Oil Filled Radiator vs Convection Heater: What to Source

I've lost count of how many buyers ask me this before they even send a spec sheet. They see both in catalogs, both look like heaters, and both promise warm rooms. But they are not the same machine, and if you pick wrong, you'll eat the return costs or lose the sale to a competitor who matched the room better.

Here's the short version: oil filled radiators heat the oil inside, then radiate heat from the steel fins. Convection heaters pull cold air in, pass it over a heating element, and push warm air out the top. That difference drives everything else: heat-up time, running cost, weight, safety, and where the unit makes sense.

Heat-up Time: The First Surprise

Oil filled radiators are slow. The oil needs 10 to 20 minutes to reach temperature. That's fine for a bedroom you pre-heat before sleep, but it's a dealbreaker for a workshop or garage where someone walks in cold and wants warmth in five minutes.

Convection panels, especially the wall-mounted ones we build, push warm air within 60 seconds. The element is exposed to airflow directly. No thermal mass to soak. If your customer is the impatient type, convection wins.

But slow doesn't mean bad. The oil radiator holds heat after the thermostat clicks off. It keeps radiating for another 20 to 30 minutes. That's a real advantage in a drafty room where the heater cycles on and off. The room temperature swings less.

Running Cost: The Real Math

Both are essentially 100% efficient at converting electricity to heat. That's physics, not marketing. The difference is how they feel to the user and how long they run.

An oil filled radiator at 1500W will run longer to bring a room up to temperature than a 1500W convection heater. Same wattage, same heat output, but the convection unit gets the air warm faster, so the thermostat cuts off sooner. Over a full evening, the oil unit might run 20% more total minutes. That's the difference between a cheap to run electric heater and one that surprises the customer on the bill.

For a small, well-insulated bedroom, the oil radiator's steady heat is fine. For a large living room or open plan, convection is the better bet because it moves air and heats the space faster. You can tell your buyer: if they want low wattage electric heater for constant background warmth, oil. If they want quick comfort, convection.

Weight, Mounting, and Safety

Oil filled radiators are heavy. A 2000W unit weighs 15 to 20 kg. Most are floor-standing with castors. That's fine for a bedroom or office, but it's a pain to ship and a pain for the end user to move.

Convection panels, on the other hand, are light. Our wall-mounted convection units run from 500W to 2000W and weigh under 5 kg. They mount on brackets, keep the floor clear, and are much cheaper to freight. For a distributor, that's a big deal. A 40-foot container holds roughly 800 oil radiators, but over 3000 convection panels. Your logistics cost per unit drops dramatically.

Safety also differs. Oil radiators have a surface temperature around 80-90°C. Convection panels can hit 110°C on the front grille. That's still within CE limits, but it matters if the buyer is sourcing for a home with kids or pets. We always recommend oil filled for bedrooms and nurseries, convection for hallways and living areas where people aren't touching the unit.

Bathroom and IP Ratings

If your buyer is asking about electric heater for bathroom IP24, both can work, but convection is easier to make compliant. We build convection panels with IP24 as standard, meaning they're splash-proof from any direction. Oil radiators are usually IP24 too, but they're floor-standing, so they take up space and are harder to clean around.

For a bathroom, a wall-mounted convection panel is the obvious choice. It's out of the way, has no exposed oil, and can be hardwired or plugged. We've shipped thousands of these to UK and EU distributors who sell them specifically for bathroom use. Just make sure the unit has a thermal cut-out and a tip-over switch, even if it's wall mounted. That's a standard safety feature on our line.

What the OEM Buyer Should Ask

If you're sourcing from a factory like ours, don't just ask for a price. Ask for the heating element type. Most cheap convection heaters use a bare wire element. Better units use a finned tubular element that runs cooler and lasts longer. That's a 20% cost difference, but it's the difference between a heater that works for 5 years and one that fails in 18 months.

Also ask about the thermostat accuracy. A cheap bimetallic strip thermostat can swing 5°C. A good electronic thermostat holds within 1°C. That matters for energy efficient electric heater claims. If you're selling on Amazon, reviews will kill you if the room never reaches the set temperature.

Our standard MOQ is 200 pcs per model, and lead time is 25-35 days depending on the finish and whether you want custom branding. CE, RoHS, and UKCA are standard. ERP is available for EU markets that require it.

The Honest Takeaway

Don't try to be all things to all buyers. Oil filled radiators are for steady, silent heat in bedrooms and offices. Convection heaters are for quick warmth in living areas, bathrooms, and workshops. If you're a distributor, carry both, but know which one your customer actually needs. If you're a private label brand, pick one and own it. Trying to sell both to the same customer just confuses them and makes you look like a commodity reseller.

And if a buyer asks for a 12v electric heater for a campervan, tell them to call someone else. That's a different product line entirely, and we don't fake it.