by Myles McMorrow, March 16, 2009
The pump is one of the most important parts of your pool's plumbing system. It is responsible for creating pressure in your pool, which forces the water to flow through the filter. Think of it as the heart of your swimming pool and without a filter pump your pool will rapidly become a pond of scum.
Unfortunately sometimes your pool pump will not work due to one of many issues that might occur. In this article I will cover most of the top reasons we hear at POOLCENTER.com for pool pump problems.
#1 The pump does pull water.
If your pump is not moving water you first want to check the skimmer and pump baskets and make sure they are empty as not to restrict water flow. Next make sure your pool filter is clean. Once you have checked these, you may want to check the pump impeller. This is the part in the pump that is connected to the motor that moves the water. Impellers will clog from time to time, especially during the springtime. To inspect the impeller, you will need to open the pump, to see inside of the impeller housing or volute.
One of the major causes for pump suction loss is an air leak in the suction line. The suction line is where the pump gets supplied with the water from the pool. You will know this may be the issue if your pump will not catch prime. Prime is when your pump is running at full capacity. A pump is designed to suck water, but it can and will suck air if given the chance. Air has less mass than water, so a pump will suck air before it will suck water. If you think you have an air leak, see #5 below.
#2 The pump is leaking water
If you see a pump leaking water it will be on what we call the pressure side. This is after the pump lint pot ( the pot and anything before is not under positive pressure but rather negative pressure or suction and will not leak but try to draw in air see #1). The causes for a leak can be a bad impeller housing oring, bad shaft seal, or bad thread sealant or shrunken threads on the plumbing discharge pipe, or the pipe that comes out of the pump. If it is an oring or seal it is best to get what they call a Go Kit, which has every seal and oring in the pump, in one kit. I always say, if you are going to take the pump apart, you might as well replace all the seals. Pool Pump Go-Kits cost about $20, depending on the pump model and are cheaper than buying all the seals one by one.
#3 The motor will not work or turns off after time.
There can be many things that can cause this issue. You want to start by checking for power to the motor. Check your breaker and make sure your timer is set to turn on the pump. If you are getting power, the next thing to check for is sounds. Can you hear the motor hum or can you hear a click? A humming motor can mean it is the capacitor. Think of the capacitor as a battery (looks like one too) that jumps the motor to start spinning. A capacitor stores up a quick jolt of electricity to start the motor. They can be located in the back of the motor housing or in a hump on the top or side of the unit.
If your motor runs but turns itself off after a time, it may be over-heating. Pool pumps use a lot of wattage and need a constant supply. If it is in the middle of a hot day and everyone in your neighborhood has the AC on high there may be a drop of power causing the motor to overheat. Not much you can do at that point but maybe run your pump at night when it is cooler. The second leading cause for this is motor fan failure or vent blockage. On the underside of the motor are vents that can get clogged up with dirt and leaves. Make sure you do not have dirt build up and keep them open and clear. I have run across cases where was just plain old sun light causing the motor to overheat. This is common in the south west and I would recommend getting a motor cover to keep the sun at bay.
#4 The motor/pump is making a loud noise.
Everyone (and their neighbors) hates a loud swimming pool pump. If your pump is loud, the first thing to do is to listen to it. What kind of sound does it make? If it sounds like there are rocks in it, this can be from it vibrating on the pad it sits on, or it could be cavitation. A piece of rubber mat under it might help to stop the noise. If that is not the case, it may be cavitation. Cavitation happens when the pump cannot get enough water fast enough, or the pump is "starved for water". The pump impeller is spinning too fast with not enough water and starts to beat the air molecules out of the water. If you didn't just install an oversize pump, you will want to check the lines for a clog, or a closed valve. In some cases it may be a clogged filter or impeller. Clear out any obstructions and you should be fine.
Now if you pump is screaming (this is what sets off the neighbors) your motor may need new bearings. Bearings are mounted on the pool motor shaft inside the motor to help reduce the friction as the electro magnates make the motor shaft spin. This is a high wear and tear item within the motor. Although the bearings are cheap (about $15) the labor is intensive. Most motors have 2 different sizes in them and usually take special bearing pullers to remove them. I always recommend taking the motor to a shop and for about $100 you can get a motor refurbished. Or, if you are a DIY-er, we sell bearings here: Pool Motor Bearings.
#5 The motor/pump is sucking in air.
Pool pumps are supposed to be air tight. With a clear pump lid, you "should" see no air in the pump basket. This is rarely the case however, small air leaks are common. When the air leak gets too large, however, it can create problems with circulation or keeping the pump primed. The most common causes of a pump air leak include bad thread sealant where the pipe enters the pump, a leaky valve stem on one of the suction valves or a break in the plumbing. Other sources of air leaking into the system include a loose or old pump lid or pump lid o-ring or an ill fitting pump drain plug. All air leaks originate BEFORE the impeller.
A good test to locate an Air Leak, and it will sound funny - is to use shaving cream (not gel). Spread the shaving cream over the suction side joints and fittings with the pump on. The pump will try to suck the foam into the pipe because it has less resistance or mass then the water. At the air leak you will start to see the layer of foam dimple as it gets sucked into the system revealing where the leak is. At this point you will know what part needs to be repaired or replaced.
Another method of locating an air leak is to use the Drain King to pressurize the suction side. Where the water leak occurs under pressure is where the air leak occurs under suction.
So, there you have it - some of the most common reasons for pool pump aggravation. We hope to have helped you through yours!