been to this pool in westchester last year. light niche cracked sealed and its been ok. this crack continues to get longer like a windshield crack.

anyone seen any problems with light niches marked specifically for FRESH WATER ONLY but now has a salt water system installed? seems to be in pentair light niches only not hayward

last question, is there any long term solution to this problem? I dont want to go in and make a repair and have to go back year after year on my on dime.. anyone know of anything to make a long term repair??

Pentair is well aware of this problem, they have admitted it is a design flaw and have authorized some repairmen to fix them, the fix involves lowering the water level and applying a sealant they provide to the entire rim and first 2 inches of the niche, they say it will last, I have major doubts because when the next liner change occurs on these pools the cracks will get worse as the screws are tightened
The issue is caused by electrolysis between 2 dissimilar metals, the ss screw and the metal screw insert, when they react the corrosion expands and cracks the niche at each screw
Bruce
I've seen over 30 of these in NY & CT

Photo of the leaking, cracked, defective Pentair light niche

Bruce
poolrepairdiver.com

good picture bruce. i have also seen cracks throughout the niche including in the twelve o clock position.

Is this a problem in Pentair plastic niches for gunite as well?

Semi-Retired asked:

Is this a problem for Pentair niches for Gunite as well?

No, this issue is only with the fresh water niche for vinyl liner pools

Bruce
poolrepairdiver.com

I had a vinyl salt water pool with two Pentair niches and they both cracked at the 12:00 position,not at the face of the niche but back in toward the cord. Wrong pipe dope ? over tightened adapter ? ground settled I don't know.

I have seen the same thing. We drained the water and applied smear ( a mixture of plastic and MEK). So far it has held.

I did not take notice of the Pentair niches I had trouble with being labeled ( fresh water only )

The Pentair "Fresh Water Only" niches are certified for both fresh water and salt water generator pools, they are not for use in Ocean Salt Water Pools (per Pentair)

Bruce
poolrepairdiver.com

Are they self tapping screws or threads into inserts / If they are threads into inserts its possible that water is trapped in the insert, as you screw it in the hydraluic pressure can build up rapidly and is maybe causing the crack. Try it with a cyclinder block/head, put a few drops oil in the blind hole and wind in a stud, make sure its and old block!

have repaired both hayward pvc niches and pentair. much less common for the pentaires to break, from my experience, but have fixed them in both vinyl and gunite.depending on the time of the service call depends on the guarantee. if the pool is being used, I can guarantee it not to leak. It seems the recuring issue with these niches, hayward inparticular, is maikng it through the winter. to me that means a couple things....A, movement of the niche with frost. B, when the water level is lowered for winter, if the level freezes hard at the niche, my feelings are it can break the niche.I have never been called back to a pentair after initial repair. I have been called back to hayward niches, I will make it clear to the client that if the inseason repair does not make it through winter, I will not repair it for free. If the water level is at the light upon opening(after initial inseason repair) I have them drop it clear of the trim ring and I apply thickened epoxy resin with fiberglass cloth to the properly prepared niche.....have not had 1 fail, but if it did, the light would get covered over, and eliminated, as per my recomendation.