230 Volt AC / 750 Watts
    Rated Pressure (bar)
    Horizontal or Vertical
    Horizontal or Vertical
    Safety Valve
    Mixing Valve
    Heat Exchanger
    Inlet / Outlet Ports
    Male 1/2" NPT
    Male 1/2" NPT
    WARNING: This product MAY expose you to chemicals, which are known to the State of California to cause cancer, birth defects and/or other reproductive harm. For more information go to


    Isotemp has a 5-year limited warranty on the Isotemp water heater tank. All other parts are covered by a two-year limited warranty with one-year warranty on labor.

    Sea Tech Water System Tubing - 1/2 Inch
    Item #: 501303
  • Diameter: 1/2" ID, Select Color
  • Material: Polyethylene, Tolerance: 180° F @ 100 PSI / 72° F @ 160 PSI
  • Sold by the Foot, ( 50 feet Maximum Continuous Length )
    Reg. Price

    Sale Price

    Model #:
    Multiple Models Available

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