Wayne CDU790 Review: The Best Choice for 1/3 HP Cast Iron and Stainless Steel Sump Pump

Sump pumps are an essential part of any home’s flood protection system. They are designed to remove water accumulated in a sump pit and can be used to drain pools, hot tubs, and other areas where water needs to be removed.

This blog post will take a closer look at the Wayne CDU790 and discuss its features, benefits, and drawbacks. We’ll also briefly overview sump pumps in general and explain how they can be used to protect your home from flooding.


First Impressions

The Wayne CDU790 is one of the most popular sump pumps on the market, and it is a good choice for anyone who needs a reliable and robust pump. The Wayne CDU790 is made from cast iron and stainless steel, making it durable and able to withstand years of use. In addition, it has a 1/3 HP motor capable of moving up to 4600 gallons per hour.

The Wayne CDU790 is also one of the most energy-efficient sump pumps on the market. It uses a float switch that turns the pump on and off as needed, so it only runs when necessary. This saves energy and helps to prolong the life of the pump.

Customer Feedback and Ratings

The Wayne CDU790 has a 4.7-star rating on Amazon (1473 global ratings), and customers have generally been delighted with the product. Many have noted that the Wayne CDU790 is powerful, efficient, and easy to install. 94% of the total ratings are either 5-star or 4-star!

Some customers have also said that the customer service from Wayne is excellent. A few customers have had issues with the pump, but these seem to be in the minority.

Benefits and Drawbacks


  • A compact structure allows the sump pump to fit in sumps with an 11″ diameter (or more)
  • Cast iron build for longevity and epoxy coating for protection against corrosion
  • The top suction strainer mechanism allows for the filtering of debris
  • Powerful 1/3 HP motor with excellent pumping output and maximum head
  • Excellent ceramic sealing for protection of internal components from water
  • A well-designed and highly responsive float-operated switch assembly
  • Excellent 3-year warranty on all parts


  • The handle could have been bigger
  • Some users complained of stainless steel parts lacking epoxy coating
WAYNE CDU790 - 1/3 HP Submersible Cast Iron and Stainless Steel Sump Pump with Integrated Vertical Float Switch - Up to 4,600 Gallons Per Hour - Heavy Duty Basement Sump Pump, Black
  • Indoor Use Only - This 1/3 HP WAYNE basement sump pump is perfect to keep your basement dry during heavy water flow. Whether it’s rain, snow melting, etc. WAYNE model CDU790 can pump up to 4,600 GPH to keep your basement dry.
  • Tough And Durable - Corrosion-resistant epoxy coated steel motor housing and stainless steel fasteners come with a cast-iron volute that provides long life in tough sump pump applications.
  • Efficient Design - The top suction design eliminates air lock and minimizes clogging from any debris in the bottom of the sump pit. Easy to install in about 15 minutes with no need to drill a weep hole!
  • Additional Features - 1-1/2” NPT discharge for compliance with building codes. The vertical float switch has been tested to 1 million cycles for long-lasting use, up to 10 time more than our competitors.
  • Quality You Deserve - Proudly assembled in the USA for quality you can trust. Warrantied for 3 years for dependable, efficient, & ultra-quiet performance.

Strongest Features

The Wayne CDU790 has many features that make it a great choice for a sump pump.

Build Quality and Design

Wayne invests a lot in creating well-designed sump pumps, which is evident in the Wayne CDU790 Submersible Cast Iron and Steel Sump Pump. The product comes with a light and compact design that allows the pump to be used in sumps 11″ in diameter.

A highly noted point about this design is the discharge and float proximity to the motor casing, without causing either part to suffer reduced functionality. Furthermore, the structure has a small cast iron base with short legs, which ensures the stability of the product regardless of the flatness of the sump bottom.

Without premium build quality, a good design is meaningless. So we find Wayne providing high-quality cast iron housing for the product to ensure it against the twin dangers of corrosion and impact of large debris. In addition, corrosion-resistant paint has been applied over all external parts to provide added defense against decay.

The only exception is the float (which is not made of metal) and the stainless steel handle and switch guard. Some users argued that this made them more susceptible to corrosion. Still, long-term users countered them, arguing that despite extensive exposure to water, these parts never did show any signs of corrosion.

Major External Parts (Discharge, Power Cable, and Handle)

The discharge is a standard 1-1/2″ NPT cast iron component capable of passing small spherical solid bodies along with the water, thus ensuring no buildup of these tiny particles at the bottom of the pump.

On the other hand, the 1-1/2″ NPT size ensures that there is never any incompatibility issue as far as the PVC piping is concerned.

It is fitted with a top suction strainer which allows the product to filter debris easily and therefore precludes the possibility of the pump being clogged up due to accumulation of debris.

The power cable, on the other hand, is of decent length, and when considered and it is fully submersible, it appears to be one of the better power cables in the industry today.

As we noted above, there is a convenient stainless steel handle at the top of the sump pump, which is shaped to ensure easy compatibility with most hand sizes.

However, a few users with extensive hands noted that they could not insert all of their fingers into the handle space and hence had difficulty raising and lowering the product.

Motor and Sealing

True to Wayne’s reputation for providing robust and dependable motors, the product comes with a 1/3HP motor, which is the maximum one can expect in this price range. Coming to the equally crucial question of pumping output, we find the product capable of pumping an incredible 3450 gallons per hour at 5′ head.

Further, as our sump pump reviews have shown, a product that consistently achieves a maximum head of 20′ is an excellent value for money proposition. This Wayne product thankfully reaches this mark and maintains it successfully for the duration of pumping operations, thereby staking claim to a position in the category of suitable sump pumps.

Longevity is a vital part of the value for money calculation, and motor sealing is a crucial part of the longevity test. The Wayne CDU 790 passes this test admirably courtesy of the ceramic seal separating the motor from the housing and disallows water from going into the vital internal components and ruining them.

Impeller and Switch

The Wayne CDU790 Sump Pump comes with a standard cast iron impeller, which not only ensures adequate support to the top suction strainer mechanism of the discharge but also protects itself and the base from damage due to collision of heavy debris with the underside of the pump.

The switch utilizes the well-reputed PVC float system that consists of the large and stable float, the steel suspension rod, and the shaft which connects to the switch. As the water level rises, the float is dislocated, and pressure is applied to the shaft through the float suspension.

This triggers the susceptible bipolar switch, causing the motor to start. Though the float is extremely durable, the precise arrangement of the system necessitates additional safeguards, which come in the form of a large and hardy stainless steel switch guard.

Is It Worth Purchasing?

Considering all of the above factors, it is not surprising that the Wayne CDU790 enjoys such a stellar reputation in the industry. This is a product that has been designed and built to last and which provides terrific value for money in terms of both performance as well as longevity.

It ticks all the boxes in terms of the features one looks for in a sump pump and is indeed a worthy candidate for being crowned the best sump pump in its class. The Wayne CDU 790 is one of the most popular pumps on the market today, and it’s easy to see why.

This product comes with all of the features that one could want in a sump pump, and is backed by the reputation of a company that has been in the business for many years.

For a better understanding, watch the video:

Frequently Asked Questions

Are Wayne sump pumps any good?

Yes, Wayne sump pumps are good. They offer a great combination of power, features, and durability, and are backed by the reputation of a company that has been in the business for many years.

What’s better, 1/3 hp or 1/2 HP sump pump?

There is no definitive answer to this question, as it depends on various factors such as the size of your sump pit, the amount of water that needs to be pumped, and the conditions of your home.

However, for similar conditions, a 1/2 HP sump pump will typically be more powerful and efficient than a 1/3 HP sump pump.

How many GPH is a 1/3 HP sump pump?

A 1/3 HP sump pump typically has a flow rate of around 3450 GPH (gallons per hour).


The Wayne CDU790 is a powerful and durable sump pump backed by the reputation of a company that has been in the business for many years. This product comes with all of the features that one could want in a sump pump and is worth considering if you are in the market for a new pump.

Granted that the product could have had a better handle and some epoxy coating on its steel components, these minor shortcomings are more than compensated for by the superior motor power, excellent overall build quality, and unsurpassable product warranty from the manufacturer.

Combined, these prove that the product is an unbelievable proposition regarding features offered for the price demanded. Furthermore, given its compactness and resultant adaptability, this plethora of features makes this sump pump one of the best budget products available in the market today.

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Bill is a DIY plumber, handyman, and homeowner with more than a decade of experience. He has replaced and repaired sump pumps, backup pumps, float switches, check valves, and many other things around his family home. An engineer and tinkerer at heart, he is always looking to see how things work and taking on new home projects that help him grow his skillsets. He is a husband and father of two boys, has a bachelors degree in Computer Engineer and minor in Mathematics and likes to make homebrew beer in his free time.

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