ProMax® 66-Gallon Electric Water Heater

ProMax® 66-Gallon Electric Water Heater

Model ECT-66

ProMax Electric Tank Water Heater ECT-66 is rated 4.6364 out of 5 by 11.
Rated 5 out of 5 by from Good tank We have owned A O Smith before and found them reliable and long lasting. The plumber that installed the unit is very high on A O Smith
Date published: 2015-01-15
Rated 5 out of 5 by from Excellent! Needed a larger capacity. This does the trick! Nice hot water all the time.
Date published: 2014-12-24
Rated 4 out of 5 by from Does what it should Bought this a month or so ago to update an old boiler. Works well and I have no complaints. Installation was quick and easy. Seems to take a bit of time to warm up once in a while, otherwise no complaints
Date published: 2014-11-02
Rated 5 out of 5 by from AOSmith Water Heater AOSmith is a well known water heater. They stand behind there productand will give years of great service.
Date published: 2014-08-26
Rated 4 out of 5 by from Pleased with Unit We've only been in our home since mid-March but no issues.. happy with service so far
Date published: 2014-08-03
Rated 4 out of 5 by from replacement We built a new home, with this water heater installed, once we started moving in, we noticed the water heater had a huge dent in the top/side of it, all tho the company and the plumbers assured us that it would be alright to use it, they were all nice enough to replace it for us. We have not had any issues with it and would highly recommend to others
Date published: 2014-07-13
Rated 5 out of 5 by from Excellent heating! I bought this product too recently to adequately review. However it is replacing an A.O. Smith water heater, same model. We never had a problem with hot water and recovery time was great. Even with lots of company, we never had to "space out" baths!
Date published: 2014-06-27
Rated 4 out of 5 by from so far great!! Was recommended by Charlie @ Home Town Plumbing they are wonderful!!
Date published: 2014-01-17

With a 66-gallon tank and 1 element delivering 4500 kilowatts, the ECT-66 delivers a first hour rating of 72 gallons at an Energy Factor of 0.88. The Coregard™ Aluminum Anode helps protect the tank from the corrosive effects of water, and is accompanied by a 6-year limited warranty.

Where to Buy

Where to Buy

Woodbridge, NJ 07095

Location #1


Edison, NJ

Se Habla Español

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Location #2

William J. Guarini Plumbing

Jersey City, NJ

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Location #3

Authorized Heating

Brooklyn, NY

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View All List My Company Here

Product Features & Options

DynaClean™ Diffuser Dip Tube

Thanks to the improved technology, the inlet tube features water jets that redirect incoming cold water into the tank, creating turbulence, which helps reduce lime build-up, therefore maintaining heater efficiency.

CoreGard™ Anode Rod

A. O. Smith’s anode rods have a stainless steel core that extends the life of the anode rod allowing superior tank protection far longer than standard anode rods.

Brass Drain Valve

Our brass drain valve is more durable and tamper-resistant than an ordinary plastic drain valve, which contributes to improved safety and reliability.

Permaglas® Glass Coating

Protects steel tank from corrosion and maximizes tank life.

How it Works

Cold water enters the water heater through an internal “dip tube” which forces the cold water to the bottom of the tank and pushes hot water out through the outlet connection. This arrangement provides the most hot water for a given tank size. There are two thermostats on a typical residential water heater. The thermostat at the bottom controls the lower heating element while the top thermostat controls the upper heating element. Usually, only one heating element is active at a time. Because the lower element sees the cold water first, the lower heating element does most of the work, while the upper heating element is used only when the entire tank is cold. Because water can corrode the steel tank, we glass line the inside of the tank and install an anode rod to help reduce corrosion. The temperature and pressure relief valve is a safety device designed to open if the internal temperature or pressure of the tank exceeds certain limits. Water heaters should be large enough to provide adequate hot water even when temperatures are cold and household demand is greatest.




limited warranty


energy factor

UL Listed means that the product met UL's safety requirements
CSA International Low Lead Content Certification in compliance with U.S. and Canadian safety standards on gas components
AHRI Air-Conditioning, Heating and Refrigeration Institute
The Blue Diamond formula is enriched with a high level of zircon, producing a coating that is harder and more water-resistant than any other in the industry

Product Specifications

Tech Specs
Gallon Capacity: 66
Recovery Gallons: 21
First Hour Rating: 72
Energy Factor: 0.88
Thermal Efficiency: 98%
Upper Element Wattage: 4500
Lower Element Wattage: 4500
Max Wattage: 4500
Limited Tank Warranty: 6 Years
Limited Parts Warranty: 6 Years
Anode: Coregard™ Aluminum Anode
Foam Insulation: 2"
Self Cleaning: Yes
T&P Relief Valve: Yes
Water Connection Location: Top
Water Connection Size: 3/4"
Dimensions & Venting
Type: Tall
Height: 60 1/4"
Diameter: 20 1/2"
Width: 20 1/2"
Depth: 20 1/2"
Shipping Weight: 178lbs/81kg


Rebate and incentive programs provide cash-back to consumers for the purchase of appliances that meet certain energy efficiency standards. Often, these standards are tied to the ENERGY STAR® program.

Cash for Appliances is designed to encourage the purchase of energy efficient appliances. Consumers who purchase ENERGY STAR® or CEE qualified appliances can receive cash rebates. Most states are offering rebates in the $50 to $250 range.


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Need More Hot Water?

There's no reason to run out of hot water. If you're not sure that the ECT-66 provides enough hot water for your needs, consider these:

ProMax® 119-Gallon Electric Water Heater

  • 6 Year Limited Warranty
  • 112 First Hour Rating

ProMax® 40-Gallon Electric Water Heater

  • 6 Year Limited Warranty
  • 52 First Hour Rating

ProMax® 55-Gallon Electric Water Heater

  • 6 Year Limited Warranty
  • 67 First Hour Rating

ProMax® 80-Gallon Electric Water Heater

  • 6 Year Limited Warranty
  • 81 First Hour Rating