Why Does My Hot Tub Cover Stink?

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Is there a funky smell coming from your hot tub cover? Is it totally ruining your chill vibe? Sometimes you can fix a stinky hot tub cover quickly and easily, but if the smell lingers and your cover is holding water, it’s time to say goodbye and get a new one. The first order of business is figuring out where that smell is coming from and how to make it disappear!


There are several reasons why your cover may be taking on a peculiar stink. In most instances though, the smell is due to the spa water condition. Maintaining the proper water balance and sanitizer level usually prevents odoriferous covers.

Outer Jacket


Figuring out where the smell is coming from involves a little process of elimination. Start by removing the cover from your tub and moving it where you can spread it out. Unzip the jacket and carefully remove the foam cores.

Spa Cover4

Thoroughly check the outer jacket for tears or holes. Small to medium holes or tears can be patched with a vinyl patch kit. Carefully cleaning and drying the spa jacket inside and out before performing repairs yields the best results. If there are large holes or deteriorating material on your spa cover jacket, it’s a lost cause and should be replaced.

Learn how to care for mold in or on the spa cover here.

Core Liner


Spa cover foam is sealed with a protective plastic liner (vapor barrier) to keep moisture out. Check the liner for holes or splits in the seams.

If the foam core vapor barrier has been punctured or opened, but the foam itself is not saturated with water, try drying the foam and repairing the liner with a patch kit. If the hole or tear is too large to patch or the foam core is saturated, it’s time to replace your cover.

Tip: A good indicator that the foam core has become rotten or waterlogged is that your cover will be very heavy.

Broken or Cracked Foam


Broken or cracked foam cores mean your cover will lose its form, eventually allowing it to make contact with the spa water. Any contact with the water will lead to further deterioration. In this instance, replacing your cover as soon as possible is best.

Trapped water inside the foam stagnates pretty quickly and starts to stink. Once your spa cover foam is waterlogged, it no longer provides any heat retention, causing your electricity bill to soar.

Spa Cover Cleaners

303 fabric guard, spaange and ecoTUB spa clean

Non-abrasive oil free cleaners specifically designed for your hot tub and cover are a no brainer. While there are other cleaners out there, these could actually harm your spa cover in the long run. Cleaners not intended for hot tub cover use could also get into your water and cause a chemical imbalance.

Not sure where to start? Check out this Spa Cover Care Kit, with everything you need to maintain your cover!

*Do not use bleach, drain cleaner other household cleaners on your spa cover, as this could accelerate cover deterioration.



Maintaining your spa cover and water are essential in keeping your cover like new.

Create a monthly spa cleaning routine that includes cover maintenance.


  • Try to keep the top of your cover free from debris, dirt and dust. This will prevent your cover from getting damaged and keep debris from getting into your water.
  • Using 303 Aerospace Protectant will protect your cover from fading and cracking.
  • Do not use silicone oil based treatments, this will accelerate sun damage and deterioration.
  • Remove your cover every few months to a dry safe place to let it air out.
  • Use a floating spa blanket to protect your cover from excess chemical evaporation and moisture.
  • Make sure your spa water is properly balanced. Out of balance water can allow bacteria growth or deterioration of your cover. Under maintained water can lead to bacteria growth on and in your spa cover.

Have questions about cover care? Ask us below!

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