How much does it cost to run a hot tub 24 hours a day?

Running a hot tub 24 hours a day can cost less than you might think, but electricity consumption varies depending on the size of your spa, its insulation, outside temperature and the condition of your hot tub cover.

In this guide, we'll look at typical UK running costs, what affects your electricity consumption and how you can make your hot tub more energy efficient.

How Much Does It Cost to Run a Hot Tub 24 Hours a Day?

As a general illustration, a domestic hot tub might use around 4-12 kWh of electricity per day once it has reached its operating temperature.

Using an example electricity rate of 26.32p per kWh, the estimated costs are:

Daily usage	Daily cost	Monthly cost
4 kWh	£1.05	£31.58
6 kWh	£1.58	£47.38
8 kWh	£2.11	£63.17
10 kWh	£2.63	£78.96
12 kWh	£3.16	£94.75

For many owners, budgeting around £45-£75 per month is a useful starting point, although poorly insulated spas and those operating in colder conditions can cost considerably more.

Remember, running a hot tub 24 hours a day does not mean the heater operates continuously. It switches on and off automatically to maintain the selected water temperature.

For more information, visit Ofgem's energy price information.

How Much Does It Cost to Heat a Hot Tub?

The cost of heating depends on the heater's power rating, the amount of water in the spa and the starting water temperature.

Using the example rate of 26.32p per kWh:

Heater power	Cost per hour
2 kW	£0.53
3 kW	£0.79
4 kW	£1.05

These figures assume the heater operates continuously at full power. In normal operation, the thermostat switches the heater on and off as required.

What Affects Hot Tub Running Costs?

There are four main factors that influence how much electricity your hot tub uses.

1. Water capacity

Larger hot tubs generally require more energy to heat because they hold more water. They can also have a larger surface area through which heat escapes. However, a well-insulated larger spa may be cheaper to maintain than a smaller, poorly insulated model.

2. Outside temperature

Hot tubs generally cost more to run during winter. Colder air and wind increase heat loss, meaning the heater needs to work harder to maintain the desired temperature.

3. Insulation quality

Good insulation helps retain heat within the hot tub, reducing how frequently the heater needs to operate. Full-foam insulation, insulated bases and well-designed cabinets can all contribute to improved efficiency.

4. Heater and pump operation

Your heater, circulation pump, filtration system and massage pumps all use electricity. The amount of time these components operate will influence your overall consumption.

Does Your Hot Tub Cover Affect Running Costs?

Yes. Your hot tub cover plays an important role in retaining heat and reducing electricity consumption.

A properly fitted, well-insulated cover helps prevent heat escaping from the water's surface. However, a damaged, waterlogged or poorly fitting cover may no longer provide effective insulation.

Look out for waterlogged foam, cracked vinyl, worn seals and compressed insulation. If your cover has become unusually heavy or no longer fits correctly, replacing it may help improve heat retention.

Can a Heat Pump Reduce Running Costs?

A hot tub heat pump transfers heat from the surrounding air into the water, rather than generating heat directly through an electric resistance element.

This can make it considerably more energy efficient than a conventional heater, particularly in favourable outdoor temperatures.

Heat pump efficiency is often measured using a Coefficient of Performance (COP). For example, a COP of 4 means the unit delivers approximately 4 kW of heat for every 1 kW of electricity consumed under the stated test conditions.

Actual performance varies with air temperature, water temperature and installation. Always check compatibility with your existing hot tub equipment before upgrading.

How to Reduce Hot Tub Running Costs

There are several simple ways to help reduce unnecessary electricity consumption:

• Keep the cover fitted: Replace it whenever the hot tub is not in use.
• Check insulation: Look for signs of deterioration or heat loss.
• Maintain your filters: Clean filters help support good water circulation.
• Review temperature settings: A slightly lower temperature may reduce the energy needed to maintain the water.
• Protect against wind: A sheltered installation can help reduce heat loss.
• Monitor electricity usage: Use a smart meter or energy monitor to understand your actual consumption.

If your hot tub is struggling to reach or maintain temperature, it may also be worth checking the condition of the heater element.

Frequently Asked Questions

For hot tub covers, replacement heater elements, heat pumps and other spa equipment, visit Hydrospares.