How to Pressure-Test Plumbing | Hunker
Step 3. Watch the gauge for 15 minutes. If it moves, there's a leak in a pipe or in a faucet. Check the faucets, and if none of them are dripping, the leak is in a pipe. Tip. If you don't want the pressure-test to include the faucets or toilet fill valves, turn off the shutoff valves for these fixtures. Plumbers often use smoke to test existing ...