Quick Answer:

When lines are opened for repair, air can get into the piping and cause every fixture to spit, surge, or run unevenly. Start by removing aerators, open the highest faucet to bleed air out, then purge the lowest tap until water runs steady. Work methodically from top to bottom and test each fixture before replacing aerators.

Why This Happens

Opening pipes or replacing a section introduces pockets of air into the water lines. Those pockets collect in high points or behind partially closed valves. When water is turned on, the trapped air moves unpredictably and causes sputtering, surging, or loud banging. If valves were replaced or worked on, you may also experience pressure shifts related to that work — Pressure problems after valve replacement. Small air pockets often settle in branch lines or at fixtures and need active purging to clear.

Step-by-Step What to Do

1. Prepare

• Have a bucket and towels ready for splashes and drips.
• Turn off appliances that could be damaged by sudden pressure changes (washing machine, dishwasher).

2. Remove aerators and showerheads

• Unscrew aerators from faucets and remove showerheads if easy to do. This prevents spitting water, removes debris, and allows air to escape freely during flushing.

3. Bleed the highest faucet

• Go to the highest faucet in the house (often an upstairs sink) and open it fully. Leave it open. This gives the trapped air an exit point at the top of the system.

4. Purge the lowest tap

• Open the lowest tap in the house (basement laundry sink or lowest hose bib). Allow water to run until the flow becomes steady and free of air pockets. This pushes water up through the lines and forces air toward the highest open faucet.

5. Work through the house

• Close the lowest tap only after water runs steady. Then move to mid-level fixtures, one at a time, running them until the sputtering stops.
• Re-check upstairs fixtures last while keeping the highest faucet open; then close the highest faucet after all lower fixtures flow smoothly.

6. Reinstall aerators and test

• Replace aerators and showerheads, then test each fixture at normal and full flow to confirm steady pressure.
• If you notice unusual noises during testing, that can point to trapped air in a specific run or a problem requiring inspection — see notes on when to call a pro and the possible link to Noise began after plumbing work.

What Not to Do

• Don’t assume air will clear on its own.
• Do not use compressed air or equipment to force air into pipes — that can cause damage.
• Don’t work on hot-water fixtures while running cold-water purges; you could get scalded if valves switch unexpectedly.

When to Call a Professional

• If sputtering or surging continues after a full top-to-bottom purge.
• If you lose pressure on multiple fixtures or find a leak while purging.
• If you hear persistent banging, hammering, or other unusual noises that do not go away after flushing — or if the issue followed valve replacement and pressure remains unstable.

Safety Notes

• Be careful with hot water. Open cold taps first to avoid scalding when air pockets shift hot water unexpectedly.
• Watch for slippery floors from flushing; use towels and keep the area dry.
• If you need to work on fixtures above shoulder height, use a stable step stool and avoid overreaching.

Common Homeowner Questions

• Why did this start after the repair? Air entered the system when pipes were opened; it settles in high points and must be purged.
• How long will it take to clear? Usually minutes to an hour if you bleed the highest faucet and purge the lowest; stubborn pockets may take longer.
• Will this damage my plumbing? Air itself seldom damages pipes, but repeated pressure surges can stress fittings — purge promptly and call a pro if problems persist.