Reversible heat pump system

A control system for controlling a reversible heat pump system capable of either heating water or cooling water to be delivered to a plurality of heat exchangers, said control system comprising:

• a plurality of zone controllers, each zone controller connected to a respective heat exchanger so as to control the delivery of water to the respective heat exchanger, each zone controller being operative to generate a demand for either heated water, cooled water or no water;
• a heat pump system controller in communication with each of said zone controllers, said heat pump system controller being operative to periodically receive each zone controller's demand for either heated water, cooled water or no water, said heat pump system controller being furthermore operative to periodically determine whether there is a predominance of heating or cooling demands being received from said zone controllers, said heat pump system controller being still furthermore operative to normally set a reversing valve within the heat pump system so as to configure the heat pump system to heating when there is a predominance of heating demands received from said zone controllers or set the reversing valve within the heat pump system so as to configure the heat pump system to cooling when there is a predominance of cooling demands received from said zone controllers;
• and
• a temperature sensor for sensing the temperature of the water returning to the heat pump system wherein said heat pump system controller is operative to set the reversing valve so as to configure the heat pump to either heating or cooling only if the sensed temperature of the returning water is within a predefined temperature range.