Identifying Vinyl Liner Pool Leaks (When To Repair & How)

The issues that a vinyl liner leak could cause can make any pool owner nervous. Your water level might fall below the skimmer and cause damage to the overheated pool pump. The leak could also be creating corrosion behind the vinyl liner. 

You can tell where a vinyl pool liner is leaking by performing a simple bucket test or turning off all devices and searching for bubbles on the surface. The most common sites to check for leaks are pool lights, skimmers, return fittings, cracks in the vinyl liner, and the main drain. The longer a pool liner leak goes unrepaired, the larger the tear repair will be. Pool owners should always inspect after signs of a possible leak.

When is water loss in a vinyl liner pool normal?

Water levels in a vinyl liner pool typically experience over one inch of decrease every week due to the natural process of evaporation. Frequent splashing and hot weather can accelerate the rate of water loss. These contributors may also cause more refills to return the water back to a normal level.

The average volume of water a pool can lose in a week 

On average, a standard vinyl liner swimming pool loses approximately one-quarter of an inch to two inches of water in a given week. That could be anywhere from 400 to 800 gallons weekly. This can add up, causing 10,000 to 20,000 gallons of loss per year — enough water for a second pool!

Average volume of water in pool

Other factors that can contribute to pool water loss 

The water loss in a vinyl liner pool might be from a leak, but it can also result from natural pool maintenance or use. Backwashing can cause a loss of up to 300 gallons of water, which drains out into the sewer waste system. Regular use, like splashing, especially in hot weather, can also cause an accelerated loss of water. 

How To Determine A Leak in Pool

To establish that your pool is actually leaking, you need a 5-gallon bucket and duct tape or marker. Using the bucket test, fill it with water to the same level as inside of the pool and mark it with tape or a marker. 

Turn off the pump and automatic-refilling devices, then leave your pool alone for twenty-four hours. If the water level of the pool is lower than the bucket’s, then you likely have a leak in the system. To check if it is an underground pipe leak, try this test again after plugging all of your pool lines. If it is still losing water, the leak is in the pool itself.

Common areas that a pool may have leaks 

Vinyl Liner Cracks: Most pool vinyl will need to be replaced every 8-16 years. You may need to check how long your type of vinyl lasts to see if it is time to get a new liner. 

The pool’s vinyl can often become cracked by wear and tear. It might show signs of sun exposure by fading in color or becoming soft and squishy to the touch. These spots can become problems if they continue to fade or are not repaired. 

Pool Lights: If you find the leak is near a light, remove the light from its niche to view any cracks or holes around it. If none are visible, try using a rubber cord stopper seal to plug the hole where the cord exits. If the leak has caused an electrical issue, it is best to leave the repairs for a professional to fix. 

Skimmers: The most common place for leaks is the pool skimmer. The dye test can find possible cracks in the plastic skimmer throat, faceplate, well, and gaskets. Any odd or strange noises can be signs of a crack or leak.  

Return Fittings: The pool’s wall fittings and faceplates can also be dye tested. You can remove the eyeball/return jet fittings and dye test to check the backside. Stripped screws on face plates or steps can be fixed by wrapping them with Teflon tape and screwing them back in. If the crack is from a fitting or faceplate, you will need to order a replacement part and install it into your pool.

Main Drain: This is tested by removing the cover, plugging the line, and testing to see if it maintains pressure. A pressure test often requires a professional, but the repair can be done yourself since the leak is often under four feet from the pool deck.

How To Tell Where a Vinyl Liner Pool is Leaking

To find the specific location of cracks and leaks, you will need a water mask or pair of goggles and a professional testing dye that is easy to see and safe for use in your pool. Using food coloring can work as well, but it will dilute much faster than a pool dye. 

  1. Turn off all of the pool pumps and other devices and allow the water to remain undisturbed. The movement will make the dye less effective for locating leaks.
  1. If you are able, search for tiny bubbles on the surface of the water.
  1. If you see any bubbles, calmly move into the water and begin squirting the dye in the areas near the bubbles or around faded vinyl, seals, or fittings. Using goggles, see if the dye is sucked into an opening and locate your problem area. 
  1. Continue Step 4 around other common areas, such as those in the section above.

Checking For leaks in filtration systems and pumps 

The three most common sites of pool pump leaks are suction side leaks, shaft seal leaks, and pressure side leaks. Generally, if you can see water outside of the pump pipes, there could be a leak from them. If there is water near any electrical parts or a short is happening, use caution and leave the leak repair to a professional.

Pool pump leaking at connection 

A leak at a pool filtration or pump connection is often caused by an ill-fitting seal or by shrunken pipes. Excessive heat and extreme cold can result in your PVC pipes having small openings where moisture will escape. Turning off your pump can help you determine if you have any leaks at a connection because it will allow water to seep out without the force of the water through the pump.

How to trace the leakage in a pump 

The leak could be in a few different places in your pump. The suction side is any part before the pump and motor. The discharge side deals with the pressure of pumping the water back into the pool. The discharge side is often where the water leaks occur. 

Signs of a leak on the discharge side can be dripping from pipe fittings and water puddles under the pump. A broken impeller can be holding buildup and preventing water flow as well. The gasket between the pump and the motor must stay sealed to avoid leaking. Often, an ill-fitting discharge pipe can cause leaks. 

How to fix pump leakage 

An issue in your suction side pool pump is any leak or crack before the actual pump itself. While the pump is running, if you find bubbles in the pump strainer basket, it is an indicator that you have a suction side leak. Make sure to check the pump strainer lid for cracks and see if the o-ring under it is still in good shape. 

If the pump is making unusual sounds, it could be due to a shaft seal failure. This kind of failure can leak water into the motor, which will make odd noises if it is trying to move the bearings in the water. As long as your motor does not appear to have damage, you should be able to just replace the shaft seal rather than the seal as well as the motor.

Dangers of leaking vinyl liner pool 

  • Leaks can cause your pool’s pH levels to be unbalanced. Having an incorrect level of pH in your water can cause a build-up of algae and bacteria. These organisms can greatly multiply and even cause your pool’s filters and devices to stop working correctly.
  • A leak in your pool can waste enough water to cost lots of money to drain out of your pockets every day. Hundreds of dollars in excess water bills can be caused by leaks in your pool. Increased energy costs can also occur, especially if the leak is caused by a motor or pump malfunction.
  • Your pool’s leak could be causing damage to your next-door neighbor’s backyard. Leaking water can cause sinkholes or even structural damage to someone else’s property. You will still be held accountable for paying the repair costs, even if it is not your yard. A once-friendly neighbor might consider suing you if their kid gets hurt in an accident caused by your leaking pool. 
  • Sinkholes could form when your pool has been leaking water into the surrounding ground. A home’s foundation can collapse from a sinkhole caused by a pool’s “small cracks.” The water will cause the soil around the pool to erode, which is the most common reason sinkholes form!  

Common causes of a vinyl pool leak 

  • Regular wear and tear over time can cause cracks in the vinyl liner.
  • Loose or poorly fit accessories, such as screws not being water sealed.
  • Tears or holes in the pool vinyl around faceplates or fittings have been installed.
  • Pumps or water refilling motors are not working properly and making strange noises.

How to patch a swimming pool liner 

You have three options when it comes to patching up your swimming pool’s vinyl liner. The low-cost waterproof tape, the pre-cut peel-and-stick patches, and a longer-term vinyl patch kit. With any vinyl kit, you’ll want to follow your package’s instructions.

  1. Clean the damaged area of the pool wall without scrubbing.
  1. Trim the patching into a circle at least two inches larger in diameter than the opening in your vinyl.
  1. Apply adhesive by either removing the paper backing of a stick-and-peel patch or by using a dauber to apply lots of adhesive onto the patch, especially the edges.
  1. Fold the circular patch in half, in the shape of a taco, with the adhesive side facing outwards. 
  1. Apply it over the opening while flattening the taco patch and smoothing it onto the pool liner.
  1. Applying weight for the next twenty-four hours can help keep your patch smooth and in place while it cures.
  1. Feel free to add a second, slightly larger patch after the first one is done setting.

Mistakes to avoid during patching 

  • Don’t drain the entire pool before repairing it. You only need to drain the water level to about an inch below the area that requires patching.
  • Not allowing enough time for the patch to set. Most repair patches require at least twenty-four hours of dry air, and most will also need to be protected from precipitation during this time.
  • Purchasing the wrong vinyl patch for your existing liner. Research your options to match the quality and color to your needs. If you are able to, try contacting the original pool manufacturer and check if they have an accurate repair match.

Tips to prevent cracks that cause vinyl pool leakage 

Vinyl pool leakage can be avoided with the following tips in mind: 

  • Maintain Water Chemistry: Keep your pool’s water at the perfect balance of pH, alkalinity, and chlorine levels. 
  • Chemicals One by One: Add each chemical separately and allow for 30 minutes of circulation before adding the next one.
  • Claws can Puncture Vinyl: Allowing your dogs to enjoy your pool can expose the vinyl to sharp claws when your pets try to grip onto the sides.

Five simple steps to prevent water loss in a pool 

To prevent water loss in a pool, apply these five simple steps. 

  1. Prevent pool evaporation by using a quick liquid pool blanket. Sounds like magic, but it is simply a mixture of alcohol and calcium hydroxide. These liquids will combine to create a barrier between your pool’s surface and the air. This will lower the rate of evaporation and keep the water at a more constant temperature.
  1. Use a pool cover to prevent much more than just evaporation! Your pool will enjoy an easily sustained temperature and stop debris from falling into its water. As a bonus, your pool cover will help reduce the pool’s chemical consumption, keeping more money in your pockets.
  1. Leave extra features off when you are away from the pool. Water slides, fountains, and waterfalls can contribute to water loss in two ways. Their motion heats up the pool, which accelerates evaporation, and they also spray more water into the air, moving it closer to the sun’s rays. Turn them off if the pool is not in use.
  1. Keeping the water temperature down will reduce evaporation. Heated pool water will become a vapor more quickly than a cooler pool. In general, you should keep your pool 2 degrees colder than the ambient temperature.
  1. Provide your pool with shade using hedges, shrubs, or greenery. Shade around the perimeter of your pool will block some of the suns and prevent it from evaporating as much of your water.

Does Homeowners Insurance Cover Pool Damage? 

Unfortunately, most homeowners insurance does not cover the majority of pool damage. Although, in most cases, your pool is protected from fire, windstorms, hail, lightning, and vandalism. 

The repairs required after a wildfire that causes damage to your vinyl pool liner are likely to be covered by your home insurance. However, any damages related to an earthquake, such as cracks in the pool’s structure, are usually not covered. 

Owners of a pool may also need to review their liability coverage for incidents that happen on their property. A pool has additional risk, and insurers recommend at least $300,000 to $500,000 as a sufficient amount for your coverage limits.

Regardless of if you own an above-ground pool or an in-ground one, liability coverages have similar rules. You’ll want to be sure to follow state and local laws and always keep your pool area safe. By having enough coverage for liabilities in your policy and following safety guidelines, such as fencing off your pool, you can help reduce any damages or out-of-pocket fees.

An umbrella policy can be worth considering for pool owners. This will help protect your assets if you are responsible for damages that go over the limits of your primary policy. 

Insurance coverages will differ from state to state and may have specific details that pool owners should be aware of. Make sure to check your policy’s features when deciding to purchase a pool or when buying homeowners insurance.


When you find out that your vinyl liner pool has a leak, you can be in a scary situation. You can verify if you have a leak with our bucket test instructions. With the information provided in this guide, you are now ready to tackle the task of locating the point of the leak. 

Be patient and use the dye test in any suspicious areas of your pool. Try and use less abrasive cleaning products as well on your pool to protect your liner.

You can help reduce thousands in possible repair costs by getting ahead of the damage. Save your pool by spending the time to find the tear now instead of a mess of corrosion years down the line.

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