Spa Pump Replacement Guide

spa pump close up

With regular use, a quality spa pump can last an average of five to ten years. If you’ve had your spa pump longer than five years and start to experience frequent maintenance problems or major breakdowns, we recommend replacing the entire pump instead of troubleshooting its various components. In this guide, we’ll go over some of the common causes for spa pump and motor failure and provide troubleshooting tips. We’ll also cover what you need to know and what steps to take to replace your spa pump.

What is a Spa Pump?

A spa pump is vital piece of equipment for any spa or hot tub. It is responsible for drawing water into the spa’s filtration system where its momentum pushes the water through the filter, heater and spa jets before the water is returned to the spa. A spa pump is comprised of two main components: the motor and the wet end. The impeller is powered by the motor and is located inside the wet end. The impeller propels the water through a discharge port on the pump located on the side or center of the housing, and this is why pumps are referred to as either center discharge or side discharge. Available in one or two speeds and horsepower ranging from 1/8 HP for spas that only need water circulation to 5 HP for spas with a large number of jets, there a variety of pumps to fit any spa size or setup.

Common Symptoms of Spa Pump or Motor Failure:

Although there are many causes for pump failure, the following are the most common:

spa pump leakLeaking
Loose frames may cause water to escape while being propelled through the pump. Check the frames and o-rings to ensure they are on secure and tight. leaking can also come from a faulty pump seal. It’s highly recommended to change out the pump seal when you replace your pump to ensure a tight, leak-free fit.
spa pump low water pressureLow Water Pressure
If your water pressure is low, there may be obstructions preventing the impeller from turning. Check and remove any debris to prevent further jamming.

spa pump noiseAbnormal Noise:Worn bearings can produce a humming sound and ultimately prevent the motor from functioning correctly. Check bearings for corrosion or dirt and replace if worn. It’s also good to check the motor coupling, brackets and other attached parts. Check to make sure all nuts, bolts and screws are tight and secure.

spa pump overheatingOverheating:Under regular conditions, you can place your hand on a spa pump without getting burned. When heat production increases and the temperature rises, it causes unnecessary energy to be released. overheating can also occur when there is not enough clean air flowing through the motor. If this is the case, there may be an issue with the motor. One preventative measure you can take is to try and place your spa pump in an area free from dirt and leaves.

spa pump inactive motorInactive MotorIf your motor isn’t working, check to make sure the power switch is on. If it is and it’s still inactive, check for failed relays, burned out wires, or possibly a blown fuse. Be sure to also check all connections including the copper bonding wire and the pump power cable for any signs of damage.

How to Choose the Right Spa Pump:

Because of all the different types of spa pumps available, it can be challenging to choose the correct replacement. To make sure you choose the correct spa pump replacement, check the nameplate of your old pump. Located on the side of the motor, the nameplate lists everything from ambient temperature to voltage information. There are five main things to look for when replacing your spa pump:

  1. Frame size: 48 or 56
  2. Speed: single or dual
  3. Voltage: 115V or 230V
  4. HP: 1/8 HP to 5 HP
  5. Pump Plumbing Size: fittings in 1-1/2”, 2”, some 2-1/2”

spa pump outside diameterCorrectly measuring the pump’s plumbing size is a very important step in replacing your spa pump. Getting it wrong may result in ordering the wrong pump. The fitting sizes listed above are pipe call-out sizes, not fitting measurements.When you’re ready to measure, remove the pump unions and measure the outside diameter (O.D.) of the intake suction port.

spa pump male fittingsYou will notice that the outside diameter is larger than the fitting size. This is the reason using the fitting size as a measurement and not the outside diameter results in ordering the wrong pump size. Having this information handy can help you choose the right replacement for your spa pump and make sure your new pump is compatible with your current spa system.

The following steps are meant to guide you through the spa replacement process. Each spa pump may have different installation procedures and additional connections. Please refer to your product manual to ensure accurate installation.

Spa pump replacement can be done in 6 steps:

Step 1: Turn Power OFF

Be sure to disconnect all power running to your spa and remove the access panel to get to your spa pump and connections.

Step 2: Remove the old spa pump

Shut the valve gates to keep spa water from rushing out when the pump is removed. Carefully locate and unscrew the two union connections. Disconnect the copper bonding wire from the pump and remove the mounting screws from the base bracket. Locate the pump power cable. If it’s still in working condition, remove it from the old pump by loosening the cable clamp screws. If your new spa pump has an included power cable, remove the old one from your spa’s control system.

Step 3: Connect the pump power cable

If you’re using the pump power cable from your old spa pump, it’s important to ensure the wires are clean and pay attention to the wire colors and connections. Be sure to replace the cable in the same manner you removed it from the old pump.

Step 4: Attach the new pump

Place the new pump on its mounting bracket and connect the union parts. Hand-tighten and secure the unions to prevent leaking. Reconnect the copper bonding wire and replace the mounting screws to fasten the pump to its base.

Step 5: Prevent air lock

Step 5 is crucial to preventing air lock and can easily be done before powering on your spa. Air lock happens when air pockets get caught around the impeller and block its function. Open the valves to fill the pump with water, effectively eliminating all air from the pump.

Step 6: Power ON and test

Replace the spa’s access panel and power on your spa to make sure all your equipment is in working condition.

If you experience spa pump failure, remember to pay attention to the symptoms and troubleshoot before considering replacement. Many times, troubleshooting will cost you less than replacing the entire pump. If you plan on replacing your spa pump, take note of your pump’s frame size, speed, voltage, horsepower, and pipe size to make finding a replacement easier. A good spa pump will last you about five to ten years and routine checks will help extend the life of your investment