October 6, 2023

What You Need To Know About Picking The Perfect Spa Pump

Hot tub manufacturers choose a pump based on their specific needs. We should follow their example when selecting a replacement.

Factors include sufficient power, meeting required GPM rates, fitting in the location, and matching plumbing sizes and voltage requirements.

Spa Pump Voltage (v)

Before installing a pump, it's crucial to ensure that the voltage rating of the pump matches your spa control system.

Failing to do so can result in the pump working in a diminished capacity, not working at all, or even causing severe damage to both the new motor and the control system.

The voltage rating can be found on the pump motor specification sticker, labeled as "Volts" or "V," and usually identified as either 115v or 230v.

Spa Pump Amperage

When it comes to measuring the power of a motor, its amperage rating is a more accurate measurement than its horsepower rating. This measurement can be found on the pump's motor spec sticker, usually indicated by "Amps," "SFA," or simply "A".

For pumps with single voltage dual speed, there will be two amperage ratings - one for high speed and one for low speed. Similarly, for double voltage pumps, two amperage ratings will reflect how much power is being drawn when wired at either 115v or 230v.

It's worth noting that the amperage rating accurately measures the ability being removed and that 230v usually pulls about half the amperage of 115v.

Spa Pump Horsepower

When choosing a pump, the strength of the motor can be indicated by horsepower, which is similar to your car. The motor spec sticker or the pump manufacturer sticker usually displays the horsepower rating, but sometimes, it may need to be listed. It's essential to keep in mind that you should not solely rely on the horsepower rating when selecting your new pump.

Connection Size

Plumbing connection size is also significant when choosing your replacement spa pump. Make a mistake, and the plumbing will not connect. Determining your connection will be fast and easy with just a couple of simple steps.

To determine the size of the connection for your pump, it's best to measure the outer diameter of the intake and discharge of your pump's wet end (outside thread to outside thread). Remember that some spa pump models may have different-sized connections for each.

For instance, you may find that your suction has a diameter of 2.5" while the discharge has a diameter of 2". It's worth noting that different types of threads may physically measure differently than how they're labeled.

For instance, a 2" Buttress Thread may measure 3". Buttress threading is standard on most spa pumps, and it utilizes a threaded union to attach the pump's wet end to the plumbing.

To measure, close the valves to isolate the pump or drain the spa. Then, unthread the unions and measure the diameter of the male threaded connections on the pump wet end. Be sure to measure the intake and the discharge to ensure everything is clear.