What Temperature is too Cold for a Hot Tub?


Who doesn’t love the feel of warm water during the winters? Most people have limited choices, though with a hot shower being the best they can get in the cold weather. But having a hot tub allows you to access warm water at any time of the day because these tubs run 24/7. If you are budget conscious, though, you might want to see how low you can bring the tub’s temperature when it is not in use.

76 °F is too cold for a hot tub. A hot tub must operate at around 100 °F when there are people in it and can be maintained at 80 °F when not in use. Bringing the temperature down further risks contamination and plumbing damage. Alternatively, you can drain the tub.

In this article, you will learn more about hot tub temperature maintenance, including what happens when the tub gets too cold or too hot. You will also discover the safe maximum and minimum temperatures for a hot tub and the ideal temperature range that is both safe and pleasurable. Now, let’s get started by addressing the risks of extreme temperatures in a hot tub.

What Happens When the Temperature is Too Low?

Even before you make a note of a safe temperature range or the ideal temperature to maintain in your hot tub, you must know the risks of your tub getting too cold. That’s because the severity of consequences can justify the expenses of keeping the tub hot. Remember, you have only two options during winters: to winterize the hot tub or simply keep running it but keep it hot throughout the day.

Hot tubs aren’t meant to be turned off even during summers, so it is evident that during winters, there’s a higher “use it or lose it” factor. When the temperature gets too low during summers, the water might get contaminated and may require replacement. 

But if you don’t keep your hot tub at the right temperature range during the winters, its plumbing might get winter damage. From the water freezing in the pipes to portions of the tub warping, your tub can get damaged irreversibly in multiple ways. Here’s why.

Tub Water Movement Isn’t Fast Enough

Hot tubs don’t circulate waters the way pools do, even if they follow a similar route. The main difference is in the rate of circulation, and even with higher circulation, pools too can’t withstand getting too cold. Hot tubs, on the other hand, have slower circulation, and water can freeze if the weather is cold enough.

Ice Expands

When water freezes, it occupies a larger area. This doesn’t pose a risk for open-ended containers as the water expands towards the open end. However, the situation is different with pipes when water freezes at both ends and turns the pipe into an airtight container. The trapped water can then freeze and expand to warp the pipe.

What Happens when the Temperature is Too High?

The risks of having your hot tub get too cold are scary enough to make you want to err on the side of heat. That’s sounds within reason, but if you go overboard, you might end up on the other extreme, which might be riskier. When your hot tub gets too hot, it might pose a serious health and safety risk. One can suffer from a heat stroke in extremely hot water.

Hot water can permanently damage hot tub equipment like PVC pipes. However, the water usually doesn’t get that, and personal safety risks are higher than equipment damage risks. That’s in part because of how hot tubs are designed to withstand high temperatures. 

In the instance of running a hot tub during winter, there’s also the contextual risk of the tub feeling too comfy. If the water isn’t too hot for the human skin but is hot enough to make one drowsy, it can still be dangerous.

Safe Temperature Range for Hot Tubs

While the ideal temperature for a hot tub is 102 degrees Fahrenheit, the safe range is broader. Generally speaking, water cooler than 78 degrees Fahrenheit is likely to start getting contaminated. So even though you might be able to dip in a hot tub that’s operating at 75 degrees Fahrenheit, you aren’t safe in it, especially if you regularly use the tub at that temperature.

In contrast, the other extreme begins at 104 degrees Fahrenheit. You’ll notice that the difference between the ideal hot tub temperature and dangerously hot temperature isn’t that big. There’s a thin line between water that’s hot enough to be refreshing and water that will boil your skin. Therefore, it is crucial to have reliable thermo-regulation in your tub.

The safe temperature range for hot tubs is between 80 degrees Fahrenheit and 102 degrees. The best temperature to maintain varies depending on the time of the year and your personal preferences. As long as the water is close to your body’s internal temperature, you’ll not get burned or freeze.

How much electricity does a hot tub use?

A hot tub uses 1500 watts to 6,500 watts of electricity per month. On average, it costs about $1 per day to operate a hot tub, with most consumers paying $30 to $50 in monthly electric expenses. Draining a hot tub can, in comparison, cost more because of the cost of fresh pool chemicals.

These are required to purify the water upon refilling and can cost $10 to $13. The cost of water that needs to be added must also be factored in. The collective price of replacing a hot tub’s water alongside re-adding chemicals makes the solution pricier than simply letting the tub run 24/7. That said, if you’re going to be away from your home for 2 months, then draining the hot tub might be a safer choice.

Final Thoughts

Hot tubs need to run 24/7, which means they consume electricity throughout the day. The hotter the tub, the more electricity it uses. To save money, you can bring the temperature of the tub down to 80 degrees Fahrenheit when the hot tub is not in use. But when you jump in, make sure the water is closer to your internal body temperature, i.e., around 100 degrees Fahrenheit.

Jed Arnold

Jed spent every year from the ages of 15 - 22 as a Lifeguard (Red Cross) and ages of 17 - 22 as a Certified Pool Operator (CPO). Between working for over a dozen facilities and owning a pool, he carries over a decade of pool experience.

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