Oil Filled Radiator vs Convection Heater: What to Source in 2024

If you're sourcing heaters for a European winter, the first question buyers ask me is always the same: oil filled radiator vs convection heater, which one do I stock? There's no single right answer, but there is a right answer for your market, your price point, and your customer's room. I've built both types on the same line since 2009, and the differences are not marketing fluff. They're engineering trade-offs.

How Each One 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 off the fins. It also creates a slow convection current as air passes over the hot surfaces. That's why it feels like a warm piece of furniture, not a blast of hot air.

A convection heater pulls cool air in from the bottom, passes it over a heating element, and pushes warm air out the top. No oil, no thermal mass. The air heats up fast, the room feels warm quickly, but the moment you switch it off, the heat is gone.

That's the core difference. One stores heat, the other doesn't.

Real Numbers: Weight, Warm-Up Time, and Energy

Take two comparable 1500W units from our factory. The oil filled radiator weighs about 14 kg dry. The convection panel weighs 4.5 kg. The oil unit takes 12 minutes to reach surface temperature of 85°C. The convection unit hits 90°C in under 90 seconds.

If your customer wants instant warmth in a bedroom before sleep, convection wins. If they want a steady, silent heat in a living room they'll sit in for hours, oil filled feels more comfortable. The surface temperature on an oil radiator stays lower, so it's safer around kids and pets.

Energy efficiency? Both are nearly 100% efficient at converting electricity to heat. The difference is in how long the heat stays useful. An oil filled radiator keeps emitting heat for 20–30 minutes after the thermostat cuts out. A convection heater stops heating the room the second it switches off. Over a full evening, the oil unit cycles on and off less, which is why many people call it a cheap to run electric heater. It's not more efficient per watt, but it's more effective at holding a steady temperature without constant cycling.

Which One Fits Which Room

Convection panels are thin, light, and mount on a wall. They're the obvious choice for a bedroom, office, or hallway where floor space is tight. A 500W wall mounted electric heater can handle a small bedroom (8–10 m²) if the room is reasonably insulated. For a larger open plan area, you'd step up to 1000W or 1500W.

Oil filled radiators are better for a garage, basement, or workshop where you want heavy, even heat and don't mind the footprint. They also work well in a living room where the heater sits near a sofa. The thermal mass means the room doesn't swing between too hot and too cold.

One honest warning: oil filled radiators are slow to heat a cold, drafty garage. If your customer needs quick heat in a workshop, an infrared heater or a fan heater is better. Oil is for maintaining comfort, not for rapid recovery.

Silent Operation and Thermostats

Both types are silent. There's no fan. The only noise you might hear is the expansion of metal as it heats or a relay click from the thermostat. If you're sourcing for a bedroom, you want a unit with a mechanical thermostat that clicks softly, not a loud relay. We've tested units from other factories where the click is audible across the room. That's a complaint you don't want to deal with.

A good thermostat is non-negotiable. A 1500W oil filled radiator with a cheap thermostat can overshoot by 5°C before cutting out. That's wasted energy and an uncomfortable room. Look for a thermostat with a differential of ±1.5°C or better. We use a capillary thermostat on our oil units, and it holds temperature within about 1°C.

If you're selling into the UK or EU, you'll also need CE and RoHS. For the UK market, UKCA is still required. ERP compliance for energy labeling is mandatory for any heater sold in the EU. That's not optional, and it affects your lead time if you need to re-test.

What About Smart Features?

We're seeing more requests for wifi smart electric heater models. They're popular on Amazon because customers like scheduling from a phone. But here's the reality: adding wifi adds cost, and the app integration is often the weakest part. If you're a private label brand, you need to test the app thoroughly before committing. A bad app experience kills your reviews.

For most distributors, a simple mechanical thermostat is the safer bet. It's cheaper, more reliable, and easier to certify. If you want to offer a premium line, go with wifi on a convection panel, not on an oil filled radiator. The thermal mass of oil doesn't pair well with quick on/off scheduling.

MOQ and Lead Time Reality

If you're sourcing from a Chinese OEM, don't expect to order 50 units and get a custom color. Our standard MOQ is 200 pcs per model. That's true for most factories that do injection molding and tooling. Lead time for a standard oil filled radiator is 30–45 days, depending on the season. Convection panels are faster, often 15–25 days, because they're simpler to assemble.

If you need a specific plug type or voltage for a market like the UK, that's easy. If you need a custom wattage or a special size, that's a tooling change and it adds weeks. Plan your product range around standard sizes first. Customization comes after you've sold through your first container.

The Honest Takeaway

Oil filled radiators are for customers who want steady, silent, comfortable heat and don't mind waiting a few minutes to feel it. Convection heaters are for customers who want fast warmth and a slim profile. If you can only stock one, stock oil filled radiators. They have higher perceived value, fewer safety complaints, and a longer product life. But don't ignore convection for your Amazon line, it's a volume seller in small rooms.

Source both if you can. Offer oil filled as your mid-tier and convection as your entry or premium wall-mounted option. That covers the two most common search intents: someone looking for a silent electric heater and someone looking for low wattage electric heater for a small space.

And when you're comparing quotes from factories, ask for the thermal cycling test data. A heater that fails after 2000 on/off cycles is a warranty nightmare. We run ours to 5000 cycles before we ship. That's the difference between a one-time order and a repeat customer.