What short cycling looks like
Short cycling is when the booster pump starts and stops repeatedly, often with little or no water demand. It may also cause pressure fluctuation, noise and premature pump wear.
Common causes
The most common causes include loss of pressure vessel charge, failed vessel bladder, incorrect pre-charge, leaking non-return valves, pressure sensor faults, small leaks or incorrect control settings.
What to check
Record how often the pump starts, whether it happens with all outlets closed, pressure gauge movement and whether any fault or alarm appears on the controller.
Why a pressure vessel check matters
The pressure vessel helps absorb demand and reduce pump starts. If it has lost charge or failed internally, the pump may cycle excessively and wear out faster.