Quality Plumbing Services


May 18, 2017 · No Comments

This is a question we get asked from homeowners over and over again. A common misconception is that higher horse power means a better sump pump. Higher horse power will draw more amps and may cost a little more to operate as it usually uses more electricity. Also, you may need larger diameter discharge pipe to handle the flow if you use a pump with more horsepower. Most sump pumps are sold based on the basis of the motor’s horse power. They are usually sold in increments of 1-horsepower (hp),  .5-horsepower (hp), .33-horsepower (hp), and .25-horsepower (hp) are the most common sizes.


As plumbers, we don't consider horsepower as a determining factor when selecting a proper sump pump for the application. We rate sump pumps by its pumping capacity in gallons per minute (GPM) at 10’ feet of head or lift. Head or lift is the vertical distance that you are able to pump the liquid. Without getting too technical, all pumps have a pump curve chart provided by the manufacturer. The higher the liquid is pumped, the less gallons per minute (GPM) the pump can remove. Industry standard uses 10’ feet of head or lift, generally because the average basement ceiling is 8’ feet high and the sump pump basin is 2’ feet deep. Therefore, a better way to measure a sump pump's capacity is its gallons per minute at 10’ feet of head.  


A good sump pump will pump anywhere from 40 to 50 gallons per minute (GPM) at 10’ feet of head or lift. This is a much more important rating than overall horsepower. Many of the pumps you'll find at the big box stores or home centers show you the pump's horsepower but not its pumping capacity. Another trick and this is especially true of the battery back up systems they carry … is that they show pumping capacities in gallons per hour (GPH). They try to dazzle you showing you a pumping capacity of 1500 gallons per hour (GPH). If we do the math, that equates to about 25 gallons per minute (1500 gallons / 60 minutes =  25 gallons per minute). What they do not tell you is that usually this rating is at 0 head or lift. So if you're factoring in the height the sump pump has to pump the water to evacuate it from your basement, that GPM drops off even further and you may have pumping capacity only 15 gallon per minute (GPM). In heavy rains like we experienced recently, the incoming water may overcome your sump pump. Even though your sump pump is currently working, it is unable to keep up with the amount of water flowing into your home.


When assessing your sump pumps capability it's very important to look at the individual sump pump's pumping capacity in gallons per minute (GPM) at 10’ feet of head, rather than just its overall horsepower rating. This is a far better indicator of how your pump will perform, and allow you to select the most efficient pump for your application.


If your sump pump has failed or you're simply looking to replace an aging sump pump, let a member of Quality Plumbing Services expert team help you choose the proper sump pump for your home. Call today 630-227-0200 or 847-259-0200 and one of our knowledgeable and friendly customer service representatives will be happy to make an appointment for you today. Don't wait until it's too late!!



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