March 24th, 2014 by Jacqui Blanton

The Different Kinds of Pump Motors

Your pump’s motor main function is to turn the impeller inside the pump. When it needs to be replaced, you need to make sure you get the right kind of motor for your pump. When replacing it, you also need to replace the shaft seal and all internal -rings. The three most common kinds of motors are:

  • Through Bolt: These kinds of motor are found on several self contained spa pumps and above grounds pool pumps. The bolts attached to the wet end extend through the back. They are generally 120V, but 240V versions are becoming more common.
  • Square Flange: They bolt to the pump with four stainless steel 7/16ths 1.5″ bolts. Their horsepower ranges from 3/4 to 1.5 as dual voltage. Square Flange motors are common on permanently installed spas.
  • Round/C Flange: Also use stainless steel bolts and are round, hence the name.

If you need to replace your motor, head on over to and check out the ones we carry.

Pool & Spa Motors