Your Pool Pump Won't Prime?  Here's What You Should Do to Troubleshoot.

It is so frustrating.  You go to turn on your equipment and your swimming pool pump won’t prime.  Ugh!  Isn’t this supposed to be a self-priming pump?  Luckily, sometimes it is an easy fix.  Other times some minor repairs will need to be handled.  Either way, let’s talk about what some of those causes may be.

Your Water Level is Too Low

The water level in our pool is super important.  We don’t want it too high or too low.  When the water gets lower than halfway between the skimmer, it is too low and can cause your swimming pool pump to suck air, causing your pump not to prime.  Your skimmer is that box on the side of your pool where your skimmer basket sits.  

Weir Gates are Stuck

Since we were on the topic of skimmers, I figured I would dive into another skimmer related issue.  On your skimmer, there may be a rectangular blade-shaped white piece of plastic.  This bobs to and fro, allowing your skimmer to skim the very top of the water.  This is where all the gunk and junk is so that is a good thing.  Sometimes, these gates, called weir gates or weir blades, get stuck.  This prohibits the flow of water through the skimmer, much like low water does.  

The Cover O-Ring is Missing or Damaged

This is probably the most common cause, in my experience, of a pump failing to prime.  I cannot tell you how many service calls I have sent guys out to, or even gone out to myself, where the pump strainer o-ring is lying on the ground next to the pump.  Or it is bone dry.  Much like all the o-rings associated with your swimming pool, this one needs to stay lubricated.  If it is flattened, swollen or pinched it also will not form a tight enough seal, allowing air to get into your pump, causing it not to prime or to cavitate.

Pump Basket Needs Replacement Or Adjustment

While we have the pump lid off, let’s take a look at the pump basket that sits just underneath.  Make sure there are no cracks, that it hasn’t melted, that it is lined up properly and that it is not jammed full of leaves and debris.

Bad Motor

If you turn on your pump and the motor just hums or makes a high-pitched grinding sound, you may have a problem with your motor.  Humming generally means that the motor has seized and could be indicative of a bad capacitor or the need to replace the whole motor. It may also mean that there is something stuck in the impeller.  Due to the electrical nature, I advise asking a professional for help if you are not 100% comfortable.  Grinding is usually attributed to the motor bearings going out.  While these can be replaced, it is recommended to just replace the motor.  Old single speed pump?  This is a perfect opportunity to upgrade to a Variable Speed Pump and start having your pool pump pay YOU.

 Is the noise coming from the pool pump? This article offers suggestions about how to resolve the issue.

A Bad Intermatic Timer

This is that yellow dial thingy in the gray metal box.  It has on and off switches called “trippers” that can sometimes get stuck in a way that prevents the tab from fully engaging when the homeowner manually tries to turn on the pump.

Bad Automation

If you have automation, sometimes when you push the button you will hear a click or nothing happens at all.  This could be a warning that you have a bad relay (the thing that tells the pump to turn on) or worse, a bad board.  This would involve calling tech support or getting a pool pro out for a service call.

Your Pump Housing Is Cracked

Sometimes the plastic/fiberglass part of our swimming pool pump just gets old and fuzzy looking.  This can cause water to seep through.  You may actually have a crack in your volute.  This could be another good time to upgrade your pump to a variable speed pump as this usually only happens on VERY old pool pumps.

You Have a Suction Side Leak

We have already touched on the cover lid o-ring, but check for any water dripping from plumbing or unions.  Water coming out when the pump is on means air getting in when the pump is off.  No bueno.

Your Pool Pump Is Old

It could just be that time to replace ol’ faithful.  Especially if you currently have the old technology of a single speed pool pump.  Variable speed pool pumps are energy efficient and save you on average $70 a month on your electric bill.  If it is Energy Star Rated, you may qualify for a rebate from your utility company.  Think you can’t afford a variable speed, quality, Energy Star Rated, five year warranty pump?  Think again, my pool-owning, savvy friends!  Check out the American-made, household name BLACK + DECKER Variable Speed Pool Pumps here.  Heck, even if your pump is working “fine”, why continue to lose money? See you poolside!

Related articles: 

Ideal Schedule for Your Variable Speed Pool Pump

What to Do When Your Pool Pump Won’t Turn On

How to Fix an Overheating Pool Pump - Before Your Energy Bill Spikes