Outstanding Performance HAMAOM hot water hanging unit heater uses the energy from a building's hot water source(outdoor wood boilers) to offer efficient, whisper quiet operation, and comes with the temperature control switch, sensing the temperature of the water inlet to control the fan start/off, provide a simple way to set your desired temperature, maximize room comfort and energy-saving efficiency. Temperature Control Switch This cleverly designed hanging unit heater comes with temperature control switch. Which automatic start the fan when the water inlet side temperature reaches the preset value, and automatic off the fan when the water inlet side temperature below the preset value. Once you have set the target temperature, you can easily open the hot water valve only, HAMAOM heater will does the rest. Whisper & Adjustable Directional Airflow The unit uses centrifugal blower, which has the characteristics of low noise, high pressure and maintenance-free. Also comes with adjustable louver deflector to direct airflow where it is needed most.