Fan Heater vs Oil-Filled Radiator: Running Cost Comparison
Updated March 2026. Default rate effective 1 April 2026 (Ofgem Q2 2026).
We compare the running costs of a fan heater (no thermostat) versus an oil-filled radiator (with thermostat) — both rated at 2,000W.
| Period | Fan Heater | Oil-Filled Radiator | Diff |
|---|---|---|---|
| Typical basis | 49.0pTypical hour | 29.4pTypical hour | 19.6p |
| Per day | £1.96 | £1.18 | 78.4p |
| Per week | £13.72 | £8.23 | £5.49 |
| Per month | £59.66 | £35.80 | £23.86 |
| Per year | £715.40 | £429.24 | £286.16 |
| Annual use | 2920.00 kWh | 1752.00 kWh | 1168.00 kWh |
Which is cheaper to run?
An oil-filled radiator costs approximately £1.18 per day (4 hours) versus £1.96 for a fan heater — a saving of 40%. The difference is entirely due to the thermostat: once the oil-filled radiator reaches temperature, it cycles off for periods.
The Oil-Filled Radiator is roughly 40% cheaper on the default assumptions, saving about £286.16 per year.
Things to consider beyond running cost
Other factors to consider: **Warmth quality** — oil-filled radiators provide gentle, radiant heat that lasts after switching off. **Noise** — fan heaters are audible; oil-filled radiators are silent. **Safety** — oil-filled radiators have a lower surface temperature.
Adjust and compare
Fan Heater
Typical annual electricity use: 2920.00 kWh
Oil-Filled Radiator
Typical annual electricity use: 1752.00 kWh
Fan Heater calculator
See the full breakdown
Oil-Filled Radiator calculator
See the full breakdown
Frequently asked questions
Common questions about electricity costs and our calculators.