Buy Bonaire MB4 ducted heater that is designed to easily fit in small and compact spaces. It comes with a multi tube heat exchanger and a modulating gas valve, minimising gas usage. Integrated four-zone control standard. Only heats rooms that you want to keep warm. You can also operate your MB4 heater with the optional Bonaire My Climate® Wi-Fi® control. Available in a Universal internal/external unit with five-year parts and labour warranty with a ten-year parts warranty on the burner.