If you're losing more than a quarter-inch of water from your pool each day, you could have a dreaded leak on your hands. Finding a leak in your pool can take some trial and error, and while leaks in your return and suction lines are rare, there are ways to locate a leak without excavation. Let's walk through how to find a leak in inground pool piping and, if necessary, perform a pipe pressure test.
Preparing to Find a Leak in Your Pool Piping
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A leak can occur in all areas of your pool, so it's important to know the signs and narrow down its source before you go playing with the pipes. Begin with a visual inspection of your pool. At this stage, there’s no need to drain your pool to find a leak. In fact, the pool water will help you find the leak and prevent further damage.
Pop on your suit and your goggles and inspect these common areas for pool leakage:
Pool liner
Joints around the steps
Connection around your skimmer or return drain
Pool floor and wall tiles
If you suspect a leak in any of these areas, purchase a pool leak-finding dye to trace the direction of your pool water around these areas.
Afterward, you should also inspect your pool's mechanical area around the pump, heater, and filter for obvious leaks. You can also inspect the ground above your pool plumbing for marshy patches of grass or puddles.
Get to Know Your Pool Piping
Further investigate your pool piping by researching your system and unique pool design. If you don't have the original plans or if you're unfamiliar with the set of pipes around your pump and skimmer, speak with a local pool service pro before starting.
Your inground pool has two sets of pipes: the suction—or skimmer—lines and the return lines. The suction lines include the skimmer and main drain pipes. They take water out of your pool, send it up through your heater and filter, and send it back through the return lines into your pool.
Consider a Pressure Testing Kit
There are two levels to our instructions below. You can perform a very simple test by plugging the return lines or the skimmer lines to determine that the leak is indeed coming from somewhere in your pool pipes.
But if you need to pinpoint a leak in your pool plumbing, you'll need to construct, rent, or buy a pressure testing kit. These kits typically start around $200 but are incredibly helpful when narrowing down the pipe with the leak. The kit often includes:
Closed rubber plugs with tightening wingnuts
Open rubber plugs with quick-connect valve
Expandable rubber plugs for hard-to-reach pipes
A pressure tester manifold
You will also need a garden hose to connect to the manifold. When hooked together, this allows you to send pressurized water into an isolated pipe to test for a leak. But, let's not get ahead of ourselves.
Turn off the Circulation System
Always begin by turning off your pool's circulation system at the pump. You do not want water moving actively through the pipes as you test the pressure or plug on one part of the system. For extra safety, turn off the breaker connected to your pool as well. Doing so cuts the power to your lights and circulatory system to cut down on the risk of shock as you access pipes.
Narrow Down the Leak
In some cases, you may choose to do this step and then stop to call your local pool service team. That is fine—this simple test can alert your contractors of the general location of the leak.
First, turn off your pool's system and the power source. Mark the waterline of your pool with a piece of waterproof tape. Using a fitted plug from the hardware store, plug up the hole at the base of each of your skimmers and close the main drain of your pool. Wait 24 hours and check if your pool is still leaking. If not, then you likely have a leak in your skimmer or suction line system.
If the pool still leaks, remove the plugs and move them to the return lines. Once again, wait 24 hours and check the water level.
While this test may determine whether or not you have a leak somewhere in your plumbing, it is not as thorough as a pressure test.
Plug the Return Lines
Always begin by reading the instructions provided with your pool pressure test. Every kit is slightly different, so be sure to follow the order exactly to avoid damaging your pool plumbing further.
And remember: turn off your pool circulatory system if you haven't already.
If you've already removed them from your last test, you'll need to plug the return lines around your pool. Remember that you can use the wing nuts on the plugs in your kit to get a strong fit.
Plug the Suction Lines
Remove the gasket of your skimmers and plug the opening of the drain at the bottom of it with a plug. The expandable plugs are helpful in this case since the skimmer can be quite deep. If they are still open, plug or close the drain lines at the bottom of the pool as well.
Test the Skimmer Line
Take a look at your user manual and head over to your pool pump area. Close the valves on your return lines but keep the skimmer line open. Open the lid of the pump to access the opening of the pipe to your suction line. Insert an open-stemmed plug into the line until it's secure. Make sure the quick-fit valve faces toward you. Attach the provided hose to the other end of the manifold and then to the quick-fit valve in the pump.
Next, attach your garden hose to the pressure manifold according to the manual and turn on your spigot. Slowly turn the valve on your pressure manifold to allow water pressure to build up inside the manifold.
Never send more pressure into your system than what it uses on a daily basis. If your pipes typically use 15 to 20 PSI, never go higher than this when testing.
Once you've sent the proper amount of pressure into the pipe, close the valve and watch the meter. If the water maintains pressure, the pipe likely does not have a leak.
If there is a leak, the pressure will drop quickly.
Test the Return Lines
The pipe coupling leading to your pool heater is often the best place to access your return line for a pressure test. You will go through the same process of testing your return lines with the instructions above, but this time, you'll use the pipe leading into the heater. Check your pool design instructions to find a similar location if you don't have a heater.
Insert an open-stemmed plug into the top of the pipe. On the other end, attach the garden hose to your manifold and flip on the water. Set your pressure valve to the same PSI as your pipes and send the water into your return lines. Yet again, wait to see if the water pressure diminishes on the meter.
At this point, you should be able to pinpoint which pipe has a leak in your system. If it was in your pipes, give your pool repair team a call. If not, then it's time to look for the source of the leak elsewhere in your pool system—local pool repair pros can help narrow it down.
DIY vs. Hiring a Pool Professional
The cost of leak detection by a pool pro costs between $100 and $500 and is one of the most common pool repair costs to include in your long-term budget. If you have access to a pool pressure test or buy one to check for ongoing problems, you could save several hundred dollars on labor, but the kit will set you back about $200.
However, keep in mind that a professional will still need to use specialized equipment to locate the exact spot of the leak in your pipes—often with listening equipment and air pressure tests.
While you can test your pipes to cut a few steps out of the leak search, a professional can help you save time and energy on this lengthy process.
Frequently Asked Questions
Yes, there are ways to fix some pool pipe leaks without digging a trench. In some cases, pool professionals use a specific polymer-based solution to travel through a pipe and plug up a leak. In other cases, they can use specialized cameras to refit the damaged area with new piping. Not only are these approaches less intrusive to your home, but they also cut down on the cost of your pool repairs overall.
Pool leaks most commonly occur around the joints of your pool, such as around the skimmer, return line entrance, main drain, or the lining of the floor tile. Tears are also common in vinyl liners between five and 20 years after installation. While leaks in pool piping are common, it does happen, and so they should be tested after you've ruled out other possibilities.
