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AO Smith DRE-52 Electric Water Heater

The AO Smith DRE-52 electric water heater is a commercial, Gold Series unit, having its own 50-gallon storage tank. A true workhorse for commercial applications, its durability has been proven over and over again. Some applications include restaurants, offices, warehouses, manufacturing plants, large and small box stores to name a few. Use these heaters in any application where sanitizing water is not required.

AO Smith DRE-52 Electric Water Heater, wallingford sales, electric water heater, commercial


The AO Smith DRE-52 electric water heater comes in 10 different kilowatt (kW) inputs ranging from 6 kW thru 36 kW. The number and wattage of each element contained in the water heater depend upon the total Kilowatt rating required. For instance, from 6 kW thru 15 kW, you would utilize three elements. This is known as a 3-hole water heater. An 18-kW water heater could have either 3 or 6 elements. From 24 kW thru 36 kW, utilize six elements making these 6-hole water heaters.

Standard voltages for the AO Smith DRE-52 electric water heater is 208 Volt, 240 Volt, 480 Volt. Order these as either single or three-phase. If you order the incorrect phase, these water heaters are field convertible from three-phase to single-phase or single-phase to three-phase. 277 Volt single phase is also available.

Field Convertable

When ordering an AO Smith DRE-52 electric water heater, you will need to know the total kilowatts (kW), the incoming voltage and phase that is required. But, let’s say that you ordered a 36 kW, 240 Volt, 3-phase water heater and it gets delivered to the job site. Then, during the installation process, you discover that you have 480 Volt line voltage feeding the water heater. There is no need to worry. Open the control panel door, and on the inside of the door, you will find all the conversion kits available for that heater.

Conversion Kits

Scroll down to find the conversion kit that matches 36 kW, 480 Volt and order that kit. Once the kit arrives, change out the elements and put the conversion kit sticker over the water heater’s rating plate. A water heater conversion kit contains UL approved elements and a label to indicate that it is a converted water heater as well as what it was converted to. Notice that all conversion kits for your particular water heater will be the same number of elements. If you have a three-element heater, all available conversion kits will be three elements — the same for six element heaters and conversion kits.


The installation process is fairly straightforward. After confirming the wattage, voltage, and phase of the water heater that was ordered is correct, set the water heater in place. Install the 1-1/4” NPT water inlet piping and the 1-1/4” NPT water outlet piping.

Many commercial water heater installers will fill the tank with water and bleed out any air before bringing power to the unit. The reason is, it avoids “dry firing” the water heater. Water heater elements must be surrounded by water to avoid burning up.

Once the tank is full of water and air bled off, you can connect the power to the unit. Next, run the T&P drain line to a floor drain. You are now ready to power up your AO Smith DRE-52 electric water heater.


The AO Smith DRE-52 electric water heater utilizes surface mount thermostats. Each element will have its own thermostat. These thermostats sense the temperature of the surface of the water heater tank where they are mounted. For this reason, they are not recommended for sanitizing water applications. You must use a water heater with immersion thermostats for sanitizing applications. Immersion thermostats submerge in the water and are more accurate at sensing and maintaining water temperature.

Features of the AO Smith DRE-52 Electric water heater are:

  • 55-3/4” Tall
  • 21-3/4” Diameter
  • 27” Depth
  • 265# weight
  • 1-1/4” NPT inlet/outlet
  • Heavy duty medium watt density, 1” screw-in elements have incoloy sheathing
  • Rated at 150 PSI working pressure
  • Factory installed Terminal Block for easy installation of power wires
  • Fusing protects all elements, thermostats and internal circuits from excess current
  • Each element has its own thermostat with a range of 120-degree F to 151-degree F
  • Two anode rods for excellent corrosion protection
  • Glass lined Tank
  • CSA Certified and ASME rated T&P Valve
  • Brass drain valve
  • Thick foam insulation reduces heat loss
  • 3-year limited tank / 1-year limited parts warranty
  • Manifold kits available for multiple water heaters installation

Manifold Kits

To view or purchase the AO Smith DRE-52 electric water heaters or view all our AO Smith Commercial Electric Water Heaters, AO Smith Commercial Gas Water Heaters and AO Smith Parts or Rheem Commercial Electric Water Heaters or Rheem Commercial Gas Water Heaters, please visit www.wallingfordsales.com.

I wish you much success!

“Keeping you in hot water…so you stay out of hot water!”

Doug Wallingford
Wallingford Sales
Water Heater Store