What is the primary function of an air separator in a closed expansion tank system?

An air separator's primary function in a closed expansion tank system is to effectively remove air from the water within the system. When water is heated or circulated in a hydronic heating system, air can become entrained due to various reasons, such as water temperature changes or system maintenance.

The air separator works by allowing the water to rise while facilitating the escape of trapped air, which is crucial because excess air can lead to corrosion, reduced efficiency, and operational issues. By efficiently directing air out of the system and into the expansion tank, the air separator helps maintain optimal water quality and system performance. This action prevents air pockets that could disrupt the flow of water, ensuring that the heating and cooling processes operate smoothly.

While it is important to consider other aspects of a closed expansion tank system, such as temperature monitoring and noise reduction, those elements are not the primary function of an air separator. Instead, the direct removal of air supports overall system efficiency and longevity.