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Hot Tub · Ofgem 1 July to 30 September 2026

4-person hard-shell hot tub running cost — Twice a week (2 h each)

Two 2-hour sessions per week — popular for couples or families. A 4-person hard-shell hot tub (3,000 W heater + 1,500 W pump) costs approximately £8.15/week at Ofgem cap 26.11p/kWh (1 July to 30 September 2026).

4-person hard-shell hot tub — Twice a week (2 h each): Active: 9.00 kWh (2 h × 4.5 kW). Standby: 6.60 kWh (22.0 h × 3.0 kW × 10%). Total/day: 15.60 kWh = £4.07. Weekly (2 days): £8.15. Annual: £423.61. Source: Which? — How much does a hot tub cost to run (electricity consumption data) + Ofgem (OGL v3.0).

Per day (used)
£4.07
Per week (2 days)
£8.15
Per month
£35.30
Per year
£423.61

Tub specification

Seats
4 adults
Heater
3,000 W
Pump
1,500 W
Active use
2 h/day
Standby load
10% of heater
Days used/week
2

Hydropool / Caldera typical 4-person hard-shell: 3 kW heater + 1.5 kW pump (Which? 2024)

How the cost is worked out

  1. Active use: (3,000 W + 1,500 W) ÷ 1000 × 2 h = 9.00 kWh.
  2. Standby: 3,000 W ÷ 1000 × 22.0 h × 10% = 6.60 kWh.
  3. Daily total: 9.00 + 6.60 = 15.60 kWh × 26.11p = £4.07.
  4. Weekly: £4.07 × 2 days = £8.15.
  5. Annual: £8.15 × 52 = £423.61.

Same scenario — other tub sizes

2-person inflatable hot tub: £2.59/wk4-person inflatable hot tub: £4.86/wk6-person hard-shell hot tub: £15.25/wk

Track hot tub running costs

Updated each time the Ofgem cap changes.

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Heater and pump specs from Which? — How much does a hot tub cost to run (electricity consumption data). Unit rate 26.11p/kWh from Ofgem — Energy price cap unit rates and standing charges (1 July to 30 September 2026), OGL v3.0.