Primary Sump Pump Basics

The following information is provided to help you understand primary sump pump basics with their features and how to use the basic information to know which sump pump is best for your situation.

Read about primary sump pump basics on page below which includes the following:

Or find a more comprehensive comparison of sump pumps at my complete website dedicated to Sump Pumps at includes sump pump types:

  • Primary battery backup
  • Water powered
  • Combination
It provides reviews by comparing pump specifications and features such as:
  • GPH (Gallons per Hour)
  • HP (Horse Power)
  • Construction Material
  • Manufacturer Brands

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Float-Switch Basics

Sump pumps are activated when the water reaches a certain level in the tank/pit where it is located.  When the water reaches the height of the float the float switch is activated and the pump operates.


There are three types.

  • Tether: The float hangs from the pump and floats up and down on the water.  As the water rises, so does the float and the switch is triggered.
  • Vertical: The float is a ball that floats above the water. As the water level raises so does the float which triggers the switch.  This float has limited movement up and down a vertical rod. 
  • Diaphragm: The membrane, located on a drum shaped mechanism on the side of the pump, is sensitive to water pressure. As the water level rises, the water pressure increases and the diaphragm become concave, thereby activating the switch to turn on the sump pump. When the water level drops, the switch turns off.


There are various types of switches.

  • Inside the pump itself.  The entire pump must be removed from the sump pit to replace the switch.
  • External to the pump.  The switch can be replaced without removing the pump from the pit.
  • Electronic.  It is electric and has no actual float. Instead, a probe wire is placed to sense the presence of water and is activated when it becomes submerged by rising water.
  • Piggy-back.  Most sump pumps come with two electrical cords.  The float switch cord is plugged directly into the electrical outlet.  The motor cord is plugged into the piggy-back switch.  If the float switch which operates automatically to turn the pump motor on fails, it is possible in an emergency to plug the pump motor cord directly into the electrical outlet.  This means the sump pump is operating manually (without the float switch).  Manual operation of the pump will burn the motor out if it is not designed to run continuously and it does not have continuous water to pump out.  
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Sump pits come in various sizes and shapes.

  • They generally range from 11" to 24" in diameter. 
  • Shapes vary.  Some have the same diameter at the top of the pit as at the bottom of the pit.  Others flare out at the bottom by an additional 6-8".

  • Connection to electricity.  Sump pumps should not be operated with an extension cord.  Each pump in the pit should have its own electrical outlet and circuit breaker. 
  • Power cord length varies from 5' to 25'.  Length is important because it should be plugged directly into the outlet not into an extension cord.
  • Means for keeping the motor cool.  Old technology uses oil which can leak into the water.  New technology uses water.

  • Horse power.  HP is generally 1/3, 1/2 or 3/4.  In general, the more horsepower, the better.

  • Pumping performance.  The rate at which water is pumped depends upon the HP and height to which the water is pumped.  The more HP and the lower the pumping height the faster a greater volume of water will be pumped out of the pit.
  • Pump Housing.  The common materials used are thermoplastic, stainless steel and cast iron.

  • Frequency of usage:  Most are continuous duty construction.

  • Styles: Submersible pumps sit in the water and operate in the water.  Pedestal sump pumps sit above the water line.  The float is adjusted to determine when the pump will run. The motor is never in the water.

  • Usage of Electricity: The amps used vary by pump.  The variance is 3 to 12 amps.

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Using the Basics to Understand Which Primary Sump Pump is Best for Your Water Pumping Needs.
  • Are you concerned about motor burn out during heavy rain storms causing the sump pump to run continuously for several hours?  The Watchdog Basement Sump Pump as well as the Little Giant, Flotec, Simer, Wayne and Zoeller Sump Pumps can run continuously without negative effect.   
  • Are you concerned about float switch failure while you are on vacation? The Watchdog Basement Sump Pump has dual switches.  If one fails the other one kicks in.  This is the best guarantee.  The Wayne Genius has no moving parts and will last 5 times longer than other switches, but eventually it too will fail.  The Little Giant has a diaphragm switch which is more reliable than a tether or vertical switch, but eventually has to be replaced.  Flotec and Simer, 1/2 and 3/4 HP, have a vertical float/switch.     
  • Are you concerned about removing the entire pump from the pit when the switch must be replaced? The Watchdog Basement Sump Pump switch is external to the pump cage.  There is no need to remove the pump from the pit.  The switch is replaced by loosening the band holding the switch to the discharge PVC pipe, raising the switch out of the pit, replacing the switch, lowering it back down and tightening the band to the discharge PVC pipe.  
  • Can your current pump handle the volume of water from heavy rain storms? If your sump pit is 18" in diameter, think about placing two 6" diameter Watchdog Basement Sump Pumps in the base of the pit.  Placing two dual switch Basement Watchdog Primary Sump Pumps in the pit would give you added peace of mind.  You would have four operational switches.  
  • Are you concerned about electricity consumption? The Watchdog Basement Sump Pump is rated most energy efficient.  The Little Giant Pump is rated second.  
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  Submersible Primary  Sump Pumps

Battery Backup Sump Pumps Top 9 Battery Backup Pump Detailed Reviews Water Powered Backup Sump Pumps  Water Powered Backup Pump Detailed Reviews
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Combination Sump Pump

Combination Sump Pump Detailed Reviews