The invention relates to a 
programmable logic controller (PLC) based monitor and control generated 
system (MCGS) 
heat pump monitoring system and a control method thereof and relates to a control device using a fluid heater of a 
heat pump. The PLC based MCGS 
heat pump monitoring system comprises a MCGS configuration computer, a PLC module, a remote water meter and an 
electric energy meter; the PLC module is connected with the remote water meter, a 
liquid level sensor, a temperature sensor, a make-up pump and a 
circulating pump; the PLC module is connected with the MCGS configuration computer and controls a 
water level of a 
water level and supply water temperatures of a hot water 
system of a heat pump according to unit 
control parameters sent by the MCGS configuration computer; the MCGS configuration computer is connected with the 
electric energy meter to obtain time-segmented 
electric energy consumption data of the hot water 
system of the heat pump; and a monitoring interface of the MCGS configuration computer real-timely monitors device states of a heat pump unit, displays alarming and maintenance alerting signals, and records device running and alarming states of the heat pump unit. The PLC based MCGS heat pump 
monitoring system has statistical functions of electric energy and 
water consumption, achieves centralized control and 
energy consumption management of an air source heat pump hot water system, and fully reflects energy saving advantages of the air source heat pump.