Description BUFF25 & BUFF50 have 4 x 1″ connections for connecting to the heat pump flow & returns. They also have a 3/4″ connection at the bottom to allow for a drain cock and a 3/4″ top connection to connect an air vent, this can be an automatic air vent for use with non flammable refrigerants such as R32. Always refer to the Heat Pump Manufacturers installation instructions regarding permissible air vents. If using the BUFF25 or BUFF50 as a volumizer use 2 x Blanking Plugs to cap off two of the 1″ connections. Automatic air vents should not be used with flammable refrigerants such as R290 unless the manufacturers installation instructions say otherwise
