Swimming Pool Pump Troubleshooting

By Author: Steve Merillat
Total Articles: 14
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How Swimming Pool Pumps Work


Most pumps are self-priming centrifugal pumps. These pumps must have a vacuum chamber, commonly known as a pump housing. The pump housing must be filled with water in order for any pump to create a vacuum, resulting in your pump pulling the water out of your pool or spa. The pump housing will remain full of water while the pump is on, and will remain full or partially full of water when the pump is shut off.

When you turn on the pump the motor will begin to rotate on high speed (dual speed pumps rotate at the preselected speed). The motor drives the pump impeller, located inside the pumps center portion at the opposite end, away from the electrical switch portion of the motor. While the motor is rotating, the tips of the impeller are sealed hydraulically inside of the pump diffuser, this allows self-priming to occur. Self-priming can only occur when the pump has a diffuser. Some pumps have a separate diffuser, others have the diffuser molded into the pump's cover, refer to your Owner's Manual for your pump. The diffuser helps to eliminate any air coming into the pump ...
... housing, suction piping, or hoses on above ground pools. When all the air is being removed from the system, you will notice the bubbles returning to the pool through the return fittings.
The impeller acts to convert water velocity into water pressure, which is registered on your filter pressure gauge. The actual Gallons Per Minute (GPM) varies with the type of pump and the horsepower. Check your Owner's Manual for more information (owner's manuals can be found online under the detailed page of your pump).

Self-priming pumps are very dependable and simple in design. They require a sufficient supply of water from the pool or spa, and no air in the suction lines.
Air could come from a loose strainer cover, a leak in any valve, a pin hole in any suction line or any crack or loose connections in the underground piping. Your pump should be kept free of dirt and also located where it can be protected from flooding during heavy rain fall. If your pump motor becomes flooded you will probably have to replace it.

Our Swimming Pool Pump is Running Too Hot and Shutting Off


This may be caused by insufficient power due to an undersized or long power wires. All wires should be according to code requirements and the motor manufacturer's recommendations.

Your local power supply may be suffering a power drop. For example: during a heat wave when every possible cooling appliance has been turned on in your area, your pump may be starved of the power it requires to run cool. Restart your pump when the weather cools to confirm that the problem is in the motor.

Your pump has a thermal overload, which will shut the motor off when it gets too hot, and it will restart itself once it has cooled down.

Our Swimming Pool Pump will not prime


Check for each of the following:
You may have a suction leak if there is not enough water in the strainer housing.
You can have a leak at any joint especially at the first fitting that is screwed into the strainer housing.
The strainer cover may be loose or an o-ring under the strainer housing cover may be worn.
You may have clogged suction piping, which is caused by items that get sucked through the skimmer into the piping, usually lodging at any turn in the piping.
Sometimes when the pump starts, a small stone or debris by-passes the pump basket it will break the impeller.
The pump may be located above the pool water level or may be too far from the pool, requiring longer periods to prime. The ideal situation is to locate the pump at or just slightly above water level, 8 feet maximum, and as close to the pool as possible, approximately 10 - 20 feet maximum.

The Swimming Pool Pump is running, but there is no pressure


Many pool owners use this term when in fact they really mean they have lots of pressure but their flow is very low. This is caused by a dirty or clogged filter, a blocked return line, or a valve that is shut off or partially shut on the return piping.

The pump's impeller may be clogged with debris. Check by first shutting off the pump. Remove the basket and check the impeller by putting your finger into the suction hole found in the pump strainer housing. If the seal is broken, replace it. For seal change instructions on any pumps, refer to your Owner's Manual that is supplied with your pump.

The Swimming Pool Pump is running, but there is no pressure


Many pool owners use this term when in fact they really mean they have lots of pressure but their flow is very low. This is caused by a dirty or clogged filter, a blocked return line, or a valve that is shut off or partially shut on the return piping.

The pump's impeller may be clogged with debris. Check by first shutting off the pump. Remove the basket and check the impeller by putting your finger into the suction hole found in the pump strainer housing. If the seal is broken, replace it. For seal change instructions on any pumps, refer to your Owner's Manual that is supplied with your pump.

The Swimming Pool Pump is running, but there is no pressure


Many pool owners use this term when in fact they really mean they have lots of pressure but their flow is very low. This is caused by a dirty or clogged filter, a blocked return line, or a valve that is shut off or partially shut on the return piping.

The pump's impeller may be clogged with debris. Check by first shutting off the pump. Remove the basket and check the impeller by putting your finger into the suction hole found in the pump strainer housing. If the seal is broken, replace it. For seal change instructions on any pumps, refer to your Owner's Manual that is supplied with your pump.
S.Merillat(r)

To learn more about Troubleshooting your Swimming Pool Pump, visit http://www.1800pools.com
Steve Merillat has been in the Pool industry for 35 years. He started early on working for various Swimming Pool supply companies before ventured out in his own business. He pioneered many processes with the installation of pools that are used as industry standards today. He regularly holds seminars and classes on how to properly maintain your Swimming Pool. Visit http://www.1800pools.com