Why is my water heater making noise?
Popping or rumbling from a water heater is usually sediment buildup on the bottom of the tank — minerals harden, water trapped underneath boils, and the tank rumbles. It shortens the heater's life and raises energy bills. Flushing the tank often quiets it; a heater over 10 years old that rumbles is usually telling you replacement is near.
Likely causes
- Sediment buildup — Popping/rumbling. Most common in hard-water areas and tanks never flushed.
- Water hammer — Banging in the pipes (not the tank) when valves close fast — a pressure/plumbing issue, not the heater itself.
- Loose heating element — Humming or vibrating on electric models.
- Pressure buildup — Hissing or whistling can signal a faulty temperature-and-pressure relief valve — treat this one seriously.
What you can check yourself
- Identify the sound: popping/rumbling = sediment; hissing/whistling = stop and read the next line.
- If it's sediment and the heater is under ~8 years old, a tank flush may fix it.
- Check around the base for leaks or rust — either changes the answer to 'replace'.
Typical cost
A professional flush in Washington, DC typically runs $150–$300. Replacement water heaters run $1,400–$2,800 installed for a standard tank.
When to call a pro
Hissing, whistling, any leak, or rust-colored water — shut the unit off and call. The relief valve is a safety device; don't troubleshoot pressure symptoms yourself.
Plumber pros in Washington, DC
- Spartan Plumbing, Heating And Air Conditioning · 1776 I St Nw Ste 900, Washington, DC · 12025590339
- Plumbers 911 Washington DC · 1915 I St NW Ste 200, Washington, DC · 8779325325
- Greenpipe Biotech Inc · 1629 K St NW, Washington, DC · +12027192525
- Grayton Plumbing · 15 O St SW, Washington, DC · 2025444366
- MM Remodeling · 2067 Park Rd NW, Washington, DC · +12024153808
- Plumber In DC · 620 Park Rd NW, Washington, DC · 2028100624
- Plumbline Plumbers · 1629 A St NE, Washington, DC · 2025439515
- District Plumbers · 2300 4th St NE, Washington, DC · 12024995726
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Data by Servik — verified local pros from official license records and public sources. Cost figures are typical ranges, not quotes; a pro's written estimate is the real number.