Quick Answer:
If water service has been restored but one or more fixtures still have no flow or very weak flow, start with one fixture: remove the aerator or spray head, open the shutoff (stop) fully and run the valve to flush. If that doesn’t restore flow, shut the local stop, remove the cartridge or valve internals and check for grit or debris. Repeat the same test on another fixture to tell whether it’s isolated or system-wide. Don’t forget showers — the balancing spools can seize and block flow.
Why This Happens
- When water is shut off and then returned, the sudden surge often carries grit, scale and rubber particles from the piping. Those particles lodge in screens, aerators, spray heads and cartridge bores.
- Fixture stop valves can get left partially closed or seize in the closed position after service, so the fixture isn’t getting full supply.
- Cartridge-style valves and shower balancing spools have narrow passages that can jam with even small particles.
- If several fixtures show the same symptom, the problem is more likely caused by debris in the supply rather than a single broken fixture.
Step-by-Step What to Do
1) Start with one fixture
- Turn the fixture off. Unscrew and remove the aerator or hand spray tip — keep a towel underneath to catch small parts.
- Open the local shutoff (stop) under the sink or supply stop fully. If there is no stop at that fixture, you’ll be testing with the house supply on.
- Turn the faucet on to full hot and cold separately and let it run for 30–60 seconds to flush out debris.
- Examine the aerator or spray head screen for grit, sand or black particles and rinse them clean before reassembling.
2) If the fixture is still dead, inspect the cartridge or valve internals
- Close the fixture stop before removing the cartridge to avoid a spray of water. If there is no individual stop, you may need to shut the house water off to be safe.
- Remove the handle and trim, then extract the cartridge or valve spool according to the manufacturer’s instructions. Look for grit, rubber pieces or mineral buildup in the bore and on the cartridge face.
- Rinse the cartridge and bore and clear any grit with a soft brush. Reassemble and test with the stop open fully.
3) Repeat at another fixture to confirm scope
- Try the same removal/flush routine on a second fixture. If the second fixture clears after flushing, the issue may be isolated; if it also shows the same blockage or cartridges contain grit, the supply likely carried debris throughout the house.
- If showers are involved, remove the trim and check the shower balancing spool — these often jam and stop water flow entirely.
What Not to Do
- Don’t replace every fixture part immediately. Start with screens, aerators and the supply stops and use targeted flushing.
- Don’t force stuck stops or valves — you can break the valve or strip the packing. Use penetrating lubricant only if you’re comfortable and know how to retighten properly.
- Don’t pour harsh chemical cleaners into fixtures or shower valves to clear grit; they won’t remove physical particles and can damage seals.
When to Call a Professional
- If multiple fixtures remain dead after you’ve removed screens and flushed cartridges, a pro can inspect filters, pressure-reducing valves or the main supply for debris or installed inline strainers.
- If stop valves are seized or start to leak when you operate them, a plumber can replace them safely without damaging the supply lines.
- If you’re not comfortable shutting off and disassembling cartridges or the symptoms include low pressure throughout the whole house, call a licensed plumber.
Related reading: House lost water but meter shows flow and Water works only when multiple taps open
Safety Notes
- Always shut the local stop or the house supply before removing cartridges to avoid uncontrolled water discharge.
- Wear gloves and eye protection when working under sinks or around old piping; grit can be abrasive.
- Keep a bucket and towels ready. If you must use any lubricant or cleaner, follow label instructions and avoid mixing chemicals.
Common Homeowner Questions
- Q: Can debris in the pipes permanently damage cartridges? — A: Usually no; most cartridges are fine after cleaning, but repeated abrasive particles can wear seals over time.
- Q: How long should I flush a fixture after water is restored? — A: Run each fixture separately for about 30–60 seconds or until the water runs clear and free of particles.
- Q: If only the shower is blocked, is the balancing spool the likely cause? — A: Yes. Shower balancing spools commonly seize with debris and can stop the shower even when sinks work.