Water heater flushing and maintenance
Flushing drains sediment from the bottom of a tank water heater through its drain valve. It quiets popping noises, helps the heater recover faster, and, with an anode rod check, is the main maintenance that extends a tank's life. Once a year is a common recommendation.
Minerals in the water settle at the bottom of the tank. On gas heaters the sediment insulates water from the burner; on electric heaters it can bury the lower element. Either way, efficiency drops and the tank works harder.
The anode rod is the other maintenance item: it corrodes so the tank doesn't, and once it's spent the tank starts to rust.
Signs you need water heater flushing
- Popping or rumbling while heating
- Hot water runs out sooner than it used to
- Sediment or grit in hot water
- Rotten-egg smell from hot water (often an anode reaction)
How water heater flushing is done
- 1
Shut off and cool
Turn off power or set gas to pilot, close the cold supply and let the water cool.
- 2
Drain and flush
Drain through the drain valve, then flush with cold water until it runs clear.
- 3
Check the anode
Inspect the anode rod and replace it if it's mostly consumed.
What affects the cost of water heater flushing
- Whether the drain valve is clogged or fragile
- Anode rod replacement
- Access to the heater
Ask for the trip fee and the total price before work starts.
Water heater flushing: what you can do yourself
Safe to try
- • Flush a younger tank following the manufacturer's manual
Stop and call if
- • The tank is old and has never been flushed (a clogged or brittle drain valve can fail)
- • The drain valve won't close
- • Water is leaking from the tank
Need water heater flushing? Call now
SteadWell is a free referral service, not a plumbing company. Calling (833) 753-0180 connects you with an independent, licensed plumber who serves your ZIP code; the plumber quotes and performs the work. Calls may be recorded.
Water heater flushing: common questions
How often should a water heater be flushed?
Once a year is common; homes with hard water or wells may need it more often, soft municipal water less.
Should I flush an old water heater that's never been flushed?
Have a plumber do the first one. Heavy sediment can clog the valve, and an old plastic drain valve may leak after it's opened.
What does the anode rod do?
It's a sacrificial metal rod that corrodes instead of the steel tank. Replacing a spent rod on a younger tank extends its life.