Loud hot tubs can produce grinding, screeching or sometimes buzzing noises, that can ruin your mood and cause frustration to you and your neighbors. This noise is usually due to a faulty or simply loud motor.

The most effective way to soundproof a noisy hot tub motor is by covering it with sound-deadening materials such as thick foams or mats. Another approach is to create a sound blocking enclosure around the hot tub. Placing the hot tub into the ground is one way of doing so, as is creating a wooden or brick enclosure and possibly covering it with mass loaded vinyl.

These methods and a few others will be explained in more details throughout this article. Now, let’s check out the common causes for a noisy hot tub motor before jumping to the best soundproofing methods for your particular situation.

Where the noise is coming from:

We often blame the electric motors for the sound annoyance, while other causes are left neglected. But the three most likely causes are:

Seized Hot Tub Pump

If the hot tub motor gets seized due to worn bearings, it might cause buzzing (or humming) noise coming along with some symptoms such as lack of water heating. Mostly, debris or buildup is the leading cause of bad bearings. Nevertheless, the replacement of bearings is the only fix for this issue.

Blocked Air Jets

Air jets are responsible for blowing pressurized heated air and carrying water circulation. And even the most minor blockage might cause an annoying buzzing sound. The only possible solution is replacement.

Amplification through the surface

Everyone acknowledges that mechanical components produce what are known as “mechanical sounds”. There is very little possibility of eliminating the sounds altogether; however, they are reduceable, by using the beforementioned sound deadening foams and mats.

How to Soundproof a Hot Tub Motor

Here are the best ways to keep the noise at bay, along with step-by-step instructions and product recommendations:

1. Create a special soundproof casing for the motor:

Hot tub motors are rarely fitted within the main body or mostly separate from the main body. When the motor is not fixed, it might not have any special casing (or housing) to sit in the main body. But, this occurrence varies from manufacturer to manufacturer. However, you can build on your own without requiring any craftsman.

Required Material: 

• MDF Sheet
• Sound-Deadening Mats
• Sound Insulation Foam Pads
• Acoustic Caulk
• Bottle of Glue
• Angular Spiral Nails

How to assemble:

1. First of all, make the proper measurement of hot tub motor dimensions on the MDF sheet. Leave some additional inches for ventilation purposes and acoustic foam pads.
2. Drilling one or two ventilation holes on one side is enough. Adding too much might not reduce the loud noises.
3. Set a thin glue layer on the back of sound-damping mats and put the sheet together while fastening the sheet’s edges with acoustic caulk. (Perform the same step for each lid side)
4. Now, you need to stick the acoustic foam pads on the sound-damping mats, again putting the acoustic caulks on the edges.
5. When it dries out, hammer the nails on lids together (one by one). After this, make sure to add some acoustic seal on the box edges.
6. Your soundproof hot tub motor enclosure is ready!

2. Fit soundproofing sheets under the motor

If you have your hot tub motor fitted within the main body, then you might not be able to make a soundproof enclosure. The possible and easiest solution for reducing the hot tub’s highly irritating sounds is putting the soundproof sheet under the motor.

These sound deadening mats are made with possibly the safest and unique rubber, thus having wide acceptance in automobiles. You will notice significant results after following the instructions.

In some models, the motor casing is screwed into the base, while others have unfixed a freely moving motor. We recommend lining the adhesive sheet beneath the motor housing (or case) precisely or fit the casing on the mat.

Note: “We do not recommend insulating the motor directly with sound-deadening sheets as it might disrupt heat transfer, causing the motor to overheat.”

Sheet Recommendation:  NOISE 6mm ThickSound Deadening Mat It has superior quality sound deadening sheets, water/oil resistant, and can tolerate higher temperatures easily. Usually priced around $20.

Tools Required: CARTINTS Smoothing Seam Roller Tool Its a metal roller with great plastic grip that allows easy and efficient working on vinyl and sound deadening sheets. It is around $15-20.

Instructions for applying:

1. Using the screwdriver, open the casing from the base.
2. Measure the base of the hot tub motor casing.
3. Mark those measurements on the backside of the sheet.
4. Now, cut the sheet according to measurement with great precision.
5. Peel off the other side of the sound-damping sheet.
6. Apply the sticky (adhesive) side to the hot tub motor casing.
7. After applying the sheet, start rolling the smoother tool on the sheet.
8. Now, let it dry for few minutes.
9. Fasten the clockwise screws.

 3. Place the hot tub on a solid base

As spoken earlier, surface materials have an enormous amplification effect on the motor’s noises (even if soundproofed). The more solid the underlying surface, the less noise it amplifies. Thus, always look out for any loose metal slats or unsteady wooden flooring.

Albeit, you have put your hot tub on something solid and hopefully a bit soft, such as sound-deadening mats. Having said that, non-adhesive, anti-vibration mats are much similar to those sound dampening sheets mentioned earlier. Try putting your hot tub on one or more of the pads.

These mats will reduce those irritating vibrations coming from the heater or water pump or even air jets. Having said that, it would be best to have accurate measurements of your hot tub before placing an online order.

Material Recommendation: DiversiTech Condenser Pad (36 inches x 36 inches pad) These condensing pads have been wisely designed for outdoor uses, durable enough to withstand harsh weather conditions. They have a unique texture and provide a firm grip on gravel and soil. You can easily grab them about $70 per pad.

Instructions for applying:

1. Move aside the hot tub, and check for the leveled ground.
2. Unwrap anti-vibration mats, and put them where you plan to set thehot tub.
3. After setting the mats, place your hot tub on the anti-vibration mats.

4. Set the hot tub within an enclosure

Aside from soundproofing the hot tub motor from the ground-up, you can also surround the hot tub with a sound blocking enclosure.

You can consider digging a hole in the ground and putting your hot tub in there as it will significantly absorb all those buzzing, grinding and screeching sounds. However, you could also construct a brick or wooden enclosure and add mass loaded vinyl internally or externally to soundproof the enclosure. MLV has multiple sound-damping properties. It works great both for airborne and vibration noises.

Material Recommendation: Arrowzoom (Mass Loaded Vinyl Sheet) These noise barrier sheets have excellent properties. Each mass-loaded vinyl sheet could cost you around $50. They are frequently used for these types of projects because of their ability to block low and high frequency sounds.

Instructions for applying:

1. Set up the enclosure.
2. Put these sheets within an enclosure. (Inside a wall it should be installed directly on the studs, or nail it directly on the wall surface.)

5. Filling the noise leaking gaps with spray foam

Spray foam has been well-proven for sealing the deep crevices surrounding every component inside the hot tub.

Be careful while spraying the internal components not to close off the air ventilation ducts. Whatever you do, never spray the filtration and heating equipment.

Material Recommendation: Great Stuff Foam Sealant (White Pack of Two) This pack of insulation foam cans is affordable and comes along with a smart dispenser, saving your time and filling gaps up to inches in proximity. It is a highly long-lasting and durable component, having quick setting time and water-resistant properties.

Instructions for applying:

1. Ensure the hot tub box’s inner side is free from debris and rust.
2. Connect the smart dispenser with an insulation can, and start spraying uniformly.
3. Double-check and avoid the copper or metal ventilation pipes and components.
4. After completing spraying, let the foam inflate.
5. Now, you can put the panels back on the casing.

Final Thoughts:

I hope some of these ideas will help you soundproof your hot tub motor for your and your neighbors peace of mind. Inspect your hot tub’s location (and your budget) and see which is the best for your situation. Hope this helps!