Oil Filled Radiator vs Convection Heater: What to Source

If you're sourcing heaters for a European winter, the first question you'll get from a buyer is usually the same: oil filled radiator vs convection heater, which one do I stock? I've been on the production floor since 2009, and I can tell you the answer isn't about which is 'better.' It's about which one your customer's room and habits will punish less.

Both units do the same job: convert electricity into heat. The difference is how they deliver it. A convection heater pulls cold air in, runs it over a heating element, and pushes warm air out. It heats the air fast. An oil-filled radiator heats a thermal mass of oil inside a metal fin. That oil holds heat and radiates it slowly, even after the thermostat clicks off.

The Real Difference Is Thermal Mass

Convection panels are light. A typical 1500W wall-mounted unit weighs maybe 5 kg. An oil-filled radiator at the same wattage weighs closer to 15 kg. That weight is the whole story. The oil acts like a battery for heat. It charges up over 20 minutes, then releases that heat over another 30 to 40 minutes after the element cuts out. That means your customer's room temperature stays steadier, but it takes longer to feel warm.

Convection heaters are the opposite. They feel warm within two minutes. But they also cool down fast when the power cycles. So if your customer wants a heater for a bedroom, they'll notice the difference at 6 AM. The room with the oil radiator will still be warm. The convection heater will have been cycling on and off all night, and the air will feel cooler.

Running Costs and Comfort

Here's a number that matters: at 1500W, both units burn the same electricity per hour. There is no magic efficiency difference. A watt is a watt. The 'energy efficient electric heater' search term you see in your analytics is mostly marketing noise. What actually changes the running cost is the thermostat behavior.

A convection heater with a cheap mechanical thermostat might overshoot by 3-4 degrees before cutting off. That means it runs longer than it needs to. A decent oil-filled radiator with a hydraulic thermostat holds temperature within about 1 degree. Over a 10-hour night, that difference can save your customer 10-15% on the electricity bill. That's the 'cheap to run electric heater' they're actually looking for.

For a garage or workshop, I'd still pick convection. Those spaces are drafty and you want fast heat when you walk in. You don't care about steady temperature. You care about not freezing while you change a tire. A 2000W fan heater or a convection panel will do that better than an oil radiator, which will spend the first 15 minutes just warming its own oil.

What You're Actually Sourcing

If you're a private label brand, the decision is also about logistics. Oil-filled radiators are heavy, and shipping costs are calculated by volume and weight. A 1500W oil radiator from our factory weighs about 14 kg. A convection panel at the same wattage weighs 4.5 kg. On a 40-foot container, you can fit roughly 1,100 oil radiators or 3,200 convection panels. Your landed cost per unit changes dramatically.

Convection panels are also easier to mount on a wall. Wall mounted electric heater models save floor space, which is a selling point for small apartments in the UK or Germany. Oil radiators are floor-standing only. They take up space, and they're a trip hazard if someone kicks the casters off.

But oil radiators have one thing convection doesn't: silent heat. No fan, no air movement, no clicking from expansion. That's why 'silent electric heater' is a phrase we see from buyers targeting bedrooms and nurseries. Convection panels are also silent, but they do cause more air circulation and dust movement. Oil radiators are better for people with allergies.

Safety and Certifications

Both types can be built to IP24 for bathroom use, but I don't recommend either for a bathroom. For a bathroom, you want a sealed fan heater with IP24 rating. Oil radiators get too hot on the surface, and convection panels have exposed elements if you don't use a fully enclosed design. For an electric heater for bathroom IP24, we build a specific low-surface-temperature fan heater that's certified for zone 2. Don't try to cut corners there.

For any heater you source, make sure you're getting CE and RoHS at minimum. If you're selling into the UK, you need UKCA. ERP compliance is mandatory for EU sales, and it affects the standby power and thermostat accuracy. We've had buyers ask for 'CE certified electric heater supplier' and then not check the ERP paperwork. That mistake costs them at customs.

MOQ and Lead Times

Our standard MOQ for either type is 200 pcs. That's not a hard rule, but it keeps the price sane. Lead time is 15-45 days depending on whether you need custom colors, logos, or a specific plug type. If you order a standard white 1500W convection panel with a UK plug, we can ship in 20 days. If you want a custom wifi smart electric heater with an app, add 10 days for firmware integration.

The Honest Takeaway

If your customer's main complaint is cold floors and drafts, sell them a convection heater. If their main complaint is that their room cools down too fast when the heater cycles, sell them an oil-filled radiator. Don't try to sell one as a replacement for the other. They serve different habits. And if you're sourcing for a whole line, stock both. That's what most of our long-term distributors do. They let the customer choose based on room size and patience, not on a marketing claim.