In this "how to" we will guide you through how to select the correct port size on a replacement spa pump. Most spa pumps are going to be offered with a port size of 1.5", 2", or 2.5". Some spa pumps will have a different intake and discharge port size. For example, some pumps will have a 2.5" intake and a 2" discharge.
If you are replacing an existing pump, it's important to go with a pump with the same port sizes. The problem is that it is not clear to many spa owners what they should be measuring to ensure they get the same port size.
1. IDENTIFY PORTS - The intake port is at the front of the pump and the discharge is at the top or side of the pump.
2. MEASURE OD OF PORTS - Remove the unions from the existing pump. Measure the outside diameter of each port.
Below are the outside measurements for each port size.
Approximate Measurement of 2-3/8" = 1.5" Ports
Approximate Measurement of 3" = 2" Ports
Approximate Measurement of 3-5/8" = 2.5" Ports
Note: Some spa pump manufacturers (Jacuzzi, Sta-Rite, Hayward) do not use standard fittings. The measurements of those ports may be slightly different.
3. PLUMBING SIZE - If you do not have the original pump or want additional confirmation of the required port size, identify the plumbing size. Most PVC plumbing will be marked every foot or so with a measurement.
If you can't find a marked measurement, measure the inside diameter of the pvc plumbing. This will tell you if you need a pump with 1.5", 2", or 2.5" ports.
If you have any other questions about pool and spa products please do let us know - we are here to help!