The place to find your Whirlpool bath, hot tub, or inflatable hot tub.

How Long Does It Take to Heat a Hot Tub?




How Long Does It Take to Heat a Hot Tub

Affiliate Disclaimer

We may earn a commission when you purchase through links on our site. However, this does not impact our reviews and comparisons. We strive to provide honest and unbiased information to help you make an informed buying decision.

Hot tubs are luxurious ways to de-stress and relax, with the heated water creating a hydro-therapeutic effect on the muscles and mind.

Whether you’ve booked a trip away with a room featuring a hot tub, or you’re planning on investing in one for your own garden, you might be wondering how long your hot tub will take to heat up.

There is nothing worse than standing on the outskirts of a hot tub, wrapped in only a towel in the freezing weather, shivering because you didn’t realize how much time went into preparing a hot tub.

Well, the length of time it takes to heat the hot tub might surprise you, so you’ve come to the right place.

We’ll be aiming to answer your burning questions about hot tubs and getting them ready down below, so keep reading!

How long does it take to heat a hot tub?

There are plenty of hot tubs on the market to choose from, so it makes sense that there is not a single definitive answer when it comes to the time frame.

In fact, many experts claim that it can take as little as 3 hours to heat a hot tub, but it could also stretch to up to 20 hours.

The typical hot tub will heat up 3 to 6 degrees every hour, so there are a number of external factors contributing to how long it will take for your hot tub to heat up.

Let’s look through these so that you can attempt to shorten the heating up process as much as possible.

What are the factors affecting how long it takes to heat a hot tub?

Some of these factors you can tweak and adjust to make them not as much of a problem; however, there are others that are unfortunately unavoidable. Below we’ll be discussing these factors and suggesting how you might get around them.

External Temperature

Where you keep your hot tub will also affect how long the hot tub will take to heat up. The majority of hot tubs are kept outside on porches or in yards, where there is little insulation to the heating water.

For example, if the temperature was below 50 degrees Fahrenheit while you were trying to heat up your hot tub, it would take much longer than if you were to use it during the summer.

On the other hand, if your hot tub is situated inside you might not have this problem. However, you’ll still have to monitor the temperature of the room to ensure that it isn’t stalling the hot tub’s efficiency.

Keeping your hot tub inside will benefit you as you’ll have more control over the external temperature.

The Efficiency of Hot Tub

You might want to check the heat rating of your hot tub before you commit to the purchase of it because this is a big factor contributing to how long it will take to heat. The higher the kilowatt of the hot tub, the hotter the water should be heated.

Some hot tubs only come with a 1-kilowatt rating, which will heat up the water much slower than a 7.5-kilowatt hot tub. The water will be heated up in a seventh of the time for the first model takes, in fact!

For this reason, the higher efficiency rating is always preferred; however, this will also consume much more energy than the former option.


Higher quality hot tubs often come equipped with impressive insulation to avoid the heat from leaking out while in use.

This will keep the water heated so that it’s not cooling down quicker than it’s being heated. Once your hot tub reaches the ideal temperature, many people advise you to keep it on to avoid having to wait another 10 hours to set it up again.

If you plan on keeping the hot tub running indefinitely, you should opt for the best insulation that you can find. This will prevent the water from cooling down completely between uses. Insulation needs to cover the entirety of the sides, as well as the lid.

The lid must be high-quality to keep the heat inside for as long as possible.

Water Temperature

The average cold water temperature in the USA is 50 degrees Fahrenheit, and the recommended temperature for a hot tub is 104 degrees Fahrenheit.

For a lower efficiency rated hot tub, this would take around 16 hours to completely heat up. However, if your hot tub boasts a higher efficiency, you might notice that it only requires 6 to 8 hours to heat up.

Size of the Hot Tub

The size of the hot tub will also affect how long it takes for the water to heat up. The most common sizes for hot tubs are 300 liters and 700 liters, and it stands to reason that the latter will take much longer to heat up than the former.

However, this will also depend on the heating element.

We would advise you to choose a hot tub that is small enough for your needs. If you opt for a bigger model and only fill one or two of the seats with every use, you’ll be heating up way too much water than you need.

This will affect your energy consumption negatively, so make sure that you’re smart about your decision.

Make sure that you don’t accidentally opt for a 700-liter hot tub that comes with a 1-kilowatt heating element, as this will take a substantial amount of time to heat up.

This often doesn’t happen; however, some budget hot tubs cut manufacturing costs by including a tiny heating element. What you save in the initial cost, you’ll spend on the additional energy.


There we have it – it takes anywhere from 3 to 20 hours to heat up a hot tub. This number can be reduced by ensuring that you’re opting for a hot tub with great insulation and efficiency, as well as the correct size of heating element for how large the hot tub is.

Having said that, there are a few factors that you cannot control such as the outside temperature. Many people like to keep their hot tubs running indefinitely to avoid setting it up again, but this might negatively impact your energy bill.

Latest posts