Marathon MR40238

The MR40238 features 3800w elements and a tank capacity of 52 gallons. This model is perfect for a family of 4 with normal hot water demands.

The lower wattage elements of the MR40238 make it a perfect fit for older homes with smaller electrical panels. The lower wattage elements do NOT affect the efficiency of the heater. Recovery times are just a little slower then its 4500w siblings.

If you have a newer home with larger electrical capacity you may want to look at the MR40245.

Marathon MR40238 Features:

  • Seamless, blow-molded, polybutene tank – impervious to rust and corrosion 
  • Multiple layers of filament wound fiberglass give the tank unmatched strength 
  • Polyurethane Envirofoam™ insulation helps reduce energy consumption 
  • The most energy efficient in its class 
  • Recessed drain valve is out of the way of brooms and scrubbers 
  • Tough molded polyethylene outer shell resists dents and scratches 
  • Bowl shaped bottom allows complete sediment draining 
  • High temperature polysulfone dip tubes 
  • All plastic tank eliminates the need for an anode rod 
  • Thermally fused element to protect tank against “dry-fire”; low watt, density for long life. 
  • Factory installed temperature and pressure relief valve 
  • Factory installed vacuum relief valve 
  • Inlet and outlet connections are 3/4″ NPT 
  • Water tight grommets keep out overhead moisture and condensation 



Capacity: 40 Gallons
Element Size: 3800 Watts (240 Volts)
Tank Height: 65 1/2 Inches
Tank Diameter: 21 3/4 Inches
Weight: 90 lbs
Standards: Meets or exceeds ANSI standard and is UL listed. 
First Hour Rating: 52 Gallons 
Energy Factor: .94 

Service Parts

Marathon offers a full line of service parts for their entire water heater line. The following service parts are available for this model: