The product is designed to control air-source heat pump water heaters. The multi-function design supports auxiliary heating function, waterflow warning, ventilation pump control, antifreeze function, sensors failures action, auto defrost and timer defrost function, auto restart function, exhaustion temperature protections, compressor delay and pressure protections. Features: Multifunction Design: with waterflow auditing, ventilation pump control, sensors failures action function. Temperature Inquiry: Support checks the temperature of all sensors, and the results keeps displaying for 3 seconds. Water Temperature Setting: support set the temperature and with the setting ranges of 10celsius -70celsius , the factory setting is 40celsius . Two Working Mode Design: there are two working modes of "AUTO" and "SAVE" for you to adjust. "AUTO" mode: keep heating according to the setting. "SAVE" mode: only heating within three set periods. You can adjust it to suit your needs. Multiple Control Function: Equipped with temperature control, aux electrical heaters control, and water ventilation pump control function. Winter Antifreezing & Auto Defrost & Timer Defrost Function: when the outdoor temperature is less than 2celsius , it will operate anti-freezing pumping, the pump runs 3 minutes for every 30 minutes; it will automatically stop when more than 3celsius .  When the temperature is -9~0celsius starts defrosting, and when the temperature is 2-30celsius stops defrosting. Multiple Protections & Warning Function: Support exhaust temperature protections function, high pressure and low pressure warning and protections, compressor delay protections, and water sensors failure warning. Auto Restart & Restore: with auto restart after power off, support for on/off power failure memory function, and support for recovery to factory settings. Specifications: Name: Water Heating Controller Material: printed circuit board Setting ranges: 10celsius to 70celsius Display ranges: -40celsius to 130celsius Working temperature: 0-50celsius Storage temperature: -10celsius to 60celsius Ambient humidity: 20-85percent RH without dew Power supply: 220VAC +/-10percent , 50/60Hz Outputs: Compressor 30A; Heaters 8A; Others 3A Hysteresis: 2~10celsius Water sensors calibration: -9.9~ 9.9celsius Heater energized from: -5~ 25celsius Defrost starting time: 10- 90min Defrost starting temperature: -9~0celsius Defrost stop temperature: 2~30celsius Maximum defrost time: 2-15min Exhaust protections temperature: 50 ~ 125celsius Item size: Display panel: 86 * 86mm / 3.39 * 3.39in Mainboard: 105 * 90 * 35mm / 4.13 * 3.54 * 1.39in Package size: 225 * 185 * 65mm / 8.86 * 7.28 * 2.56in Package weight: 651g / 1.44lb Packing List: 1 * Mainboard 1 * Display Panel 4 * Temperature Sensors