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Pressure Test Water Lines — Restore Water and Check for Leaks

Beginner3 hours

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How to Install a Water Hammer Arrestor to Stop Banging Pipes · Step 5 of 5

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In this video

After all water lines are run and the fixture stub-outs are capped, the final step before inspection is to test for leaks. Go to the main supply valves and slowly open them to allow water to fill and pressurize the new pipes. Once the system is under full pressure, meticulously inspect every single connection, joint, and fitting with a flashlight. Look and feel for any signs of moisture or dripping. Leave the system pressurized for an extended period to check for slow leaks.

Goal: Plumbing System Inspection

  • Wipe all fittings with a dry paper towel before pressurizing. Any moisture will be much easier to spot on the dry surface.

Used in this video

  • Flashlight (Tool Type: Hand Tools, Power Source: Battery)Visually inspecting fittings and joints for moisture in dimly lit areas.
  • Pressure Gauge (Tool Type: Testing equipment) · optionalAttaching to a hose bib or stub-out to verify the water pressure in the system and monitor for pressure drops, which indicate a leak.
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FAQs

How do I accurately identify the source of water hammer before installing the arrestor?

Listen carefully for the banging sound when a specific faucet, toilet, or appliance (like a washing machine) shuts off abruptly. You can also try gently touching the water lines near suspect fixtures to feel for vibrations when the noise occurs. Installing the arrestor as close as possible to the identified source will yield the best results.

What crucial safety steps must I take before cutting into the water line?

Always turn off the main water supply to your entire home first. Then, open the lowest faucet in your house (e.g., in a basement or outdoor spigot) and the highest faucet to completely drain the water from the pipes. This prevents unexpected water leaks and potential injury while you work.

Do I need special tools to cut copper pipes, and how do I ensure a leak-free connection?

Yes, a copper pipe tubing cutter (e.g., AUTOCUT 1/2 in.) is essential for a clean, straight cut. After cutting, use a reamer and deburring tool (like the Husky 1-5/8 in.) to smooth the pipe's interior and exterior edges. This deburring step is critical for proper sealing and preventing leaks, especially with push-to-connect fittings.

What's the best way to prevent leaks when installing the tee fitting and water hammer arrestor?

Ensure the pipe ends are perfectly clean, smooth, and free of scratches or burrs. Use a depth gauge (like the Tectite Depth Gauge) to mark the correct insertion depth on the pipe for push-to-connect fittings, ensuring it's fully seated. For the arrestor's threaded connection, apply several wraps of PTFE plumber's tape (Harvey 1/2 in. x 260 in.) clockwise to the male threads before tightening.