Hot tub motors vary in type depending on frame size; number of speeds; and power efficiency values, such as voltage and horsepower. Spas depend upon the hot tub motor and attached impeller combination, or pump, for moving water rapidly through the jets and filtration system. The motor can fail over time, requiring immediate replacement.
Two frame sizes are available for hot tub motors. The most common size is the 48 frame, measuring about 5.5 inches (14 cm) in diameter. A larger size motor is referred to as the 56 frame, with a diameter of 6.5 inches (16.5 cm). The 48 frame is normally the factory-installed motor, since its smaller size creates a lower overall price tag for the spa.
One advantage of a 56 frame motor is a lower running temperature. The smaller 48 frame generates more heat in its compact space, reducing motor service life. The larger 56 frame distributes heat more efficiently, retaining a cooler internal temperature and lengthening its work life. In addition, the 56 frame boasts more power for forceful jet outputs. On the downside, the larger frame motor can be expensive to purchase initially.
Hot tub motors are available in one or two speed versions. One speed motors provide a constant water movement for both the jets and filtration processes. Two speed motors provide low and high speed choices; low speeds for water filtration circulation and high speeds for jet motion. The two speed motor saves energy by alternating between low and high modes, also saving on electrical costs for the spa owner.
Each motor has a specific horsepower and voltage value, based on the impeller's specifications and the spa's electrical system. Spa owners can upgrade their hot tub motors to a higher horsepower value for stronger jet action. Spa specialists suggest that horsepower should not exceed more than one horsepower above the spa's specified value. The entire pump may become damaged with excessive horsepower needs.
Spas can run on 120 or 240 volt pumps, depending on their specific electrical design. Those that are wired for 110 to 120 volts must use a 120 volt pump. Higher voltage spas, between 220 and 240 volts, can use either a 120 or 240 volt pump. When replacing the motor, the spa owner should verify the needed voltage in the owner's manual before purchasing.
Replacing hot tub motors requires handling electrical wires. The spa's electrical system should be disconnected from the main electrical panel when working near or directly on the motor. Only when all loose wires are securely attached to the new motor should the spa be reconnected to the main electrical supply.