Taco Air Vent, 1/8" (400-4)

The Taco Hy-Vent Air Vent (TACO-AV-01, model 400-4) is a compact 1/8-inch automatic air vent that removes trapped air from hydronic heating and closed-loop water systems. Air accumulation is a common enemy of these systems, causing noisy operation, cold spots, reduced efficiency, and even circulation problems. The Hy-Vent purges that air automatically and continuously, helping the system run quietly and at peak performance without manual bleeding.

Taco Hy-Vent air vents are well known for being simple to use, easy to install, and compatible with virtually any heating system. For best results they are often paired with Taco Air Scoops, which feature a matching 1/8-inch top outlet designed to collect and direct entrained air up to the vent. When service is eventually needed, the vent is easily maintained by simply unscrewing the vent cap, a refreshingly straightforward design that keeps maintenance quick.

• Compact 1/8-inch automatic air vent (Taco Hy-Vent model 400-4)
• Automatically purges trapped air from hydronic and closed-loop systems
• Brass body with nickel-plated finish for durability and corrosion resistance
• Threaded 1/4-inch connection for straightforward installation
• Operating pressure ratings up to 150 psi for demanding systems
• Serviceable by unscrewing the vent cap; pairs with Taco Air Scoops
• Compatible with virtually any heating system

Air trapped in a hydronic loop interferes with the smooth circulation that these systems depend on, leading to gurgling noises, uneven heat delivery, and corrosion as oxygen attacks metal components from the inside. An automatic air vent continuously addresses the problem so the system stays full of water and free of the air pockets that cause trouble.

Available across a range of styles including the Slim-Line and High Pressure versions, Hy-Vents are engineered to meet the requirements of installations large and small. The brass-body, nickel-plated construction stands up to the heat and moisture of continuous service, while the 150 psi rating suits even substantial systems. For contractors and facility maintenance teams keeping hydronic and circulating water systems air-free and efficient, this Taco Hy-Vent air vent is a trusted, easy-to-service solution. Backed by the Taco name, it is a small component that delivers an outsized benefit, quietly protecting system efficiency and longevity by keeping troublesome air pockets out of the loop.