Quick Answer:
If your kitchen sink started draining slowly after a city water outage or main repair, it’s often caused by sediment or air trapped in the pipes. Start by running a strong cold-water flush at the sink and nearby fixtures for several minutes. Check the strainer, garbage disposal, and P‑trap next. If flow doesn’t improve after flushing and basic checks, call a plumber.
Why This Happens
When the city shuts water off or works on mains, pressure changes can dislodge rust, sand, and mineral debris inside the public pipes. That material can travel into your service line and then into home plumbing, where it hangs up at narrow points like strainers, faucet aerators, or the P‑trap. Air pulled into the lines during repairs can also cause sputtering and slow flow until the line is flushed. This is similar to problems homeowners see after winter work on plumbing, such as Drain slows after winterization.
Step-by-Step What to Do
1. Run a long, strong flush
- Open the cold-water faucet at full force for 5–10 minutes. If you have a separate hose bib or utility sink, run that too to help push debris out of the service line.
- Flush the line well after city work: maintain steady flow so grit and air are carried through the house plumbing and toward the sewer.
2. Check the faucet aerator and strainer
- Turn off the faucet, remove the aerator or sink strainer, and rinse any trapped particles. A clogged aerator can cut flow dramatically.
3. Inspect the garbage disposal and dishwasher connections
- If you have a disposal, run it briefly while flushing to help move debris. Make sure the disposal is powered off before you reach in to clear it.
- Check the dishwasher air gap or connection for blockages if both the sink and dishwasher drain slowly.
4. Clean the P‑trap
- Place a bucket underneath, remove the P‑trap, and clear out any debris. Reassemble and test flow. This often removes buildup that shows up after a surge of sediment.
5. Test other drains
- Run water in other sinks, tubs, and outdoor spigots. If multiple fixtures are slow, the issue is likely in the main service line or sewer rather than a single fixture.
6. Try a safe mechanical clean if needed
- Use a handheld drain snake for a localized clog in the kitchen tailpiece or trap. Avoid mixing chemical drain cleaners with other methods.
What Not to Do
- Do not assume outages fix themselves. If slow drainage persists after flushing, investigate or call a pro.
- Do not pour harsh drain chemicals down the sink right away — they can damage pipes, the disposal, and create hazardous mixes if other cleaners were used.
- Do not stick your hand into the disposal without disconnecting power first.
When to Call a Professional
- Flow remains poor after thorough flushing and cleaning the aerator, trap, and disposal.
- Multiple fixtures are slow or you notice sewage smells and gurgling — signs of a main sewer issue.
- You see backed-up water, recurring clogs, or raw sewage in drains. These require immediate professional attention.
Safety Notes
- Always turn off electrical power to a garbage disposal before reaching inside or working nearby.
- Wear gloves and eye protection when removing traps or handling debris.
- Do not mix chemical cleaners. If you’ve used a chemical product already, tell the plumber so they can take precautions.
Common Homeowner Questions
- Why is it only the kitchen? Often the kitchen has more narrow fittings, a disposal, and frequent use that exposes problems; check the aerator and P‑trap first.
- How long should flushing take? Run full cold flow for at least 5–10 minutes; longer if you heard work or saw discolored water during the outage.
- Can I use chemicals after an outage? Avoid chemicals initially — flush and try mechanical cleaning first; chemicals can make conditions worse or unsafe.
If the sink is still slow after the steps above, consider contacting a licensed plumber to inspect the service line or sewer. For related slow-drain situations, see advice about Kitchen sink draining slowly.