Proper Ways to Pressure-Test Your Plumbing

Plumbing system is one of the most important parts of your house, although it is largely out of sight. That very fact means that you won’t know that something is wrong until it’s too late and once the signs of malfunction show up, consequences may already be severe. Pressure-testing your plumbing system is one of the most efficient ways of inspecting if there are leaks in new installation or Drain/Waste/Vent (DWV) system. There are two ways to convey this test – by using water and the air – and here, we will cover both of them and give you a short guide how to perform them properly.

How to Air-Test New Plumbing

1: Preparing the Caps

For the start, you should cap all of the stub-outs that are connected to a system you are testing. If you are working with DWV system that would mean gluing caps to every stub-out with plastic pipe and if the water system is being tested you may even have to solder caps, depending of what kind of pipes you have. After the test is complete you can easily cut them off.

2: Preparing the Hose and Gauge

You should find appropriate fitting, or install the new one if there is none, to connect pressure gauge and compressor hose to the system. If you are testing water system, you will have to leave one stub-out without cap and later install adapter for the gauge and hose and the tee on that very stub-out, while the waste testing will demand of you to screw an adapter to clean-out fitting in order to install a tee.

3: Proceeding to Test

Now is the time to turn on the air compressor and continue to fill the pipes with air all the way to the point where gauge reaches test pressure reading. If you are testing water system, that reading should be 80 psi. With drain systems it is considerably lower, only the 5 psi. After achieving these numbers you should turn off the compressor and leave the whole system for about 15 minutes. If you don’t detect pressure reduction over that period you are not facing any kind of leak.

How to Air-Test Existing Plumbing

1: Draining the Water

In a recent chat with the people from Force Plumbing and Heating, we found out that air-testing is generally more suited for new plumbing, while water-testing is more preferable method for existing one, so we have to point this out first. If you want to proceed with air-testing, first thing you should do is to shutoff valve, drain all the water from the system and after doing that turn off all faucets.

2: Air-Testing Properly

You will have to screw pressure gauge and this time you will use one of the faucets, preferably the one in laundry room or even some threaded faucet outside the house. Adapter that will allow you to connect a compression hose should be attached to another faucet. The very process of testing is largely the same like in the previous example but desired reading should be around 60 psi. If the pressure remains stable after 15 minutes you are good to go.

How to Water-Test Existing Plumbing

This beast is much easier to handle because there is no need for draining. You just have to find some laundry or outdoor faucet on which you will attach pressure gauge, like you would do with air-testing and double check if all other faucets are closed. Screw gauge to the spout, open the faucet and then turn off main shutoff valve. If you notice movement in the gauge during next 15 minutes you are facing a leaking pipe.

As you can see pressure-testing is not that complicated but it can be very beneficial. You know how they say, better safe than sorry. Check your pipes, be sure that everything is all right and proceed with your life without any doubts.

Image credit: Plumbing by Russ Morris, on Flickr