How to Heat a Hot Tub Quickly and Efficiently

Whether you’re a new hot tub owner or a spa master, your first priority after starting a hot tub is probably going to be how to heat a hot tub. After all, a hot tub with no heat is just a tub. How you heat it depends on your hot tub’s condition, efficiency, and location.

Good things may come to those who wait, but we say it’s no fun waiting longer than necessary. Every hot tub is different, but you can find ways to get your tub a-bubblin’ quickly with the right techniques, regular maintenance, and a few strategic upgrades.

How to Heat a Hot Tub Quickly and Efficiently

Seriously—How Long Does It Take to Heat a Hot Tub?

If it’s working properly, the heater in your spa will usually heat the water at a rate of 3°F–6°F (2°C–3°C) per hour.

Were you looking for a longer, more complicated answer? Nope. That’s it.

Factors That Can Affect Hot Tub Heating Efficiency

Your hot tub might heat up more or less quickly depending on a number of factors, including:

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Ambient Temperature

The warmer the water and surrounding air, the less time your hot tub will need to heat to the proper temperature. What’s the proper temperature? For adults, health experts suggest that 104°F (40°C) is the upper limit for how hot a hot tub should be. You’ll probably find your spa is most comfortable somewhere between 100°F (38°C) and 102°F (39°C).

For example, let’s say it’s 76°F (24°C) outside, and your water is at the same temperature. Heating your hot tub to 100°F (38°C) will take around 4–8 hours. If, on the other hand, it’s a frosty 52°F (11°C) outside, and your water is the same temperature, then you’ll need 8–16 hours to reach 100°F (38°C).

PRO TIP: As the temperature climbs, monitor it with a floating spa thermometer If you click this link and make a purchase, we earn a commission at no additional cost to you. . Compare the readings with your system temperature to make sure the thermometer built into your hot tub control panel works properly.

Ambient Weather Wireless 8-Channel Floating Spa Thermometer Price: $36.59
Ambient Weather Wireless 8-Channel Floating Spa Thermometer
If you click this link and make a purchase, we earn a commission at no additional cost to you. Last Updated: 09/20/2018

Hot Tub Cover Placement

Another way to speed up your hot tub heating is to leave the hot tub cover on while you wait.

Most of the heat lost from your hot tub disappears into the air above it. Leaving the cover in place traps heat and helps warm things up more quickly.

PRO TIP: An old, damaged hot tub cover can reduce efficiency and harbor all sorts of funky grime and microbes. If yours has seen better days, consider replacing it If you click this link and make a purchase, we earn a commission at no additional cost to you. to improve not just your hot tub’s heating efficiency, but the overall healthy and safety of your spa.

The Cover Guy Deluxe Hot Tub Cover - 5” taper Price: $349.99
The Cover Guy Deluxe Hot Tub Cover - 5” taper
If you click this link and make a purchase, we earn a commission at no additional cost to you. Last Updated: 09/20/2018

Hot Tub Hardware

A malfunctioning heater or pump, or defective jets can throw a monkey wrench into your plans for a relaxing soak. Regular hot tub maintenance helps keep everything working at peak efficiency.

PRO TIP: As you probably guessed, your hot tub’s heater is the most important component when it comes to putting the hot in “hot tub.” You may have to troubleshoot a hot tub heater that’s on the fritz. If you find the heater is beyond repair, it may be time to replace it If you click this link and make a purchase, we earn a commission at no additional cost to you. .

Hayward Electric Spa Heater - 11 kw. Price: $555.98
Hayward Electric Spa Heater - 11 kw.
If you click this link and make a purchase, we earn a commission at no additional cost to you. Last Updated: 09/20/2018

How to Heat a Hot Tub Even More Efficiently

Beyond leaving your cover on and performing regular maintenance, you can help your hot tub heat up more quickly with a few upgrades to your spa and its surroundings.

Warm Up to Spa Landscaping

It can be all too easy to overlook the importance of not just beautiful but functional landscaping when you’re setting up your hot tub. In addition to keeping heat in, you can help keep cold out by blocking wind and weather from your hot tub.

Wind can increase evaporation and cooling, making your hot tub work harder to reach the right temperature, and maintain it once it’s reached. Planting trees in your yard can cut wind considerably. You can also make a smaller, more localized windbreak around your hot tub area by planting shrubs. Single, double, or even triple rows of the right plants will cut noise and precipitation as well as excess wind. They’ll also provide more privacy, not to mention beauty.

You can also install special screens If you click this link and make a purchase, we earn a commission at no additional cost to you. around your hot tub to block the wind and help keep your hot tub warmer longer. Like landscaping, these panels help keep your hot tub more private and comfortable, too.

SimLife Retractable Folding Screen with Steel Support Pole - 5.9 ft. x 9.8 ft. Price: $95.99
SimLife Retractable Folding Screen with Steel Support Pole - 5.9 ft. x 9.8 ft.
If you click this link and make a purchase, we earn a commission at no additional cost to you. Last Updated: 09/20/2018

Improve Your Hot Tub’s Insulation

While the bulk of heat is lost from your hot tub through the open surface of the water, you might also be losing some heat due to tiny leaks in the cabinet.

Bulking up your hot tub’s insulation can help keep more warmth in and cold air out, making it easier to heat your spa. It will also help keep it warm, so you won’t need as much time or energy to bring your hot tub to the right temperature if you haven’t used it in a few days.

You can install wall or attic insulation on the inside of your hot tub cabinet panels to boost warming power. Or, if you’re more of a DIYer, you can build a cabinet surround—basically, a cabinet for your cabinet—and fill it with insulation If you click this link and make a purchase, we earn a commission at no additional cost to you. .

Frost King Cotton Insulation - 16 in. x 1 in. x 48 in. Price: $8.67
Frost King Cotton Insulation - 16 in. x 1 in. x 48 in.
If you click this link and make a purchase, we earn a commission at no additional cost to you. Last Updated: 09/20/2018

Power Up Your Hot Tub Cover

Trapping ambient heat and reducing evaporation by leaving a well-maintained hot tub cover If you click this link and make a purchase, we earn a commission at no additional cost to you. in place while you heat your spa is a good start. But if you’re looking for Buster Poindexter levels of hot, hot, hot, consider adding a floating spa cover If you click this link and make a purchase, we earn a commission at no additional cost to you. in addition to your main hot tub cover.

Adding a blanket cover can boost your spa’s R-value, or insulation efficiency rating, by nearly a third. That means less heat loss, and faster heating when you’re ready for some tubbin’.

Horizon Ventures Floating Spa Cover - 8 ft. x 7 ft. Price: $92.96
Horizon Ventures Floating Spa Cover - 8 ft. x 7 ft.
If you click this link and make a purchase, we earn a commission at no additional cost to you. Last Updated: 09/20/2018

Should You Leave Your Hot Tub Running?

The answer to this question depends on how and when you use your spa.

If you live in a colder climate and you like to use your hot tub a few times a week, you’ll save time and money by leaving it running. You won’t have to use extra energy or wait for hours and hours to heat things up whenever you want to take a soak.

On the other hand, if the climate is milder in your area, and you only use your hot tub occasionally, shutting it down between uses makes sense.

If you have sub-zero winters where you live, and your hot tub is outside, you’ll have a different choice to make. If you plan on hot tubbing while the snow flies, you’ll need to keep your hot tub running all winter.

If you’re not a member of the Polar Bear Club and are more worried about hot cocoa than how to heat a hot tub, you’ll need to know how to winterize your hot tub.

Either way, you’ll keep the water from freezing inside your spa and protect your hot tub during the winter.

No More Lukewarm Soaks For You!

Until science finds a way to give mankind Superman’s heat vision, we’ll have to wait for our hot tubs to heat up. But you get to your soak sooner by taking the time to implement just a few tactics that will not only warm things up more quickly, but can save you time, energy, and money.

Happy Soaking!

Learn How to Keep Your Hot Tub Clean and Clear All Year Long with This Illustrated eBook

You'll save $100 right away with this easy-to-follow digital handbook. This is the guide that hot tub manufacturer doesn’t provide you.

Click here to learn more
The Hot Tub Handbook

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