Lots of problems can happen with our swimming pool pumps.  They can leak, squeak, hum and grind.  They can also do what is known as “surging”.  What is pool pump surging and what can we do if we are experiencing this?

What is a Pool Pump?

Think of your swimming pool pump as the “heart” of your circulation system.  Every swimming pool has one or more.  As the pool water is drawn form the skimmer and/or main drain, it is then pushed or pumped back through your system.  It makes several stops along the way.  You may have a heater or salt system.  You may have an inline chlorinator.  You definitely have a filter, which is the other required piece of equipment on a swimming pool. Pool pumps come in single, two-speed and variable speed.

What is Pool Pump Surging?

Also known as pulsing, a pool pump surge is when as the water flows into the pool pump, it does so intermittently.  As it does this, it starts to catch prime.  But then, OH NO!, it loses it.  Then it will catch it again.This is obviously not good and could cause your pool pump to run dry, causing damage.  What are some of the causes of pool pump surging?

Obstruction in the Plumbing

A cause of pool pump surging could be due to one of your suction pipes gets clogged.  Suction pipes include your skimmer, vacuum and main drain.  Even a partial clog could cause this.  Clogs can be debris such as leaves, acorns and whatever else may fall into your pool.  If the surging happens right after, or during vacuuming, this is the most likely cause.

If you Winterize your pool and used too small of a plug, it can actually slip down the pipe.  In both instances the unwanted traveler will get caught at the first curve in your plumbing. If this happens, you can hire a professional to blow your lines with a CO2 tank.  Or, you can buy a product like the “Drain Jet” which attaches to a garden hose.  You insert this into the front of the pump and pushes the clog backwards.  Eventually it ends up in the skimmer where you can easily grab it.

Your Water Level is Too Low

Another common issue that can cause surging is not having enough water in your swimming pool.  The water should always be filled halfway up the skimmer.  We are aiming for a vortex in our skimmer to suck the water down and towards the pump.

Your Weir Blade is Stuck

Sometimes, a skimmer’s side walls can bow inward.  When this happens, your weir gate can become stuck in a vertical position.  This obviously will block the flow of water, causing surging. I am told this can be tricky to determine because when you go to check it out, the weir gate may have fallen back to the right position.  To resolve this, remove your skimmer cover with the pump off and push the weir to a vertical position.  Check it out to see if it sticks there.

A Pump Switch is Lose

This is something new that I learned.  This problem can often be paired with a clicking sound.  This could mean one of the switches in the rear end of the pump is switching on/off repeatedly.  Depending on the type of motor you have, there may be a centrifugal switch on the end of your motor shaft that possibly could be loose which causes it not to fully engage.  If you tighten the center screw and check and make sure it is aligned with the tab on the triangular shaped stationary switch.

Speaking of the stationary switch, this could also pose a problem if it is turning off and on.  The screw at the bottom can come loose.  You can look for this screw at approximately 6 o’clock.  

An Air Leak

This is the number one cause of a surging pump.  A suction side air leak.  While you pump is building water flow, you create a vacuum which increases.  This can make a small leak a BIG problem.  Pumps prefer to pump air over water because it is easier to move.  The most common cause of a suction side leak is the cover o-ring on the pump itself.  I can’t tell you how many service calls I have been on and it was the cover o-ring either not being lubricated, swollen or laying on the ground next to the pump.  No.  I am not joking.  This is the first place I tell my customers to check.  You also have valves that could need o-rings.  The fittings that attach to the pump could become warped.  The air leak will always be before the impeller.  This is because after the pump you will see a water leak versus an air leak.

You Need a New Pool Pump

If you have tried all of the aforementioned and are still having a surging problem, your pump may need to be replaced.  Whether it is required by law or not, we recommend installing a variable speed swimming pool pump.  These energy efficient machines run at a variety of revolutions per minute (RPMs) giving you the power to customize you water movement.  Think you can’t afford a variable speed pump?  Think again!  You can get a name brand, quality, household name of a Black & Decker variable speed pool pump for about half of what you would pay for pumps at your local pool store.  Check them out here

See you poolside come Spring!