In the zone-by-zone flushing, what is done for the first riser closest to the valve?

• A. Remove the cap and flush for 2 minutes
• B. Flush without removing any caps
• C. Remove all caps and bypass flushing
• D. Cap all risers before flushing

Answer: (A)

Zone-by-zone flushing is done one section at a time to push out air and any debris, starting at the valve end so you can clearly see and control the purge. For the first riser closest to the valve, removing the cap and flushing for about two minutes creates a clear path for water to start moving, lets air escape, and reveals any initial debris. The cap removal is essential to vent and flow properly, and the two-minute flush gives enough time to purge the line so you reach a steady, clean flow before progressing to the next riser. Other approaches would trap air, bypass the controlled purging sequence, or prevent effective flushing by keeping caps in place.