How to Fix a Noisy Hot Tub Pump Motor

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If your hot tub is making a loud buzzing or grinding noise, you can usually bet it’s the motor. This sound is not only obnoxious, but it’s also an indication that soon (if not already) your hot tub will be out of service. We’ll walk you through the steps to pinpoint to cause of the noise and how to fix it below.

NPump1

My Breaker is Tripped

A tripped breaker is usually caused by either a bad heater or a bad hot tub pump. To determine the cause of the tripped breaker, try disconnecting the heater first, and then flip the breaker. If the breaker still trips with the heater disconnected, disconnect the pump and flip the breaker again. If the breaker does not trip with the pump disconnected, you’ve found the source of the problem – a bad spa pump.

Warning

NOTE: If your breaker is tripped but the pump does not hum when you flip the breaker back on, it could just be a bad fuse. In this case, use a multi-meter to test the fuse(s).

Fuse Testing

If all fuse(s) are good, testing the voltage on the back on the motor will verify if the motor is bad.

Pump Voltage Testing

My Pump is Buzzing/Humming

A steady or intermittent buzzing/humming noise can be an indication of a seized hot tub pump. When the pump is seized, this noise happens in conjunction with the following symptoms:

  • Tub will not heat
  • Topside shows a code of OH, DR, FLO, or DRY (codes vary depending on equipment system)
  • Tub will not circulate

A pump will commonly seize due to worn out bearings or trapped debris/foreign objects. The remedy is replacing the spa pump. While there are companies that rebuild pumps, this is often just as expensive (or more) as purchasing a new one.

My Pump is Making a Loud Grinding Noise

A loud grinding or screeching noise is indicative of a motor with bad bearings. Bearings go bad over time due to wear and tear.

A loud pump will eventually stop working completely, so order a replacement sooner rather than later to avoid down time.

Note: There are companies that rebuild motors and/or offer rebuild kits, this is often just as expensive (or more) as purchasing a new complete pump and motor.

Hot Tub Pump Lifespan

The average hot tub pump lasts 4-10 years depending on pump quality and how well the water chemistry has been maintained. Low pH, alkalinity or excess bromine/chlorine can all cause premature pump failure.

Test and balance your water weekly to protect your spa equipment from unnecessary damage.

TestStrips2

Replacing your Hot Tub Pump

Finding a replacement hot tub pump may seem difficult, but it is actually pretty simple. The label on your current spa pump will usually tell you everything you need to know. Gather this information:

  1. Voltage
  2. Amperage
  3. Frame size
  4. Discharge orientation
  5. Plumbing size
  6. Any name brands on the assembly

Pump Cross Reference

Some retrofitting may be necessary for non-standard plumbing. If ever in doubt, email us a photo of your pump and we will happily help you find the correct replacement.

When shopping for a replacement pump and motor, pick a well-known brand. Waterway and AquaFlo pumps are best known for quality and durability.

Looking for more information? Read our Complete Guide on Spa Pump Replacement.

Have questions or comments? Post a Comment below!

4 comments

  1. Helpful info i need to know the diff between frame 48 and 56 as
    I have two pumps in my spa one of each also neither one has hp listed on label

    Like

  2. Hi Tony,
    The best way to find the frame size is by measuring the distance between the through-bolts. Less than 4″ is a 48 Frame, and a 56 Frame will be more than 4″.
    For horsepower, it may be better to find a replacement based on amperage. Here’s a link to our pump article with some images on frame size, a chart at the bottom with pump amperage and other factors, and more info on pump selection and replacement:
    http://www.spadepot.com/spacyclopedia/pumps.htm
    Let me know if there is anything else I can help you with.
    Thank you,
    Sarah
    SpaDepot.com

    Like

  3. Hi Tony,
    My Aqua-Flo circulation pump finally packed up after about 7 years although I had the bearing replaced. However, the brand new Aqua-Flo circulation pump is very noisy and in my mind running hot. it is too hot to hold one’s hand on the case. I measure the outside case temperature which was about 67 Degrees Celsius. I then checked with the supplier who verified that this was within an acceptable operating range so let it be. I also think that the flow seems stronger than from what I recall with the previous pump but cannot be sure. It is still very noisy which is a nuisance. Any suggestions will be appreciated.

    Like

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