Basement Watchdog BW4000 Review: A Great Combo of Primary & Backup Sump Pumps

If you live in a home prone to flooding or water damage, you know how important it is to have a dependable sump pump. The Basement Watchdog BW4000 is one of the most popular models on the market, and for a good reason. It’s a great combo of a primary and backup sump pump that will give you peace of mind in a power outage or other emergency.

So, if you were worried about your basement flooding during a rainstorm or power outage, the Basement Watchdog BW4000 would be an excellent investment. It’s a reliable pump that will get the job done when you need it most.

This blog post will review the features of the Basement Watchdog BW4000, as well as its pros and cons. By the end, you should have a good idea of whether or not this pump is suitable for your home.


First Impressions

The Basement Watchdog BW4000 is a great combo of a primary and backup sump pump that will give you peace of mind knowing your basement is protected from flooding. It’s easy to install and works great.

I live in an area where power outages are common, so I wanted to ensure my basement was protected from flooding in case of an outage. The Basement Watchdog BW4000 has been a significant investment. It’s easy to install and has worked flawlessly.

The Basement Watchdog BW4000 comes with two pumps, one for primary use and one for backup. The primary pump is strong enough to handle most situations, and the backup pump kicks in if the power goes out or the primary pump fails.

Customer Feedback and Ratings

Today, there are more than 160 global reviews on Amazon, with 60% 5-star and 17% 4-star reviews. However, there is a significant amount of 14% of 1-star reviews.

Most people are overwhelmed with the combo of two pumps because it gives them a sense of safety and reliability even when the owner is not available or asleep. People also loved how easy it was to install. The heavy-duty construction and the fact that it is made in the USA are also pluses.

On the other hand, people did not like the wear and tear of the unit. The maintenance required for the unit is also a turn-off for some people. Others found that the float switch got stuck sometimes, causing the pump to run continuously. There were also a few reports of the pump failing after a few months of use.

Benefits and Drawbacks

According to the study by IBISWorld, the US market for Submersible Pumps is worth $2.4 billion in 2022. Basement Watchdog BW4000 is one of the most popular models in the market. There are many reasons for its popularity.


  • Dual pumps with polycarbonate design for durability and efficient functioning.
  • Standard discharge system to tackle heavy workloads.
  • The excellent pumping capacity of both primary and secondary pumps.
  • Automatic diagnostics forewarns against possible risks.
  • Reed switches ensure sensitivity.
  • A small footprint.
  • A sturdy impeller allows for the maintenance of excellent water output.


  • No battery is included with the product. (and the acid)
  • The product is somewhat heavy and is difficult to move in the absence of a handle.

Strongest Features

The sump pump is a great product for its two pumps, one primary and one backup, as well as its durability and easy installation.

Build Quality and Design

The Basement Watchdog BW4000 takes a radically new approach to product design. The backup sump pump has been placed midway along with the housing of the primary pump, and the peripherals have also been placed on the same level. The discharges of the two units, on the other hand, have been merged and placed at the top of the housing of the primary pump.

Together, these produce a somewhat novel but exciting design that does not create a considerable footprint and can work efficiently by allowing the backup to complement the primary in case of heavy water load, etc.

The build quality, on the other hand, is conservative. Tough polycarbonate and polypropylene have been used to make the product’s exteriors and individual functional parts.

These make powder coating redundant and provide a decent amount of protection against debris flux in the sump. Further, some sturdy steel holders have been placed at various critical points to ensure that there is never any issue with looseness.

Major External Parts (Discharge, Power Cord, External Battery)

The Basement Watchdog BW4000 has a common discharge for both the backup and primary sump pumps, and this is connected to a PVC pipe using the metal brackets provided with the unit. Like all good units, this product’s discharge also offers the standard 1-1/4″ NPT diameter, thus making it compatible with standard plumbing.

One of the critical steps in installing a sump pump is to find a power source that is somewhat close to the location of the sump. The alternative is to find a long power cord, and Basement Watchdog takes no chances, providing users with a large power cord with water repellent properties.

More interestingly, the product uses a battery-backup sump pump system, and any major sump pump battery can be employed. Batteries and battery fuel, however, are not included as part of the package. On the plus side, one gets a battery case that can easily accommodate a broad range of batteries.

Watch the video for the installation of a Basement Watchdog Combination Sump Pump System:

Motor and Sealing

As one would expect, there are two sets of motors, the primary one rated at 1/3HP. This translates to a healthy 53.33 GPM at 10′ head for the main pump. The secondary pump, in comparison, manages 28.33 GPM at the same head.

While this may look weak compared to the primary pump, one has to remember that the function of this unit is to work only when there is an outage or when the water level is so high that the primary pump cannot handle it on its own. The latter feature works automatically, thus ensuring that the sump pump never gets overwhelmed.

Another exciting innovation concerns the automatic diagnostic system of the unit, which allows users to know through a system of beeps and flashing lights when something is wrong with their unit.

While the manufacturer does not reveal the exact procedure for such diagnostics, users have commented that this unique feature often warns them of impending problems in advance by pointing out small problems.

Lastly, both the motors come with hermetic sealing that allows the unit to survive the harsh flux of the sump without any damage occurring to the motors.

Switch and Impeller

The benefits of using a sump pump are directly proportional to the sensitivity of the switch. The Basement Watchdog BW4000 achieves this by providing a pair of highly sensitive reed switches that can detect minute changes in the water level without difficulty. Further, these reed switches take up less space than the float switches, which translates into a compact unit.

On the other hand, the polycarbonate impeller is sturdy enough to handle heavy water flux. This is more important because the backup and the primary sump pumps have a common impeller. When both work together, an enormous amount of water is removed, thus putting pressure on the impeller.

Thankfully, the excellent design of the base prevents the influx of large debris into the blades of the impeller, thus allowing the impeller to work with water and small debris only.

Is It Worth Purchasing?

The Basement Watchdog BW4000 is an excellent product with many features not found in other sump pumps. Some of these features include high-quality materials, a sturdy build, a sensitive switch, and a reliable backup system.

If you are in the market for a sump pump with a backup pump at the time of need, then the Basement Watchdog BW4000 should be on your shortlist.

American Fluorescent Bw4000 1730 Gallons Per Hour Basement Watchdog Combination Primary and Back-Up Pump System
  • Package contains: Controller, charger, two dual micro reed float switches, primary pump and backup pump, instruction manual (battery and acid sold separately)
  • Back-up starts immediately after loss of power or if flow of water is too great for the AC pump alone
  • Back-up features unique monitoring systems to diagnose problems and sound an alarm
  • Compact, fits in pits as small as 12-Inch in diameter.

Frequently Asked Questions

How long does the Basement Watchdog pump last?

The average lifespan of the Basement Watchdog sump pump battery is about 15-7 years. So if your system reports a problem, it is likely time to replace your pump.

Does the basement watchdog charge the battery?

Yes, the Basement Watchdog sump pump will charge the battery while plugged into an AC outlet. However, please remember that the control unit is to be ONLY used for LEAD-ACID batteries, NOT dry cell batteries.

Are water-powered sump pumps reliable?

Water-powered sump pumps are just as reliable as any other type of pump on the market. Many people believe that the simple design of water-powered sump pumps makes ‘no maintenance’ a reality.


With a separate backup sump pump, robust motors, and an automatic diagnostic system, the Basement Watchdog BW4000 is one of the best sump pumps on the market. If you are looking for a reliable and durable sump pump, this is the unit for you though a few customers have complained about the wear and tear of certain parts.

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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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