Hayward HeatPro® Heat Pro All Models - Page 28

Heat Pump Pool / Spa Heater Owner's Manual FLOWRATE MODELS: PE 42** / PE22** / HP-4* / PE 32** The 3 ¼ HP is designed for nominal water flow of 45 gpm through the condenser. A minimum flow of 20 gpm is required to insure sufficient heat removal from the condenser, thus avoiding overheating the unit. Flow rates above 75 gpm will begin to create excessive pressure drop through the condenser and require unnecessarily high pumping energy. MODELS: PE 52** / HP-5* The 5 HP is designed for nominal water flow of 55 gpm through the condenser. A minimum flow of 30 gpm is required to insure sufficient heat removal from the condenser, thus avoiding overheating the unit. Flow rates above 75 gpm will begin to create excessive pressure drop through the condenser and require unnecessarily high pumping energy. EXTERNAL BYPASS If the flow rate exceeds 75 gpm, a bypass loop must be installed around the heat pump (refer to page 20). The bypass loop piping should be sized to provide approximately 40-60 gpm to the heat pump. Pump capacity versus backpressure performance curves for the pump used in the pool system should be consulted to determine the flow rate. This may require a pressure or flow gauge measurement at the pump discharge. UNIONS A detachable connection (union) must be utilized immediately adjacent the heater to facilitate servicing and winterizing the unit. (See example on previous page) INSTALLATION OF POOL HEATER ABOVE POOL SURFACE If the pool heater is installed more than three feet above the surface of the pool water install directional flow fittings on the end of the return water line to the pool. This will create adequate backpressure at the heater to operate an important water pressure switch. A pool supply company can help you with directional flow fittings. In some cases, such as when the heater 6-8 feet above the pool surface, it may be necessary to install a positive flow switch such as AQUALARM™ in the water line instead of the pressure switch. INSTALLATION OF POOL HEATER BELOW POOL SURFACE Adjustment Knobup decreases pressure setpoint down increases the setpoint Water Pressure Switch A water pressure switch is integrated into our systems to ensure that the unit only operates when water is flowing through the heat exchanger. If a pool surface is above the heat pump, backpressure of water from the pool can cause problems with an internal water pressure switch setting. The water pressure switch is located in the control panel of the heat pump. Backpressure from the pool can close this switch, whose function is to tell the heat pump that the filter pump is running. This pressure switch setting should be adjusted so that the unit is running only while pool filter pump is operating. Caution: If the heat pump runs for more than a couple of minutes without the filter pump in combination, the unit will overheat and be damaged. 27