Assess the causeFollow the evidence.
Assess incoming pressure, power supply, pump command, restrictions and the pump's condition.
The exact model and operating conditions determine which tests apply. These are possible inspection directions, not a list of components that must be changed.
Before the appointmentKeep the useful details.
Mention whether flow changes with water-supply timing and whether there is unusual pump noise.
Record the timing, previous work and accessible model label. Do not remove covers or handle live, refrigerant or pressurised components to obtain information.