Water heater needs flushing due to sediment buildup

Symptoms

• Tank has never been flushed or not in over a year
• Rumbling or popping noise during heating
• Reduced hot water capacity or slower recovery
• Sediment visible if you look into the drain valve output

Likely causes

• CommonMineral sediment from hard water settling at the tank bottomCalcium and other minerals in incoming water settle out as the water is heated repeatedly.
• CommonTank never flushed since installationSediment accumulates steadily without any maintenance to remove it.
• PossibleInfrequent hot water use allowing sediment to settle undisturbedTanks used less often can build sediment layers faster relative to water turnover.

What to do

1. Turn off power (electric, at the breaker) or set the gas control to pilot, and let the water cool somewhat if recently used.
2. Turn off the cold water supply valve to the tank to prevent it from refilling as it drains, or leave it on per your model's guidance to flush more thoroughly.
3. Connect a garden hose to the drain valve and route it to a floor drain, outside, or a large bucket.
4. Open a hot water tap elsewhere in the house to let air into the system and help the tank drain.
5. Open the drain valve and let water flow until it runs clear of sediment, periodically opening and closing the cold supply briefly to stir up remaining sediment if needed.
6. Close the drain valve, remove the hose, refill the tank fully (confirmed by water flowing steadily from the open hot tap), then restore power or gas.

Tools and parts

• Garden hose
• Bucket if no floor drain access

When to call a pro

If the drain valve is clogged with sediment and won't open or close properly, a plumber can clear or replace it during the flush.

Safety