Are Hot Tubs Expensive To Run?

Are hot tubs expensive to run?

When researching hot tubs for the first time, customers are often turning to Google to research eco friendly hot tubs or calling us to ask about running costs, as they need to know how much a hot tub costs to run before they can consider ordering one. It's a fair point, so we're going to get to the bottom of it here.

You can either enjoy the short video below or read the entire article to get all the information you need to make an informed decision when choosing whether or not to order a hot tub.

How much does it cost to run a hot tub?

OK, so it's actually a multi-part answer. We know, you'd rather it was easy... but bear with us here because you need to understand all the different factors which will affect how much it will cost to run a hot tub at home. There's a number of variables to take into account here, including where you live, your energy supplier, the quality of the hot tub and how you want to use it. Let's get started.

Baby, it's cold outside.

One of the first factors that will affect the running cost of your hot tub is... where's it going to live?

The ambient temperature outside will affect your hot tubs energy usage, as in cooler climates the heating system will need to work harder to maintain your desired temperature. Also, the time of year will also have an effect. If it's winter and the thermometer reading is low enough to justify putting on a jumper, it's going to affect your hot tubs heating system and how efficient it can be at getting the water up to temperature, or keeping it there.

We urge customers to consider dropping their water temperature by 2-5°C during the winter months for more efficient running. See our tips for using your hot tub during the winter to learn more about this.

Give me energy.

Another factor at play is your energy tariff. Making sure you're on the most cost-effective electricity tariff is key to keeping your hot tub running costs down. If you're considering a hot tub, it's well worth checking out a price comparison website such as Look After My Bills to see who gives the best energy deals and ensure that you're on the most efficient electricity tariff for owning a spa.

We recommend that customers look for energy providers who offer lower cost electricity rates at night time, when the ambient temperature is cooler and your hot tub is keeping things warm, as it will mean your heating system kicks in less often, thus consuming less electricity.

According to WhatSpa, when asked how much does it cost to run a hot tub they say that “the most energy-efficient hot tubs on the market will cost between 75p and £1.00 per day at energy tariffs of around 12-13p per kWh."

Of course, the energy market has gone a little bit crazy recently. Based on our research and real-world feedback from customers in 2022 with the current energy price cap tariffs of £0.34 per kWh, for a 5-6 seater family spa it costs around £3 - £4 per day to run a hot tub in the UK. For smaller spas, or 13A eco-friendly spas, this will be closer to £2.50 - £3 per day. For those looking for a more wallet-friendly option, Plug & Play hot tubs can often benefit from lower running costs.

We also offer a range of energy efficient hot tubs with air source heat pumps, which reduce the electricity consumption by up to 75% - this can be great during the current high energy costs period we're going through as it will reduce running costs almost down to what they were before the market went a bit crazy. In addition, once things calm back down again, it will make your hot tub extremely energy efficient.

Remember, you should leave your hot tub running all the time for it to be at its most efficient and make sure when checking or changing an energy tariff to choose the lowest unit rate for electricity, rather than focussing on standing charge.

How often will you use it?

Frequency of use is something that will play a role in the running cost of your hot tub. It goes without saying really, but the more you use your hot tub, the more expensive it will be to run. More use will require more heating... it's pretty simple and is something that's worth bearing in mind.

Many people ask if they should turn off their hot tub when they aren't using it... this is a bad idea and should not be done.

Once you've chosen your desired temperature on your spa's control screen, you'll save both energy and money by just leaving it there. If you turned the hot tub off, it would use a lot of energy to heat it up again... bear in mind that most spas will heat water at around 1-2 degrees per hour, so it would take almost a whole day of solid heating to reach your temperature target.

Plus, if there's no power then there's no filtration and your water will go murky and horrible. It will inevitably then need a drain, clean and refill.

What we do recommend is turning the temperature down by 2-5°C overnight, and down by as much as 10°C if you're going away for a week or more.

Gimme that heat!

Many people falsely believe that a bigger heater will be more energy efficient - this isn't necessarily true! The heater system for a hot tub will come with a number of different kW ratings (usually lower for Plug and Play hot tubs because they can't draw too much power from a 13A plug socket).

A hot tub with a larger kW rating for it's heater will definitely heat the water quicker. It also won't need to stay on for as much time in order to get your water to your chosen temperature. That being said, a lower kW rating heater will take longer, but use less energy in the process.

In theory, a 3kW heater might take 1 hour to raise the temperature by 1.5°C whereas a 1.5kW heater would take 2 hours to do the same job. So it's actually pretty even... and you don't need to decide between speed and energy usage.

Bigger isn't always better

Naturally, the larger the volume of water your spa contains, the more energy will be required in order to keep that water warm. So when you're choosing a model, consider how many people are going to use the hot tub on a regular basis. If there's just the two of you, there's no point in going for a huge 6-seater spa that is bigger than you need. Our recommended rule is around 250 litres of water per person.

Other factors...

Cleaning your hot tub can require a thorough drain & refill, which will require around a day of solid heating time once you've filled it up again with fresh water. You should drain and refill your hot tub around 3 times a year. Learn more in our article about how to clean your hot tub.

Insulation in your hot tub will have an effect on the energy efficiency of your spa. The insulation materials that have been using inside the cabinet of your hot tub will include spray-on foam insulation on the underside of the spa's shell, plus foil-wrapped insulation around the cabinet to reflect the heat back inside. Some spas have full foam sprayed inside the hot tub cabinet, but exercise caution... it can be difficult to access parts for maintenance, and your pump and heating system also need good airflow to be able to operate safely and efficiently.

The lid of your hot tub is important too. When cleaning your hot tub, keep your lid in good condition and make sure it doesn't take on too much moisture. If your lid starts to bow, it'll come up at the sides allowing precious heat to escape... not what you want!

For more reading, take a look at our article about how to keep your hot tub running costs low.

Ready to start your hot tub journey?