Last updated: September 2026
A 2 kW fan heater costs about 70 cent an hour to run on a typical 2026 Irish electricity plan - and so does a 2 kW oil-filled radiator, a 2 kW convector and a 2 kW "energy-efficient" panel heater. Every plug-in electric heater turns electricity into heat at close to 100%, so the price tag and the marketing do not change the running cost; only the wattage and the hours do. This guide gives the real cost per hour for each type of heater sold in Ireland, when a plug-in heater is the cheap option and when it is the dear one, and how the same heat compares from gas, oil or a heat pump.
⚡ Quick Summary
🌿 The only formula that matters: kilowatts × hours × your unit rate. A 2 kW heater for 4 hours at 35c/kWh = €2.80 a day, about €340 over a 120-day winter.
🌿 2026 unit rates: standard 24-hour rates are around 38c/kWh (Electric Ireland since 1 July 2026); discounted first-year plans about 32-35c; NightSaver night rate roughly 17-21c.
🌿 There is no "efficient" plug-in heater: fan, oil-filled, convector, halogen and infrared all deliver the same heat per kWh. They differ in how fast and where the heat lands.
🌿 Cheapest per unit of heat: gas (~12-14c per kWh delivered) and oil (~15-16c) beat direct electric (35-38c) by a wide margin; an air-to-air heat pump at ~12-13c matches gas.
🌿 Where plug-in heaters win: one person, one room, a couple of hours - cheaper than firing the whole central heating system for a bedroom or home office.
🌿 Buy the smallest heater that does the job, with a thermostat and a timer. A 600 W infrared panel at 21c an hour heats a desk; a 2 kW fan heater at 70c heats a room you may not need heated.
🔌 Why Every Electric Heater Costs the Same to Run
A heater rated at 2,000 W draws 2 kWh of electricity for every hour it runs flat out, and turns almost all of it into heat. That is physics, not a brand feature. SEAI's own fuel-cost comparison assumes 100% efficiency for electric fires and panel heaters, 90% for storage heaters (because some heat leaks out at the wrong time) and a multiple of 250-560% for heat pumps - the only electric heating that produces more heat than the electricity it consumes.
So "energy-efficient electric heater" on a box means one of two honest things: it has a good thermostat and timer so it runs fewer hours, or it directs heat at people rather than at the ceiling. Both are worth having. Neither lowers the cost per kWh.
🔹 Cost per hour by heater type (2026)
At a 35c/kWh discounted rate, with the standard 38c figure in brackets:
🌿 Fan heater, 2 kW: 70c (76c) an hour. Instant heat, noisy, cools the moment it stops. Retail €20-130.
🌿 Convector or panel heater, 2 kW: 70c (76c). Quiet, gentle background heat, slow to start. Retail €40-150.
🌿 Oil-filled radiator, 1.5 kW: 53c (57c); 2.5 kW models 88c (95c). Slow to warm, keeps radiating after it switches off, the best choice for a bedroom overnight on a low thermostat. Retail €90-140.
🌿 Halogen or quartz heater, 1.2 kW: 42c (46c); many run at 400-800 W. Radiant heat you feel immediately, little effect on the room. Retail €30-100.
🌿 Infrared panel, 600 W: 21c (23c); 350-500 W panels for a small room, 1,000-1,200 W for a large one. Warms people and surfaces rather than air, so it suits a desk or a draughty room. Retail €250-700.
🌿 Storage heaters (night rate): around 17-22c per kWh of useful heat on NightSaver - see our storage heaters guide.
Run your own numbers - wattage, hours, your actual rate - below.
🔹 Electric heater running cost calculator
Indicative estimates only. Every plug-in electric heater turns electricity into heat at close to 100%, so cost depends on wattage and hours, not the type. Comparison assumes gas at ~12c/kWh through a ~90% efficient boiler, kerosene at ~€1.37/L (10.2 kWh/L) through an ~87% efficient boiler, and an air-to-air heat pump delivering about 3 kWh of heat per kWh of electricity. Standing charges excluded.
🔥 Electric vs Gas vs Oil vs Heat Pump: Cost per Unit of Heat
The fair comparison is the cost of a kWh of heat that actually reaches the room, after boiler losses:
🌿 Plug-in electric heater: 35-38c per kWh of heat (100% efficient, so the unit rate is the cost).
🌿 Storage heater on night rate: 17-22c.
🌿 Oil central heating: kerosene at ~€1.37 a litre (national average, late August 2026) holds about 10.2 kWh, so ~13.5c per kWh of fuel and 15-16c through an 85-90% efficient boiler. Prices move daily - see heating oil prices.
🌿 Gas central heating: unit rates of roughly 11-13c on 2026 plans give 12-14c delivered.
🌿 Air-to-air heat pump: 35c ÷ a COP of 3 = about 12c, and it can cool in summer - our air-to-air guide covers the €7,500 grant.
The practical reading: heating one room with a plug-in heater for an evening is cheaper than heating the whole house with the boiler. Heating the whole house with plug-in heaters all winter is two to three times dearer than the boiler, and a bad idea.
🧠 Which Heater for Which Job
🌿 Home office, one person, all day: a 350-600 W infrared panel aimed at the desk, or a 400 W desk fan heater - 12-21c an hour, far less than heating the room to 21°C.
🌿 Bedroom overnight: an oil-filled radiator on its lowest thermostat setting, timer set to stop after two hours. Silent, no exposed element, keeps the chill off.
🌿 Bathroom for 20 minutes: a wall-mounted fan heater on a pull cord (a plug-in heater in a bathroom is a safety problem). 2 kW for 20 minutes is about 23c.
🌿 Sitting room, evening, family: the central heating, zoned if you have it. A single 2 kW heater cannot hold a large room at temperature and will run flat out for hours.
🌿 Conservatory or draughty extension: radiant (halogen or infrared) heat you feel directly, since warming the air is a losing battle in a leaky space. The permanent fix is insulation, not a bigger heater.
🌿 Damp room: heat alone pushes moisture around; a dehumidifier at 150-250 W does more for condensation than a 2 kW heater does.
💶 Cutting the Cost of the Heater You Already Have
🌿 Use the thermostat: a heater cycling on and off to hold 19°C draws power perhaps half the time - the calculator's "hours" figure should be hours actually drawing, not hours switched on.
🌿 Timer, always: a heater left on in an empty room is the most common winter bill shock.
🌿 Shut the door: a 2 kW heater is sized for one closed room, not an open-plan floor.
🌿 Heat the person, not the room: radiant heaters and, cheaper still, an electric blanket or heated throw at 50-150 W (2-5c an hour).
🌿 Check your unit rate: the gap between a standard 38c tariff and a discounted 32c one is 16% off every hour of heating - the switching gap is worth €550+ a year on an average household.
🌿 Night rate: a storage heater or an oil-filled radiator on a timer between 11pm and 8am costs roughly half the daytime rate per unit on a NightSaver meter - see our night rate guide.
🔥 Safety: The Boring Part That Matters
Dublin Fire Brigade and Electrical Safety First give the same short list: keep heaters at least a metre from curtains, bedding, furniture and anything that burns; never dry clothes on or over a heater; plug directly into a wall socket rather than an extension lead, which can overheat under a 2 kW load; switch off before leaving the room or going to sleep; and buy halogen or fan heaters with a tip-over cut-out. Electric heaters produce no carbon monoxide, so a CO alarm is not the issue - fire is.
⚠️ Common Mistakes to Avoid
🌿 Paying extra for "efficiency": a €300 panel and a €30 convector of the same wattage cost the same per hour. Pay for controls, build quality and the type of heat, not for a claim that defies physics.
🌿 Heating the house room by room with plug-ins: at 35-38c per kWh against 12-16c for gas or oil, a winter of whole-house electric heating can cost €1,500-2,500 more than the boiler.
🌿 Ignoring the wattage: "low energy" halogen heaters are often 1,200 W; "mini" heaters can be 1,500 W. Read the label.
🌿 Extension leads and multi-plugs: the most common cause of heater fires.
🌿 Treating a heater as the fix for damp: warm damp air condenses on the next cold wall. Ventilate and dehumidify first.
❓ Frequently Asked Questions
🔹 What is the cheapest electric heater to run?
The lowest-wattage one that keeps you warm. Per kWh they all cost the same; a 400 W desk heater or a 350 W infrared panel is cheapest per hour because it draws least. For heating a whole room, none is cheap - the boiler or a heat pump is.
🔹 How much does it cost to run a 2 kW heater for 8 hours?
16 kWh, so about €5.60 at 35c or €6.10 at 38c if it runs flat out; roughly half that if a thermostat cycles it.
🔹 Are oil-filled radiators cheaper to run than fan heaters?
Not per kWh. They feel cheaper because they hold heat after switching off and are usually run at lower wattage settings on a thermostat, which means fewer hours drawing power.
🔹 Are infrared heaters worth it?
For heating a person at a desk or in a draughty room, yes - 350-600 W of radiant heat does what 2 kW of warm air fails to do. As the main heating for a home, no.
🔹 Is it cheaper to leave a heater on low all day?
No. A heater on "low" still draws its low-setting wattage every hour. Heat the room when you are in it; insulation is what makes a room hold heat, not a heater ticking over.
🔹 Do electric heaters need a CO alarm?
No - carbon monoxide comes from burning fuel. Gas, oil and solid-fuel appliances need CO alarms; electric heaters need clearance and a timer.
📚 Related Guides
🌿 Best Electricity Provider
🌿 Electricity Prices & Average Bill
🌿 Night Rate Electricity
🌿 Pay-As-You-Go Electricity
🌿 MPRN & GPRN Numbers
🌿 ESB Smart Meter Error
🌿 Appliance Running Costs
🌿 Hot Water Costs
🌿 Dehumidifiers
👉 All guides and calculators
Climate Jargon Buster is an independent resource. Running costs are indicative, based on Irish unit rates and fuel prices correct as of September 2026, and will change with your tariff - check your own bill and supplier price sheet. We are not affiliated with any supplier, retailer or the SEAI.