In brief: Pentair large-format pool light niche gasket set. Pentair part number 79200400.
Sealing a large light niche
With a large-format niche, the sealing surface is larger, and even the slightest unevenness in compression can create a leak path. This gasket set is designed for this specific geometry.
These gaskets age due to exposure to chlorine, ultraviolet light, and tightening cycles. They harden and take on the permanent imprint of the liner or wall they were compressed against.
In a vinyl pool, replace them whenever the liner is changed. They are one of the parts that should never be reused.
Official Pentair specifications
| Part number |
79200400 |
| Type |
Gasket set, large format |
| Application |
Pool light niche |
| Genuine part |
Yes, Pentair part |
Frequently asked questions
Large or small format?
Measure the diameter of your niche and count the holes in the ring before ordering. The 79200400 is the large-format set; the 79200300 is the 8-hole version for a small niche.
Should they be replaced when changing the liner?
Yes, always, in a vinyl pool.
How should they be installed?
On clean, dry surfaces, without sealant, tightening in a cross pattern in gradual passes.
Service on the North Shore
Piscines Geyser keeps Pentair parts in stock in Blainville and serves the Laurentians. Send us a photo of your installation if you're unsure about compatibility: we'll confirm before shipping.
