How Do I Pressure Test My Pool Lines?

by | Nov 19, 2023 | Pool Care

A pool is a wonderful addition to your home. And like your house, a pool requires a certain amount of maintenance. Regular pool maintenance and repairs can easily taken care of by our professional technicians at Lone Star Pool Services. However, there are some tests that you can do on your own for pool line maintenance. This article is our way of helping you keep your pool in good working condition.

Plumbing systems are a constant source for water loss for many reasons ranging from pipe material, installation quality, age, configuration and soil conditions. It is important to first to determine where the leak is originating from. Is it in the plumbing system, or in the structure of the pool itself?

Begin by checking the water levels daily. Mark the water level of the pool at the skimmer. Use a piece of tape or grease pencil to mark the water level. Check the mark 24 hours later. Your pool should lose no more than 1⁄4 inch (0.6 cm) per day. If it is losing more water, then you have a leak.

If you are losing water, look at the filter, pump, heater and the pipe valves.  Find out if there are wet areas around the pool.  Check the ground for dampness. Walk around the pool and the equipment. Check for wet soil and sunken or eroding areas. If you have a vinyl liner, look for tears or separations around all the fittings, skimmers, returns, cleaner line, lights, steps and the corners.

If you do not see any problems by checking the above items, it is time to pressure test your pool lines.  We will walk you through the process step by step.

Tools to Test Pool Line Pressure

The first step is having a pressure testing stick or kit. You can find a stick or kit at your local Lowe’s, pool supply company or Amazon. Depending on what the stick or kit is designed to test, it can run you between $60.00-$250.00. You also build a pressure stick from PVC pipe and a few other items found at a local hardware store. You may need to also purchase a high pressure gas cylinder.

Pool Line Maintenance and Set Up Procedures

Turn off pump and heater (if you have one) before completing any pressure test. Identify all openings of the section of plumbing you will be testing. Complete pressure testing of plumbing systems involves a two-step process.

You will use an Open Stem Plug with a quick connect attachment. This will allow the hook-up to your Pressure Tester. It should be inserted into the highest opening of the system you will be testing. This will generally be an opening at the equipment such as the inlet of the pump or at the coupling after the heater.

Next, affix the Pressure Tester to this open plug. Ensure that the male quick connect fitting screwed to the top, using the female quick connect fitting on the end of the five-foot length of hose. Once that is connected, attach a garden hose and airline to the appropriate connections on the Pressure Tester.

The remaining openings of the plumbing system must be plugged with the appropriately sized plug. There are different sizes and types of plugs. Size wise, plugs are available in 1/16” to 1/8” increments to provide complete coverage of all fittings and pipe sizes.

Water Test

A water test is performed in order to isolate the section of plumbing that is leaking. The initial test of the line should be done with water.

  1. Assure that the valve handle on the Pressure Tester is in the straight up, or straight down “closed” position then turn on the water at the spigot.
  2. To introduce water into the plugged plumbing system, slowly turn valve handle on the Pressure Tester toward the water connection. You will be able to control the amount of water entering the system by moving the handle. Since the pressure gauge will show an inaccurate reading as water is flowing, occasionally turn the valve handle to the closed position to check system pressure
  3. Once you have reached 20 psi turn the valve handle to the off position and watch the pressure gauge. A leak and will be indicated by an easily detectable drop in pressure within minutes. Most problem leaks will drop all the way to 0 psi.
  4. If the line initially shows a drop in pressure that stabilizes above 0 there may not be a leak in the line but instead the line pressure is equalizing as air and water move within it.
  5. Add more water to see if you can increase this stabilized pressure. If you can, and if this stabilized pressure holds, a leak is unlikely. If the line holds pressure, there is not a leak. Release any pressure from the line by opening the bleeder valve after this test is complete.

Once the water test is complete and no leak has been found, you can move onto the next test for pool line maintenance.

Air Test

  1. An air test is used to identify underground plumbing leaks. The air escaping from a leak into water saturated soil creates a “bubbling and gurgling” sound that is easy to hear with the proper device such as a high-pressure gas cylinder (nitrogen or SCUBA tank) with a single stage pressure regulator.
  2. Adjust the regulator on your air source to maintain a constant pressure of 10 -15 psi.
  3. Allow air into the plumbing system by turning the valve handle on your pressure tester toward the airline and leave it open. You must maintain a constant flow of air into the line and out of the leak.
  4. Walk along the path where the lines are buried. Stop at two foot intervals along the path and you should be able to hear sounds caused by the air escaping from the leak into the water saturated soil.
  5. The leak will usually be directly beneath the point where the noise is the loudest and most distinct.

If your pool doesn’t pass the tests or is in need of pool line maintenance then call the professionals.