There are two important parts that make up a hot tub pump; the hot tub motor or spa motor and the wet end. The wet end as its name implies is the part that actually holds the water. The hot tub motor is the mechanical portion of a hot tub pump. The hot tub motor will control how much power is generated and how fast the impeller can move water through the wet end. The main things to look for in a hot tub motor are the horsepower, the number of speeds, frame and the voltage.
Horsepower (HP) is a unit used to express the amount of power being put off by an electrical motor. Hot tub motors used for hot tub jet pumps normally range in horsepower from 1 horsepower to 5 horsepower. The higher the horsepower the stronger flow the pump will produce. If you are looking to replace a motor, you would normally want to stick with the amount of horsepower that was on your original motor as put in by your spa manufacturer as they determine the need for power based on the number of hot tub jets you have and the power needed. If you do wish to have a spa motor that puts off more/ less power it is recommended that you do not go up or down by more than 1 horsepower rating.
Example: If you currently have a 3 HP motor, you should not change to anything smaller than a 2 HP motor or large than a 4 HP motor.
Hot tub motors are rated as either a 1 speed motor or a 2 speed motor. The speed describes how many settings there are on the hot tub motor. A 1 speed motor will have 1 speed setting, basically on/ off. A two speed motor will have a high speed and a low speed setting.
Hot tub motors normally come in one of two frames, a 48 Frame or a 56 Frame. These frames refer to the size and bolting patterns of the motor. When replacing a motor it is important to note the frame of your previous motor so the bolting pattern will match up. That being said, some manufacturers sizing varies a little so one manufacturers 56 frame motor may not be an exact match to another manufacturers 56 frame. If you are replacing just the wet end for your pump it also very important to note the frame of your spa motor as the wet end will not be able to mount to the motor unless it is the correct frame size.
It is important to know what voltage of electricity will be powering your hot tub motor. Motors are generally available in 115 volt (V) or 230 V. Trying to use a motor with the wrong voltage will result in huge problems!
If you are trying to replace your hot tub motor be sure to match up horsepower, speed, frame, and voltage of your existing motor to ensure you are getting a proper replacement.