Voltage: 220-240V

Speed: 2-speed: 3450 RPM high/1725 RPM low

Horsepower: 4 HP

Amperage: 12A high/4.4A low

Gallons Per Minute: 240 GPM (high speed)

Frame Size: 56 Frame

Intake: 2.5” plumbing (3.625” O.D. pump threads)

Discharge: 2” plumbing (3” O.D. pump threads)

Discharge Type: Side

Wet End Discharge Orientation: Top (can easily be rotated)

Overall Length: 16.75”

Waterway Cross Reference: 3721621-13, 3721621-0306, 3721621-0385V, 3721621-0385B, 3E21821-6310, PF-30-2N22M

Motor Cross Reference: RB817, B235, 5KCP49UN9314X

Warranty: 12 Month Limited Warranty

Horsepower Ratings

Choosing a pump based on Horsepower (HP) can be misleading. The horsepower listed in your spa manual or on old pump's label may be overinflated, inaccurate, or even left blank. Horsepower ratings are often listed as Break Horsepower (BHP), which is not the same as continuous horsepower. Selecting a pump with too much power for your spa can cause significant damage.

To avoid choosing the incorrect pump, use the Amperage rating listed on the old pump's label to find the correct replacement instead of the horsepower. The amperage rating is listed with both high/low speed for a 2 speed pump.

Determining Spa Pump Plumbing Size

Pump plumbing sizes are nominal and not actual outside diameter (O.D.) of the threaded intake or discharge. Use a tape measure and check the diameter of your old pump thread size.

• 1.5” Pump thread measures approx. 2-3/8” O.D.
• 2.0” Pump thread measures approx. 3” O.D.
• 2.5” Pump thread measures approx. 3-5/8”

Orientation of Wet End

Pump wet ends can be oriented in 90º increments to meet your installation requirements. Loosen the four through-bolts from the back of the motor and pull them back enough to disengage. Then rotate the wet end to the desired position realign and re-tighten the bolts. 

Side or Center Discharge

The two spa pump form factors refer to the outflow or discharge fitting on the Wet End. Your old pump will be either Center Discharge or Side Discharge.

In most cases you need to match the existing form factor to get the components to match up. If you can use either form, select Side Discharge, which is more efficient than a Center Discharge pump of the same horsepower.

Motor Frame Size

The physical size of the pump motor is referred to as frame. Spa main pumps will have a size of either 48 frame, which are approx. 5.5" diameter, or 56 frame, which are approx. 6.5" diameter.

Since motor manufacturers do not label frame size consistently, you should determine a motor's frame size by measuring the spacing between the through-bolts on the back of the motor. Bolt spacing on a 48 frame motor will be less than 4 inches. A 56 frame motor's bolts will be spaced more than 4 inches apart.

Note: Because of their lower cost and compact size, most spa pumps in service are 48 frame. The larger 56 frame motors are a little more expensive and somewhat stronger. They tend to operate a bit cooler than 48 frame units, which can mean longer service life.

Configuring a Pump for 2 or 1 Speed Use

Our 2-speed pumps can easily be configured for 1-speed. Wire the common and high speed terminal connections, while leaving the low speed terminal blank.