How Long To Heat a Hot Tub

Soaking in a hot tub can be a wonderful experience after a long day at work. The hot water works great for taking away the stress and the aches of the day. But to enjoy the warmth of the hot water, you have to heat up the water first. Keep in mind; several factors can influence the rate at which the water will get hotter, and you have to switch on the hot tub accordingly so that you can have a tub full of hot water whenever you reach home.

Under ideal conditions, a 110v hot tub heats water at a rate of 1-2 degrees per hour. For 220v hot tubs, the heating rate can be around 3-6 degrees an hour(1). It can take up to 24 hours for a 500-gallon hot tub to reach the temperature of 104 degrees F. So, if you are thinking how long to heat a hot tub, you should first look at these factors that might impact the heating time.

Factors That Affect Heating Time

  1. Size of Your Tub – The larger your tub, the more time it will take for the water to get hot. If you own a small tub that is suitable for 2-4 people, you can set you your tub to get hot till 104 degrees F with a timer feature. For a larger tub, you might need to heat it up for a full day for the water to reach the required temperature.
  2. Level of Water in The Tub – If the water in the tub is not filled properly to the recommended level, it might not get hot properly(2). Follow the instructions provided with the hot tub and fill the water to the appropriate level. Also, if you fill up more water while the tub is getting heated, it might interfere with the time it will take for the water to get hot.
  3. Electric Voltage – A hot tub that accepts 220v power will heat up the water quicker than a 110v hot tub and keep the water hot too. The downside is that you will need to get a professional electrician’s services for fixing the 220v power supply in your house. But this one-time expenditure can give you an excellent way to heat up water in your hot tub.
  4. Outside Temperature – If the temperature outside is low, then your hot tub will heat up at a lower rate than usual as the water transfers heat to the outside atmosphere. Your tub needs to be properly insulated and covered to minimize heat loss to the atmosphere.
  5. The condition of Heating Equipment – Old and malfunctioning heating equipment will not heat up the water as quickly as heating equipment that is in good working condition. If your hot tub is not heating water as per your expectations, make sure you get your hot tub checked by an experienced technician.
  6. Starting Temperature of the Water – The starting temperature of the water matters a lot when you want to heat up water quickly. If the water is at a moderate temperature, it will get hotter quickly. You can also fill up the hot tub with hot water from a tap if you want it to heat up quickly. If you are trying to heat up water that is cold, you can expect a longer running time for the heater.

How To Speed Up Heating of Water in Hot Tub

So far, we have looked at the various reasons that can impede proper heating of the water. Let’s take a look at some ways through which you can speed up the rate at which water gets hot.

covered hot tub

  • Use a Better Heating Element – You can invest in a better quality heating element than that comes with your hot tub. A good quality heating element will transfer heat efficiently with minimal heat loss.
  • Keep the Cover Closed – This is one mistake that most hot tub owners make while heating up their hot tubs. Keeping the cover of the hot tub closed while the water is heating adds to the insulation and ensures the water will get hot quickly and stay hot for a longer period.
  • Don’t Switch on the Jets – The bubbles and water pressure from the jets can cause excessive water movement that can lead to increased heating time. Keep the jets off so that water can get hot quickly.
  • Enclose Your Hot Tub – If your hot tub is placed in an open area, it will take longer to heat up as the water keeps losing heat to the atmosphere. If possible, you can keep the hot tub in an enclosed area that is hidden from the elements so that there is minimal heat loss to the environment.
  • Avoid Using The Tub While It’s Heating Up – If people keep going in and out of the tub, it can lead to inefficient heating as the movement of water and exposure to the elements can lead to longer heating times. Let the hot tub heat up properly to the desired temperature before getting into it.
  • Clean Up The Filters – Clean filters mean the hot water circulates better through the hot tub, and it can help to heat up the water quickly. A clogged filter does not do a good job of circulating the water, and it can lead to higher power bills, too.


Heating up the water in a hot tub can take as long as 24 hours in most cases, and if you plan to use your hot tub every day, then it is advisable to keep it running. By taking care of certain small points, you can make the hot tub heat up efficiently and keep the water warmer for a longer period of time.

If you still feel that your hot tub is not heating the water properly, then call a technician and get the hot tub inspected. Keep the unit regularly serviced so that any old or near-failure components can be changed and you can enjoy soaking in your hot tub.

How long do you heat up your hot tub? Do you have any other tips and tricks for increasing the efficiency of the hot tub? Let us know in the comments!


Hi, I'm Richard the Chief Editor at I worked in the Hot tub maintenance field for a few years, and I thought to share my knowledge about Hot tub on our blog. My team and I share useful information related to Hot Tubs.

Click Here to Leave a Comment Below 2 comments
Don - November 20, 2020

Nice tips.

    Lilla Dagg - August 25, 2021

    consider you will sees there


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