By the HotTubAdviser.co.uk Team · Updated May 2026 · Independent, reader-supported

Hot Tub Running Costs UK Per Month: Honest Figures for 2025

If you're thinking about buying a hot tub, the purchase price is only half the story. Most UK owners are surprised by the ongoing electricity costs—but the actual bill depends heavily on how you use your tub and which model you own. Here's what you'll realistically spend per month.

What Actually Costs Money

The biggest expense is heating water. A typical 4–6 person hot tub uses a 1.5–2 kW heater that runs intermittently to maintain temperature, usually 37–40°C. Outside of the heating season (roughly November to March in the UK), costs are noticeably lower because your tub loses less heat overnight.

Jet pumps are the second cost—usually 0.75–1.5 kW when running. Most people don't run jets continuously; they're typically on for 20–40 minutes at a time. The circulation pump (which keeps water clean and moving) runs 24/7 but draws only 0.3–0.5 kW, so it's not your main expense.

Water treatment and chemical costs run £10–20 per month on average, though this varies by water quality and whether you use salt chlorinators or traditional chemicals.

Monthly Costs by Season and Tub Size

Electricity costs vary enormously depending on:

• Tub size: A 2-person portable model (1,000–1,200 litres) versus a 6-person built-in (2,000+ litres)
• Insulation quality: Budget models lose heat much faster than premium builds
• Ambient temperature: Running costs double in January versus September
• Usage patterns: Using jets for 2 hours daily costs more than 30 minutes

Rough monthly estimates (UK average electricity at roughly 28p per kWh):

• Small portable tub (2–3 people), summer: £15–25
• Small portable tub (2–3 people), winter: £45–75
• Medium tub (4–5 people), summer: £30–40
• Medium tub (4–5 people), winter: £80–130
• Large tub (6+ people), summer: £40–60
• Large tub (6+ people), winter: £120–180

These are electricity costs only. Add £10–20 monthly for chemicals, and you're looking at £25–200 per month depending on your setup.

The Hidden Cost: Poor Insulation

This is where affiliate advice sites often mislead you. A tub with thin shell insulation and no lid will cost 30–50% more to run than an equivalent model with proper foam and a well-fitting cover. The difference between a budget £3,000 tub and a mid-range £6,000 tub often comes down to insulation, not features. Over five years, better insulation pays for itself.

A quality insulated cover is not optional—it's essential. An uncovered hot tub loses roughly 1°C per hour overnight. A cheap cover barely slows this. A proper thermal cover reduces heat loss by 75%, cutting monthly heating costs by roughly £20–40 in winter.

What Increases Your Bills

Temperature setting: Maintaining 40°C instead of 38°C costs roughly 10% more. Running at 36°C saves money but reduces the therapeutic benefit most people buy for.

Jet usage: Running jets for two hours daily instead of 30 minutes adds £15–25 monthly in winter.

Outdoor location: A tub in a sheltered spot (e.g., against a south-facing wall) costs less to heat than one exposed to wind.

Climate: Scotland and northern England pay more than the south, simply because outdoor temperatures are lower.

Electricity tariff: If you're on Economy 7, running your tub during off-peak hours saves significantly. Some owners program heaters to run mainly between 11pm and 7am.

How to Calculate Your Own Costs

Find your tub's heater wattage (usually on the specifications label or manual). In winter, estimate the heater runs 40–50% of the time when not actively in use. Add 10–15 minutes of jet pump use per day.

Example: 2 kW heater, 1 kW jet pump

• Heater running 50% of the time = 360 hours per month = 720 kWh
• Jets for 15 minutes daily = 7.5 hours per month = 7.5 kWh
• Total: 727.5 kWh × £0.28 = £204 per month (winter)

In summer, the heater might run only 20–30% of the time, bringing that down to £60–80.

Real Cost-Saving Steps That Work

Upgrade insulation: If you buy a new tub, this is the single biggest variable. Premium brands (Jacuzzi, Sundance, Thermospas) cost more upfront but run 20–30% cheaper than budget alternatives.

Use a thermal cover: Non-negotiable. A decent cover costs £80–150 and pays for itself in 2–3 months through heating savings alone.

Run jets strategically: Enjoy the jets, but don't leave them running unnecessarily. 20–30 minutes daily is plenty for relaxation and circulation.

Lower temperature slightly: Dropping from 40°C to 38°C saves roughly 10% on heating. You probably won't notice the difference.

Service your heater: A blocked heater works harder. Clean filters monthly and have the system serviced annually.

Consider a smart timer: If your tub allows it, programming heating to run mainly during Economy 7 off-peak hours or before you're likely to use it saves 15–20%.

The Bottom Line

A typical 4–5 person hot tub costs £50–90 per month in summer and £100–150 per month in winter, including chemicals. That's realistic for a reasonably insulated model with moderate use.

Budget models might run £30–60 in summer but spike to £180–220 in winter. Premium insulated tubs stay closer to £80–120 year-round.

The people most surprised by bills are those who bought the cheapest option and expected budget prices to continue. The £3,000 hot tub that costs £180 per month in winter is actually more expensive than the £6,000 tub that costs £100 per month.

Before buying, ask the retailer for winter running-cost estimates based on your local electricity rate. Factor in an insulated cover immediately. That's the difference between hot tub ownership being a manageable expense or a monthly shock.