How Long Does it Take to Heat a Hot Tub? [Let’s Find Out…]

By Dillon •  Updated: 01/29/21 •  10 min read

How long does it take to heat a hot tub?

It can take between 3 to 8 hours to heat a hot tub. Some factors include starting water temperature, ambient air temperature, and how powerful the heating element is in the hot tub. larger hot tubs will take longer to heat, smaller hot tubs will be faster to heat up.

Check out my list of high-quality hot tub products to help keep your hot tub clean and running great all year long!

My recommendation for an immersible heating element is the LIVEBAY Immersion Water Heater if you need one to help heat your hot tub.

Here I have discussed how long it will take for heating the hot tub in different scenarios.

Let’s get started!

How Long Does it Take to Heat a Hot Tub?

Your hot tub can take 3 hours to 8 hours to finally reach the temperature that you want. There are different factors that play a vital role here. These include the surrounding air temperature, total volume of the hot tub, water temperature coming out of the hose, etc. Most of the hot tubs, on average, will take approximately 4 hours to hit 100 degrees.

If this is your first time dealing with the hot tub, then you must know that initially, it will take a bit longer. You can raise the temperature of the hot tube by 5 degrees to 6 degrees each hour depending on the efficiency of the heater and the size of the hot tub.

So, when the water from your garden hose has a temperature of about 55 degrees Fahrenheit, you can notice that the process of heating up is very slow. In fact, it can even take about 2 days to heat up the entire average-sized hot tub.

Hot Tub Water Heating can Take Time

Definitely, the technologies have improved and many modern appliances are available in the market right now, but the water heating is still the same. Many people believe that as water is a great electricity conductor, it can also get heated up faster. But that is not always the truth.

Have you noticed how long a pan of water takes to heat on the stove? If that much water can take so much time, then you can imagine what it will take for thousand liters of water.

Even the process of heating is different from solid when it comes to liquid. As the molecules in the liquid swirl around, it can easily lose heat energy. This is because the molecules actually share the heat with other molecules surrounding them.

You can take an example of a cup of tea. How rapidly it can cool down? You can now imagine how poor the water is when it comes to heat conduction.

Here, the heater, surrounding temperature, hot tub size, season, and water temperature play a vital role in how long does it take to heat a hot tub.

How Long does it Take to Heat a Hot Tub

Do the Jets Help to Heat the Hot Tub Water Faster?

The straight answer to this question is – Yes! There is no doubt that the jets can be a great addition to your spa. They can help you to relax and enjoy complete comfort while getting a gentle massage. Though these are the known facts, something that you may not know is that these jets can help to heat the hot tub much faster and quicker.

You can turn on the spa jets in the hot tub and it will start the water circulation efficiently. This will help to disperse the heat in an even way in the hot tub. When you don’t use the jets, there can be some cold water pockets in the pipes of the hot tub. When the jets are turned on, the circulation can easily flush away these cold pockets and mix the heated water with the cold one.

But unless and until the tub is full, don’t turn on the heater or the jets. Many people start to heat the water as soon as it touches the first jet. But that is not the right way. Unless and until all the jets are fully submerged in the water, you will not be able to run water through those jets.

If there is no jet in your hot tub, then you can surely try to do it manually with your hand or with the help of the pool needle. But it doesn’t work as well as the jets.

Still, it can help you to heat the entire tub of water a bit faster. You can also use a lid to cover the water as it will heat the tub faster than stirring it manually. Hence, you can use a cover for better results.

How Can You Heat the Hot Tub Faster?

Most of the residential hot tubs, these days, are heated with the help of an electrical heating method. This element which helps the water to heat is installed in a cylinder made up of stainless steel. You can easily control the thermostat of the element to get the right temperature. This comes with features like high-limit temperature settings and shut-off sensors. These are useful to make sure that the water doesn’t get too hot to burn the users. Even extremely hot water can damage the equipment inside the tub.

The water circulation throughout the hot tub can take a lot of time. Hence, you have to be patient before your hot tub is ready to use.

Some of the methods to heat the water faster and quicker are:

Use a very powerful heater for heating. There are generally 3 main types of heaters that you can use for heating the pool. These are 150K BTU, 400K BTU, and 250K BTU. 400K BTU is the most powerful one and it can be too much for the spa. So, the best that you can buy for your hot tub is 250k BTU which can help to heat the water faster.

You can also place a lid or cover over the hot tub. If the water comes in contact with the cold air outside, it can take more time to heat. Hence, a lid can keep the water separate from the colder air outside and help to heat the water faster. If you don’t have a lid, then you can definitely try the tarp.

The third method is to turn on all the jets as well as the water feature that are in the hot tub. This will help to accentuate the circulation process and the water will start to heat up evenly. Once the water covers all the jets, turn on the heater. This will help to heat up the water faster and quicker.

Adding Some Water Into the Spa to Increase Temperature

If you throw some boiling water into the hot tub or even the water with an approx. A temperature of 110 degrees, can burn the lining of the hot tub.

Remember one thing that the material used for designing the hot tub cannot withstand the scalding temperature. This can result in melting away the material.

So, if you want to add some hot water to the tub, then you have to fill the tub first with regular water. When the regular water reaches halfway, you can start dispersing the hot water over it.

Make sure that the heated water doesn’t go directly into the filter or the pump. If the water is hotter than the temperature setting of the spa, then it can ruin the jets, pumps, filter as well as lining of the hot tub.

How Does an Electric Hot Tub Heater Work?

Most of the residential hot tubs, nowadays, are heated with the help of an electrical heater. These heaters can be operated with the help of a thermostat which you can control on your own. Once the temperature reaches the designated limit, the sensor will detect it. Then the heater will be shut off automatically.

When you start heating, the water will circulate through pipes and the skimmer before it reaches the three-way valve. Then the water will filter out and finally, it will enter into the heater. This process takes a lot of time. But once the entire water is heated, you will be able to enjoy a warm and cozy experience in the hot tub.

My recommendation for an immersible heating element is the LIVEBAY Immersion Water Heater if you need one to help heat your hot tub.

Heating Effectiveness of the Hot Tub

It is very rare where you have to heat the entire tub of water from cold. Mainly, you will leave the heater of the tub on. But with time, the tub will lose some of the heat when it is not being used.

But some of the modern tubs are designed in such a way that they will not lose heat and efficiently hold it as long as possible. This will allow your heater to work less and also you will be able to save a lot on your energy bill.

Check out this article from thecoverguy.com about heating your hot tub in winter.

Heating Effectiveness of the Hot Tub

It is very rare where you have to heat the entire tub of water from cold. Mainly, you will leave the heater of the tub on. But with time, the tub will lose some of the heat when it is not being used.

But some of the modern tubs are designed in such a way that they will not lose heat and efficiently hold it as long as possible. This will allow your heater to work less and also you will be able to save a lot on your energy bill.

Some of the hot tubs are manufactured with high-grade materials that improve insulation. This can hold the heat of the water well within it. Even you can use the high efficient covers that can help you to retain the heat into the water. These covers are very effective in trapping a lot of heat into the hot tub when you are not using them.

But the hot tubs that are comparatively cheaper will not be as efficient as the expensive ones. Here the heater has to work harder and longer to maintain the required temperature. This can also result in higher energy bills.

If you are looking for a cheaper hot tub, check out our article!

How Long Does it Take to Heat a Hot Tub: Conclusion

how long does it take to heat a hot tub

Heating a hot tub can sometimes be a delicate process of patience and determination. Depending on the type of hot tub you have, the heating element, how cold your water might be, and how large your hot tub is will determine how long it takes to heat the water.

I hope you found this article on how long does it take to heat a hot tub informative.

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Dillon

I'm Dillon, creator of SpaToolKit.com. During the day I'm a software developer for an engineering company. At night I enjoy sitting in my hot tub and relaxing. My hope is that Spa Tool Kit will be a place where you can find the best information on hot tubs, spa equipment, setups, parts, and accessories. Let's get started!

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