What method should be used to prevent the end user from activating the system during the decommissioning process?

• A. Install a padlock on the main valve
• B. Inform the customer that the system is temporarily isolated, turn off water and label the stop valve
• C. Drain the water heater
• D. Disconnect electrical supply to the pump

Answer: (B)

The idea behind preventing activation during decommissioning is to create a clear, immediate stop to any flow and make that stop unmistakable to anyone who might switch things back on. By turning off the water at the main supply, you physically isolate the system so no new water can enter. Informing the end user that the system is temporarily isolated ensures there’s awareness and accountability—people know not to re-activate it. Labeling the stop valve makes the status visible at a glance, reducing the chance someone will overlook that the system is still out of service. This combination addresses both the physical shut-off and the human factor, which is crucial for safety and control during the decommissioning process.

Draining the water heater or disconnecting the pump only tackles a part of the risk and doesn’t guarantee the entire system won’t be re-energized or reactivated by someone else. A padlock on the main valve can be useful in some situations, but it depends on key control and may not provide the same immediate, documented signal as a labeled, clearly communicated shutdown.