How To Install A Portable Hot Tub Pump

Has the water stopped circulating in your portable hot tub? Has the motor started making strange noises? Worst of all, have the jets stopped blowing? If any of the answers are “yes,” then it’s likely you need to install a new hot tub pump.

The pump is the beating heart of your hot tub. For most portable hot tubs, it draws water through your hot tub’s filtration system, then pushes it through the heater and back into the hot tub via the jets. The pump handles most of your hot tub’s functionality, so its absence is missed when things go wrong. Happily, with preparation, installing a new pump in your portable hot tub isn’t particularly difficult. That said, if you’re in doubt about your skills, we recommend having a service professional install the pump for you.

Repair Or Replace?

You might be asking yourself if you need to replace the entire pump, or just replace the motor inside the pump. The answer to this question lies in the age and condition of your existing pump. If the pump looks to be in good condition and only the motor has stopped functioning, replacing only the motor is a more cost-effective solution. However, if the pump is old and worn, and the motor is rusted or damaged, installing a new pump is the easy choice. An added benefit here is that newer pumps are more hydraulically efficient than older ones.

Choosing The Right Pump

First, a quick note: the following guide is written for portable hot tubs. The procedures for replacing in-ground spa and hot tub pumps are notably more complicated, and we recommend hiring an expert technician to handle it for you.

That said, when replacing the pump in your portable hot tub, it’s important to buy a new pump with the same specifications as your old one. Your hot tub was designed to use a specific kind of pump; matching the original pump should be your top priority. The label on your old pump’s motor contains all the details you’ll need to order the correct replacement. Particularly of note are the following specifications:

  • Frame Type (FR) will be either 48 or 56.
  • Horsepower (HP) will vary between 3/4 to 5 HP.
  • Voltage will be either 115V or 230V.
  • Discharge (the outlet of the pump) will be either top or side.
  • Speed will be single, 2-speed, or variable speed.

If you appear to have two different pumps, they’re both likely single speed. If you’re capable of changing the force of your water flow, the pump is a variable speed or 2-speed pump.

One other important aspect of your hot tub pump is the diameter of the plumbing unions. While most pumps use a 2" type of threaded connection, they can vary from 1-1/2" to 2-1/2". Of note: when measuring the pipe diameter of your plumbing, always measure the inner-diameter. For example, a 2" pipe has an average inner diameter of 2.047" and an outer diameter of 2.375". Additionally, some pipe adapters are designed to go inside the pipe, while others are designed to go over it. In general, just try to match the connections in your existing system.

Disconnecting Your Old Pump

When you have your new hot tub pump on hand, it’s time to install it. But first, you have to take the old one out. Start by shutting down all power to the hot tub by flipping the circuit breaker. Leave a note by the breaker explaining why you’ve turned it off so that no one else turns it back on by mistake!

Having ensured that there’s no power going to your hot tub, you can remove the pump. Drain the hot tub completely per the manufacturer’s recommendations, then loosen the union nuts on the connections. Several gallons of water may drain out; this is completely normal.

Disconnect the bare copper bond wire from the pump, then remove the bolts securing the pump to your hot tub. Once the pump is free, you’ll have access to the wires entering the rear of the motor. Open the cover plate and remove the individual wires from the terminal screws. Afterward, pull the power cord, which includes the wires, out of the motor. Note: if there is an electrical conduit with wires attached to the motor, remove the individual wires from the terminal screws and disconnect the conduit. If the power cord and/or conduit are still in good condition, you should be able to use it with your new pump, so set it aside for the time being.

Connecting The New Pump

Connecting the new pump is effectively the same as disconnecting the old one, just in reverse. With the pump still free of the hot tub, connect the wires of your power cord or electrical conduit to the same terminals they were connected to on the old pump. Ensure that the connections are tight and that no wires are touching each other. With the wires secured, you can replace the cover plate.

Place the new pump onto the hot tub’s mounting bracket, but don’t screw the bolts back down quite yet. First, connect the bare copper bonding wire to the new pump. Then, check the plumbing unions to see if their O-rings are still intact. If not, you should replace them before going any further. With that taken care of, tighten the plumbing unions onto the motor, then bolt the pump into the mounting bracket.

The Finishing Touches

Before powering on your hot tub and taking your new pump for a spin, you need to prevent “air lock” from happening. An air lock can stop the water from reaching the pump’s impeller, which actually moves the water. To prevent this from occurring, you first need to refill your hot tub. Afterward, just open up the suction and pressure side valves of your hot tub (if applicable), filling the pump with water. Check for any leaks during this process and tighten up the valves if necessary.

When your hot tub is full and there are no leaks in the system, you can restore power to the hot tub. Your water should start heating up and your jets will start up again. In a few short hours, you can hop right back into the tub! If you still need help with your pump installation, check in with the experts at your local Leslie’s. They can give you all the help you’ll need to have your hot tub bubbling back up in no time!

Essential Products

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Leslie’s makes every effort to provide accurate recommendations based upon current ANSI/APSP/ICC-5 2011 (R2022) standards, but codes and regulations change, and Leslie’s assumes no liability for any omissions or errors in this article or the outcome of any project. You must always exercise reasonable caution, carefully read the label on all products, follow all product directions, follow any current codes and regulations that may apply, and consult with a licensed professional if in doubt about any procedures. Leslie’s assumes no legal responsibility for your reliance or interpretation of the data contained herein, and makes no representations or warranties of any kind concerning the quality, safety, or suitability of the information, whether express or implied, including, without limitation, any implied warranties of merchantability or fitness for a particular purpose.