Answer: This can be determined at your pressure tank. A short hose ( washing machine hose works best) and a 5 gallon bucket will be needed. Connect the hose to the boiler drain at the base of the pressure tank, drain water into the bucket until the water pump is activated, stop removing water from the tank and let the system pressure build up and water pump shuts off. (Empty the bucket) Then, shut the power off to the well pump, remove 5 gallons of water or all the water available from the pressure tank, whichever comes first. If water removed does not fill a 5 gallon pail the amount of water should be measured to know how much was removed.
(WHILE THE POWER IS OFF) Remove the cover to the pressure switch and make sure the electrical contacts are closed. If not, push down at the base of the springs and the electrical contacts should close. Reinstall the pressure switch cover and turn power back on to the water pump, making sure you time how long it takes from power being turned back on until the water pump reaches shut off pressure. The amount of water removed divided by time taken to refill in seconds, times 60 seconds will give you your water pumps production rate in gallons per minute under normal system operations.
example : 5 gallons divided by 30 seconds times 60 seconds equals 10 gallons per minute