Brand New Genuine Fernox TF1 28mm Heat Pump Antifreeze Valve (Part Number: 62664). Up for sale is a 100% original, brand new, and completely uninstalled Fernox TF1 Antifreeze Valve from the highly regarded Fernox Renewable Range. The item is immaculate and remains safely tucked inside its original factory cardboard retail box as shown in the photos. This high-performance valve is an essential requirement for water-based external air-source heat pump setups. It provides vital mechanical frost defense without relying on electricity or building management controls.