Testing Plumbing with a Compressor?

I was just wondering if anyone had ideas about this one.

I will be inspecting a vacant house in a few days. I have been advised that there is a leak at the main water shut off for the house. The bank holding the property has given the buyer a credit to replace the main shut off valve?

The realtor asked if I test the water with a compressor. Does anyone perform a plumbing inspection with a compressor. The times I see a situation like this, if the leak is severe enough, I will disclose the leak and that the plumbing could not be fully inspected and tested at the time of the inspection.

Thanks in advance



Before a plumber walks away from a job, he tests it with a compressor, presumably.

Unless you intend to replace a line when it blows under pressure, you will not be conducting such a test as the plumber would conduct.

Stick to your SOP.

James is right. That is the plumbers job, and you would be stepping out of your area to do this. Then if there are problems, the bank will look at you to be responsible, since you pressurized it.

Unless you are a licensed plumber, you would not only be exposing yourself to unreasonable liability as a Home Inspector, you would likely be violating your state’s plumbing license requirements. Offer to schedule or refer them to a plumber who can perform that specific test while you are doing the home inspection.

It would be like when you winterize a house, you presssurize the system to blow out the lines. In theory a pressure check is no different, just use about 35 psi. Pressurize the system to about 35psi, continue with inspection, check pressure guage on compressor preiodically, and so forth. Not much added liability…and if it fails, just state it failed under testing…the bank already recognized at least one leak, chances are there are more.

Good luck.

No it’s not.

It’s not even close.

Blowing water out of an open line is NOT a pressure check, for crying out loud.

Where are these people coming from??? OMG!!!

On one thread, a brand new inspector wants to know how we think about his “new” idea of writing soft reports for sellers so that RE salesmen call him more often. The next thread is a real estate salesman wanting to take a home inspection licensing test, but has never heard of the plumbing term “air gap” and wants someone to explain. Here, we have someone considering assuming the liability of pressurizing a plumbing system…and someone else equating it to blowing out a line.

The economy is bad and people need work…but home inspecting is not the place to learn the basics. I’m sorry … but someone has to say this.

Come on Jim, are you kidding me!!! If you have every winterized a house then you know that when you are done you perform a pressure check of the system…at say, uh, 35psi give or take, for 15 minutes. It is a verification that there are no leaks in the system.

However Jim, I will agree on one point you make, pressurizing a plumbing system is not home inspection related work and can get an inspector in trouble if not done properly. But it certainly is one way to check a system for potential leaks.

If you’re certified you’re good to go. Pressurizing the plumbing system with an air compressor is creating an air gap,… isn’t it??? I think I’m ready for the test. Do you think I’m ready for the ICC test??

Putting an unused system under a pressure test really doesn’t tell you anything. You can almost count on some of the plumbing seals drying out and failing. Therefore the vacant system isn’t going to hold pressure anyway. Is it a leak, is it a busted pipe, is it a broken seal? Who knows. Once you get to this point are you then going to get out the stethoscope and try to identify and isolate the leaking location? I don’t think so. Not to mention the fact that a pressure test does nothing to check the waste system.

I’ve considered this very thing, and don’t see how it adds enough value to be a marketable service (if done ethically, which in my opinion is the only way.)

Of course if you wanted to, you could charge an extra $100.00 hook up the compressor, and add a canned comment to your report that the system doesn’t hold pressure, and needs to have a plumber evaluate the whole system.

Personally, I just skip the pressure test, skip the charge, and put my canned comment of the possibilities in the report for free.

35 psi?

I’ve never seen it recommended over 20 psi and in some cases, only 5 psi. If there is a leak, the pressure will not hold no matter how much you are putting in. This is part of maintaining a plumbing system…not conducting a home inspection.

It is a crazy thing to do unless you charge enough extra for the test to pay for your repairs. If you are conducting this test as part of a home inspection, odds are almost perfect that your insurance carrier will not cover your damages.

To be clear…for anyone who might not know this…it is okay to say “no” to a real estate salesman.

“and while you are there, would you mind mowing the grass and doing a little weeding?”

That btw isn’t a joke. Years ago we got asked if we would be interested in doing these small petty types of things.

Now, not to pee on anyone’s parade but when I took Residential plumbing, we did do pressure checks but it was done with only a few lbs of pressure and had to remain overnight, not 15 mins. It isn’t going to tell you where the leaks are so it is pretty much a waste of time. That is only one test as we would later test the system with water on it, before drywall goes up. The pressure test was done at the end of the rough in, all the supply lines were capped, making it a closed system. Later when the fixtures were to be installed the caps would be cut off and stop valves, etc. would be installed. Trying to determine if a system has leaks after it has been completely built is a waste of time. The leaks could be inside walls or in the attic or slab, etc. etc. etc.
As stated, most faucets are going to leak air so how are you going to determine if there are legitimate leaks or just air escaping through old and or dried out gaskets, washers and stem valves. Might impress the client and fool them into thinking you are a real whiz but not accomplishing a damn thing.

Well Jonathan, there you have it. Several opinions on the matter.

I guess my take on it is if it is impossible to have the water turned on for the inspection then doing a pressure check is still a viable option. And that is strictly my opinion and nothing else.

I personally agree with most of the comments here. As a Home Inspector do the HI leave the blow job to the pro’s who get paid to do blow jobs.

You mean THIS GROUP? :wink:

It can be done. Your right Dave, however, we are not licensed plumbers and our SOP does not cover pressure checks. No water, no inspection for leaks it’s that simple. Also ideally, if you decide to test you should test water supply and DWV (drainage, waste and vent) pipes when the entire system is installed, but nothing is covered by drywall or otherwise inaccessible. If you do a pressure check you better have in your report that not all areas could be tested.

I find the best way to test plumbing systems is to cross connect with the gas lines.
You can then use your lighter to check for where all the leaks are.

Not dissimilar from my liquid gas in the drain line clean out method.
Not only does it burn out the clogs ,but it helps you find where all the waste stacks are.:slight_smile:

Thank you everyone for the feedback. This is honestly the first time I have ever been asked this, so I just wanted to make sure I covered myself. I will be looking for evidence of water damage in the property and disclose the leak and the limitations to the inspection.

Thank you all again for this very informative thread.