No mystery to it. Here is exactly what happens from the moment you call to the moment we hand the job back.
Water loss, no flow, reduced flow, noise, tripping breaker or discolouration each point in different directions. Precision here shortens the diagnostic considerably.
Water level monitored with the pump running and with it off. This single comparison separates plumbing and splash-out problems from basin and waterproofing failures.
Pump, valves, electrical and controls checked in sequence. Access to the vault or equipment room is usually the practical constraint on how quickly this proceeds.
Component work completed, or a structural scope developed if the basin or waterproofing has failed. The two outcomes have very different timelines.
System run and checked, water treatment and cleaning regime agreed, and seasonal shutdown scheduled if the climate requires it.
None of this is required — it just makes the visit quicker.