Trouble-shooting Air Leaks in Filter System

What is an Air Leak?

An "Air Leak" is any point where air (a little or a lot) can get into the suction side of the filtration system.

If any of these symptoms are occurring, chances are that you have an air leak. This situation, while seemingly confusing and difficult, is actually really easy to eliminate.

One important thing to remember with an air leak is the you can have a leak without having water leak out.

Air leaks occur when the pump is turned on and for whatever reason air is pulled (sucked) into the system.

One way is from a small crack or hole from the pump motor seal to anywhere back to the water level of the pool.

Another way is any interrruption in the flow of water to the pump that causes the pump to lose its prime. (For example: not having all the air out of the vacuum hose or connecting the vacuum hose to the skimmer too slowly or with the pump on. More explanation to come.)

Why is it a problem?

Large air leaks can greatly reduce the suction from the pump. No suction means vacuuming the pool is nearly impossible. Automatic pool cleaners will start briefly, only to top and just sit at the bottom of the pool. Extremely frustrating...if you don't know how to solve the problem.

Here is a list of what check for a leak.

Our suggestion is to check the most common causes first.

If those don't solve the problem, then procede to the less common causes.

The most common examples of air leaks:

Most common cause: not enough water in the pool or missing skimmer weir. If you see a small whirlpool in the skimmer, then this is most likely where the air is coming from.

Second most common cause: you have just emptied the pump basket and forgot to completely tighten the clear lid on the pump. Having trouble getting the unscrewing the lid on the pump? See "How to avoid an air lock".

Third most common cause: while attaching the vacuum hose to the pool, too much air gets in. Try attaching the vacuum hose to the vacuum plate adaptor WITH THE PUMP MOTOR OFF. You can take your time and attach it properly. With the motor on, you must be very fast while making the connections. For a visual example,  Check out PoolCo's Video "How to Attach Your Vacuum"

Other possible solutions:

Check the hose connection from the bottom of the skimmer and the hose connection from the front of the pump. The hose clamps must be extremely tight. A small sliver of duct tape, the width and length of your pinky finger, wrapped around the fitting before you slip on the hose, is often helpful to create a complete seal.

Consider replacing this hose if it is over 2 years old. The sun is really hard on anything that is exposed to it day after long hot day. A small pinhole can develop that will be undetectable, even upon close inspection.

Check the orings on the clear lid above the basket and the pump plug(s). Are there any fine cracks the air could seep into? If they look worn or are several years old, they should be replaced.

Definitely lubricate the oring with a silicome based grease. Don't use vasoline.

Check the bottom of the skimmer for hair-line cracks.

Check the bottom of the pump lint body (holds the basket) for hair-line cracks.

Replace the pump seal.

If you aren't getting good circulation, it may not be an air leak, but an obstruction that isn't allowing the water to flow back to the pool at the proper rate.

Possible obstructions that can greatly reduce flow:

Pump and/or  skimmer baskets are full of leaves, bugs, pine needles, etc. Empty them.

Pool filter needs to backwashed, chemically cleaned or replaced.

Pump impellor is jammed with pine needles or small twigs that can slide through holes in the baskets. Unplug the pump and remove these.

Pool hose from the skimmer to the pump has collapsed and is sucked shut. Replace it.

Automatic or manual vacuum has a rock, sweet gum ball, twig blocking the opening at the vacuum head.

A solar heater can slow your flow down. ( a lot of tubing for the water to flow through).

A pool fountain can slightly slow your flow down.