Video · Water Heaters
How Does a Water Heater Work? Two Techs Cut One Open to Show You
How does a water heater work? Cold water enters through a dip tube to the bottom of the tank, elements or a burner heat it, and hot water leaves from the top. Two techs cut an old electric tank open to show the parts.
Job footageSwiftPro
- Topic
- Water Heaters
- Length
- 0:38
- Posted
- September 22, 2026
- Shot by
- The SwiftPro crew, Northern Virginia
What you’re seeing in this video
Outside the shop, in front of a SwiftPro van, two techs go to work on an old GE electric water heater. One kneels in safety glasses and a black cap; the other, bearded, helps pry. They cut through the outer metal jacket and peel back the layer of foam insulation that holds the heat in between uses.
Under the foam is the steel tank itself, and once it's open, the inside is coated in gunk. In an electric heater like this, two elements, upper and lower, each with its own thermostat, do the heating, while the anode rod hangs down from the top to draw corrosion away from the steel.
This is what it looks like inside your water heater. That is what's inside your old water heater. Absolute gunk. That's what you're showering in, bathing in, washing your dishes with.
Knife? The knife? Look at
Why it matters in your house
- The dip tube carries cold water to the bottom so it doesn't mix with the hot water up top. A cracked dip tube is one reason hot water suddenly runs lukewarm.
- The anode rod is meant to corrode in place of the tank. Once it's used up, the steel starts rusting from the inside, which is how tanks end up like this one.
- Minerals settle at the bottom as sediment. In an electric tank, that buildup surrounds the lower element, makes it run hotter and shortens its life.
What's inside a water heater tank?
A glass-lined steel tank wrapped in foam insulation and a metal jacket. Inside are a dip tube for incoming cold water, a hot water outlet at the top, an anode rod that sacrifices itself to slow rust, and the heat source: two elements on an electric unit, a burner and flue tube on a gas one. A relief valve on the side handles safety.
Want it done at your place? See Water Heaters at SwiftPro or call (703) 997-9757.
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