How to Pick the Best Submersible Sump Pump

Submersible sump pumps are the preferred choice for most residential applications, offering quiet and effective water removal that protects your foundation and property from water damage.

However, selecting the right pump is a critical sizing exercise—not a "bigger is better" guessing game. An improperly sized pump can lead to constant cycling and premature burnout.

With personalized support and a wide range of trusted brands, Ferguson Home provides this guide to help you confidently select the right submersible sump pump for reliable basement protection.

Sump Pump Sizing: Four Major Factors

To properly size a submersible pump, you must focus on the following core considerations:

• Horsepower (HP): The pump's power output.
• Flow Rate (GPH) and Head Pressure: How much water is moved and how high it must travel.
• Float Switch Type: The mechanism that turns the pump on and off.
• Backup System: Your defense against power failure.

Choosing the Right Horsepower (HP)

Horsepower determines how much power your pump can produce to empty the sump pit through the discharge piping.

1/3 HP Submersible Sump Pumps

For most average-sized homes in areas with average water tables, a 1/3 HP sump pump should be sufficient. Typically, 1/3 HP pumps can handle 7' - 10' vertical lifts from the sump pit if they have one 90-degree elbow and a horizontal pipe run between 3 feet and 25 feet.

1/2 HP Submersible Sump Pumps

If you live in an average-sized home with an above-average water table, you will most likely need a 1/2 HP sump pump. These pumps will generally pump about 35%-40% more than their 1/3 HP counterparts, and can also handle higher vertical lifts for water being pumped through your discharge pipe.

When you have a slightly higher vertical lift (10-15 feet) or a long horizontal run (example: 30-150 feet), you may notice a loss of water flow due to the increased friction from the longer runs. For those conditions, you may need a higher pumping capacity (HP and GPH) to overcome that loss.

3/4 HP - 1 HP Submersible Sump Pumps

Those in high water table areas, flood plains, low-lying areas susceptible to flooding, or homes with deeper basements will likely need a stronger 3/4 HP sump pump or a 1 HP sump pump.

Note on Pump Curves: Every submersible pump has a unique pump curve. Always check the manufacturer's specifications on the product page to see the total output, often measured in Gallons Per Hour or GPH, at various lift heights.

If your old pump performed adequately, a good rule of thumb is to stick with the same HP rating. Always check the data plate on the old pump for its HP and model number.

Understanding Head Pressure and Flow Rate

The pump's capacity to move water is directly affected by the distance and direction the water must travel. This is known as Head Pressure or Vertical Lift:

• Vertical Lift: The height (in feet) the water must be pushed up out of the sump pit to the point it exits your home.
• Horizontal Run: Longer horizontal distances increase friction, requiring more power (HP) to overcome the loss of water flow.

When working with higher HP pumps that move more water (GPH), pay special attention to the discharge pipe diameter to prevent friction problems and premature wear.

Selecting the Right Float Switch

The float switch is what activates and deactivates your pump. A reliable switch is crucial for preventing short cycling and ensuring the pump only runs when needed.

• Electronic Float Switches: We often recommend these as they take up less space in the sump pit and are among the most reliable switches available on the market.

Securing Your System with Protection & Accessories

A reliable primary pump is only half the solution. A comprehensive sump system requires protection against inevitable disruptions:

• Backup Sump Pump Systems: Your best defense against flooding during a power outage when a generator isn't available. These can be purchased separately or as a Combination Sump Pump System, where the backup pump is included with the primary unit.
• Water Alarms: Essential for peace of mind. Wi-Fi-enabled alarm systems are particularly useful, as they can call, text, or email you if an issue arises with your sump pit, which is vital if no one is home to hear a traditional beeping alarm.

Ferguson Home offers the selection and expertise you need, available both online and in showrooms nationwide. We're here to help you find the right components for a reliable water management system that protects your home.