Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Air Pressure Test

1887House
1887House Member Posts: 3
in THE MAIN WALL
Greetings:
I'm adding a radiator circuit to my system. It's 1/2 inch PEX feeding 3 cast iron baseboards. There are 6 ground joint unions attaching the radiators. When I pressured the circuit up to 30 PSI, it dropped 2-3 pounds over 4 days. I am assuming ZERO drop is the result I'm looking for. I have ball valves I close after pressurization. Any helpful hints would be greatly appreciated. Do I need to hose down the unions with leak detector bubbles?

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 24,126
    Air tests are very unreliable (as well as dangerous). Now that you have done that, though, and find you have no catastrophic leaks, do it again with water. Pressurize it to 20 psi or so, close it off from the rest of the system, and watch it for an hour or two. No drop? Good to go.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,092
    Yeah, put water to it. the air test proved there are probably no big leaks
  • JUGHNE
    JUGHNE Member Posts: 11,204
    Not full house pressure, as said 20 PSI is plenty.
    Your boiler relief valve will only allow 30 max.....20 may be normal operating pressure.
    It is just that water is thicker than air and probably not leak after your first test results.
  • mattmia2
    mattmia2 Member Posts: 10,368
    You could leave the air for a couple days and see if it continues to fall. It can vary a bit with temp but if it keeps falling and never goes back up it is a leak. I had a really tiny leak in a propex fitting that I saw a very slow decrease in air pressure but I was able to see a bead of water once I added water to the system(I used a funnel and a bucket then used air to pressurize it, not the ideal method).

Categories