Top 7 Pool Water Leaks

5 min. read time | #PoolLeaks #PoolRepair

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This is a very common leak in concrete pools. Even thoughit’s one of the weak spots for leaks in a concrete pool, it not that easy tospot this leak. Where this leak occurs is at the bond in between the plastic ofskimmer mouth and tile grout, plaster or pebble tec. At this spot it is hard todo a dye test because water is always moving and leaf flap inside the skimmermouth is sometimes in the way. Therefore, if you see a gap in between skimmerplastic and grout/ plaster it is smart to patch that area either with epoxy putty or even better with pool tile groutor hydraulic cement.

Example of skimmer to pool bond leakis in this video:



It seems like a leak you can’t miss, but you would besurprised how many times we get called to a pool and all that is leaking is thebackwash valve. Some pools have backwash discharge pipe connected to theirsewer or away from their backyard, so when the backwash valve starts leaking(not closing and sealing off properly) they never seen any water. Easy fix isto replace O-Rings on backwash valve pistons. Most sand filters use Pentair or Jandypiston, and repair sets can be easily found online.

If your sand filter has a Zodiac or Pentair multiport valveon top, you’ll most likely need to replace the whole port guts.




Both fiberglass and concrete pools and spas are prone tocracking. Cracks in plaster pools are easier to spot, but not so much in pebbletec. You’ll need to dive in with apool dye syringe and a diving mask in order to spot this kind of leak. Divingweights also help- they will keep you underwater. This inspection is best leftto a pool leak detection professional, but if you are set to do it yourselftake extra caution- this can be dangerous.


You can see how a crack in pebble tech looks like in this video:


To fix this leak you will need to call a pool repair company.In the meantime, you can slow down the leak using underwaterepoxy putty. Follow the instructions carefully and you might stop thatleak for a whole year.



Another very common leak in concreteand vinyl pools. There are two spots where a pool lights usually leak. One isat the conduit and the other at the bond to outer ring of the light niche. Somelight niches don’t have the outer ring so you only need to check the conduit.To spot light leaks you will have to dive in with some pool dye, take out thepool light housing and shoot some dye by the conduit inside the light niche. Bydesign, water is supposed to get inside light conduit, but if that conduit hasa crack somewhere water will leak out at that spot.

To repair conduit leak you can use butyl tape, just make sure you roll up a goodamount of it around the conduit wire and shove it inside the conduit opening inthe light niche. All of this can be done under water, but it is not easy forsomeone who doesn’t have diving experience and some dive weights. It is saferto drain the pool first, and then repair this type of a leak. All underwaterrepairs are best left to professionals who have the necessary equipment andexperience.

To see examples of these leaks, go tovideos section of our website:



 We see this type of leak on remodels or even newly builtpools. While drying, plaster or pebble tec doesn’t stick well to PVC exposing avoid which lets water get in contact with shotcrete behind that is also notoriousfor not bonding well to PVC. For some reason this happens more often aroundmain drain than side return outlets, but it is worth checking both areas.

To check if your pool is leaking around pipe outlets, you’llneed to dive in and inspect it with leak dye.


Here is a video example how this leak looks like:



Broken underground pipe is something that every pool owner isafraid off. To find whether or not you have a pool plumbing leak you will needto hire a professional who can pressure test pool pipes and has the equipmentto pinpoint and precisely locate the leak on pool plumbing. This is usuallybeyond the scope of work for most pool guys, so you will need to call a leakdetection company.

Good news is that most underground pipe breaks can beefficiently fixed and it actually doesn’t require ripping out entire pool deckor replacing an entire pipe like some pool owners think. Usually, a hole in thedeck approximately 2ft by 2ft will be sufficient enough to reach the leak anddo the necessary plumbing repair.  



Even though skimmer boxes are madeout of durable ABS plastic, after years of wear and tear they can crack out andstart leaking. To inspect your skimmer box, take out the leaf basket, turn poolpump off and using a flashlight inspect the bottom of the skimmer verycarefully. You can also use some pool leak dye if you see a crack to see howbad it leaks.

You can see an example of a crackedskimmer box in this video:


Cracks in auto-fill boxes are similar,but a little bit harder to spot in concrete autofill boxes. To spot theseleaks, you will have to shut the autofill off, and then clean out the bottom ofthe concrete box (cracks often hide in the dirt that accumulates at the bottom)and then visually inspect the bottom and walls of the autofill box.