The sound of running your hot tub 24/7 seems like an expensive waste of electricity and a risk to safety. So should you turn your spa off or leave it running between uses?
You should leave your hot tub running at all times. Hot tubs have been designed with insulation which means it’s far more economical to maintain a set temperature than it is to heat up the water from cold each time. It’s perfectly safe to run your hot tub permanently so long as you maintain the water chemistry.
In this article, I’m going to show you:
- The financial benefits of leaving your hot tub running
- What to do when you go on vacation
- When it’s necessary to turn the power off (and how to do so safely)
What temperature should I keep my hot tub when not in use?
Although it seems counter-intuitive, it’s way more cost-effective to leave your hot tub running all the time when it’s being used regularly. But at what temperature?
Experts advise lowering your hot tub temperature by 10°F (5°C) when it’s not in use. Lowering the temperature saves money on your energy bill and should be done if the hot tub is used once or more a week. Lowering more than 10°F can offset savings by increasing energy costs from the power needed to raise the temperature.
Depending on the outside temperature and the quality of your spa’s insulation, each time you lower your hot tub by 2°F (1°C), you can reduce the energy costs by 10%.
Is it really worth lowering the temperature?
Initially, it seems like a great idea to lower the temperature to save a bit of money on electricity. But is it really worth it? What are the actual savings in cold, hard cash?
The average cost per month to run a hot tub is $30. Every time you turn the temperature down by 2°F (1°C), the savings become less even though they consistently drop by 10%.
Before we get into the math, let’s assume you like to bathe in water at 100°F (38°C). I’ll now show you the difference in running costs each time the temperature is lowered by 2°F (1°C).
| Temp. | Cost before lowering temp. | Cost after lowering temp. | Cost difference | Total monthly saving |
|---|---|---|---|---|
| 98°F (37°C) | $30 | $27 | $3 | $3 |
| 96°F (36°C) | $27 | $24.30 | $2.70 | $5.70 |
| 94°F (35°C) | $24.30 | $21.87 | $2.43 | $8.13 |
| 92°F (34°C) | $21.87 | $19.68 | $2.19 | $10.32 |
| 90°F (33°C) | $19.68 | $17.71 | $1.97 | $12.29 |
Sorry if that made your head spin. In summary, lowering your hot tub by 10°F (5°C) results in a saving of $0.40 per day ($12.29 per month). But that figure assumes you never use it.
Each time you fancy a soak, you’ll have to heat the water back up. Raising the temperature requires a lot more energy than maintaining it.
Factor in the added expense of having to heat the water for an hour or two before you use it each time, and you’re probably closer to a saving of 30 cents per day ($9.22 per month).
Turning the heating down between uses is inconvenient as it means having to plan your soak. Each time you want to use your spa, you’ll have to go out and turn the temperature up and then wait around while it heats.
With an annual saving of around $110, or the price of one night out a year, it really doesn’t seem worth the hassle.
And by having it up to temperature at all times, you can enjoy your hot tub exactly when you want to with no waiting around.
Can I turn off my hot tub in the summer?
With a lack of desire to soak in hot spa water because of the scorching temperatures outside, you might be tempted to switch the hot tub off. But should you?
Never turn off the power to your hot tub in the summer. The summer heat is not enough to keep the water temperature high enough. The water isn’t able to circulate through the filters without power, causing a build-up of bacteria. For cooler temperatures, use economy mode to reduce the temperature to 80°F (26°C).
The water can only be circulated around a spa when the pump is powered on, which leads to the following important question.
Should my hot tub pump run all the time?
The pump is designed to run at all times to keep the hot tub running effectively. While it’s possible to reduce the number of cycles that run each day, the pump should run for a minimum of eight hours per day. Pumps have safety settings to automatically shut off if the water becomes too hot or cold.
Always leave the hot tub pump running as it has several jobs to do that ensure that the spa continues to function properly.
High-quality, modern hot tubs are fitted with circulator pumps that help prevent the water from stagnating and becoming a breeding ground for nasty bacteria.
A circulator pump circulates the water through the filters, trapping any particles that have found their way into the water. The movement of the water from the pump stops you from having to skim off algae each time you get in.
Circulating the water also ensures that sanitizing chemicals are evenly distributed for the correct water chemistry balance.
Lastly, the spa’s pump also moves the water through the heater so that the water is constantly held at your chosen temperature.
When should I put my hot tub in economy mode?
Economy mode reduces your spa’s temperature by around 20°F (11°C). A lot of energy is required to raise a hot tub by 20°F, and it takes between 1.5 and 3 hours to do so. So when should economy mode be used?
Economy mode should only be used if you’re not going to use your hot tub for more than a week. Any less than a week, and it’s more efficient to keep it in standard mode. This is because the cost of raising the temperature is more than the savings had by lowering the temperature in the first place.
It sounds surprising, but even if you only use your hot tub once a week, it’s far more economical to maintain a standard bathing temperature.
If you’re going on vacation for up to 2 weeks, it’s worth turning on economy mode. Over the course of the two weeks, you’ll save around $10.
While the savings aren’t huge in the grand scheme of things, there isn’t the inconvenience that there is when turning the hot tub temperature down while the hot tub is in regular use.
What do you do with a hot tub when you go on vacation?
If you’re going away for longer than 2 weeks, or you simply aren’t planning on using the spa for whatever reason, then it’s best to drain the water.
The reason for doing so isn’t because of the wasted energy from running the hot tub unnecessarily.
Leaving your spa unattended over a prolonged period of time means that you’re not able to balance the constantly changing water chemistry. Bacteria may start growing in a hot tub without chemicals within 2-3 days.
If you can’t maintain the sanitizing chemicals in your hot tub, the build-up of bacteria in the water can cause damage to the hot tub and reduce its lifespan.
Unless you have a trusted friend or neighbor that is able to periodically monitor your hot tub’s water and adjust the chemistry accordingly while you’re away, it’s best to drain all of the water.
What do you do with a hot tub in the winter?
If you don’t want to use your hot tub during the winter and it’s going to be left empty, you’ll have to properly winterize it with antifreeze. Winterization protects the spa from serious damage to the plumbing.
It’s best to winterize your hot tub before the cold weather sets in. Carrying out winterization while the weather is still warm avoids the risk of any water left inside the plumbing from accidentally freezing.
It’s even more important to winterize your hot tub before the winter hits if you live in particularly harsh conditions. The remaining water in the pipes can quickly freeze during the winterization process before you’re able to add the antifreeze.
Can you use a hot tub in winter?
New hot tub owners worry about running their hot tub during wintertime because of issues with freezing. So is it safe to use a hot tub in winter?
It’s perfectly fine to use a hot tub in the winter. Modern spas have been designed with excellent insulation so that they can run efficiently during the winter. So long as the hot tub has constant power and there are no mechanical issues, there is no danger of the pipes becoming frozen.
The mechanical parts inside the pump are designed to be constantly moving, so it’s better for them to be working than sitting idle.
When should I switch my hot tub off?
Aside from the winter, when might it be necessary to switch your hot tub off?
A hot tub should be turned off and emptied when it’s not going to be used for 2 weeks or more. With the power turned off, drain all of the water, remove any remaining water pools in the seating area and foot-wells, wipe it down clean, and leave it with the cover on.
Never leave your hot tub with the power off while there’s water still inside. As I mentioned earlier, power is needed to circulate the water and chemicals to prevent a build-up of harmful bacteria.
Make sure that the cover is properly sealed too, as the last thing you want is for any pests to find their way into the hot tub while it’s left unattended for an extended period of time.
