How often should you flush your water heater tank?

Skipping it eventually leads to water damage or an expensive repair.

Staying on schedule matters beyond the repair bill: a consistent maintenance record is one of the factors in a home's Roots Home Health Score, and well-kept homes typically sell faster and closer to asking price.

How to do it

Minerals settle to the tank floor and insulate the water from the burner. The rumbling of an old heater is steam popping under that sediment layer. A garden hose and gravity clear it; the two rules are power off first, and refill completely before the power comes back.

1. Cut the power: flip the breaker (electric) or set the gas control to Pilot.
2. Close the cold-water inlet valve on top of the tank.
3. Open a hot tap somewhere upstairs to break the vacuum.
4. Connect a garden hose to the drain valve at the tank's base, run it to a floor drain or outside, and open the valve.
5. When the flow runs clear, briefly reopen the cold inlet in bursts to stir remaining sediment off the bottom, and drain again.
6. Close the drain valve, remove the hose, reopen the cold inlet, and let the tank fill until the upstairs hot tap runs steadily with no air.
7. Only then restore power/gas. Check the drain valve for drips. A garden-hose cap stops a slow drip.

Alternatives & optional extras

• Quick partial flush: run a few gallons out of the drain valve until clear. Less thorough than a full drain, far better than nothing.
• Tank over 5 years old and never flushed? Have a plumber do the first one. Scale chunks often clog the drain valve.
• A drained tank is also the natural moment to check the anode rod.

Time: ~1 hour · Typical cost: Free with a garden hose; $120–$250 for a pro flush

What you'll need

• Garden hose (a dedicated drain hose, not one you drink from)

If you skip it

Sediment steadily eats capacity and efficiency, then the tank itself: the insulating layer overheats the steel beneath it, accelerating corrosion from the inside. It's the difference between a heater that lasts 15 years and one that fails at 8, often as a leak in a finished space.

Other water heater maintenance

• Test water heater pressure relief valve — once a year
• Check water heater anode rod — every 3 years
• Check water heater for leaks and corrosion — every 6 months

Related systems to keep on schedule

• Boiler / radiators — start with: schedule boiler service, once a year, ideally in September
• Furnace / heating system — start with: replace hvac air filter, every 3 months
• Mini-split / ductless AC — start with: clean mini-split filters, once a month
• Air conditioner — start with: schedule ac tune-up, once a year, ideally in April