# How to test new plumbing work for leaks



## Gusaroo (Mar 6, 2008)

I am just about to run a second loop of baseboard heat in a small addition on my home, I plan to have a licensed plumber do the actual connection to my boiler, but I plan to do most of the grunt work of installing the radiators myself to keep down costs. I have done quite a bit of basic plumbing and feel that this is within my capabilities. But for peace of mind, Id like to be able to test my work.

How can I test my work prior to connecting this new loop? Is there a cheap all in one "pressure test" kit I can purchase to test the circuit for leaks? Whats the process for doing this? I am assuming I would some how cap one end, install some sort of gauge on the other end, pressurize the system with air, then watch the gauge for movement. I am just wondering how the pros would do this, if they had to...

Thx guys.


----------



## fireguy (May 3, 2007)

Pressure testing is fairly simple if you have the equipment. Hook your pressure testing pump to a water supply, then the outlet of the pump connects to the pipe you want to test. Pipe and fittings are normally rate at 175 PSI working pressure. On sprinkler systems we test to 350 PSI for a length of time. If no leaks develop and the system holds pressure, everything passes. My electric pressure test pump cost about $800.00. we use it onece or twice a year. You can buy a manual pump for $150.00. It would be cheaper to hire someone to pressure test your work. You cannot use air. It is dangerous to use air to pressure test. Should a pipe or fitting break under water pressure, it leaks quickly. If a pipe or fitting breaks under air pressure, an explosion results. Ever seen a pipe freeze? The fitting breaks, but not with great force. A plastic pipe shatters when frozen. Besides, when pressure testing with water, you just look for the wet spots. 

The only time I have seen air used to leak test is on gas lines, and then only to 60 PSI max. Normally the pressure used is 10-15 #.


----------



## Bob Mariani (Dec 1, 2008)

I have seen pressure test using air all the time. Water is not turned on in a new building until inspections, Which require the pressure test with air letting it sit overnight to show the system is still holding air.


----------



## Termite (Apr 13, 2008)

Water testing is not commonly done in residential plumbing work, and might be a bit of a challenge for most DIYers. I'd air test.

Any plumbing supply house will sell you a pressure dial gauge that screws onto 1/2" pipe threads (less than $20). Shut off all the shutoff valves and install the gauge somewhere in the system. You can use reducers or bushings as necessary to install it. It has a shraeder valve just like your tires do, so you simply use an air compressor to pressurize the system. 

The code requires that residential systems be air tested to at least 50psi. If you have 75psi water pressure, it makes sense to test to 80 or 90psi. I wouldn't advocate going too much higher in a residential system. Pump the system up and take note of exactly where the gauge needle is at. Give it a couple hours and see if it drops even the slightest amount. If it does, check for leaks using soapy water at each fitting. 

Remember that substantial changes in temperature will change the pressure inside the pipe. So if it is 60 degrees when you pump it up, a 30 degree temperature drop will change the reading on the gauge at least a couple psi. 

Remove the gauge and cap the line when you're done.


----------



## daveshark (Jul 9, 2012)

*Not working for mE*

Any plumbing supply house will sell you a pressure dial gauge that screws onto 1/2" pipe threads (less than $20). Shut off all the shutoff valves and install the gauge somewhere in the system. You can use reducers or bushings as necessary to install it. It has a shraeder valve just like your tires do, so you simply use an air compressor to pressurize the system.

I bought a pressure gauge and first tested an outside line that has water hose bibs for the yard and it pumped up to 50psi and it held then I opened the valve going to the whole house(the house is off grade) and I can't get the needle to move off zero. Evidently I have a leak as fast as I pump air in. How long should it take for the house to pump up? Its only a 1200 squ. ft. home with 2 bathrooms. and I'm using an air compressor to pump it. Its takes two people one to hold the air nozzle on the shrider valve and one to look for leaks and the one holding the air nozzle get tried after a while.
I open valves on the inside where the washer goes and can hear air on the hot and cold side but not very strong. Its not working out very good any suggestions?


----------



## fireguy (May 3, 2007)

If if is glued plastic, you may have a joint that is not glued, and has popped off. Or an open valve. I do not know what size compressor you have, we can fill most dry sprinkler system in less than 30 minutes with our compressors. http://www.dewalt.com/tools/compressors-wheeled-portable---electric-d55146.aspx

Recently I filled a system w/air in less than 30 minutes, 100 feet + of 4", 200 feet + of 2.5" , 300 feet + of 1" and some I did not bother to measure. It may worth renting a larger compressor than what you have. 

Automotive parts houses will have a Schrader valve equiped with a hold-on-device. 

When you turn on the compessor, do not connect it to the piping until the compressor shuts off. Then unplug the compressor power cord and plug the air hose onto your pipe. Sometimes the compressor is so noisy, you cannot hear small leaks. Sometimes, you can hear leaks by using an automotive stethascope. Never worked for me, but some claim it works. 

You can also use peppermint oil. Put some in the open pipe, connect your comppressor and smell your way around the piping. But, it takes at least 2 people for that test. The person putting the oil in the pipe takes the oil outside and stays outside until the test is done. You need a couple of people to smell the piping. Again, this is a test that has not worked for me.


----------

