Oil-Filled Radiator vs Convection Heater: Which to Source?

A buyer in Poland asked me last month why his oil-filled radiator returns were triple his convection panel returns. Same wattage, same price point. The difference wasn't the factory. It was the use case he sold into.

If you're sourcing electric heaters for distribution, you need to know which technology fits which customer. Get this wrong and you'll eat return shipping for a year.

How each one actually heats

A convection heater pulls cold air in at the bottom, runs it over a finned element, and pushes warm air out the top. It heats the air in the room. Turn it off, the air cools within 20 minutes. That's it.

An oil-filled radiator heats the oil inside sealed columns. The metal surface gets hot, and that surface radiates heat. It also warms the air around it, but the thermal mass means it keeps putting out heat for 15 to 30 minutes after you cut power.

That thermal mass is the whole story. It's why an oil-filled radiator is quieter and feels more like central heating. It's also why it's slower to warm a cold room and heavier to ship.

Where buyers get it wrong

A distributor in the UK sold oil-filled radiators as "instant heat" for garages. Bad move. A 2000W oil radiator takes 10 to 15 minutes to reach full surface temperature. A 2000W convection panel takes 2 to 3 minutes. If your customer wants to feel heat now, convection wins.

Flip it: a buyer sourcing for bedrooms wants silence and no fan noise. Oil-filled wins. No moving air, no dust circulation, no clicking thermostat every 90 seconds. That's why silent electric heater searches keep climbing for bedroom use.

The numbers that matter for sourcing

Power draw is identical at the wall. A 2000W oil-filled radiator and a 2000W convection heater both pull 2000W. Running cost per hour is the same. The difference is how long they run. Oil-filled cycles on and off less often because the oil holds heat. In a well-insulated room, that can cut duty cycle by 20 to 30 percent. In a drafty garage, it makes no difference.

Weight matters for freight. A 2000W oil-filled radiator ships at 11 to 14 kg. A comparable convection panel is 3 to 5 kg. If you're importing from China, that's a real cost delta. A 40HQ container holds roughly 1,200 convection panels but only 600 oil-filled units. Your landed cost per unit changes fast.

MOQ for either type is 200 pcs standard at most OEM factories. Lead time runs 15 to 45 days depending on whether you need custom tooling, private label packaging, or CE/UKCA certification updates.

Certifications and safety

Both types need CE and RoHS for the EU. UKCA for the UK. ERP compliance for energy labeling. If you're selling into Germany, check the ERP lot 20 requirements for local space heaters. Most Chinese factories have this handled, but ask for the test report before you place a deposit.

For bathrooms, you need IP24 minimum. Oil-filled radiators are rarely rated for wet zones because the housing isn't sealed. Convection panels with IP24 are common. If a buyer asks for an electric heater for bathroom IP24, don't quote oil-filled unless you want a warranty claim.

Which one to stock

If your customers are homeowners replacing a broken central heating zone, stock oil-filled. They want steady, silent heat and they'll pay for it.

If your customers are renters, workshop owners, or people heating a room they use for two hours a day, stock convection. Faster, lighter, cheaper to ship, cheaper to retail.

If you're sourcing for Amazon, look at your reviews. Convection heaters get complaints about fan noise and dry air. Oil-filled get complaints about weight and slow warm-up. Neither is wrong. They're just different products for different people.

One honest takeaway

Don't let a factory rep talk you into one technology for your whole catalog. The oil-filled radiator vs convection heater decision isn't about which is better. It's about which customer you're selling to. Stock both. Price them differently. Write product pages that tell the truth about warm-up time and weight. Your return rate will thank you.