Tips for Choosing the Correct Pump Wet End

When choosing the correct hot tub pump or wet-end replacement, in addition to knowing the specifications such as Horsepower, Amperage, Speeds, Voltage and Frame Size, you will need to confirm your pump wet-end style and the connection sizes of the intake and pressure side.

There are two primary orientations you will generally encounter, either the more standard side discharge, where the discharge is off-center from the intake, or center discharge, where the pressure side is centered with the intake side.

Side Charge:

Center Discharge:

You will also need to confirm the wet-end connection sizes to make sure that it fits correctly with your pump union plumbing connections.

The most common sizes are 1.5”, 2”, and 2.5”

To determine the size of your wet-end connection (also called buttress), measure the outside diameter (OD).

If the OD measures closest to 2-3/8”, then the wet end connections are 1.5”

If the OD measures closest to 3”, then the wet-end connections are 2”

If the OD measures closest to 3-5/8”, then the wet-end connections are 2.5″

*Please note that some pumps have different-sized connections for the suction and pressure side of the wet end, so it is a good idea to confirm both connections.