1). High/low pressure protection and sufficient water flow protection, automatic units on/off timeclock 
2). Automatic reversing defrosting function enables units to work reliablely in hard winter 
3). Units run automaticlly according to setted water temperature. 
2. Special defrosting technology makes the heat pump more efficient, higher COP 
3. Special heat exchanger designs provide excellent performance at low ambient temerature and high humidity. 

Air source heat pump water heater have good responds from many customers in many different countries, both in quality and price!