Which of the following should be omitted when recording data for a central domestic hot water system?

The omission of sulfur-reducing bacteria test results for the system when recording data for a central domestic hot water system is justified because these results are not typically a critical aspect of monitoring for Legionella risk in such systems. While these bacteria can indicate the presence of an anaerobic environment which may lead to other issues, the monitoring focus tends to be more on factors that directly affect Legionella growth and control, such as water temperature, mixing valve settings, and pump specifications.

By focusing on hot water temperatures, for example, you can evaluate whether the water is being maintained at appropriate levels to prevent Legionella proliferation. Thermostatic mixing valve settings are crucial because they ensure that the hot water is delivered at safe temperatures to prevent scalding, while still keeping it at levels that discourage bacterial growth. Pump specifications may provide essential information about system performance and flow rates, which are also relevant for ensuring good water circulation and temperature maintenance.

In contrast, sulfur-reducing bacteria tests do not provide the same level of actionable data concerning Legionella management and control. Therefore, they can be considered non-essential for routine data recording in the context of effective Legionella risk management in central domestic hot water systems.