Assess the causeFollow the evidence.
Compare incoming supply, filter restriction, pump operation, tank condition and the model's dispensing arrangement.
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.
Say whether the tank fills normally and when the filters were last serviced, if known.
Record the timing, previous work and accessible model label. Do not remove covers or handle live, refrigerant or pressurised components to obtain information.