For which systems should you note the type of backflow prevention on the line from a domestic water system?

The note regarding the type of backflow prevention is particularly relevant for heating hot water systems. In these systems, maintaining safe water quality is crucial due to the potential for cross-examination contamination between potable water and heated water. Backflow prevention devices, such as check valves or air gaps, help to protect the domestic water supply from being contaminated by the water within heating systems.

Heating hot water systems operate at elevated temperatures and pressures, and without proper backflow prevention, there is a risk of hot water flowing back into the potable supply during pressure changes, creating a health hazard. Documenting the type of backflow prevention used ensures compliance with plumbing codes and helps in assessing the effectiveness of the protection measures in place against such risks.

While other systems like sanitation systems, cooling towers, and irrigation systems do have their own backflow prevention needs, the specific mention of heating hot water systems highlights the immediate concern of thermal cross-connection and the need for stringent safeguards in those systems.