How to Heat a Hot Tub Faster

So you have bought your hot tub, set it up, and filled it, and now you are itching to get in and start relaxing. But, frustratingly, you now have to wait for the water to heat up before you can.

I bought my first hot tub during a UK winter, so the water from the faucet I filled it up with was very cold, and it took 18 hours to heat up!

What can you do to speed it up? For instance, should jets be on when heating the hot tub?

Read on to learn how it works, what other things you can do to speed up the heating process of your hot tub water, how long it typically takes to get hot, and how to keep the water temperature up when it is not being used.  

How to heat a hot tub faster

Is there anything that can test your patience more than waiting for the hot tub to heat up enough for you to use it? 

Sometimes, it can be hours before it’s warm enough to hop in for a soak after filling the tub with cold water. You’ve already put on your swimsuit and put your towel out. Maybe you’ve got friends waiting, or maybe even a date.  

The last thing you want to do is wait six or more hours for the hot tub to heat up to a pleasant temperature, especially if it shortens the time you have to use it.  Learn how to shorten your heating time to maximize your soaking time. 

If your tub takes more than 4 hours to heat up, you can try a few different things to make it heat more efficiently.  

Turn on your hot tub jets

If you’ve been heating your hot tub without the jets on, you have missed an easy, effective trick to help the hot tub heat quickly.

Having the jets on while heating your hot tub will reduce the heating time as the jets circulate the hot water more evenly and efficiently around the whole hot tub.  They can also ensure no cold pockets remain trapped in the pipes or hose.

Check your filter

Sometimes, a dirty filter can cause the water to heat more slowly by restricting water flow. If you’ve noticed your hot tub struggling to heat up, this could be the problem. 

Luckily, there’s an easy fix.  All you need to do is take out your filter and thoroughly rinse it to clean it off. Then, you can put it back and see if your tub heats faster.

Use a hot tub cover

A cover placed over the hot tub while it’s heating can keep the temperature much more efficiently. If the ambient air temperature is lower than the hot tub temperature, particularly outside in the cold air, it will constantly be cooling it off, even if just slightly. 

You should also leave your hot tub cover on when your tub is not in use to keep the temperature up, which will mean the heater does not kick in so often.

If the hot tub is outside and in a windy position, having the cover on will reduce heat and water loss through evaporation. Even on a warm sunny day, there will still be a significant difference between the air and water temperatures.

Update your heater

If you have an older hot tub, you may want to consider checking your heating system.  If the heating element is past its prime efficiency or isn’t running as well as it used to, it may be time for a tune-up or an update. 

As hot tubs have developed, the heating systems have become more efficient, reducing the time it takes to heat up.  

How long does a hot tub take to heat up?

Hot tubs can take an average of 4 hours to reach 100 degrees, but this depends on the temperature of the water used to fill. Some hot tubs, under certain circumstances, can take three to eight hours or more to reach that same temperature.  

There are a few factors that affect how quickly your tub heats up, and these include:

• The outside temperature
• The water temperature inside the tub
• The hose water temperature pumping in
• The voltage – 220v hot tubs heat faster than 110v.
• The tub capacity
• The power of your tub’s heater
• The state of your filter
• If you have a cover or not (if you haven’t, then make sure you buy one)
• The jets being off or on

If all of these things work for you instead of against you, you can expect your hot tub to heat anything to 6 degrees per hour.  This is optimistic and can result in 3-4 hours of heating time to reach the desired temperature.  

If any or all of these things work against you, you could be looking at a heating time of more than 8 hours.  Most people don’t have that kind of time or patience for a quick soak in the hot tub.

More efficient heating = Lower cost of heating

When you find ways to shorten your hot tub’s heating time, you aren’t just saving yourself time; you are also saving yourself money in energy costs. Every minute saved could put more change in your pocket or more dollars in your account.

When choosing, installing, maintaining, or heating a hot tub, you can take a few extra steps to increase your heating efficiency in the short and long term.  

These things may seem like long-term investments, but with a lower energy cost, they can pay off sooner than you might think, especially if you are a frequent hot tub user.  

Does a hot tub heat up faster with the cover on?

This may sound like a repeat, but investing in a good-quality hot tub cover can save you hundreds of dollars. You’ll want one that locks into place and hugs the sides and corners of the tub to prevent heat from escaping. This can keep your tub substantially warmer between uses. 

Hot tub covers can also serve the dual purpose of cleaning your hot tub. They seal it shut and prevent dirt, bugs and other debris from getting into the water. This will keep the water clearer and decrease the need for frequent cleanings. 

Keep the temperature steady

Even if you don’t use your hot tub very often or for long periods of time, it is most efficient to maintain it at your preferred bathing temperature. The ideal temperature for most people is between 102 and 104 degrees Fahrenheit. 

Keeping your hot tub at that temperature will ensure the best use of energy and money. At the very least, you can set the tub to 5 degrees below your preferred bathing temperature, but it isn’t recommended to set it below 90 degrees Fahrenheit. 

The time and energy it would take to heat it to your preferred temperature each time are more than the maintenance requires.

Keeping the hot tub at the perfect temperature allows for one of the great things about them – taking a spontaneous dip. I often feel like going in my hot tub on the spur of the moment. It would spoil the moment if I had to turn the temperature up and wait a few hours to heat the water.

Keep the hot tub on through all seasons

Many people wonder if they should turn their hot tubs off and on throughout the year or leave them on all the time, depending on their usage and needs. While this may seem intuitive, it is not such a great idea unless they will not use it for a while.  

Keeping your hot tub on at all times ensures the most efficient use of energy for heating and keeps it cleaner. Hot tubs have very good insulation around the tub shell, which, coupled with a good cover, helps retain great heat. 

The circulation of water from the hoses and occasionally the jets keeps the heated water much fresher between uses. It can also prevent algae or bacteria from clinging to the tub’s shell.

Summary

In summary, while hot tub jets do not directly heat the water, they contribute to the overall heating process by circulating and distributing the warm water. However, running the jets while heating may not significantly accelerate the heating speed.

Remember, the jets are not required to be on for the hot tub to heat up, but they enhance the heat distribution and can help heat it quickly.

Other hot tub information

How much chlorine to add to hot tub first time?

What is shocking a hot tub?