Hayward Universal H-Series Service/Installation: H150FDN H200FDN H250FDN H300F - Page 27

27 Figure 17 illustrates a typical pool piping diagram and layout for the pool equipment. Figure 18 illustrates a multiple heater installation for very large pools with and without a manual bypass valve. Figure 17: Typical plumbing to pool Figure 18: Multiple heater system INSTALLATION ABOVE POOL/SPA SURFACE: If the heater is installed less than three (3) feet above the surface of the pool/spa water, install eyeball fittings or directional flow fittings on the end of the return water line to the pool/spa to create adequate back pressure at the heater to operate the pressure safety switch when the filter pump is running. If the heater is installed more than three (3) feet above the surface of the pool/spa water, install a loop as shown in Figure 19 to prevent drainage of water in the heater during a filter change. For installation below the pool/spa surface, refer to Section III. Figure 19: Heater installation above pool/spa AUTOMATIC CHLORINATORS AND CHEMICAL FEEDERS: If used, a chlorinator must be installed downstream from the heater in the pool return line and at a lower elevation than the heater as shown in Figure 20. Install a separate positive seal corrosion resistant check valve between the heater outlet and the chlorinator to prevent highly concentrated sanitizers from backsiphoning into the heater. Backsiphoning usually occurs when the pump is shut off and a pressure differential is created. Figure 20: Automatic chlorinator USE ONLY HAYWARD GENUINE REPLACEMENT PARTS Pomona, CA Clemmons, NC Nashville, TN Tel: 908-351-5400 www.haywardpool.com