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Reasons Why Your Hot Tub Cover Is Losing Heat

When was the last time you paid a second look to your hot tub cover? If it’s been a while—as in several years—you’re going to want to run outside and take a good look.

Hot tub covers aren’t meant to last forever, which means that over time, your cover can slowly fail at its job due to the wear and tear of the elements. This can cost you a lot of grief when it comes to repairs and your electric bill, as your hot tub loses heat and critical components begin to break.

To learn more about why your hot tub may be losing heat and whether it’s time for a new one, keep reading.

The Importance of Your Hot Tub Cover

Covers are an essential part of your hot tub, and for several reasons. Some of those reasons you may not even be aware of. Regardless, having a sufficient cover over your hot tub is a non-negotiable part of hot tub ownership.

Here’s what having a hot tub cover brings to the table:

Sun Protection 

Most hot tubs are made from acrylic material, which can deteriorate quickly under constant UV ray exposure. Leaving your hot tub uncovered under the sun over time will cause you to lose out on your overall investment.

Temperature Maintenance 

Hot tub covers provide insulation to help trap in the heat. Maintaining a consistent temperature for your hot tub’s water when it’s not in use is critical, especially during the wintertime. Leaving the water exposed to the elements will cause it to work overtime to maintain a consistent temperature, which will cause an increase in your energy bill as well as a decrease in the hot tub’s efficiency over time.


If nothing else, hot tub covers serve the purpose of keeping your hot tub clean. They protect the water and materials from dirt, debris, leaves, free flowing garbage, pollutants, bugs, and even animal dander. This cuts down on your cleaning time as well, since you’ll only have to deal with the upkeep rather than skimming out all of the above-mentioned contaminants.  


Most hot tub covers come with some sort of lockable safety measure. This serves to keep young children with capable hands from removing the cover, climbing in, and possible drowning or becoming injured. In general, a hot tub cover provides safety from animals as well. The last thing you want is the family pet or a wild animal hopping in and damaging the interior components—or drowning. 

This is especially true if you live in an area that has larger wild animals roaming around, such as bears. There’s nothing worse than getting ready for a nice long, relaxing soak in your hot tub only to find that a stray bear has wandered in and beaten you to it. 

Reduced Chemical and Water Costs

Anything that touches the water in your hot tub—dirt, debris, rain, UV rays, etc.—can alter its chemistry. It also causes water loss via evaporation. By keeping a cover on your hot tub, you’ll be able to provide protection from these alterations and escaping water which will save you money in the end on both chemicals and damage.

The Anatomy of a Hot Tub Cover

Hot tub covers are a bit more complex in their make up than most people realize. Understanding the anatomy of these covers is the key to ensuring you choose the right one for your hot tub when the time comes, as well as addressing the signs that there’s an issue.

Here’s the breakdown of what the typical hot top cover is made up of:

  • A solid foam core sealed in plastic to avoid water absorption
  • A vinyl covering, usually heavy-duty marine-grade for waterproof protection and added insulation
  • Hinges, heat seal shoes, and handles, usually tapered and reinforced for durability
  • Locks and straps

While some hot tub covers are automatic, they’re all built relatively the same, and with the same purpose: To seal the hot tub ensuring no heat escapes, no elements enter, and that each component is protected and insulated. Their hinges allow for compartmentalized opening, folding half the cover back and then stacking on top of the other half. This is meant to make the process of removing the cover easier, as they tend to weigh between 30 and 75 pounds. 

It’s also important to note that while the term “heavy-duty” is often used to describe a hot tub cover’s materials, this does not equate to its weight bearing capacity. Most hot tub covers can only withstand a few pounds. Even if the manufacturer claims that their hot tub covers can handle a lot of weight, they’re not designed for people or animals to walk or lay on.

Reasons Why Heat Is Escaping

A poorly manufactured cover can be responsible for roughly 80% of your hot tub’s heat loss. However, the same goes for aging hot tub covers. 

The average cover is meant to last up to five years with proper care. However, premature wear and tear can happen with improper handling, allowing children to play with the covers, allowing animals to trek across the covers, and so on. These are all things that lead to heat loss.

Over time, the materials will deteriorate. How long this takes depends on several variables, including your climate, the quality of your hot tub cover, and how well you take care of your hot tub and its cover in general. As the cover’s materials begin aging and deteriorating, water begins to find its way into the foam core, causing irreversible damage. It becomes heavier and misshapen, causing it to seal improperly, allowing the heat to escape through the seams. 

On top of that, water serves as a perfect conductor of all temperatures, which will not only absorb colder temperature allowing heat to escape, but it’ll significantly affect your electric bill. Aside from the irreversible water damage, wet foam becomes a breeding ground for bacteria, causing further deterioration—not to mention a foul smell. 

The Signs it’s Time to Replace Your Hot Tub Cover

Sometimes, the heat loss via hot tub cover is only a subtle indicator that it’s time for a new hot tub cover. That means you’ll need to learn the more specific signs that your cover has met its expiration date.

Here are the signs that it’s time to replace your hot tub cover:

1. The Vinyl Is in Questionable Condition

When you notice that the vinyl covering has begun to dry out, crack, tear, and is dirty—it’s a sure sign that you need to replace it right away. You can fix small tears here and there with a vinyl repair kit. However, those quick fixes will only last you so long. Additionally, the larger the tear, the less likely you’ll be able to patch it up. Either way, there will come a point when the issue goes beyond the vinyl covering, and seams begin to come loose as well.

2. The Cover Is Losing its Shape and Sagging in the Middle

We mentioned earlier that there comes a time when your hot tub cover will no longer maintain its sealing quality. This allows for the heat to escape and creates an opening for the elements to enter as well as dirt, debris, and other contaminants. It also means you’ll have to continuously add more water to combat evaporation.

The primary way a hot tub cover loses its shape is when it begins to sag in the middle. It’s also one of the clearest signs that it’s time for a replacement cover. The main culprits of a warped hot tub cover are usually heavy rain and snow falls that pool in the middle and compromise the structure of the cover. 

3. There Are Broken Components

The unsung heroes of your hot tub cover are the tie-down straps, handles, hinges, and locks. These are all things that keep your hot tub cover in place, safe and secure, and allow you to remove the cover with ease.

If just one of the tie-down straps on your hot tub cover is broken, then your entire cover is compromised in terms of sealing power. Torn hinges can also allow heat to escape as well as prevent you from uncovering your hot tub with ease. In most cases, locks and handles can be repaired or replaced. However, after a while, it won’t be worth it.

4. It’s Gaining Weight

Once the foam core in your hot tub begins absorbing water, it becomes heavier. Not only does waterlogged foam cause immense heat loss, but it makes removing the cover much harder.

If you have an automatic cover lifter, the weight gained over time can cause this function to break as well. If you don’t have an automatic cover lifter, you can test out the weight by simply attempting to lift your hot tub’s cover. If you can’t manage it by yourself, it’s a sign that the foam core is indeed waterlogged—and there’s no turning back.

5. It Smells

As we’ve also mentioned before, wet foam attracts bacteria that grows over time in dark moist spaces, such as mold, for example.  After a while, the bacteria and mold growth will begin to emit a noticeably foul odor. So, when you go to open up your heavy hot tub cover and notice a bad smell, you’ll know it’s time for a new cover.

What to Look for in a New Cover

If you’ve noticed one or more of the above signs indicating that you need a new hot tub cover, you’re probably wondering where to start in your search. The hot tub cover market isn’t overwhelmingly saturated. However, there are a lot of so-so products out there claiming to be better than they are for an “affordable price.” 

Price is arguably the last thing you should consider when it comes to investing in a new hot tub cover. Instead, look at the following first: 

The Materials

We discussed the anatomy of hot tub covers above. They’re made up of solid foam cores, sealed-in plastic casing, and vinyl coverings on top of that. 

The foam core piece, or pieces, are designed with a specific density that contribute to the cover’s energy efficiency. The density, including the depth and thickness of the foam, also affects the amount of weight the cover can handle before the foam core gives.

The foam core is given an R-value rating denoting the density and thickness, which is directly related to its insulation quality. Essentially, the more dense the foam, the better. 

The Taper

The taper refers to the steepness of a hot tub cover at its center hinges. Hot tub covers fold at a hinge point and are tapered (or at least, they should be) from the middle to outer edges to allow snow and rain to roll off rather than pool in the middle. It’s similar to how a roof works.

The steeper the taper, the better it’ll be able to shed the wetter elements. A two inch taper from the center to the edge of the cover is standard for most. However, you should settle for a taper that’s below two inches.

The depth of the foam core at the end of the taper is also an important factor as it dictates the cover’s weight-bearing capacity as well as its insulating factor.

The Seals

If the hot tub cover doesn’t have a heavy-duty gauge poly wrapper, i.e., marine-grade vinyl, encasing the foam core, then it’s not worth looking at. Your hot tub cover needs to repel water, not allow it to seep through. Additionally, the vinyl covering should also be UV-resistant to protect from the sun’s damaging rays.

The Hinge

The hinge areas of your hot tub cover are incredibly important because they can potentially let heat escape. You want to make sure your new hot tub cover has wrapped and protected seals to ensure that no heat can escape.

Find the Perfect Hot Tub Cover Today

Your hot tub cover is essential to the longevity and protection of your hot tub. It’s important that you maintain it and replace it when it has expired. If you found the information in this article helpful, our blog and online resource center has plenty more useful health and lifestyle tips about hot tubs.

If you have any questions about hot tub covers or hot tubs in general, our experts at Ace Swim & Leisure are standing by to assist you. Also, feel free to browse our hot tub selection and more! 

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