To conclude,
I re checked my set up this afternoon. I was wrong first time! The raw water comes in through strainer , on through the Reverse Forward box and then on to the Pump. From the pump it goes up to the Syphon Breaker and onto the Heat exchanger . I guess ,but I must I must look a little closer to see if I have a Syphon breaker with a small valve to prevent continuous peeing out of water due to pump pressure. Anyway it looks like my set up is as described by a few contributers. I've learned a bit about Syphon breakers and my cooling system so thanks to everyone for inputs .
