40 Gallon ProMax Residential Electric Water Heater - Short Model Zoom

40 Gallon ProMax Residential Electric Water Heater - Short Model


Brand: AO Smith

AO Smith
ECS-40 has been discontinued.
Please contact customer service at
(888) 757-4774 for help finding an alternative.



Intended Household: 2-3 Person
Application: Plumbing
Capacity (Gallons): 40
Fuel Type: Electric
Number of Elements: 2
Max Input (KW): 6
Height (Inches): 44
Diameter (Inches): 20-1/2"
Weight (lbs): 115 lbs
1st Hour Delivery (Gallons): 52
Energy Factor: 0.92
Recovery 90°F Rise: 21 GPH
Warranty: 6 yr Tank/6 yr Parts Limited

Description for AO Smith ECS-40

ProMax electric water heaters offer exceptional energy savings and durability.


  • Dynaclean diffuser dip tube - helps reduce lime and sediment buildup while maximizing hot water output. Made from long-lasting PEX cross-linked polymer.
  • Coregard anode rod - aluminum anode with stainless steel core protects tank against corrosion longer than ordinary mild steel anodes.
  • Durable tamper-resistant brass drain valve
  • Permaglas glass coating - protects steel tank from corrosion.
  • CSA certified and ASME rated T&P relief valve
  • Meets or Exceeds the Federal Efficiency Standards effective January 20, 2004, according to the National Appliance Energy Conservation Act (NAECA) of 1992. Also meets or exceeds the thermal efficiency and/or standby loss requirements of the US Department of Energy and current edition of ASHRAE/IESNA 90.1.
  • Certified to UL 174 for household electric water heaters

PLEASE NOTE: The product weighs 103 lbs. and may require the use of a
lift gate.
If you do require a lift gate at your delivery, you'll have the option to add this FREE of charge when you checkout.

40 Gallon ProMax Residential Electric Water Heater - Short Model


by PowerReviews

(based on 1 review)

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Reviewed by 1 customer

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(3 of 5 customers found this review helpful)


So far so good...

By R.O.

from Tampa, FL

Verified Reviewer

Home use for 3 people.

Had it for a couple of months. Improved efficiency over my old (2001) Rheem.

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  • 40 Gallon ProMax Residential Electric Water Heater - Short Model


    how old is this model
    Asked on 10/16/2010 by Anonymous

    1 answer



      Production on the ECS-40 started in 2004.

      Answered on 10/18/2010 by PexSupply Staff from NY
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