Directional flushing

Directional flushing is a routine maintenance procedure used to remove sediment, mineral deposits, and rust from the water distribution system.

Crews close valves in a specific sequence to direct water through the mains at high velocity, scouring the interior of the pipes. The water is discharged through fire hydrants.

During and shortly after flushing, you may experience discolored water, reduced water pressure, or a temporary change in taste or odor. These effects are temporary.

During flushing

• Minimize water use. The less water flowing through your home’s pipes during flushing, the less sediment enters your plumbing.
• Do not do laundry. Sediment can permanently stain clothing, especially whites and light colors.
• Do not run hot water. This prevents sediment from entering your water heater tank.
• Turn off your ice maker and any timed water appliances (sprinklers, dishwashers on delay, coffee makers with auto-brew).
• Close the cold water inlet valve on your water heater, if accessible. This keeps sediment out of the tank during flushing.
• Store drinking water in advance if you prefer not to use tap water while work is underway.

After flushing: flush your home’s plumbing

Once flushing is complete in your area, clear any sediment that may have entered your home’s pipes.

1. Start with the cold water faucet closest to where the water line enters your home (often a hose bib or ground-floor faucet).
2. Run it at full pressure for 3–5 minutes or until the water runs clear.
3. Work through the house, running each cold water faucet until clear.
4. Flush each toilet once or twice.
5. Remove and rinse faucet aerators. Trapped sediment in aerators is the most common cause of low water pressure after flushing.
6. Once the water runs clear, run an empty dishwasher cycle and discard one or two batches of ice from your ice maker.

Flush cold water lines first. Do not run hot water until the cold side is clear.

Draining your water heater

Sediment that enters the water heater tank during flushing can reduce efficiency, cause noise, and shorten the life of the unit. If discolored water reached your home, draining the water heater is recommended.

The videos below are from licensed plumbers and trusted sources. They are provided as a reference. If you are not comfortable performing these steps, contact a licensed plumber.

Tank water heater

Most homes have a standard tank water heater (a large cylinder, typically located in a garage, utility closet, or attic). You will need a garden hose and approximately 30 minutes.

1. Turn off the power (electric: breaker; gas: set to “pilot”).
2. Turn off the cold water supply valve at the top of the heater.
3. Connect a garden hose to the drain valve at the bottom of the tank and route it to a safe drainage area.
4. Open the drain valve and one hot water faucet inside the house to allow air into the tank. The water draining from the tank will be hot. Use caution.
5. Let it drain until the water runs clear.
6. Close the drain valve, turn the cold water supply back on, and let the tank refill completely before restoring power.

Tankless water heater

Tankless water heaters do not store water, but sediment can accumulate in the heat exchanger. Flushing a tankless unit requires a pump, hoses, and a cleaning solution (white vinegar or a commercial descaler). The process takes approximately one hour.

Refer to your manufacturer’s maintenance guide or contact a licensed plumber. The video below demonstrates the general process.

Frequently asked questions

Is the water safe during flushing? Discolored water is caused by iron and mineral sediment being disturbed in the mains. It is not a contamination event. However, we recommend using stored water for drinking and cooking until the water runs clear.

How long will discoloration last? For most homes, the water clears within a few hours after flushing is completed in your area. If discoloration persists beyond 24 hours, contact us.

Can discolored water damage my appliances? It can stain laundry and deposit sediment in your water heater, ice maker, or appliances with filters. Avoid running these appliances until the water is clear.

Do I need to drain my water heater? If you noticed discolored water in your home during flushing, yes. If you closed your water heater’s inlet valve before flushing began, it is likely unnecessary — but draining is still good preventive maintenance.

What if my water pressure is still low after flushing? Check your faucet aerators. Remove each one, rinse out any trapped sediment, and reattach. If pressure remains low after cleaning aerators, contact us.