new pool owner here. We recently purchased a new home with a pool, the pool was built in 2006 and is a Saltwater system. The salt cell is a aquapure plc1400. I've been through the troubleshooting guide and it appears the sensor is bad. I had several pool people over and they looked at the code on the display ( 170 ) and they said it was the sensor. So I purchased a replacement sensor from one of them but when I got it, the original sensor had 3 ports on it. The replacement only has 2? Is this correct? I can provide pictures if need be.