Cheap to buy, expensive to run
A plug-in electric heater is one of the cheapest appliances to buy — you can pick one up for the price of a takeaway dinner — which is exactly what makes it a trap. The purchase price hides the running cost, and for heating that running cost is where almost all the money goes.
Nearly every portable electric heater, whether it is a fan heater, an oil-filled column, a panel heater or a radiant bar heater, is a resistance heater. That means it converts electricity into heat one-for-one: a 2400W (2.4kW) heater draws 2.4 kW whenever the element is on, full stop. At 35c/kWh that is about 84 cents an hour. Run it four hours an evening across winter and a single heater quietly adds well over a hundred dollars to the season.
The uncomfortable truth is that all resistance heaters cost essentially the same to run per unit of heat. A pricey designer panel heater and a cheap fan heater of the same wattage cost the same to run. The differences are comfort and controllability, not efficiency.
Why a reverse-cycle unit beats them all
The one electric heater that breaks the one-for-one rule is a reverse-cycle air conditioner, because it is a heat pump. Instead of turning electricity into heat, it moves heat from outside to inside, delivering roughly three units of warmth for every unit of electricity it draws. That makes it around a third the running cost of a plug-in heater for the same warmth.
This is the heart of the cheap-heater trap. Spending $50 on a portable heater feels frugal, but if you already own a reverse-cycle air conditioner, using it to heat the room instead costs a fraction as much to run. Over a winter the reverse-cycle system can save more than the plug-in heater cost to buy in the first place.
Getting the most from a plug-in heater
Sometimes a portable heater is the right tool — a small heater warming one person at a desk for a short burst can be cheaper than firing up a whole-house system. The key is to heat the person and the small space, not the room, and to run it only as long as needed.
A thermostat and timer make a real difference. An oil column or panel heater with an accurate thermostat cycles off once the room is warm instead of drawing full power continuously, and a timer stops it heating an empty room. Lower wattage settings cost proportionally less to run, so use the lowest setting that keeps you comfortable.
How to cut electric heating costs
- If you own a reverse-cycle air conditioner, use it to heat instead of a plug-in heater — it costs roughly a third as much to run.
- Heat the person and the small space you are in, not the whole room or house.
- Use the heater's thermostat and lowest comfortable setting so it is not drawing full power continuously.
- Fit a timer so the heater is not warming an empty room.
- Rug up, close doors and seal draughts so the heater's output is not leaking away.
- Never leave a resistance heater running overnight to hold a temperature — the running cost stacks up fast.
Where EnergySorted fits
When you are running heaters that draw full power every minute they are on, the rate you pay per kilowatt-hour is everything. A home on a stale, overpriced plan pays a premium on every hour of winter heating. EnergySorted costs your real usage across more than 16,000 plans without retailer commissions, so you can see whether your rate is quietly inflating the winter bill.
If your heating load is concentrated in the evenings, the comparison can also flag whether a time-of-use plan would suit you or work against you. The Bill Health Score keeps checking that your plan stays sharp through the cold months, so the winter bill reflects the heat you used, not a rate you have outgrown.