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A.O. Smith ProMax SL 40-Gallon Natural Gas Water Heater Tank

Original price $598.62 - Original price $618.57
Original price
$598.62 - $618.57
Current price $598.62


A.O. Smith residential natural gas hot water tanks are energy efficient and inexpensive.


  • An internal microprocessor gives you precise sensing and faster heating response to optimize performance
  • Stainless steel core CoreGard anode rods greatly extends the life of the anode rod. Provides tank protection much longer than standard anode rods.
  • Thermopile generates the power needed to operate the electronic gas control, and eliminates the need for an external power source
  • Blue Diamond glass-coated tank provides better corrosion resistance compared to typical hot water tank glass lining
  • The DynaClean diffuser dip tube reduces scale, lime and sediment buildup. This maximizes hot water output for many years. Made from long-lasting PEX (cross linked polymer).
  • Ball type drain valve made from solid brass is tamper resistant and has enhanced flow
  • Light the pilot quickly and easily with single-handed, Piezo, push button spark ignition
  • Factory installed heat trap nipples
  • T&P relief valve is CSA certified and ASME rated
  • Patented ecological design reduces NOx emissions by up to 33%. Complies with requirements for < 40 ng/J


BTU 40,000
Capacity 40 gallon
CEC Compliant For sale in CA
Maximum Temp 160°F
Model series Promax
Color/Finish Grey
CSA Certified Specifications CSA 4.1
ANSI Specifications ANSI Z21.10.1
UL Listed No
NSF Certified No
Depth, Width and Diameter 22 inches
Height 51.5 inches
Water End Connection 1 type NPT
Supply Pipe Connection size 3/4 in
Energy Star Compliant No
Fuel Type Natural Gas
GSA Approved No
Ignition System Push Button
Material Aluminum
Pressure - Maximum 150 psi
MBH 400
Control Power Source Gas
Energy Factor (EF rating) 0.62
Water Heater Type Atmospheric Vent


6 year warranty on the tank. 6 year warranty on parts. This warranty is for products installed in USA, Canada and Puerto Rico. See a complete copy of the warranty included with the heater or at


ProLine User and Installation Guide


Installation Help and Recommendations

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