The advanced water-source heat pump controller with a digital diagnostic display indicates either the current operational mode or a fault lockout code. The digital display greatly enhances the ability of service personnel to check the operation of the unit in a timely manner. The Vacated Premises Control feature of the HPC-4000 Series ensures that the unit will operate a minimum of one or two hours per day during extended periods of vacancy. This option also includes an automatic reset feature. If a fault occurs, the system will shut down, but then automatically reset every 24 hours. If the same fault exists each day, the unit will lockout on the fourth day and have to be manually reset. Other standard features of the controller include high- and low-pressure controls, water coil and air coil low-temperature protection, over/under voltage protection, and condensate overflow lockout. An anti-short cycle timer and a random restart timer prevent premature cycling of the compressor. The HPC-4000 Series can be set up to work with either a PSC or X13 fan motor. Selectable dip switches can be used to configure OEM custom options such as compressor and fan delays.