What risk arises when a hydronic system is directly connected to a domestic water system without proper backflow protection?

When a hydronic system is directly connected to a domestic water system without proper backflow protection, the primary risk is the potential for cross connections, back pressure, and back siphonage.

Cross connections occur when the potable water supply comes into contact with non-potable water, creating a pathway for contaminants to enter the drinking water system. This is critical because the hydronic system may contain chemicals or other materials that are harmful if ingested. Without proper backflow prevention measures, these hazardous substances could inadvertently flow into the domestic water supply, posing a serious health risk to consumers.

Back pressure refers to the scenario where higher pressure in the hydronic system forces water back into the potable system. This is often a concern in systems where thermal expansion or high-pressure differentials can occur, leading to potential contamination of the clean water supply.

Back siphonage happens when there is a drop in pressure in the domestic water system, potentially causing unprotected outlets to pull water back into the system. This can happen during events such as a water main break or when a fire hydrant is opened, which creates a vacuum that draws water from the hydronic system.

Collectively, these issues underline the importance of backflow prevention to safeguard public health and maintain water quality