Most homeowners think about the water heater only when the shower runs cold. Meanwhile, the tank quietly collects sediment, the grit and mineral flakes that drop to the bottom as water heats. Over time that layer can make the heater work harder, run louder, and deliver less hot water. A yearly drain, done before the heating season pushes demand up, is a practical habit for most households.
This week, industry news has focused on big institutions. Water Finance and Management reported that the Association of Metropolitan Water Agencies named its next leader, noting that Dan Hartnett "has been selected to serve as its CEO on a permanent basis effective Nov. 1, 2026." That kind of news is worth reading, but it does not change what sits in your tank. Your water heater is a home task, and it needs a home routine.
What Sediment Does in the Tank
Sediment usually comes from the water supply itself. Minerals that were dissolved in the water come out of solution as it heats and settle on the tank floor. Some of it also comes from rust inside an older steel tank. A softener helps with scale on the heating element and in the pipes, but it does not remove the grit that settles at the bottom. Those are two different problems, and a flush addresses the settled layer.
You may notice the signs before you check the tank. Popping or rumbling sounds during heating, lukewarm water sooner than before, or a faint rust tint at the hot tap can all point to a buildup. None of these signs proves a specific cause on its own, so treat them as a reason to look, not a diagnosis.
Before You Start
Read the owner's manual first. Flush instructions, recommended intervals, and the location of the drain valve vary by model, and the manual will tell you what your heater expects. Gather a garden hose, a bucket for testing the water, and a pair of gloves. Plan for about an hour, and choose a time when no one needs a long hot shower.
Safety comes first. Water in a recently used tank can be hot enough to scald, so let the heater rest for a few hours before you drain it if it has been running. Keep children and pets out of the work area.
The Drain Steps
- Switch off the power. For an electric heater, turn off the breaker. For a gas heater, set the control to the pilot or off position as the manual describes.
- Close the cold water supply valve at the top of the tank.
- Attach the hose to the drain valve near the bottom of the tank. Run the other end to a floor drain or an outdoor spot where hot water will not cause harm.
- Open a hot tap elsewhere in the house. This lets air into the system so the tank can drain freely.
- Open the drain valve and let the water run out. Once the flow starts to clear, briefly open the cold supply to stir up the remaining sediment, then drain again until the water runs clear.
- Close the drain valve and remove the hose. Open the cold supply valve, and keep the hot tap open until the flow is steady with no sputtering. Then close the tap.
- Restore power or set the gas control back to its normal position.
Check the hot tap for a few minutes after refilling. Spitting or air noises usually mean air is still trapped, and running the tap a little longer clears it.
When to Call a Pro
Stop and call a licensed plumber if the drain valve will not close fully, if it leaks after you tighten it, or if the tank has no working drain valve at all. Call as well if the water comes out heavily rust-colored, if the tank is near the end of its typical service life, or if you smell gas near a gas unit. A flush is a reasonable homeowner task, but a valve that will not seal is a repair problem, and it is better handled by a professional.
Make It a Yearly Habit
Pick a date tied to something you already do, such as changing smoke alarm batteries or setting the furnace for the season. Write it on the calendar, and note what you found, including how long the water took to run clear. Over several years, those notes show whether your water is building up sediment faster than expected, which is useful information for any future plumbing or water-treatment decision.