Video · Water Heater Flushing and Sediment
Water Heater Sediment, Cut Open: Inside a Tank Never Flushed
Water heater sediment is the mineral grit that settles on the bottom of a tank over years without flushing. A SwiftPro tech saws open an old Whirlpool gas tank at the shop so you can see what it does.
Job footageSwiftPro
- Topic
- Water Heater Flushing and Sediment
- Length
- 0:35
- Posted
- September 29, 2026
- Shot by
- The SwiftPro crew, Northern Virginia
What you’re seeing in this video
Beside a SwiftPro van at the shop, a tech with hair pulled into a bun, safety glasses on and a black shirt with red sleeves, cuts into an old Whirlpool gas water heater, the logo still readable on the jacket.
Once the steel is open, the inside shows years of corrosion and crusty buildup. On a gas tank, sediment piles up right on the bottom, directly over the burner, so the flame has to heat through a layer of mineral grit before it reaches the water.
All right, we are cutting open a water heater to show what's inside an old water heater. If you've ever wondered why your water heater may not be working as well as it used to and you've never flushed it, well, this could be what's inside your water heater. Lots and lots of gunk. Imagine showering, bathing, washing your dishes in this awesome stuff.
Why it matters in your house
- That layer is why an older, unflushed tank takes longer to recover after a shower and costs more to run. The burner is working through insulation it was never meant to have.
- Sediment holds heat against the tank bottom and speeds up corrosion there, which is where many tanks finally leak.
- A water heater flush once a year keeps the layer thin. If yours has never had one and it's past six or seven years, ask a tech whether a flush still makes sense.
How do you get sediment out of a water heater?
With a flush. The heater is shut off, a hose goes on the drain valve at the bottom, and water runs through until it comes out clear, sometimes with the cold supply opened in bursts to stir the grit loose. If the sediment has hardened for years, it may not all come out, and that's often a sign the tank is near its end.
Want it done at your place? See Water Heater Flushing and Sediment at SwiftPro or call (703) 997-9757.
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