Hot Tub Running Costs — How to Reduce Your Electricity Bill

A poorly maintained or inefficient hot tub can cost £150–£200 per month to run. A well-maintained one with the right setup typically costs £40–£80. Here's how to get to the lower end of that range.

How much does a hot tub cost to run?

The main variables are:

• Heater element power: Most UK hot tubs have a 3kW heater. At 30p/kWh, that's 90p per hour of heating.
• Insulation quality: A well-insulated tub loses heat slowly and the heater runs infrequently. A poorly insulated tub heats almost continuously.
• Set temperature: Every degree higher means more energy to maintain it.
• Cover quality: A waterlogged cover loses heat rapidly — this alone can double running costs.
• Climate and location: Exposed, wind-swept locations cost significantly more.

The single biggest improvement: an air source heat pump

Replacing your standard heater element with an air source heat pump is the most impactful change you can make. A quality heat pump with a COP of 5 costs one-fifth of what the heater element costs for the same heat output. See our heat pump guide for full details.

Cover condition

A waterlogged cover can lose 3–4 times as much heat as a new one. If you suspect your cover is waterlogged (heavier than it used to be, sagging in the middle), replacing it will make an immediate difference to running costs. A new cover typically saves £20–£50 per month in electricity.

Temperature and schedules

• Every degree Celsius reduction in set temperature saves approximately 8–10% on heating costs
• If you use your tub at set times, consider a schedule — heat it to temperature an hour before use and drop it 2–3 degrees when not in use (rather than a full economy mode, which requires lots of energy to recover)
• Don't drain and refill more often than necessary — heating fresh water from cold is expensive

Insulation improvements

• Ensure the cabinet panels are all securely fitted — gaps allow warm air to escape and cold air in
• Foam pipe insulation on exposed plumbing reduces heat loss
• In winter, a thermal blanket floating on the water surface under the cover can halve heat loss through the water
• Position the tub in a sheltered location if possible — a windbreak reduces heat loss significantly

Maintenance impact on running costs

A dirty filter makes the pump work harder and reduces flow to the heater, making it run longer. A scaled heater element is less efficient. Regular maintenance — filter cleaning, pipe flushing, water balancing — keeps everything running at peak efficiency.

We can carry out a running cost assessment as part of any service visit and recommend the most cost-effective improvements for your specific setup.