Oil Filled Radiator vs Convection Heater: What to Source

If you're sourcing heaters for a European or North American market, the first question you'll likely get from a buyer is: oil filled radiator vs convection heater, which one should I stock? It's not a trick question. They're different tools for different rooms, and if you pick wrong, you'll eat the cost in returns and chargebacks.

I've been building both types for over a decade at Hearthcore. We run lines for wall-mounted convection panels and oil-filled radiators side by side. The differences are not subtle. Let me break down what actually matters when you're deciding what to put in your container.

How Each One Heats

A convection heater pulls cool air from the bottom, passes it over a heating element, and pushes warm air out the top. It heats the air directly. The room warms up fast, but the air gets drier and the heat disappears quickly once you switch it off.

An oil-filled radiator works differently. It has a sealed metal body filled with thermal oil. The element heats the oil, the oil heats the metal fins, and the fins radiate heat into the room. It also creates some convection, but the main effect is radiant. The metal stays hot for a long time after the thermostat clicks off.

That's the core trade-off. Convection is quick and light. Oil-filled is slow and steady.

The Real Numbers: Warm-Up Time and Running Cost

Let's talk about a typical 1500W unit. Our convection panel will push a 20m² bedroom from 15°C to 21°C in about 20 minutes. An oil-filled radiator at the same wattage takes closer to 40 minutes for the same space. That's a big difference if a customer wants to heat a bathroom before a shower.

But here's the part that buyers miss. Once the oil-filled radiator reaches temperature, it cycles on and off less frequently than a convection heater. The thermal mass of the oil holds heat longer. In a well-insulated room, an oil-filled radiator can use 15-20% less energy over an eight-hour heating period compared to a convection unit doing the same job. That translates directly to what your customers care about: how cheap to run electric heater claims hold up in real life.

If you're selling to people who leave a heater on all night in a bedroom, the oil-filled unit wins on running cost. If they need a quick blast in a workshop or office, convection is the better call.

Safety and Mounting

Here's a hard truth about oil-filled radiators: they are heavy. A typical 2000W unit weighs around 15-16 kg when filled. That's a pain for shipping, and it means you're almost always selling them as freestanding units with castors. Wall mounting an oil-filled radiator is possible, but it requires serious brackets and a solid wall. Most retail buyers won't do it.

Convection heaters, on the other hand, are light. Our wall mounted electric heater panels weigh between 4 and 6 kg. You can hang them on standard drywall with two screws. That's why they dominate the wall-mounted market, especially in Europe where space is tight.

For safety, both types need proper thermal cutoffs and tip-over switches. But oil-filled radiators have one advantage: the surface temperature stays lower than a convection unit's exposed element. The metal fins on an oil-filled radiator typically reach 90-110°C, while the outlet grille on a convection heater can hit 150°C. If you're sourcing for homes with kids or pets, that lower surface temp is a selling point.

IP Ratings and Bathroom Use

If your buyers are asking about electric heater for bathroom IP24, they're usually thinking about convection panels. Oil-filled radiators are rarely rated above IP24 because they have more openings and a less sealed construction. Our convection panels can be built with IP24 rating as standard, meaning they're splash-proof from all directions. That makes them a natural fit for bathrooms.

But don't assume every bathroom heater needs IP24. IP24 is for zone 2 and beyond. If the heater is going in a dry area like a hallway or bedroom, IP20 is fine. Don't pay extra for an IP24 rating you don't need.

What to Source for Your Market

Let me give you a practical guide based on what our customers actually order.

If you're selling to Amazon in the UK or EU, oil-filled radiators move well in the winter months. They're a known category with steady demand. The downside is shipping weight. A 40-foot container of oil-filled radiators carries about 40-50% fewer units than the same container of convection panels. That hurts your landed cost per unit.

Convection panels are lighter, cheaper to ship, and easier to install. They're also better for the growing smart heater segment. Our wifi smart electric heater panels are a big chunk of new business because customers want app control and scheduling. Oil-filled radiators can be made smart too, but the market hasn't embraced it as much.

For private label brands, I'd say this: start with convection panels if you're new to the heater game. Lower freight cost, fewer safety certifications to juggle, and a simpler supply chain. Once you've got a sales history, add oil-filled radiators as a premium SKU for customers who prioritize steady heat and lower running costs.

One Honest Takeaway

Don't let your customer pick between these two based on brand preference or price alone. Ask them where the heater will live and how long it will run each day. If it's a short burst in a garage or office, convection is the honest answer. If it's overnight heating in a bedroom or living room, oil-filled is worth the extra freight weight. Source accordingly, and you'll have fewer returns and more repeat orders.

At the end of the day, a heater that's cheap to buy but gets returned is the most expensive unit you'll ever sell. Make the spec match the use case, and you'll be fine.