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Hot Tub · Ofgem 1 July to 30 September 2026

4-person hard-shell hot tub running cost — Economy mode (heat off overnight)

Heat is switched off overnight and back on in the morning — reduces standby cost but uses more to reheat. A 4-person hard-shell hot tub (3,000 W heater + 1,500 W pump) costs approximately £20.84/week at Ofgem cap 26.11p/kWh (1 July to 30 September 2026).

4-person hard-shell hot tub — Economy mode (heat off overnight): Active: 9.00 kWh (2 h × 4.5 kW). Standby: 6.60 kWh (22.0 h × 3.0 kW × 10%). Total/day: 11.40 kWh = £2.98. Weekly (7 days): £20.84. Annual: £1083.46. Source: Which? — How much does a hot tub cost to run (electricity consumption data) + Ofgem (OGL v3.0).

Per day (used)
£2.98
Per week (7 days)
£20.84
Per month
£90.29
Per year
£1083.46

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
7

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 = 11.40 kWh × 26.11p = £2.98.
  4. Weekly: £2.98 × 7 days = £20.84.
  5. Annual: £20.84 × 52 = £1083.46.

Same scenario — other tub sizes

2-person inflatable hot tub: £7.02/wk4-person inflatable hot tub: £13.16/wk6-person hard-shell hot tub: £38.02/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.