All well pumps have a certain flow rate which basically means how many gallons can flow in one minute. In order to find out your well pumps flow rate it is easier than you may think. With help from the experts at Five Star Plumbing Services, a plumbing company in Harford County, Maryland, we will walk you through how to calculate your well pumps flow rate. 

How to find out your well pumps flow rate? 

Pumps are set to turn on typically at one pressure automatically and off at a higher pressure, usually 20 PSI higher than the low pressure. With that, we are talking about a standard submersible well pump or booster pumps that are single speed. Some people use a “constant pressure system” where it maintains a constant pressure in the home, and these will use variable-speed motors. They do not fluctuate between a high and a low.

These are the steps to determine your well pumps flow rate:

  1. Measure the number of gallons drawn down from the pressure tank until the well pump turns on.
  2. When you hear the pump turn on, immediately close the hose bib.
  3. Time the period in seconds it takes for the well pump to build back up to pressure that is, between the cut-in and cut-out of the pressure switch. The pressure switch turns on the pump at a lower pressure and turns off the pump once it reaches a higher pressure.
  4. The simple formula for determining the flow rate is gallons drawn down (that were measured above), divided by the seconds required for recovery, then multiplied by 60: (Gallons/Seconds) X 60= Gallons per Minute (GPM) flow rate

An example, if 20 gallons are drawn down and it takes 120 seconds to build pressure back up, then 20 divided by 120 = .166 Then multiple .166 X 60 = 10 gallons per minute flow rate.

Need Help From An Experienced Plumber? 

Are you in need of service on your well pump? Contact Five Star Plumbing today. We provide homeowners throughout Baltimore County and Harford County with well pump replacement and repair services. So whether you are upgrading your well pump or need to install a replacement fast, we can help! Contact us today or give us a call at 410-836-0118 to schedule your appointment.