Running an electric heater without a shocking bill
Every electric heater is 100% efficient, so no model is cheaper to run than another at the same wattage. What varies is how much of the heat lands on you.
The claim to distrust
Advertising for electric heaters leans heavily on efficiency. Ignore it. Every electric heater converts essentially all its electricity into heat. A 2 kW convector, a 2 kW fan heater and a 2 kW oil-filled radiator all produce the same heat and cost the same to run per hour.
Anyone claiming their electric heater is more efficient than another is describing physics that does not exist. What genuinely differs is where the heat goes and how quickly you feel it.
What the money actually buys
| Type | Warms | Best for |
|---|---|---|
| Convector / panel | The air, evenly | Background warmth in a room you sit in for hours |
| Fan heater | The air, fast | Quick warmth in a small room |
| Oil-filled radiator | Slowly, holds heat | Overnight in a bedroom |
| Infrared / flame effect | Objects and people directly | Sitting in one spot, draughty rooms |
The arithmetic
At €0.25 per kWh, a 2 kW heater costs €0.50 an hour at full output. Four hours an evening across a winter month is roughly €60 — from one heater in one room.
That figure is why the thermostat matters more than the model. A heater with a working thermostat cycles off once the room is warm and may draw full power only a third of the time. One without runs flat out until you notice.
Where the saving actually is
- Heat the room you are in, not the house. This is the entire case for a portable electric heater over central heating in a mild spell.
- Close the door. Obvious, routinely ignored, and worth more than any feature on the box.
- Use the thermostat and the timer. A heater running in an empty room is pure loss.
- Block the draught first. A €5 draught excluder under a door does more than €50 of extra wattage.
- Sit near it. With radiant and flame-effect heaters, proximity is most of the benefit.
Safety, briefly
Never run a portable heater from an extension lead or a multi-way adaptor — 2 kW is close to the limit of a domestic socket circuit and extension leads are a common cause of fires. Keep half a metre clear of furniture and curtains, and never dry clothing on one.
If you take one thing: compare wattage and thermostat quality, not efficiency claims. Two heaters at the same wattage cost exactly the same to run. The one that switches itself off when the room is warm is the cheaper machine.