Oil Filled Radiator vs Convection Heater: What to Source

If you're sourcing electric heaters for a retail line or a private label, the first question you'll ask is usually about cost. The second is about which type actually sells. Oil filled radiators and convection panels are the two most common options, and they're not interchangeable. Here's what fifteen years on the factory floor has taught me about the difference, and why it matters for your market.

The Short Version

Oil filled radiators heat slowly and keep heating after the thermostat cuts off. Convection panels heat fast and stop fast. That's the core difference. Everything else follows from that.

An oil filled radiator is a sealed metal unit filled with thermal oil. The oil is heated by an element, then the oil warms the metal shell, then the shell radiates heat into the room. It's a thermal battery. It takes ten to twenty minutes to reach full output, but once it's hot, it keeps radiating even when the element cycles off.

A convection panel is a flat unit with a heating element inside. Cold air enters at the bottom, warms, and rises out the top. The air heats the room, not the unit. It's a direct air heater. It starts warming the space within a minute or two, but it stops heating the moment you turn it off.

Why the Difference Matters for Buyers

Your customers are not buying a heater. They're buying a solution to a specific problem. That's why the search phrase "oil filled radiator vs convection heater" gets so much traffic. People are trying to figure out which one fits their room, their habits, and their electricity bill.

For a bedroom, you usually want an oil filled radiator. Why? Because people run it all night. The slow heat means it doesn't cycle on and off as aggressively, and the residual heat means the room stays warm even when the element is off. It's also silent. No fan, no clicking, just a soft ticking as the metal expands. That makes it a natural fit for "silent electric heater" searches.

For a living room or an office where people are awake and moving around, a convection panel is often better. It warms the space faster, and if you pair it with a good thermostat, it maintains the temperature without the lag. It's also wall mounted, which saves floor space. That's why "wall mounted electric heater" is a common search for this category.

Efficiency and Running Cost

Here's the blunt truth: both types are essentially 100% efficient at converting electricity to heat. That's not marketing. Every watt of power becomes heat, whether it's in oil or in air. So the phrase "energy efficient electric heater" doesn't mean one type uses less electricity. It means one type does a better job of keeping the room comfortable without wasting heat.

That's where the real difference shows up. An oil filled radiator holds heat, so it can cycle off for longer periods once the room reaches temperature. That reduces the average power draw over time. A convection panel heats the air directly, so it cycles on more frequently, especially in a drafty room. In a well insulated space, the difference is small. In a leaky garage or workshop, the convection panel will run more often and cost more to operate.

For a garage or workshop, I'd actually recommend a convection heater over oil filled. Reason: those spaces are usually drafty and you want quick heat when you walk in. You don't want to wait twenty minutes for an oil radiator to warm up a cold concrete floor. The same goes for a greenhouse. Fast air heat is better for keeping plants above freezing.

What to Look For When Sourcing

If you're buying from a factory like ours, you need to know what to ask for. Not just the type, but the specs.

First, wattage. A standard 1500W heater is enough for a 150 to 200 square foot room with average insulation. If your target market is larger spaces, you need 2000W or 2500W. But be careful with 2500W units. In many countries, a standard wall socket is rated at 16 amps, which is roughly 3680W at 230V. So a 2500W heater is fine, but a 3000W unit will trip breakers unless it's hardwired. That's a common mistake we see from new importers.

Second, thermostat quality. The cheapest heaters use a bi-metallic strip thermostat that can swing by several degrees. That means the room feels stuffy, then cold, then stuffy again. Good heaters use an electronic thermostat with a digital display. They hold within one degree. If you're sourcing for a market that searches "best electric heater with thermostat," you need the electronic one. It costs a bit more, but it's worth it.

Third, safety. For any heater going into a bathroom, you need IP24 rating. That means it's protected against splashing water. For a convection panel that's easy to achieve with a sealed casing. For an oil filled radiator, it's harder because of the exposed metal fins. So if your buyer wants a bathroom heater, push them toward a convection panel with an IP24 rating. That's a hard requirement, not a nice to have.

Fourth, certifications. For the EU market, you need CE and RoHS. For the UK, you need UKCA. For energy labeling, you need ERP compliance. A reputable OEM electric heater manufacturer in China should have these already. If they don't, walk away. It's not worth the risk of a customs hold or a recall.

The MOQ and Lead Time Reality

Our standard MOQ is 200 pieces per model. That's a container-friendly quantity for a small to mid-size distributor. Lead time is 15 to 45 days depending on the model and whether you want custom branding. Custom color or logo adds about a week. Custom packaging adds two weeks. If you want a completely new mold, that's a different conversation, but most buyers don't need that.

One thing I'll tell you straight: don't order a mixed container of both types if you're testing a market. Pick one, order 200, and see what sells. The data from your first order is worth more than any guess. If you're wrong, you've only got 200 units to move. If you're right, you can scale up fast.

The Honest Takeaway

Oil filled radiators are for steady, overnight comfort. Convection panels are for quick, targeted heat. Neither is "better" overall. The right choice depends on your customer's room, their habits, and their tolerance for waiting. Source the one that matches the problem your market actually has, not the one that looks better in a catalog. And if you're not sure, ask for samples of both. Run them in your own office for a week. You'll know the difference in your bones, and then you'll be able to sell it with confidence.

That's the way we've done it here for fifteen years, and it hasn't failed us yet.