Pool Pump Not Priming

Taking care of your pool equipment might be the most responsible thing a pool owner can do considering how expensive it is these days but sometimes things happen when you are not around to catch it like your filter system losing prime and shutting down for a period of time that can affect your pool and may even ruin valuable equipment. Why is my pool pump not priming?

The most common reason for a pool pump not priming is:

  • Low water level
  • Clogged skimmer basket
  • Pump strainer cover leak
  • Closed suction or discharge valve at the filter
  • Air Leak in glued fittings on the suction side
  • Union air leaks on the suction side
  • Clogged pump Impeller
  • Pump speed to low to pick up prime

All these common reasons for keeping a pool pump from priming can be found and eliminated if a daily maintenance schedule is kept up by the pool owner using observation as the biggest tool.

Pool Pump Not Priming


When its time for the filtering system to start with the electric timer most times you won’t be there to examine the pool pump to make sure the pressure is right and the pump and system self primes chasing the air out of the system and filtering pool water at proper pressure and pump flow rate.

For a minute or two, check the water pressure gauges at the pump and tank. If the gauges are not rising in pressure (or if the water tank is not filling with water – is not getting heavier) then the pump has not been successfully primed.

Common reasons why a pool pump loses its prime:

  • Check the multi-port handle that it’s seated properly
  • Closed suction or discharge valve-open
  • Suction side leak-check for loose fittings-plugs-cracks
  • Pressure side leak-check for loose fittings-cracks
  • Low water level– check the level of your pool- it should be halfway up the skimmer opening
  • The skimmer weir gate stuck in the up position-clear
  • Clogged skimmer basket– check and clean baskets
  • Damaged valve O-rings or gaskets-inspect the O-ring gasket for cracks-add silicone and reinstall the gasket in the pump lid-or replace
  • Damaged pump lid– replace
  • Obstructions in the pump strainer basket or impeller-power down the pump at the breaker-open lid-pull basket and reach inside to clear the impeller-use a screwdriver

There may be a closed suction or discharge valve at the filter that was inadvertently turned down or turned off. Or the pump speed on a 2-speed pool pump is set to low to pick up decent prime again pulling air and locking out pool water needed to prime the pump.


What is a pool pump capacitor and what does it do? 

A pool pump capacitor is similar to a battery in a car, the same reason cars need a battery to start, Pool pumps need a capacitor to start, pumps may have 1 or 2 capacitors one to start the pump, & a Run capacitor that brings the pump up to speed (3450) RPM..………………………………………. Read more

How to Prime a Pool Pump


Steps to prime the pool pump:

  • Turn the pump power off
  • Turn the Filter multi-port handle to Re-Circulate assuming you have a sand filter
  • Remove the pump lid-add water to help create suction on the pump
  • Replace the pump basket lid-turn on the pump
  • If the pump basket fills then the system is primed
  • Or try the steps again

If the pump won’t prime and you suspect something wrong:

  • Remove the skimmer basket-add water with a garden hose through the suction lines-to fill the system from the opposite side
  • Take all nozzle & fittings off the garden hose and place the end of the hose into the Suction Line as far as it will go from the skimmer box towards the pump
  • Turn the hose on fully-you should see and hear the hose water chase the air out of the line.
  • Close the  pump strainer lid
  • Open the filter air relief valve while the pump is trying to prime.
  • Run the pool filter


If the pool pump loses its prime then go over the list above for Pool Pump not Priming. Most times the system is pulling air from a seal or gasket on the pump lid at the filter, it’s a lot easier to buy a new O-ring gasket at the pool supply store.


Why won’t my Pool Pump turn on?

  • The external Power outage breaker tripped
  • Pool timer-ensure that it reset to cycle properly
  • Clogged Pump Impeller-Clean out impeller-Look for the reset button on the back motor
  • Broken pump Capacitor
  • Air locked
  • Overheated motor from being covered
  • The pump shaft is seized .…………………………………………….. Read more


JimGalloway Author/Editor


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