What you may notice
A booster pump that is not working may cause no water, very low pressure, alarms, a silent pump set, a pump that hums but does not run, a control panel fault, or a system that will not build pressure.
Safe checks
Do not remove covers or open electrical panels unless competent. Safe checks include looking for fault codes, checking whether power appears to be available, checking for visible leaks and confirming whether the incoming water supply or break tank has water.
Possible causes
Possible causes include motor failure, overload trip, inverter fault, failed pressure sensor, empty break tank, float fault, control panel issue, seized pump, failed capacitor on smaller systems or a valve left closed.
What to send with an enquiry
Send photos of the booster set, control panel, pressure gauges, pipework, any fault code and the pump make/model if visible.