The Laars Heating Systems FT1321 Air Vent is an automatic air-elimination component designed for compatible Laars FT Series boilers and hydronic HVAC heating systems. It works through an internal float and valve mechanism that automatically releases trapped air from the boiler’s water circulation system while closing when water reaches the venting chamber. By removing unwanted air, th... https://www.partshnc.com/laars-heating-systems-ft1321-air-vent