How much does it cost to run a immersion heater?
A immersion heater typically draws about 3,000 W. At the current Ofgem price-cap electricity rate of 26.11p/kWh (1 July to 30 September 2026), a typical 1-hour use costs about 78.3p, and one hour costs roughly 78.3p.
Immersion heater running cost: ~3.00 kWh per hour β 78.3p/hour. A typical 1-hour use β 78.3p at 26.11p/kWh.
Immersion heater running-cost calculator
A immersion heater draws about 3,000 W. Set how long you run it and we apply the current Ofgem electricity unit rate of 26.11p/kWh.
Cost to run for 1 hour
78.3p
Uses 3.00 kWh at 26.11p/kWh.
- Per day
- 78.3p
- Per week
- Β£5.48
- Per year
- Β£285.90
Per-day/week/year figures assume one 1-hour run each day. Wattage is typical/indicative β your model may differ.
How the cost is worked out
- Wattage: a immersion heater draws about 3,000 W.
- Convert to kW: 3,000 Γ· 1,000 = 3.00 kW.
- Multiply by hours: 3.00 kW Γ 1 h = 3.00 kWh.
- Multiply by the unit rate: 3.00 kWh Γ 26.11p β 78.3p.
Frequently asked questions
How much does it cost to run a immersion heater?
A immersion heater draws about 3,000 W. At the Ofgem cap rate of 26.11p/kWh (1 July to 30 September 2026), a typical 1-hour use costs roughly 78.3p, and one hour costs about 78.3p.
How much electricity does a immersion heater use per hour?
At 3,000 W, a immersion heater uses about 3.00 kWh per hour, which is roughly 78.3p at the current cap rate.
Running costs for other appliances
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Wattage (3,000 W) is typical/indicative β your model may differ. Source: Heatable β How much energy do appliances use (typical ratings; draws on Energy Saving Trust / Centre for Sustainable Energy). Electricity unit rate from Ofgem β Energy price cap unit rates and standing charges (cap period 1 July to 30 September 2026, fetched 2026-06-18). Ofgem figures Β© Ofgem, Open Government Licence v3.0. Appliance wattages are typical/indicative, not measured. Ofgem.