Oil Filled Radiator vs Convection Heater: What to Source

If you're sourcing heaters for resale, the first question buyers ask me is usually the same: oil filled radiator vs convection heater, which one do I stock? That's the right question to ask, but the answer depends on who your customer is, not on which one is "better."

We've built both types at our factory since 2009. I've watched hundreds of containers leave our dock. Here's what I'd tell a buyer sitting across my desk, without the marketing gloss.

How Each Heater Actually Heats

An oil filled radiator heats oil inside a sealed metal fin. The oil holds heat, the metal gets hot, and the heat radiates out. It also creates some convection, but the dominant effect is radiant heat from the surface. It's slow to warm up, but it keeps throwing heat after the thermostat clicks off.

A convection heater pulls cool air in from the bottom, passes it over a heating element (usually a finned tube or a PTC ceramic), and pushes warm air out the top. The room warms up faster because the air itself is moving. But the moment the element cuts off, the heat stops almost immediately. There's no thermal mass to carry over.

That difference alone decides which product fits which use case.

Room Size and Warm-Up Time

For a large room, like a garage or a workshop, a convection heater is usually the better fit. Why? Because you don't want to wait 20 minutes for the oil to heat up. You want warm air moving quickly. A 2000W convection panel can raise the perceived temperature in a 20 square meter garage noticeably within 10 minutes. The air will feel dry, but it works.

For a bedroom or an office, where people sit still for hours, an oil filled radiator is more comfortable. It doesn't blow air, so it's quieter and doesn't kick dust around. It also holds heat, so it cycles on and off less frequently. That makes it feel more stable. If your customer complains about "that blast of cold air when the heater kicks on," they're describing a convection heater, not an oil radiator.

One real comparison number: in our lab, a 1500W oil filled radiator takes about 25 minutes to raise a 15 square meter test room from 10°C to 18°C. A 1500W convection heater does the same in about 12 minutes. But the oil radiator holds the temperature for about 8 minutes after power-off. The convection heater drops back to 14°C within 2 minutes.

Running Cost and Energy Efficiency

Here's the blunt truth: neither type is more energy efficient than the other in terms of converting electricity to heat. Both are nearly 100% efficient at that. The difference is in how the heat is distributed and how often the thermostat cycles.

An oil filled radiator with a good thermostat and a timer can be cheaper to run because it holds heat and cycles less. But if your customer puts it in a drafty room, it will run constantly and cost the same as any heater.

A convection heater with a precise thermostat (we use a +/- 1°C accuracy digital thermostat on our better models) will actually be more energy efficient in a room where you need quick warm-ups. The key is the thermostat, not the heating technology.

If your customer asks about an energy efficient electric heater, the answer is not "buy this type." It's "buy a heater with a real thermostat and a timer, and size it correctly." A 2000W heater in a small room will cycle on and off and waste energy. A 1000W heater in the same room will run longer but use less total electricity.

Wall Mounted vs Portable

Oil filled radiators are heavy. A typical 2000W unit weighs 18-20 kg. You don't want to wall mount that unless you have a solid bracket and a stud finder. Most of our oil radiators are portable with castors.

Convection heaters, especially wall mounted electric heater panels, are much lighter. A 2000W wall panel weighs about 6 kg. That's a huge advantage for installation. If your customer is buying for a rental property, a hotel, or a new build, wall mounted convection panels are the obvious choice. They're out of the way, they don't take floor space, and they look clean.

But wall mounted units have a limitation: they heat the air near the ceiling first. If the room has high ceilings, the heat stratifies. You get warm heads and cold feet. That's a common complaint we hear from customers who installed wall panels in a garage with 3.5 meter ceilings. The fix is to install the panel low, around 30 cm from the floor, which defeats the purpose of wall mounting.

Safety and Certifications

Both types need the same basic safety features: overheat protection, tip-over switch (for portables), and a thermal fuse. For bathrooms, you need IP24 rating. We make both types with IP24, but the reality is that an oil filled radiator is safer in a bathroom because it doesn't have exposed heating elements or a fan that can blow moisture into the electronics. Still, if you source a convection heater with IP24 and a sealed terminal box, it's fine.

Don't skip on certifications. If you're selling into Europe, you need CE and RoHS. For the UK, you need UKCA. The ERP directive (energy-related products) is also mandatory for EU sales. We've seen buyers get stuck at customs because they sourced from a factory that only had CE on paper. Ask for the test reports, not just the sticker.

MOQ and Lead Times

Standard MOQ at our factory is 200 pcs per model. Lead time is 15-45 days depending on the model and whether you want custom branding. A private label electric heater with your logo and custom packaging is the same lead time as a standard unit, as long as you approve the artwork early.

If you're doing a first trial order, 200 pcs is low enough to test the market without risking a container load. We've had many Amazon sellers start with 200 units, sell through in a month, and then reorder 1000.

Which One Should You Stock?

If you're a distributor with a broad customer base, carry both. They serve different needs. Oil filled radiators are the safe, comfortable choice for bedrooms and living rooms. Convection heaters are the fast, lightweight choice for garages, workshops, and offices.

If you can only pick one, look at your market. In Northern Europe, oil filled radiators outsell convection heaters roughly 2 to 1 because of the comfort factor. In the UK, where houses are smaller and heating is more intermittent, convection panels sell well. In the US, garage and workshop heating is a big segment, and convection heaters dominate there.

One last honest piece of advice: don't get caught up in the "infrared vs convection" or "oil vs convection" debate as if there's a magic winner. The real differentiator is build quality. A cheap oil radiator will leak oil or develop a cold spot in a year. A cheap convection heater will have a thermostat that drifts 5 degrees. Source from a factory that tests every unit before packing, not just a sample.

We test 100% of our units on a 5-minute run at full wattage before they go into the carton. That's not a marketing line, it's the only way to keep your return rate under 2%.

Choose based on your customer's room, not on the hype. That's what a 15-year factory veteran would tell you.