Hello,

I have a pool pipe that goes from my skimmer to pump. It sprang a leak. The pipe was copper about 1.25 inch diameter. The pool company cut off the pipe at the leak (around 1 foot from pump) and fit on a larger diameter PVC pipe with some type of transition coupler over the copper pipe. Now I have a constant supply of air in the line, could this be cavitation cuased by the larger diameter pipe or would this cause some other type of pressure change that cuases less water to be sucked into the pipe. <b> Thanks </b> Would the problem be fixed if I have a constant diameter of pipe ?

Bob, there should never be a time when air is introduced to a closed water line. The coupling they put on most likely hasn't been 100% sealed. If you haven't noticed a drop in your water level then it might not be a big deal. Copper to pvc is a tricky situation, espically on older pools. I wish there was better news than this but reducing pipe doesn't cause any change as far as air is concernced. If your water level is high enough for the skimmer to operate properly, then there is still an incorrect seal in the skimmer line to the pump

All in all it might not be enough to notice a drop in water level and if you can live with it, then no one will be none the wiser. If you can however get the pool company to fix the situation, that would be your safest bet.

Hope that helps,
Pool plumber in cape coral, fl

It sounds like you may have air being sucked into the system where the new coupler was added. I would suggest adding silicon around the joints on both ends of the coupler. This will not look very good but it may seal off a small leak. If this ends up being the case you will then know where the leak is and can attempted fixing the pipe again.

I am wondering if what they put on was a CPVC union. They are cream colored and have ends that screw on compressing a rubber sleeve. An easy fix of a short bad spot. If so, I would unscrew the ends and check the rubber sleeve. If it is damaged, I am not sure you can buy replacements. But, you can likely buy a whole new coupling for $3 most places that sell pipe fittings. If the rubber sleeves look OK, it could just be needing to tighten the ends up better. If it is some other style of fitting, maybe the silicone is the best idea. If you can't get it fixed yourself, perhaps call a real plumber.

A leak on the suction side of a pump, will allow air to be sucked in reducing the water pumped, damage the pump by cavatation, but not lose much water. The pipe diameter has nothing to do with the problem.

Firstly I have to say after 15 years experience in fixing hot tub, jacuzzi and pool leaks, by pasting silicone on the outside of a pipe to seal a leak will never fix it! It will stop it for a while until water penetrates through. All leaks have to be sealed from the inside if done properly. On a suction line the pipe will not leak when pump is running, it will suck air and only leak when pump is turned off and only minimal drips. I would suggest you get a plumber to weld a fitting onto the copper pipe that has a 1.25"thread on one end so it can be properly adapted to pvc fittings and the into your pump.

If this were my swimming pool I would insist that the copper pipe is removed completely. Why would you leave one foot of pipe that you know to be a weak link in your system? It can be difficult to replace the connection at the skimmer depending on if your skimmer is brass or ABS/PVC and also how the original connection was made. That being said, this is a do-able job and a much better solution than leaving a section of pipe that will almost certainly fail in the future... if not right away.

Air being pulled into the suction line will leak water minimally when the circulation system is on, and more so when the system is shut off. Silicone will not fix this problem, even a two part waterproof epoxy will eventually fail.

The leak in the line will be most apparent when you are trying to prime your pump after it has been shut down. It will be difficult or impossible to prime if the pump location is higher than the water level in your pool.

I hope this information is helpful.

Steve Goodale
Serendipity Pools