The cheapest way to heat a bedroom in Ireland
Quick answer: The cheapest way to heat a bedroom in Ireland is a heater sized to the room, run on a thermostat and a timer. A typical 12 m² bedroom in an averagely insulated house needs about 840 W, so a 1 kW heater such as the MYLEK 1KW Smart WiFi Slim Panel Heater costs at most €0.38 an hour at the day rate of €0.38/kWh, or €0.18 on a night rate. If you only need a warm bed, an electric blanket at 70–120 W costs €0.03–€0.05 an hour.
Heating a bedroom is a different job from heating a living room: you want it warm for an hour before bed and maybe first thing in the morning, not all day. That changes which option is cheapest. Below are the real options with their cost per hour at Irish electricity prices, how big a heater a bedroom needs, and the habits that cut the bill.
What each option costs
| Option | Power | Per hour (day) | Per hour (night) | 1-hour warm-up before bed (day) | 8 hours overnight, flat out (night rate) |
|---|---|---|---|---|---|
| Electric underblanket Best Electric Blankets in Ireland | 70–120 W | €0.03–€0.05 | €0.01–€0.02 | €0.03–€0.05 | €0.10–€0.17 |
| Oil-filled radiator Warmlite 650W 5-Fin Mini Oil Radiator | 650 W | €0.25 | €0.12 | €0.25 | €0.94 |
| Panel or wall heater MYLEK 1KW Smart WiFi Slim Panel Heater | 1 kW | €0.38 | €0.18 | €0.38 | €1.44 |
| Fan or ceramic heater Dreo 1500W Ceramic Space Heater | 1.5 kW | €0.57 | €0.27 | €0.57 | €2.16 |
| Oil-filled radiator Midea 2000W Oil-Filled Radiator (9-Fin) | 2 kW | €0.76 | €0.36 | €0.76 | €2.88 |
How the cost is worked out: rated power in kW × €0.38 per kWh (day) or €0.18 per kWh (smart-meter night rate), cross-checked against SEAI energy price statistics, July 2026. Power figures are the manufacturers’ published ratings. Every figure is a ceiling at full power; a thermostat brings it down.
How big a heater does a bedroom need?
A heater that is too small runs flat out and never gets the room warm; one that is far too big is fine on a thermostat but costs more to buy. Our sizing rule is the same one our running cost calculator uses: watts per square metre of floor, depending on how well the house holds heat. Under each figure is the smallest heater size in our guides that covers it and what it costs per hour at full power.
| Bedroom | Draughty / older house (BER E–G) | Average (BER C–D) | Well insulated (BER A–B) |
|---|---|---|---|
| 9 m² | 900 W 1 kW heater: €0.38/hour | 630 W 650 W heater: €0.25/hour | 405 W 600 W heater: €0.23/hour |
| 12 m² | 1200 W 1.5 kW heater: €0.57/hour | 840 W 1 kW heater: €0.38/hour | 540 W 600 W heater: €0.23/hour |
| 15 m² | 1500 W 1.5 kW heater: €0.57/hour | 1050 W 1.5 kW heater: €0.57/hour | 675 W 1 kW heater: €0.38/hour |
Five habits that cut the cost
- Warm the room, then let the thermostat take over. One hour on a 1 kW heater before bed costs at most €0.38. After that, a thermostat keeps it topped up instead of running flat out.
- Use the timer. Set it to switch off after you fall asleep and on again before the alarm. Eight hours flat out on the same heater would cost €3.04 at the day rate.
- Use the night rate if you have one. On a smart meter with a night rate of about €0.18/kWh, every hour costs roughly half.
- Close the door and the curtains. The smaller the space you heat, the less power you need.
- Warm the bed, not the room. If the room temperature does not bother you, an electric underblanket does the job for a fraction of the cost. See our electric blanket guide.
Which heater suits a bedroom
An oil-filled radiator is quiet and gives steady heat, so it suits a bedroom you heat for hours; the Warmlite 650W 5-Fin Mini Oil Radiator (650 W) is the smallest oil-filled radiator in our guides. A slim panel heater with Wi-Fi control, like the MYLEK 1KW Smart WiFi Slim Panel Heater (1 kW), can be switched on from your phone before you go up. A fan or ceramic heater such as the Dreo 1500W Ceramic Space Heater (1.5 kW) warms the room fastest, but it makes noise and is best switched off before you sleep. The full comparison is in oil-filled radiator vs panel heater vs fan heater.
Frequently asked questions
What size heater do I need for a bedroom?
Roughly 70 W per square metre in an averagely insulated Irish house, 100 W in a draughty older one and 45 W in a well-insulated one. A 12 m² bedroom therefore needs about 540–1200 W.
Is an electric blanket cheaper than a heater?
Much cheaper, if what you want is a warm bed. An underblanket at 70–120 W costs €0.03–€0.05 an hour, against €0.38 for a 1 kW heater. It warms the bed, not the room.
Is it safe to leave a heater on overnight in a bedroom?
Use a heater with a thermostat, a timer and overheat protection, keep it well clear of bedding and curtains, plug it into a wall socket rather than an extension lead and never cover it. A timer that switches it off after you fall asleep is cheaper and safer than leaving it on all night.
Is a night rate worth it for heating a bedroom?
If you have a smart meter on a time-of-use tariff, yes: eight hours of a 1 kW heater costs €1.44 at €0.18/kWh against €3.04 at the day rate of €0.38/kWh. Check the hours of your night rate on your bill.
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.