Leaking Pool Return Lines

Leaking return lines are the most common cause of unexplained water loss in swimming pools as should always be scrutinized heavily when searching for an unexplained leak. Returns are installed in two stages with the initial stage being a two piece flange that is mounted through a hole in the galvanized steel wall of the pool. This is the receiver portion of the return faceplate and gasket which allows for the watertight seal over the vinyl liner in the finished product.

This return fitting itself will seldom be the cause of a leak due to cracking, and more often cause of leak due to improper return gasket installation or failure. The return line pipe is connected into the back of this return fitting via primer and glue for PVC pipe, and utilizing stainless steel clamps for the older polypropylene style pipe. This connection point to the back of the return point is the single most common point for swimming pool leaks.

Why Are Return Leaks So Common?

When a pool installer attaches the pipe to the swimming pool return, the pipe must elbow down immediately. If you do not turn the pipe ninety degrees downward directly out of the return fitting, over time the migrating soil conditions will cause a leverage point where the pipe meets the return fitting.

By turning the pipe downwards you alleviate the potential leverage of this joint. Should the pipe exit the return fitting and go straight out horizontally a foot or two the end farthest from the pool return needs to only shift a half inch to one inch for the joint where the pipe meets the return to fail. I can not stress how common this problem is which the vast majority of installers today even still making this common mistake.

Additional Return Line Symptoms

An immediate cause for concern is when you can see that the deck area of your swimming pool has been broken open and repaired by one of the return fittings, but not by another. In this situation the returns have already proved to be unreliable and it can be a matter of time before further failure is experienced.

Bubbles, large or small coming from the return ports of your pool is a clear indication into a leak in the plumbing system. The only exception to this is if you have an ozonator system installed on your pool which will also cause small bubbles in the return ports as part of its routing operation.

The menu on the right is a chronological step by step process to determine where a swimming pool is leaking. This website is written as a readthrough technical assistance guide for locating leaks. When you believe you have identified where the pool is leaking you need to go to our sister website to see pictures and learn more about the actual swimming pool leak repair process.