Quick Answer:
If one fixture sputters or has choppy flow after you replaced its shutoff valve, first confirm the new valve is fully open and the supply line isn’t kinked. Run the faucet slowly to purge trapped air. If the sputter stays limited to that fixture after purging, remove and inspect the aerator and the cartridge screens for air pockets or debris.
Why This Happens
When you open a new shutoff or angle-stop valve you can introduce a small amount of air into the short length of supply line to that fixture. Flexible supply lines can also trap a pocket of air if they were folded or kinked during installation. If only the fixture you worked on is affected, the problem is usually local — the valve, the short run of supply line, or the fixture’s aerator/cartridge. This is similar to issues covered in related topics like Air in washing machine supply lines and Hot water spits air first.
Step-by-Step What to Do
1. Confirm the shutoff is fully open
- Turn the new valve counterclockwise until it stops (for typical angle-stops). If it’s a quarter-turn ball valve, make sure the handle is parallel with the pipe.
- Don’t force it—feel for a firm stop so you know it’s all the way open.
2. Check the supply line for kinks
- Follow the supply line from the shutoff to the fixture. Flexible lines can fold or pinch where they bend.
- Straighten any sharp bends or replace a damaged/kinked line before proceeding.
3. Purge the line slowly
- Open the faucet slowly to a trickle and let it run for 30–60 seconds. This helps air travel out without creating a big splash or sudden pressure changes.
- Increase flow gradually until full stream, watching for sputter to stop.
4. Inspect aerator and cartridge screens
- Unscrew the aerator or water outlet and check for trapped air bubbles or debris. Rinse or soak parts and reassemble.
- If the fixture has a cartridge (single-handle faucets), remove the handle and cartridge screens and rinse them—air can sit behind these small screens.
5. Re-test and isolate the issue
- If the sputter is gone, the purge worked. If it remains only at that fixture, the aerator/cartridge or the short supply run is likely the cause.
- If multiple fixtures sputter after opening the valve, there may be wider air in the plumbing and you should purge the system more fully from other supply points.
What Not to Do
- Don’t keep redoing the shutoff install to “fix air.” Verify valve position and line kinks first, then check the aerator and cartridge screens.
- Don’t use compressed air or try to blow air into the pipes—you can damage fittings or create unsafe pressure spikes.
When to Call a Professional
- Air or sputtering continues after you’ve confirmed the valve is open, removed kinks, purged the line, and cleaned screens.
- You find a leaking or damaged shutoff, or the valve won’t operate smoothly or fully open/close.
- You’re unsure how to remove a cartridge or reassemble the faucet without causing leaks.
Safety Notes
- Have a towel and a small bucket handy when loosening fittings to catch water.
- If you decide to shut the water off at the home’s main valve, be aware this affects the whole house. Turn fixtures off before you restore supply.
- Do not overtighten plastic aerators or supply fittings—hand-tight plus a small turn with a wrench is usually enough.
Common Homeowner Questions
- Why does only one fixture sputter? If you only worked on that fixture, the air or debris is usually local to that shutoff, supply line, or the fixture screen.
- How long will the sputtering last? Usually it stops after a short purge—minutes, not hours—if the valve and line are correct and screens are clean.
- Can I fix this without tools? Yes: confirm the valve position, straighten the supply line by hand, and run the faucet slowly. Removing aerators or cartridges may need simple tools like pliers or a screwdriver.
Related Articles
If you’re troubleshooting a similar symptom, these guides may help:
For the full directory, see Air in Pipes After Shutoff.