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How To Pressure Test PEX Water Lines? [A Complete Manual]

PEX pipes are being widely used these days, especially for bathroom water lines. Pressure testing is necessary to ensure the safety of your water lines. If you want error-free water flow in your house, you must run a pressure test.

How to pressure test PEX water lines?

You need a water pressure gauge to do that. Attach the water pressure gauge to the pipeline and turn on the tap. Take the static water pressure measurement. Then take the reading of the flow rate. These measurements determine whether your pipeline has any issues or not. 

This is a small briefing of the pressure testing process. We have prepared a detailed discussion on testing PEX water lines.

Let’s jump into the next segment for more information!

Pressure Testing PEX Water Lines: 4 Simple Steps

Pressure testing pipelines with water is also known as Hydrostatic testing. It is the safest way of pressure testing PEX water lines. 

You have to conduct at least three pressure tests for an accurate reading. Each test has to be run with the same time durations and intervals. We have a formed guideline to get you through today.

Needed Tools

Before going into the steps, you have to collect these necessary tools. Here’s the list of the things you need to conduct the test-

  • Pressure gauge
  • Measuring container
  • Stopwatch

Now that we have the products, let’s go through the steps:

How To Pressure Test PEX Water Lines? [A Complete Manual] 1

Step 1: Turn off the Taps of Your House

First and foremost, turn all the taps off. Make sure there’s no running water coming from any appliances. Don’t forget to check the taps of your bathroom. If you have a leaky shower, fix it before running the test.

This is important for taking accurate measurements. Remember, an inaccurate pressure test can put you in a hazardous situation.

Step 2: Connect the Pressure Gauge With the Tap

A pressure gauge steps in when it’s time to measure the pressure and flow of fluids. You must have a water pressure gauge to run a pressure test in water lines.

We have a list of top-notch water pressure gauges for you. Take a look at them-

Product 1
Product 2

These are the best water pressure gauges out there. As they are sturdy and enduring, you can use them carefree. The pressure gauge comes with a hose with threaded fitting. 

First, attach the water pressure gauge with the tap spigot you want to test. Turn it on after you are done attaching the hose pipe to the tap.

Step 3: Check the Static Water Pressure 

After turning on the tap, let the water flow at full force. The needle of the gauge will start to move.

The reading should show 40-60 PSI (pressure per square inch). This means the needle will stay within the 40-60 number range. This is standard pressure for your PEX pipelines. 

Step 4: Check the Flow Rate

Now take a large measuring bucket that is marked with weight numbers. Let the water run at maximum speed. Note down how long the bucket takes to get completely filled. 

Find out the flow rate using a simple formula. Just divide the amount of water by bucket filling time to get your answer.

Suppose you have a 6-gallon bucket and it took 1 minute to fill the bucket. And your static pressure reading was 50 PSI. It means the flow rate is 6GPM (gallon per minute), at 50 PSI. The ideal water flow rate for any house is 6-12 GPM. 

Now you know how to take the reading of flow rate and water pressure. You must know what to do if the test result is not ideal. Let’s take a look- 

What to Do If the Pressure Test Readings are Not Ideal?

The test results can be different from the ideal result. Like- low static pressure, high static pressure, and irregular flow rate. After identifying the problems, you should fix them immediately.

Each of these readings indicates different problems. And they have different solutions.

Result 1: Low Static Pressure Reading

If the static reading is below 30 PSI, it indicates issues in the water pump. A water pump is usually used to increase the water pressure in households. If the pump can’t produce enough pressure, the test shows low readings. 


You have to install a new highly efficient pump to fix the issue. If there is any leak, block, or crack in the pipe, take help from a professional plumber.

Result 2: High Static Pressure Reading

If the pressure is higher than 30-80PSI, it indicates irregular water pressure in the pipes. Irregular water pressure can damage your household appliances.


To fix the irregular water pressure, use a pressure regulator. A regulator controls and regulates the water pressure in the pipelines. The extra pressure of water can’t damage any appliances.

Result 3: Irregular Water Flow Rate

If the water flow rate is higher or lower than 6-12 GPM, it indicates irregular water flow. It means, there’s something overlooked in your water hammer arrestor. Water hammer arrestor controls the flow of water in pipelines.


Check if your water hammer arrestor is damaged. If it’s gone bad, grab a new arrestor to replace it.

That’s all you needed to know about pressure testing PEX pipelines. Now you’ll understand the reading and take proper measurements.


Question: Can we run an air pressure test in PEX water lines?

Answer: No, you cannot run an air pressure test in PEX water lines. Air pressure test is a very risky process. It can burst the pipes and cause a huge accident. 

Question: Is PEX pipe good for water lines?

Answer: PEX pipes work for carrying both hot and cold water. They don’t get rusty like metal pipes. PEX pipes are good for water lines.

Question: What is the maximum pressure for PEX pipes?

Answer: A PEX pipe can handle up to 160 PSI water. But the water pressure shouldn’t be more than 100PSI to avoid damage.

Final Words

Now you know everything about how to pressure test PEX water lines. Hopefully, you won’t face any problems in running the test now.

Make sure to take proper actions if your readings aren’t usual.

Till then, take care and have a wonderful day!