How To Heat Up A Jacuzzi (Really Fast Ways)

Chloe Meltzer
by Chloe Meltzer

Owning a jacuzzi is a fun way to enjoy the night air in the winter, or even to relax in the summer. They are extremely versatile as you can change the temperature of the water depending on the season.

If you are a new owner of a jacuzzi, after creating a level space for your tub and having it delivered to your home, you may be wondering how to heat up the water.

Leave the lid on when you turn on your jacuzzi if you want it to heat up quickly. Turn on your jets to help heat your jacuzzi quickly and evenly. Install a heater that operates at 250k BTU so that your jacuzzi can easily heat up.

There are also other methods of heating it more efficiently, and tricks to master regarding your jacuzzi in general.

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How Long Does it Take to Heat a Jacuzzi?

Whether you have recently purchased a jacuzzi, or recently drained one, then you may be wondering how long it takes to heat a hot tub. Depending on how hot you want your water, and the model of your jacuzzi, it can take anywhere from three to eight hours.

On average though, you should expect it to take about four hours to reach 100 degrees Fahrenheit.

Other factors include:

  • Capacity of the tub: The larger the tub, the longer it will take to fill.
  • Air temperature: If you have a lid, keep it closed for quicker heating.
  • Size of the heater
  • Temperature of the fill water: When you are filling your hot tub on a warm sunny day, the fill water might be 80 degrees! This means that you’ll only have to warm it up for three hours or so. In other seasons with fill water that is only 60 to 70 degrees, it could take a while longer. 

Times You Will Need to Reheat Your Jacuzzi

  • After purchasing the tub or draining it.
  • If you lower the temperature in between uses, you will need to reheat it again before use.
  • If you power down and winterize it at all during the cold months.

How to Heat Your Jacuzzi Faster

Leaving the Jets on

Jets are a wonderful addition to any jacuzzi. They allow the user to relax and receive a gentle massage. They also double as a method to heat your jacuzzi quicker.

This works by circulating water, moving it around, and pushing the heat as well. When you do not use jets, there are often pockets of cold water within the pipes. By using jets, the circulation flushes the pockets, getting the cold water out into the heated water.

By placing the heaters on you can speed up the process by up to six degrees per hour! Just make sure you do not turn the jets on until the tub is full of water. You cannot run water through the jets until they’re all submerged or you can damage the system.

If your hot tub doesn’t have jets you can use your hands or a paddle to move the water around. Keep in mind though that if you have a lid, it is always a better option to keep it closed and let it heat itself.

Use a Cover

When you leave your tub exposed without a lid, the cold air outside will make it harder for your jacuzzi to heat up. Even if you are experiencing summer temperatures, any temperature lower than your desired water temperature will work against heating it. Alternatively, if you do not have a lid, you can use a tarp.

Purchase a More Powerful Heater

Similar to how you can purchase a more powerful water heater for your home, you can do the same with your jacuzzi. There are three main types of heaters used in pools and jacuzzis: 150k BTU, 250k BTU, and 400k BTU.

Typically a 400k BTU heater is not used for a jacuzzi, but if you currently have a 150k BTU heater, then a 250k BTU heater will heat it a lot faster. Using a larger heater can reduce your heat time by an hour or more.

Optimal Jacuzzi Water Temperature

Most of the time, the general consensus for setting your jacuzzi is known to be 100-102 degrees Fahrenheit. This can sound hot to some people, so there are a few questions you should ask yourself first before setting your tub temperature.

  • Do adults want to use it for a quick soak?
  • Will there be children under 12 using it often?
  • Is it extremely hot or extremely cold where you live?
  • Does anyone who uses the tub have any medical conditions?

Health conditions, outside temperatures, direct sunlight, and alcohol or prescription drug use always dictate personal tub temperatures and use times. If you have health issues or are on prescription medication, be sure to ask your doctor what they recommend.

If you have children you may want to set the tub to 98 degrees. You can always raise the temperature, but it takes a bit longer to lower it. Generally, there is a guide for how long you should soak at individual temperatures:

Jacuzzi TemperatureMaximum Soak Time
98° F (36.6°C)30 Minutes
99° F (37.2°C)28 Minutes
100° F (37.7°C)25 Minutes
102° F (38.8°C)20 Minutes
104° F (40°C)15 minutes

Filling a Jacuzzi With Hot Water

Since it can be frustrating to wait for your jacuzzi to heat up for three to eight hours. Many people think about putting hot water into their jacuzzi to get it to warm up faster. Although this sounds like it might work, it is actually a bad idea.

When you boil water it is going to be at least at a temperature over 110 degrees once it reaches your tub. The highest setting on most jacuzzis is 104 degrees. This means you should never fill your jacuzzi with water that is higher than 104 degrees.

When you throw in hot, boiling, water, it has the potential to sear the lining of your spa. This means that the acrylic or other material of your spa will melt away. If you want to add hot water, be sure to fill it up at least halfway with normal, hose water.

This will allow it to mix with the hot water and avoid damaging the pump or filter. In general, it might speed up the healing process slightly, but it really is not worth the risk.

How to Improve the Efficiency of Your Jacuzzi

There are several things you can do to improve the efficiency of your jacuzzi, reducing the time it takes to heat up and saving you a bit of money in energy costs.

Keep Your Cover Closed and Clean

While the sides of your jacuzzi are very well insulated to keep heat inside at all times, the top is fully exposed. Therefore, it is crucial that you have a quality jacuzzi cover. The cover not only keeps the tub secure, it also keeps the heat inside.

However, having a cover is not enough when trying to make your jacuzzi efficient. Your hot tub cover needs to be cleaned regularly, replaced when ripped, and kept securely placed over the top of your jacuzzi.

Service Your Jacuzzi

Over time your jacuzzi may have parts that wear out. These can be your filtration system or even your jets. When these wear out, the water and heat will no longer be able to flow freely as they once did. This results in a longer time period to heat and less efficiency.

By servicing your jacuzzi regularly you will increase its efficiency in heating.

Reduce Airflow

When setting up your jacuzzi you need to reduce the pull of heat from your tub. Trees can be used as a cover for this, or you can purchase windshields. Airflow will cool down your jacuzzi too quickly and cause it to be less efficient.

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Related Questions

How often should I change my jacuzzi water?

Change the water in your jacuzzi every 3-5 months. This will depend on how often you use it. 

What chemicals should I put in my jacuzzi?

There are two main chemicals to put into a jacuzzi, bromine, and chlorine. Bromine is better for sensitive skin, and it kills viruses as well as bacteria much better than chlorine. Bromine also remains in hot water longer which means it requires less frequent applications. You can avoid using both of these chemicals if you are willing to perform maintenance more often.

Should I leave my jacuzzi running?

The answer to this question entirely depends on the situation. For instance, if you use your jacuzzi at least a few times per week and live in a colder climate, then you probably should leave it running. However, if you only use your jacuzzi occasionally, and you live in a mild weathered area, then you can turn it on a few hours before you want to use it.Of course, if the area you live in experiences below freezing temperatures during the winter and your hot tub is outside, you will have to either keep it running all winter or close it up and winterize it for the season. This will prevent the water from freezing and damaging the jacuzzi in the process.

Chloe Meltzer
Chloe Meltzer

Real estate agent and copywriter, originally from California. Chloe brings her real estate expertise into her writing to create effective and helpful home guides for you! When not writing or selling homes, she spends her time as a digital nomad traveling the world.

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