What causes a diaphragm flush valve to have a prolonged flush cycle?

A prolonged flush cycle in a diaphragm flush valve is primarily caused by the bypass hole in the diaphragm being plugged or dirty. The diaphragm is integral to the operation of the flush valve, controlling the flow of water. When the bypass hole is blocked, it restricts the airflow that typically allows the diaphragm to return to its resting position after a flush. This blockage can lead to a situation where water continues to flow longer than intended, resulting in an extended flush cycle.

Ensuring that the diaphragm and its bypass hole are clean and unobstructed is crucial for the proper operation of the flush valve. Regular maintenance and inspection of these components help prevent prolonged flushing, thus conserving water and maintaining efficient plumbing operation.