... Source Heat Pum -CE Certificate -High Efficiency&Muti-fuction LTWH Series High Quality Ground Source Heat Pump for Houses and ... CIRCUITCopper tube connection with charge valves, filter, thermostatic expansion valve, gas-liquid separator, high pressure switch and low ... .04.54.86.1Control SystemDedicated heat pump controller,PID regulatorSecurityOverload, high voltage, wrong Phase, water, oil, antifreeze ...