Oil Filled Radiator vs Convection Heater: Which to Stock?

A distributor in the UK asked me last month which one sells better: oil filled radiators or convection panels. I told him it depends on whether his customers care more about silence or speed. He didn't like that answer. But it's the truth. We build both at our factory, and the two product types solve different problems. If you're placing a container order and want to avoid dead stock, you need to know where each one wins.

How They Actually Heat

Oil filled radiators work by heating diathermic oil inside sealed fins. The oil warms up, the metal radiates heat, and the unit keeps giving off warmth for 20–30 minutes after you switch it off. That thermal mass is the selling point. It's also why they're slow. A 2000W oil filled radiator takes 15–20 minutes to reach full output. Convection heaters heat a metal element and let natural airflow do the rest. Hot air rises out the top, cool air gets pulled in the bottom. They hit peak temperature in 2–3 minutes. For a bedroom where someone wants to feel warm before they fall asleep, convection wins. For a living room where the heater runs for four hours, oil filled is more comfortable because it doesn't cycle on and off as hard.

The Noise Question

Neither type has a fan, so both are silent. That's a real advantage over fan heaters, which move air but also make noise. If you're sourcing a silent electric heater for a nursery or office, either oil filled or convection works. The only sound you'll hear is the thermostat clicking. That matters for buyers who list on Amazon and get returns because a product "rattles." We test every batch for that. A loose fin on an oil filled unit is a warranty claim waiting to happen.

Running Cost and Wattage

Most residential models are 1500W or 2000W. A 2000W heater running at full power for one hour uses 2 kWh. At UK rates around £0.30/kWh, that's £0.60 per hour. But here's the thing: oil filled radiators don't run at full power the whole time. Once the oil is hot, the thermostat cycles and average consumption drops to maybe 40–60% of rated wattage. Convection heaters cycle more frequently because they lose heat faster. In a well-insulated room, the difference in electric heater running cost between the two is smaller than most buyers think. In a drafty garage, both are expensive. That's why we tell buyers to push 12V or low wattage electric heater options for RV and campervan customers who are off-grid. A 500W oil filled unit won't heat a garage, but it'll take the chill off a small campervan bunk.

Wall Mounted vs Portable

Oil filled radiators are almost always portable. They're heavy, they have castors, and they get moved from room to room. Convection panels are usually wall mounted. If you're sourcing a wall mounted electric heater for a bathroom, you need IP24 at minimum. Oil filled units aren't built for wet zones unless you specify a sealed design, which adds cost. For a large room or office, wall mounted convection panels save floor space and look cleaner. For a basement or workshop where you need spot heat, portable oil filled makes more sense. We ship both from the same line. MOQ is 200 pcs per model. Lead time is 15–45 days depending on whether you need custom packaging or a private label electric heater program.

Certification and Safety

CE and RoHS are baseline for Europe. UKCA for the UK. ERP compliance matters for energy labeling. If you're selling on Amazon in Germany, you'll need to show test reports. We've seen buyers get burned by suppliers who claim CE but can't produce a test report from a notified body. Don't accept a self-declaration for a heater that pulls 2000W. Ask for the file. For safety, tip-over switches and thermal cutouts are standard on our units. Overheat protection is not optional. A heater that fails that test is a fire risk and a recall waiting to happen.

What Actually Sells

In our order history, oil filled radiators outsell convection panels in the UK and Northern Europe. Buyers there associate oil filled with "proper" heating. In Southern Europe and the US, convection panels move faster because they're cheaper to ship and easier to mount. If you're a private label brand, oil filled gives you more perceived value. You can charge more. Convection is a volume play. Neither is better. They're just different tools.

One Honest Takeaway

Don't stock both unless you have a clear plan for each. Pick the one that fits your market's housing stock and climate. If you're not sure, order a sample of each. Run them in a cold room for a week. You'll learn more from that than from any spec sheet. And if a supplier can't tell you the oil volume in milliliters or the exact wattage tolerance, walk away. That's the real test.