Intro to Pool Pumps And Troubleshooting

Having wrapped up many of the numerous chemicals we utilize everyday in the aquatic professionals average day, it’s time we take a closer look at the mechanics of what you may (or may not) be seeing in your pump or mechanical room.

Part one of this series will focus on a few the various pumps you are likely encounter in your facility. Whether they’re used for pumping thousands of gallons of water around, or slowly pushing through chemicals, you’re sure to have a few of these common pumps in your pump room.

Pump Basics

While there are several different common types of pumps used in the average commercial pool pump room, there are a few principles that apply to most of them that will ensure the ones you use are running properly.

  • Tight Seals: No pump, whatever the type, should have water, or chemicals leaking out in any way shape or form. Whether it’s a minimal drip, or a steady stream, it’s an indicator that the connection, or something in or around the pump isn’t working perfectly. It’s always best to address these issues when they are small as they can continue to grow in size, creating a bigger issue down the line.
  • Flow: In order to function properly, every pump will need open flow on each side (going to the pump and going away from the pump). Without open flow, the pumps will not work properly (seems obvious I know, but it’s a common issue), and it can even damage your expensive pumps, and the connections to them.

Standard Motor Pumps (Impeller)

The most common type of pump used is the standard pump that uses an impeller to draw water into the pump and then expel it.

Common Applications

Being the most common type of pump used, it can have several different applications. Most commonly, large sized pumps are used for primary circulation pumps. Smaller models are often used as “booster” pumps to aid in the flow of chemical feed systems that are farther away from the main circulation line, such as chlorine feed systems, usually in conjunction with a venturi pump/junction.

Special Considerations

Standard impeller pumps are the pipes that can be damaged by running them without proper flow. If you have no flow going to or from the pump, it can burn out the motor on the pump. If you have no flow to the pump, it will try to pull so hard it can cavitate the impeller inside, causing costly, sometime irreparable damage. And when I say costly, I mean it. Depending on the necessary size of the replacement pump, we could be talking thousands of dollars!

Troubleshooting

As with anytime you’re in your pump room, it’s important to get a baseline. The easiest way to tell when things aren’t right before they become an issue that impacts operations is to check your pump room frequently and not only visually inspect things, but listen, even smell it. It’s important to take notice of things that sound different than normal. While all loud, impeller pumps that are damaged, or not functioning properly don’t hum the same as those that are, there will often (but not always) be a sound of grinding, or shrill whining.

If you suspect your pump may not be running properly, if possible turn off the pump and inspect the relevant piping for flow, and the pump itself for leaks.

Peristaltic Pumps

Opposed to the often times, larger and more expensive impeller pumps, peristaltic pumps are much easier to handle. They can’t sustain damage from flow like the standard pumps do. They are much simpler, not in the physics at work inside them, but in terms of their operation, and much easier to handle, in their size and cost, and easier on your budget.

Utilizing rollers on a flexible tubing, the process of peristalsis draws liquid into the tubing and out the other side. While lacking the force necessary to circulate water like our motor pumps, they do have particular usefulness as they can also control rates, and provide metered feeds.

Common Applications

The most common application of peristaltic pumps is in acid chemical feed systems. Due to the relatively low pressure (or priming requirements) they can be the only pump necessary for your acid feed lines to your pool.

Special Considerations

Since their use is chemical, when handling them use typical personal protective equipment for muriatic acid.

Troubleshooting

Unlike loud motor pumps, peristaltic pumps don’t make more noise than normal when they are malfunctioning. So it is important to visually inspect them to see if the soft tubing that the rollers draw the liquid through are not leaking.

Using the linked product as an example, in the clear plastic chamber you should see the rollers moving around, and if there is a leak in the tubing, you will likely see liquid inside the chamber.

Venturi/Jet Injection Pump / Junction (Vacuum)

While not strictly speaking a pump, venturi/jet injection junctions is a method commonly used to force water through systems such as chemical feeds, or pool boilers by utilizing physics.

Venturi junctions, pipes, or valves, work by constricting your flow down, and providing an off chute that the buildup of pressure at the junction forces water through. On the other side of the junction, the flow is still released, creating a vacuum that helps pull the flow from the returning off chute. For a more detailed description, find look to the sources here.

Common Applications

Most commonly, venture’s are utilized in conjunction with booster pumps for chemical feeds that require high flow rates, and with boilers heating pools.

Special Considerations

As they are connected to our mainlines, and particularly chemical and temperature feeds, they can build up deposits in the constricted area, restricting flow too much.

Troubleshooting

If you’re having issues with flow, chances are good that there is a buildup in the venturi junction that is restricting flow too much, if not in the junction itself, than in the tubing on either the upstream, or downstream side that is too restricted to provide proper flow.

Honorable Mention: Valve Restriction

Like venturi junctions, you can force water through a system (again, often chemical feed, or heat feeds) by using partially closed valves, with off chutes on each side of the valves to force the desired amount of water into other systems before mixing back into your main line.

Common Applications

This will most commonly be utilized with chemical feeds requiring high flow, and pool heating systems.

Special Considerations

It is important to never completely restrict either side when your main pump is on; doing so could damage the pump, the valves, or the piping.

Troubleshooting

If encountering lower than desired flow, it may be necessary to adjust the closure angle of the valves on both sides. Again, never completely restrict either side while your pump is running.
Valves adjusted while the pump is running can become loose, or misaligned and unable to close or adjust properly (frequency depends on the type of valve).

Have any questions about any of the pumps/mechanisms mentioned? Let us know below! Had any other issues you encountered with these pump types? We’d love to hear about it!

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