Rheem Water Heater Rusty Water — What’s Happening
Rusty water from a Rheem water heater is a symptom, not an error code. It means the hot water is discolored, usually brown or rust-colored, and typically points to internal corrosion, a depleted anode rod, or sediment and rust inside the tank. Rheem says rusty, muddy, or foul-smelling hot water is a warning sign the heater is in trouble.
Persistent discoloration often indicates the tank is corroding from the inside or the anode rod has worn out. Once the steel tank itself starts rusting, Rheem says replacement is usually the only safe and cost-effective fix. If the unit is 10 to 15 years old or older and the rusty water continues, the heater is likely nearing the end of its life.
Most Likely Causes
- Depleted anode rod The anode rod is the sacrificial part that protects the tank from corrosion, and once it is spent the tank begins to rust.
- Internal tank corrosion Rust-colored water commonly means the steel tank lining has corroded and the tank is deteriorating from the inside.
- Sediment buildup inside the tank Hardened sediment and rust at the bottom of the tank can mix with water and cause discoloration.
- Aging or end-of-life unit Rheem says recurring rusty water in a unit 10 to 15 years old or older is a strong sign the heater should be replaced.
- High water pressure stressing the tank Water pressure above 60 psi can stress the tank and connections, accelerating corrosion and shortening tank life.
How to Diagnose and Fix
- Run hot water only at a faucet and check if the discoloration appears, then run cold water only to confirm the rusty water is coming from the heater and not the supply line.
- Inspect the base and sides of the water heater for visible rust, corrosion, or leaks, which indicate the tank itself is failing.
- Drain and flush the tank to remove sediment buildup, then run hot water again to see if the discoloration clears.
- Locate and inspect the anode rod (usually accessed through a hex plug on top of the tank) and replace it if it is heavily corroded or worn down to the core wire.
- Check water pressure at a nearby fixture and verify it is within 40 to 60 psi, adjusting the pressure-reducing valve if needed.
- Evaluate the age of the unit and whether rusty water persists after flushing and anode replacement, since Rheem says recurring issues in a 10 to 15 year old heater usually mean replacement is the better option.
- If rust returns after maintenance or the tank shows internal corrosion or leaking, plan to replace the water heater rather than attempt further repairs.
Parts You Might Need
| Part | Notes |
|---|---|
| Anode rod | Amazon | Rheem recommends replacement every 3 to 4 years to protect the tank from corrosion. |
| Pressure relief valve (T&P valve) | Amazon | Inspect during maintenance, though not the direct cause of rusty water. |
Related Error Codes
If your appliance also shows a code on the display, these match this problem:
When to Call a Pro
Call a professional if you see leaks at the base of the tank, if rust and discoloration persist after flushing and anode replacement, or if the water heater is 10 to 15 years old or older with recurring issues. Rheem says internal tank corrosion and end-of-life units require replacement, and a licensed plumber or water heater technician can safely evaluate the tank condition, perform anode rod service, and handle installation of a new unit if needed. Professional service also includes inspection of the pressure relief valve and verification that water pressure and connections meet code. For gas line, burner, or igniter work, or if you ever smell gas, stop and call a licensed technician.