Quick Answer:
If brown water appears after you turn the main back on, don’t panic. It’s usually loose rust or sediment washed into the system by the pressure change. Start by removing faucet aerators, open several taps (cold first) to flush lines, and watch for flakes. If discoloration continues or only the hot side is affected, stop using the water and get professional help.
Why This Happens
- Pressure changes from shutting and reopening the main can dislodge rust, scale, or sediment that has built up in older pipes or the service line.
- Work on the municipal main or a sudden change in flow can push material into your home plumbing.
- Water heaters, especially if not flushed for years, can contribute rusty water on the hot side.
- Most cases are cosmetic (rust, iron oxides) rather than biological—but the water should be flushed before drinking.
- If you recently read about similar situations, see notes about Brown water after plumbing repair for related examples and typical causes.
Step-by-Step What to Do
1. Stop using the water for drinking and laundry
- Don’t run dishwashers or washing machines until the water clears to avoid staining fabrics and dishes.
- Use bottled water for drinking and cooking until you’re sure the supply is clear.
2. Check whether it’s cold, hot, or both
- Turn on a cold tap and a hot tap separately. If only the hot water is brown, the water heater is a likely source.
- If both are brown, the issue is in the supply side or house piping.
3. Remove aerators and screens
- Unscrew aerators from faucets (use pliers with a cloth if needed). Clean or rinse the small screens—brown particles often collect there.
- Keep aerators off while you flush so they don’t trap debris again.
4. Open multiple faucets to purge the system
- Open several faucets throughout the house at once—start with cold water. Include outdoor hose bibs if you have them.
- Let the water run for several minutes and watch for flakes or settling particles. You may see brown flakes that clear after the flush.
- Flush toilets a few times and check for any lingering staining or Brown streaks in toilet bowl as an indicator of remaining particles.
5. Check the water heater (if hot water is discolored)
- If the hot side is the only problem, turn off the heater (gas or electric) and consider flushing the tank or calling a technician. Sediment buildup inside the heater is common after pressure changes.
6. Reinstall aerators and test
- Once flow looks clear at multiple taps, reinstall cleaned aerators and test each faucet briefly to confirm clarity.
- If short flakes return, stop and move to the next step (call a pro or the utility).
What Not to Do
- Do not cycle the main valve repeatedly; scale can break loose faster and make the problem worse.
- Don’t keep using appliances that could stain (washers, dishwashers) until water is clear.
- Avoid drinking or cooking with obviously discolored water.
When to Call a Professional
- Discoloration persists after extensive flushing (15–30 minutes at several taps).
- Only the hot water is brown and you suspect the water heater—call a licensed plumber or heater technician.
- There is reduced flow, strong metallic taste, or visible pipe corrosion inside exposed plumbing.
- If neighbors are also affected, contact your water utility—they may need to flush the main or issue an advisory.
Safety Notes
- Rust-colored water is usually not a microbiological hazard, but if in doubt, use bottled water for drinking and cooking until the source is identified.
- Do not attempt major disassembly of service lines or the meter yourself—leave that to your water utility or a licensed plumber.
- Wear gloves when handling dirty aerators or collecting samples to avoid staining your hands and clothing.
Common Homeowner Questions
- Is discolored water dangerous? Usually it’s from rust and not immediately dangerous, but avoid drinking it until clear and contact the utility if concerned.
- How long should I run the taps? Run several taps for at least a few minutes; if it doesn’t clear in 15–30 minutes, call a pro or your water utility.
- Can this stain my laundry? Yes—do not run washing machines until water is clear to prevent brown or rust stains on clothes.
For more related articles, see the Brown or Rust-Colored Water Events hub.