Flushing Water Lines Before Reopening a Building

Protect Returning Employees and Customers by Flushing Water Lines

Business owners and property managers are eagerly looking forward to reopening their buildings. As we prepare to reenter workplaces and determine what our new normal looks like, it is important to follow water supply safety procedures for reopening a long-quiet building.

Flushing the plumbing system and then testing the water supply in empty buildings can curtail pipe damage and prevent illness in employees, residents, and customers following a long shutdown period.

If you need help preparing your facility’s plumbing for the return of employees and customers, call your local Mr. Rooter^® Plumbing.

Why Should You Flush a Building’s Water System?

When a building’s water supply system is unused for an extended period of time, the water that lingers in the supply lines undergoes several changes. Municipal water supplies contain disinfecting agents; as water sits still in pipes for days or weeks, the disinfectants dissipate in the supply lines.

As biofilm forms inside pipes, colonies of microorganism may pose a health threat to people if water supply systems are not properly flushed. During a long-term shutdown, the protective scale that naturally occurs inside water pipes also breaks down. This can result in lead and other metals leaching into the water supply.

How to Flush Water Lines

Before people return to your facility following a prolonged shutdown, it’s critical to thoroughly flush the water lines and test water quality to ensure that the water is safe to use. The steps outlined below will be of particular interest to those who own, manage, or work in facilities that have been closed for an extended period of time, including:

• Commercial and retail buildings
• Warehouses
• Factories
• Educational facilities
• Dormitories
• Office buildings
• Hotels and resorts
• Restaurants
• Community centres
• Social clubs
• Sports facilities

Here’s how to flush water lines effectively in five steps:

1. Run the cold water from faucets for approximately 30 minutes. Identify zones within the building and flush one zone at a time.
2. Empty, flush, and refill all equipment and appliances that store water, including:

• Water heaters
• Water filtration systems/purifiers
• Water softeners
• Boilers
• Ice machines
• Humidifiers
• Cooling towers
• Toilets
• Drinking fountains

3. For appliances with internal filters, such as humidifiers or ice machines, clean or replace their filters as you go through the flushing process in step 2.
4. Once water heaters are refilled, run the hot water in all faucets for another 30 minutes, one zone at a time.
5. Disinfect plumbing fixtures, including kitchen and bathroom taps, showerheads, kitchen sprayers, and drinking fountains. If possible, remove aerators from faucets and disinfect them as well.

Perform Water Quality Testing and Repeat Process, If Necessary

The next step is to test water quality to determine whether more flushing will be necessary. Use a test that checks for microorganisms and heavy metals. If the water quality test indicates there are still problems with the water supply, repeat the flushing steps above.

If the test indicates that the water is safe, it’s still important to run each faucet and flush each toilet daily until foot traffic in the building returns to normal. This will prevent metal accumulation and microorganism growth from reoccurring in the water supply.

Routine commercial plumbing maintenance can improve performance and extend the life of your system.

Get Your Building Ready for Business with Mr. Rooter

If you would like a professional plumber to flush the water supply system in your building for you, your local Mr. Rooter is ready to help. Our licensed plumbers can help you get back to business by quickly and safely flushing your building’s water lines. Call us at to learn more or request a job estimate online.

Mr. Rooter is part of Neighbourly’s network of trusted services professions, which is ready to help with any of your other service needs and get your building ready for business.

“The information provided herein is obtained from publicly available sources. Please see https://esprinstitute.org/ and other related websites for more information.”