Hot tub running costs UK 2026: and how to cut them in half
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If you've noticed your electricity bill creep up since getting a hot tub, you're not imagining it. A hot tub is one of the most energy-hungry appliances in your home — and with UK electricity prices rising again from July 2026, the cost of keeping that water warm is only going in one direction.
The good news is that most hot tub owners are paying far more than they need to. In this guide we'll break down exactly what you're likely spending, what's driving the cost, and — most importantly — the single change that can cut your heating bill by 50–70%.
What does a hot tub actually cost to run in the UK in 2026?
The honest answer is: it depends. But here are some realistic figures based on current UK energy prices.
The Ofgem price cap currently sits at 24.67p per kWh for electricity (rising to 26.11p from 1 July 2026). A typical hot tub with a standard electric heater uses between 3 and 6 kWh per hour of heating time, depending on:
- The size and volume of the tub
- How well insulated it is
- The outside air temperature
- How far the water temperature has dropped
For a mid-size hot tub (around 1,200 litres) kept at a steady 38°C and used 3–4 times a week, you can expect to use roughly 250–350 kWh per month on heating alone. At current rates, that works out to roughly:
| Usage pattern | Estimated monthly heating cost |
|---|---|
| Light use (1–2 times/week) | £40–£55 |
| Moderate use (3–4 times/week) | £60–£85 |
| Heavy use (daily, or in winter) | £90–£120+ |
These figures assume a standard electric heater. If you have an older or poorly insulated hot tub, or you're letting the temperature drop between uses and reheating from cold each time, your costs could be higher still.
The 3 things that drive your running costs
1. How you heat the water
This is by far the biggest factor — and the one you can actually change. A standard electric heater converts electricity to heat at roughly 1:1 efficiency. For every kilowatt of electricity you put in, you get one kilowatt of heat out. There's no getting around that.
An air source heat pump works completely differently. Instead of generating heat, it moves heat from the outside air into the water — and it does this with remarkable efficiency. A good heat pump produces 3 to 5 units of heat for every unit of electricity it uses. That ratio is called the COP (coefficient of performance), and it's why heat pumps change the economics of hot tub ownership so dramatically.
2. Your hot tub cover
A well-fitting, high-quality cover can reduce heat loss by up to 75%. If your cover is old, waterlogged, or doesn't seal properly at the edges, your heater is working overtime to compensate. This is a cheap fix with a big return — a replacement cover typically costs £150–£300.
3. Your water temperature habits
Letting the temperature drop right down between uses and then reheating from cold every time is one of the most expensive things you can do. Modern hot tubs are more efficient when maintained at a steady temperature. If you use your tub regularly, it's cheaper to keep it warm than to keep reheating it from cold.
How a heat pump cuts your costs
Let's put some real numbers on it. Take the moderate-use owner above, spending around £75 per month on electricity to heat their hot tub with a standard electric heater.
With a quality air source heat pump running at a COP of 4 (a reasonable mid-range figure for UK conditions), you're using a quarter of the electricity to produce the same amount of heat. That same owner is now spending roughly £18–£22 per month on heating — a saving of over £50 every single month.
Over a year, that's more than £600 saved.
A heat pump for a standard hot tub starts from around £899. At those savings, many owners find their heat pump pays for itself within 12–18 months — and then continues saving money for the 8–10 years the unit typically lasts.
| Electric heater | Air source heat pump | |
|---|---|---|
| Monthly heating cost (moderate use) | ~£75 | ~£20 |
| Annual heating cost | ~£900 | ~£240 |
| Annual saving | — | ~£660 |
| Typical payback period | — | 12–18 months |
Figures based on 24.67p/kWh (current Ofgem rate) and a COP of 4.
Will energy prices keep rising?
Unfortunately, the direction of travel is upward. The Ofgem price cap is rising by 13% in July 2026. Every increase in the unit rate makes the case for a heat pump stronger — because the bigger the gap between what you're paying and what you could be paying, the faster the payback.
If you've been thinking about making the switch, there's a genuine financial argument for doing it sooner rather than later.
What size heat pump?
As a general rule:
- Up to 1,200 litres (most 4–5 person hot tubs): a 5–7kW heat pump is sufficient
- 1,200–1,800 litres (larger hot tubs and smaller swim spas): look at 9–11kW
- Swim spas and large installations: 11kW+
The bottom line
If you own a hot tub and you're still heating it with a standard electric heater, you're almost certainly paying more than you need to. The combination of UK energy prices in 2026 and the efficiency of modern heat pumps makes switching one of the most financially straightforward decisions you can make.
It doesn't require any major changes to your hot tub, the installation is straightforward, and the savings start from day one.
Browse the Hortus Collection heat pump range — we stock units suited to all sizes of hot tub and swim spa, starting from £899, with free UK delivery.
Last updated: June 2026. Energy price figures based on Ofgem price cap data.