Before changing settings on a pump during a routine check, ensuring that the pump is off is essential for safety and preventing equipment damage. This precaution helps to avoid accidental activation of the pump while adjustments are being made, which could lead to injury or unintended consequences, such as water spillage or damage to the system.
When a pump is operational, internal components may still be moving, and changing settings could create erratic behavior or even catastrophic failure. By first turning off the pump, the technician can safely proceed with necessary adjustments, checks, or maintenance tasks without the risk of unexpected operation.
Other actions, such as notifying the operator or checking water flow, may be important during operational phases but do not address the critical safety consideration of managing the equipment's state before modification. Referring to the manual is always a wise practice, but it does not substitute the need to turn off the pump prior to making changes. Therefore, confirming the pump is off is the most suitable step to take first in this scenario.