Oil Filled Radiator vs Convection Heater: What to Stock

If you're sourcing heaters for resale, the first question buyers ask me isn't about wattage or price. It's usually: "What's the difference between an oil filled radiator and a convection heater, and which one should I put my money on?"

That's a fair question, because both sell well, but they serve different rooms and different customer expectations. Mix them up in your catalog and you'll get returns, complaints, and chargebacks. Let me break it down the way I'd explain it to a procurement manager sitting across my desk in Foshan.

The Core Difference: Heat Transfer, Not Heat Output

Both heaters use electric resistance elements to generate heat. The difference is how they release it into the room.

An oil filled radiator heats thermal oil inside sealed fins. The oil holds heat long after the element cycles off. It radiates warmth from the metal surface, heating objects and people directly, and also creates a mild convection current. It's slow to warm up but steady. Think of it as a heavy cast-iron pan: takes time to get hot, but stays hot.

A convection heater pulls cold air in from the bottom, passes it over a heating element (usually a bare wire or a finned tube), and pushes warm air out the top. The room warms faster because air is actively circulated. But the moment you switch it off, the warmth disappears. It's like a hair dryer on a stand: quick blast, no residual heat.

That's the first thing to tell your customers: oil filled radiator vs convection heater is not about which is 'better' — it's about which matches the use case.

Where Each One Wins

Oil filled radiators are the default recommendation for bedrooms and living rooms. Why? Because they're silent (no fan), they don't dry the air as aggressively, and they maintain a stable temperature. A customer who wants a silent electric heater for a nursery or a light sleeper will pick the oil radiator every time. The surface temperature is lower than a fan heater, so it's safer around kids and pets. We build ours with a tip-over switch and thermal cutoff as standard, and the CE and RoHS certs cover all EU markets.

Convection heaters are better for spaces where you need quick heat on demand — an office, a workshop, or a garage that's only used a few hours at a time. They're also lighter and easier to mount on a wall. A wall mounted electric heater in a 200W to 1500W range can be tucked under a window to counter cold drafts. That's a classic convection application.

But here's the catch: for a large room, say 25 square meters or more, a single convection heater will struggle to distribute heat evenly. You'll get a warm spot near the unit and cold corners. An oil filled radiator with a 2500W output and fins spaced correctly will do a better job of evening out the temperature, even if it takes 20 minutes longer to get there.

Running Cost and Efficiency: Be Honest

There's no magic here. Both types are essentially 100% efficient at converting electricity to heat. The difference in running cost comes from thermostat behavior and heat retention.

An oil filled radiator stays hot after the element switches off, so it cycles less frequently. In a well-insulated room, that can cut energy use by 10-15% compared to a convection heater that cools down instantly and has to reheat from scratch. That's why people search for an energy efficient electric heater and often land on oil filled models. But if the room is drafty or the thermostat is placed badly, that advantage disappears.

A convection heater with a good digital thermostat and a programmable timer can be just as cheap to run, because it can pre-heat the room only when needed. We ship both types with thermostats that hold within ±1°C, and we offer wifi smart electric heater options for both — that lets your customers control schedules from a phone, which is a strong selling point for Amazon.

One honest number: in our lab, a 1500W oil filled radiator in a 20m² test room at 5°C outside kept the room at 20°C with an average draw of 620W over 8 hours. A 1500W convection heater in the same room averaged 780W. That's a 20% difference in running cost. But the convection heater reached 20°C in 18 minutes; the radiator took 42 minutes. You sell one for comfort, the other for speed.

Safety and Certifications

Both types can be made safe, but the failure modes are different. Oil filled radiators have a sealed oil circuit — if it leaks, that's a problem. We pressure-test every unit before packing, and we use welded seams, not crimped. Convection heaters have exposed elements, so they need good ingress protection. For bathrooms, you'll want IP24 rated units — that's a must for any wall mounted electric heater in a damp zone. We do IP24 on our convection panels, and we also offer a 12v electric heater for RV campervan use, which is a niche but growing category.

All our heaters come with CE, RoHS, and UKCA as standard. ERP compliance is done on the convection panels. If you're selling into the UK, don't skip UKCA — we've seen buyers get stuck at customs because they assumed CE was enough.

MOQ, Lead Time, and What I'd Stock

Our standard MOQ is 200 pieces per model, mixed colors and voltages are fine. Lead time is 15 to 45 days depending on the line and whether you want custom branding or packaging. For a first order, I'd suggest starting with one oil filled radiator (1500W or 2500W) and one convection panel (1000W or 1500W). That covers the two main search intents: "oil filled radiator vs convection heater" and "wall mounted electric heater."

If you're targeting Amazon, the convection panel is easier to ship (lighter, flatter box) and has a lower return rate because there's no oil to leak. The oil filled radiator has higher perceived value and better reviews for comfort, but it's heavier and more expensive to freight. You need to know your logistics cost per unit before you commit.

How to Choose Electric Heater: A Simple Rule

Tell your customers this: if the room is used for sleeping or long sitting (bedroom, living room, study), choose oil filled. If it's a short-stay space (office, workshop, garage, bathroom), choose convection. If they want the lowest running cost over a full winter, go oil filled with a programmable thermostat. If they want to feel heat within five minutes, go convection.

And if they ask about infrared vs convection, that's a different conversation — infrared heats objects, not air, and it's better for spot heating in a drafty workshop. But that's a separate article.

The Takeaway

Don't stock both just to cover all bases. Stock both because they solve different problems, and make sure your product descriptions tell the customer which problem each one solves. A buyer who knows why they're picking an oil filled radiator over a convection heater is a buyer who won't return it. That's the whole game in this business — matching the right box to the right room, and being straight about the trade-offs.

We've been building these since 2009, and the technology hasn't changed much. What changes is how well you explain the difference. Do that, and your sell-through will take care of itself.