Instinct floor standing boilers include a Caleffi 548 Series separator, left or right-side boiler/gas connections, Wi-Fi connectivity, CTRLMAX 60-second setup, a stainless-steel fire tube heat exchanger, a piece- of-mind warranty, and Combi-units have incredible 5-plus- gpm DHW output, Caleffi explains. Available in Solo 110, 155, 199 and Combi 155, 199.