Oil-filled radiator vs panel heater vs fan heater: which is cheapest to run in Ireland?
Quick answer: At the same wattage none of them is cheaper to run: an oil-filled radiator, a panel heater and a fan heater all turn the electricity they use into heat, so a 2 kW model of any type costs €0.76 an hour at full power on Ireland’s day rate of €0.38/kWh. The cheapest to run is the lowest-wattage heater with a thermostat that still warms your room. For a short burst a fan heater costs least; for a long evening an oil-filled radiator or a panel heater with a thermostat usually does.
Ask which electric heater is cheapest to run and most answers point to oil-filled radiators. That is half right. Below is what each type costs per hour at Irish electricity prices, how quickly it heats, what it is good for and what to watch out for, using the 25 heaters with a published power rating in our five buying guides.
Oil vs panel vs fan heater at a glance
| Type | Power range | Cost per hour at full power (day rate) | Price in our guides | How fast it heats | Best for | Watch out for |
|---|---|---|---|---|---|---|
| Oil-filled radiator 10 models we track | 650 W–2.5 kW | €0.25–€0.95 | €21–€236 | Slowest to get going: the oil has to warm up first, then it keeps giving off heat for a while after it switches off | Long, steady heat: a living room for the evening or a bedroom overnight | The fins get hot to the touch; heavy to move; poor for a 20-minute warm-up |
| Panel or wall heater 3 models we track | 600 W–1.5 kW | €0.23–€0.57 | €61–€110 | Medium: warms the room by convection, with little stored heat | Wall-mounting, timers and smart control; bathrooms only if the model is IP-rated | A slim 1 kW panel will struggle in a large or draughty room |
| Fan or ceramic heater 12 models we track | 1.5 kW–2 kW | €0.57–€0.76 | €12–€155 | Fastest: blows warm air at you within minutes | Short bursts: a cold room before you dress, a home office for an hour | Noisy; a model without a thermostat runs flat out until you switch it off; keep it clear of bedding and curtains |
How the cost is worked out: rated power in kW × €0.38 per kWh (domestic day rate, cross-checked against SEAI energy price statistics, July 2026). Prices are indicative Amazon.ie prices from our guides and change often.
Same watts, same cost per hour
Every electric heater turns essentially all of the electricity it draws into heat in the room. No type makes more heat out of a kilowatt-hour than another, so at full power the cost per hour depends only on the wattage:
| Power | Oil-filled radiator | Panel or wall heater | Fan or ceramic heater |
|---|---|---|---|
| 1 kW | €0.38 | €0.38 | €0.38 |
| 1.5 kW | €0.57 | €0.57 | €0.57 |
| 2 kW | €0.76 | €0.76 | €0.76 |
The lowest-power heater in our guides is the Purus 600W Electric Radiator (Bathroom Safe, IP24) at 600 W, which costs €0.23 an hour, but it suits a small room only. A low-wattage heater in a room that is too big for it simply runs flat out and never gets the room warm.
Where the real difference comes from
Short bursts: the fan heater wins. Thirty minutes on a 2 kW fan heater costs €0.38 and you feel the warm air almost at once. A 2 kW oil-filled radiator uses the same €0.38 in those 30 minutes, but much of that heat is still in the oil when you leave the room.
Long evenings: the thermostat wins. A 2 kW heater left on for 5 hours at full power costs €3.80 at the day rate. If a thermostat holds it at full power for 60% of the time, the same evening costs €2.28. The 60% figure is an assumption (the same one our running cost calculator uses), not a measurement; a well-insulated room needs less, a draughty one more. Oil-filled radiators and panel heaters are built for this kind of steady use, and the oil keeps releasing heat while the element is off.
Night rate. On a smart-meter night rate of about €0.18/kWh, every figure above roughly halves: 2 kW costs €0.36 an hour.
Examples from our guides
- Oil-filled radiator: Warmlite 650W 5-Fin Mini Oil Radiator, 650 W, €0.25 an hour at full power.
- Panel or wall heater: Purus 600W Electric Radiator (Bathroom Safe, IP24), 600 W, €0.23 an hour at full power.
- Fan or ceramic heater: Dreo 1500W Ceramic Space Heater, 1.5 kW, €0.57 an hour at full power.
Safety
Oil-filled radiators and panel heaters get hot on the surface, so keep children and pets from leaning on them. Fan heaters blow hot air, so keep them well clear of curtains, bedding and clothes. Whatever the type, never cover a heater or dry clothes on it, plug it straight into a wall socket rather than an extension lead, and switch it off when you leave the room. On a heater that stands on the floor, look for tip-over protection, which the Dreo 1500W Ceramic Space Heater lists in its specifications. For a bathroom, use only a heater rated for it, like the Purus 600W Electric Radiator (Bathroom Safe, IP24).
Frequently asked questions
Which type of electric heater is cheapest to run in Ireland?
Per hour, none: at the same wattage every type costs the same, €0.76 an hour for 2 kW at €0.38/kWh. Over a whole evening, a thermostat-controlled oil-filled radiator or panel heater usually costs less than a fan heater left running, because it spends part of each hour switched off.
Do oil-filled radiators use less electricity?
No. A 2 kW oil-filled radiator draws 2 kWh in an hour at full power, exactly like a 2 kW fan heater. It feels cheaper because the oil stores heat and the thermostat cycles, so over a long evening it is at full power for less of the time.
Is a fan heater expensive to run?
Not for short use: 30 minutes on a 2 kW fan heater costs €0.38. It gets expensive when it is left on all evening without a thermostat: 5 hours flat out is €3.80 at the day rate.
Which type of heater is safest?
None should be left unattended near curtains, bedding or clothes, covered, or run from an extension lead. For long use, a thermostat-controlled oil-filled radiator or panel heater with overheat protection is the usual choice; a fan heater is best for short, supervised use. In a bathroom, use only a heater rated for it (an IP rating such as IP24).
PickIreland is reader-supported. When you buy through links on our site, we may earn an affiliate commission at no extra cost to you. Running costs on this page are calculated from manufacturer-published rated power and are indicative, not measured.