1.a special controller for engineering heat pump water heater, 2. contains 3 temperature sensors 3.Power Supply: 220V 4. Out ... the special controller for engineering heat pump water heater, it contains 3 temperature sensors (water temperature, outdoor temperature, exhaust temperature), 3 controlling output (compressor, ... standard:Q/320585 XYK 01 (NA8634-HTDX) digital heat pump temperature controller