Building Reopening & Flushing Checklist
Water that sits unused in a building's plumbing can change in quality. Here's what to check before reopening.
Short answer: Flush every outlet, check hot-water systems, inspect for visible issues, and document the process before reopening a building after a seasonal closure, renovation, or extended vacancy. For Legionella or other health-risk concerns, use a qualified building-water-management professional rather than a DIY approach.
Who this is for: facility managers of seasonal properties, schools, offices, manufactured-home and apartment communities, and any building with an extended closure.
Reopening checklist
- Confirm the building's water source and whether the utility has issued any notices during the closure period.
- Flush every fixture (sinks, fountains, bottle fillers, hose bibs) until water runs clear and any stale odor clears.
- Check hot-water systems and set temperatures appropriately.
- Inspect for visible leaks, corrosion, or damage that may have occurred during the closure.
- Check ice machines and other low-use water-using equipment.
- Review cross-connection/backflow devices for obvious issues.
- Document the flushing date and any issues found.
When to bring in a professional
Buildings with complex plumbing, cooling towers, decorative fountains, or known risk factors for Legionella should use a qualified building-water-management professional for reopening, not just a basic flush. This is especially relevant for larger facilities, health-care sites, and buildings closed for extended periods.
Common mistakes
- Reopening without flushing at all
- Flushing only a few "obvious" fixtures and skipping low-use outlets
- Treating a DIY flush as sufficient for Legionella risk in a complex building
- Not documenting the reopening process for facility records
Official sources
- U.S. EPA guidance on building water system reopening
- Delaware Office of Drinking Water (for utility-level notices during closures)
Related
- Drinking Fountain Maintenance
- Saltwater Intrusion (for seasonal coastal properties)
How long should I flush a fixture after a long closure?
There's no single universal time that applies to every fixture and building. Flush until water runs clear and any stale odor clears, and consult a qualified professional for complex buildings or extended closures.
This page provides general educational information and is not a substitute for a qualified building-water-management professional where Legionella or other health risks are a concern.
Last reviewed: 2026-07-11. Report a correction.