Rusty or Discolored Water
Updated February 20, 2026
Brown or rusty water? Could be corroding pipes, deteriorating heater tank, depleted anode rod, or a municipal main disturbance. First step: hot only, cold only, or both? That narrows the source immediately.
Overview
The color tells you the cause. Brown or rust: iron corrosion from pipes, heater tank, or disturbed municipal main. Yellow or orange: early rust or high iron in well water. Black particles: deteriorating gasket, failing dip tube, or manganese. Run hot and cold separately near the heater. Hot only discolored? Water heater. Both? Pipes or municipal main.
Symptoms
- Brown, rust, or orange water when you first turn the tap -- most visible in a white sink or tub
- Hot side only discolored -- water heater is the source
- Both hot and cold discolored -- pipe or municipal supply issue
- Clears after running 30-60 seconds -- standing water in corroded pipes, not continuous
- Metallic taste or rusty smell even with faint discoloration
- Rust stains on fixtures, brown laundry stains, white clothing turning yellow
Common Causes
- Depleted anode rod -- sacrificial rod corrodes in place of the tank. Fully consumed after 3-5 years, then the tank itself corrodes. Rust enters hot water only. Often the first sign the heater is nearing end of life.
- Corroding galvanized pipes -- homes pre-1960s. Corrode from inside out, release rust particles. Both hot and cold affected, worse in the morning after sitting overnight. Progressive, eventually needs repiping.
- Municipal main disturbance -- hydrant flushing, main repair, or break stirs up settled sediment. Sudden, widespread, affects all water. Temporary, clears in hours to a day.
- Sediment stirred up in the heater tank -- not flushed in years, thick layer at the bottom. Any disturbance (pressure surge, turning it off/on, plumbing work) stirs it up. Temporary hot-water discoloration.
- Well water iron or manganese -- naturally high mineral content. Iron: orange or rust. Manganese: brown or black. Filtration or treatment, not plumbing repair.
What You'll Need
How to Fix It
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Run the Diagnostic Test (Hot vs Cold)
Faucet near the heater. Cold only for 2-3 minutes, sample in a white cup. Hot only for 2-3 minutes, separate sample. Compare. Cold clear, hot discolored? Water heater. Both discolored? Pipes or municipal. Clears after a minute of running? Standing water in corroded pipes.
Tip: Test at multiple faucets. Only one faucet discolored? Corrosion may be localized in that specific supply line. -
Check and Replace the Anode Rod (Hot Water Only)
Hot only? Anode rod. Heater and cold supply off. Hex fitting on top (1-1/16 inch), socket wrench with breaker bar. Pull straight up. Healthy: thick coating. Depleted: mostly bare wire or dissolved. Replace with magnesium (preferred) or powered rod (never depletes). $20-50.
Tip: Low ceiling clearance? Flexible or segmented anode rod. Designed to bend for tight spaces. -
Flush the Water Heater Tank
Power and cold supply off. Garden hose on the drain valve to a floor drain or outside. Open and drain completely. Water will be very discolored. Open cold supply briefly to flush remaining sediment. Repeat until clear. Close, refill, restore power.
Warning: Old tank (10+) never flushed? Drain valve may clog with sediment. Very little water despite valve open? Wire or screwdriver to break the blockage. Valve itself may need replacing. -
Assess the Tank Condition
Anode depleted and rusty hot water for a while? Tank may be corroding internally. After flushing, monitor. Discoloration returns within days despite new rod and flush? Lining is compromised. Cannot be repaired. Plan replacement before emergency failure.
Tip: 8-12 year range with rusty water, popping sounds, rust at fittings? Proactive replacement beats waiting for a catastrophic leak. -
Address Pipe Corrosion (Both Hot and Cold Discolored)
Both hot and cold? Check for galvanized pipes: dull gray, threaded fittings, common in older homes. Consistent discoloration (not one-time) means internal corrosion. Long-term: repipe with copper or PEX. Short-term: whole-house sediment filter reduces visible discoloration.
Tip: Planning a remodel? Include repiping. Running new pipe is much easier with walls already open. Section by section during projects is a practical approach. -
Contact the Water Utility (If Sudden and Widespread)
Sudden and all faucets? Check with your utility first. Hydrant flushing or main repair is temporary. Run cold at the lowest faucet (laundry or outdoor) for 15-30 minutes until clear. Do not run hot until cold clears -- you do not want sediment filling the heater tank.
Tip: On a well? Check for recent heavy rain or pump changes. Shallow wells stir up from rainfall. Test for iron, manganese, coliform. Iron filter or oxidizing filter for persistent mineral discoloration.
When to Call a Pro
Call a plumber if the heater is corroding and needs replacement, if galvanized pipes need assessment, if discoloration persists after flushing and new anode rod, if you need a well water treatment system, or if discoloration comes with a pressure drop (severe corrosion). Camera inspection can assess pipe condition without opening walls.
Prevention Tips
- Anode rod every 3-5 years. Single most important task for preventing tank corrosion.
- Flush the tank annually. Removes rust sediment before it accumulates.
- Galvanized pipes? Plan gradual repiping during renovations.
- Well water? Annual test for iron, manganese, minerals. Filtration based on results.
- After municipal main work, run cold at an outdoor spigot 15-30 minutes before using indoor fixtures. Flushes sediment before it reaches the heater.
- Heater over 8 years? Check the anode rod annually, not every 3-5. Corrosion accelerates as the rod depletes.