Why Is My Hot Water Brown or Discolored?

Brown Hot Water Is More Common Than You Think

Turning on the tap and seeing brown, rusty, or discolored hot water is alarming — but it's a problem many homeowners face. The key to fixing it is figuring out where the discoloration is coming from. In most cases, if your hot water is brown but your cold water runs clear, the problem is your water heater, not your city's water supply.

Let's walk through the most common causes and what you can do about each one.

How to Diagnose the Problem

Before you start troubleshooting, run a quick test to narrow down the source:

1. Run the cold water at several faucets. Is it clear? If both hot AND cold water are brown, the issue may be with your municipal water supply or your home's pipes — not the water heater.
2. Run the hot water at several faucets. If only the hot water is discolored at every tap, the water heater is almost certainly the culprit.
3. Check a single faucet. If discoloration only appears at one faucet, the problem is likely a localized pipe or aerator issue.

1. Sediment Buildup in the Tank

This is the most common cause of brown or murky hot water. Over time, naturally occurring minerals — iron, calcium, magnesium, and manganese — settle at the bottom of your water heater tank. As these deposits accumulate, they get stirred up when water flows in and out, discoloring your hot water.

Signs

• Water has a brownish, yellowish, or murky tint
• Rumbling, popping, or crackling sounds from the tank
• Hot water takes longer to heat up than usual
• Reduced hot water capacity

How to Fix It

Flush your water heater tank. This is the single most effective fix and something every homeowner should do at least once a year:

• Turn off the power (electric) or gas supply (gas water heater)
• Turn off the cold water supply valve
• Connect a garden hose to the drain valve at the bottom of the tank
• Run the hose to a floor drain, outside, or into a bucket
• Open the drain valve and open a hot water faucet somewhere in the house to allow air in
• Let the tank drain completely
• Turn the cold water supply back on briefly to flush remaining sediment — repeat until the water runs clear
• Close the drain valve, remove the hose, refill the tank, and restore power

Pro tip: If you live in an area with hard water, flush the tank twice a year. Consider installing a water softener or whole-house sediment filter to reduce buildup.

2. Corroded Anode Rod

Every tank water heater has an anode rod — sometimes called a "sacrificial rod." It's a metal rod (usually magnesium or aluminum) that hangs inside the tank and attracts corrosive minerals, protecting the tank lining from rust. Think of it as a bodyguard for your tank.

The problem? The anode rod is designed to corrode over time. Once it's fully consumed (typically after 3-5 years), it can no longer protect the tank. The corrosion products themselves can also discolor your water — especially if the rod contains aluminum, which can create grayish particles.

Signs

• Rust-colored or orange-tinted hot water
• A metallic or iron taste
• The water heater is more than 3-5 years old and the anode rod has never been checked

How to Fix It

Have a plumber inspect and replace the anode rod. Replacement rods are inexpensive (typically $20-50 for the part), and installing a new one can extend your water heater's life by several years. Some homeowners choose a powered (impressed current) anode rod, which doesn't corrode and never needs replacement.

3. Rusting Tank Interior

If the anode rod has been depleted and not replaced, the tank itself begins to rust from the inside. Once internal corrosion starts, rust flakes and particles mix into your hot water, causing a persistent reddish-brown color.

Signs

• Persistent rust-colored water even after flushing the tank
• Visible rust or corrosion on the outside of the tank
• Water pooling around the base of the heater
• The water heater is more than 10 years old

How to Fix It

Unfortunately, once the tank itself is corroding, there's no way to reverse the damage. Replacement is the only real solution. A corroding tank will eventually leak, which can cause significant water damage to your home. If you're seeing these signs, it's time to start shopping for a new water heater.

Not sure how old your water heater is? Use our free Water Heater Age Checker to find out instantly.

4. Old Galvanized Pipes

If your home was built before the 1960s, you may have galvanized steel water pipes. These pipes corrode from the inside out over decades, building up layers of rust that flake off into your water. Because hot water accelerates corrosion, the discoloration is often worse on the hot side.

Signs

• Brown water that's worse first thing in the morning or after the water sits unused
• Reduced water pressure over time
• Visible rust or white mineral deposits at pipe joints
• Discoloration affects specific areas of the house more than others

How to Fix It

The long-term fix is repiping — replacing old galvanized pipes with modern copper or PEX piping. This is a significant investment but eliminates the problem permanently. In the short term, running the water for a few minutes until it clears can help, and a whole-house water filter can reduce rust particles.

5. Bacterial Growth

If your water heater temperature is set too low (below 120°F), or if the unit sits unused for extended periods (like a vacation home), bacteria can grow inside the tank. While not usually the cause of brown water specifically, bacterial growth can make water appear cloudy or murky and often produces a rotten egg smell.

Signs

• Murky or cloudy hot water
• Rotten egg or sulfur smell from hot water taps
• Water heater thermostat set below 120°F
• The unit wasn't used for several weeks

How to Fix It

• Set your water heater thermostat to at least 120°F — this temperature inhibits most bacterial growth
• Flush the tank thoroughly
• For persistent sulfur smell, a plumber can temporarily raise the temperature to 140°F to kill bacteria (be careful of scalding risk), then lower it back to 120°F
• Replacing the anode rod with an aluminum/zinc rod can also help reduce sulfur-producing bacteria

6. Municipal Water Supply Disturbance

Sometimes the brown water has nothing to do with your water heater at all. City water mains can release sediment when:

• Fire hydrants are flushed or used
• Water main repairs or construction disturb old pipes
• Water flow direction changes due to system maintenance
• Heavy demand periods stir up sediment

How to Tell

If both hot and cold water are brown at every faucet, it's likely a supply issue. Check with your neighbors — if they're experiencing the same thing, contact your water utility.

How to Fix It

This is usually temporary. Run your cold water at a bathtub faucet (which has no aerator to clog) for several minutes until it clears. Avoid running the washing machine or dishwasher until the water is clear to prevent staining clothes or dishes.

Is Brown Water Safe?

Brown water from sediment or rust is generally not toxic, but there are important caveats:

• Don't drink or cook with it until you've identified and fixed the cause
• Iron and manganese in water aren't usually harmful in small amounts, but high levels can encourage bacterial growth
• Lead risk: In homes with very old pipes (pre-1986), corroded pipes may leach lead into the water. If your home has old plumbing, get your water tested
• Brown water can stain laundry, damage appliances, and leave deposits on fixtures
• If the water has an unusual smell (beyond a metallic taste), have it tested by a certified lab

Quick Reference: What to Do Based on Your Situation

Situation	Likely Cause	What to Do
Hot water brown, cold water clear	Water heater sediment or rust	Flush tank; check anode rod
Both hot and cold brown, clears after running	City water disturbance	Wait it out; contact water utility if it persists
Brown water at one faucet only	Local pipe rust or clogged aerator	Clean aerator; check that fixture's pipe
Water smells like rotten eggs	Bacterial growth in tank	Set heater to 120°F+; flush tank
Water heater is 10+ years old with recurring rust	Corroded tank interior	Replace the water heater

Prevention: How to Keep Your Hot Water Clear

• Flush your water heater once or twice a year — the single best preventive step
• Inspect and replace the anode rod every 3-5 years
• Keep the thermostat at 120°F to prevent bacterial growth
• Install a sediment filter on your water supply line if you have hard water or well water
• Replace your water heater at 10-12 years before corrosion becomes a problem
• Consider a water softener if you live in a hard water area

When to Call a Professional

Contact a licensed plumber if:

• Brown water persists after flushing the tank
• You notice a metallic taste or unusual smell
• There are visible rust flakes or particles in the water
• Your water heater is leaking or more than 10 years old
• You suspect old galvanized pipes need replacing
• You want your water tested for lead or other contaminants

Check Your Water Heater's Age

If your hot water is consistently discolored, your water heater's age could be a major factor. Most tank water heaters last 8-12 years, and older units are far more prone to sediment buildup and internal corrosion.

Use our free Water Heater Age Checker to find out when your unit was manufactured — just enter your brand and serial number for instant results.