Oil Filled Radiator vs Convection Heater: What to Stock in 2025

If you sell electric heaters, you've probably had a customer ask the difference between an oil filled radiator and a convection panel. It's not a trick question. They heat differently, cost differently, and suit different rooms. Get this wrong and you'll eat returns. Get it right and you'll build a repeat buyer base.

Both are popular for good reason. But they're not interchangeable. Here's what I tell buyers when they visit our factory in China: think about how the heat moves, not just what the box looks like.

How Each One Actually Heats

An oil filled radiator works by radiation and some natural convection. The oil inside is heated by an element, then the metal fins get hot. That heat radiates out to objects and people nearby. It also warms the air that touches the fins, which then rises and circulates slowly.

A wall mounted electric heater, like a convection panel, pulls cool air in from the bottom, passes it over a heating element, and pushes warm air out the top. The air moves by convection. There's no oil, no fins that glow red, and the surface stays cooler.

That sounds simple. But it changes everything about performance.

Room Size and Heat Distribution

Oil filled radiators are better for steady, whole-room warmth in a sealed space. They're a common choice for bedrooms and living rooms where people sit still for hours. The heat is even, and the unit keeps radiating after the thermostat cuts off. That lag helps avoid big temperature swings.

Convection heaters are faster to warm a room because the air moves immediately. But the heat tends to stratify near the ceiling, especially in taller rooms. That's why a convection panel is often a good fit for a workshop or a garage where you just need the air warmer, not the furniture.

If you're sourcing for customers who ask for an electric heater for a large room, I'd push them toward oil filled. A 2500W oil radiator can handle up to about 25 square meters in a well-insulated room. A convection panel of the same wattage will do okay but may need to run longer to feel the same.

Running Cost and Energy Efficiency

No electric heater is 100% efficient. Every watt becomes heat. The difference is how long it runs and how well it holds temperature.

Oil filled radiators use a thermostat to cycle on and off. Because the oil retains heat, the element stays off longer than a convection heater's element would. In a room that's already warm, that can make an oil radiator cheaper to run over a full day. In a cold garage with poor insulation, both will struggle and cost similar money.

Convection heaters have a faster response. If you only need heat for an hour while you work, a convection panel will use less energy because it heats the air quickly and you can shut it off. Oil radiators take 20–30 minutes to fully warm up, so they waste energy if used for short bursts.

There's no magic answer. That's why you see both in our catalog. The honest line to your customer is: match the heater to the usage pattern, not just the room size.

Safety and Mounting

Oil filled radiators are heavy. A typical 2000W unit weighs 15–20 kg. They sit on castors and are stable. The surface gets hot, around 90–100°C, so they're not ideal for homes with toddlers unless the model has a cool-touch cover. Most of our oil radiators have thermal fuses and tip-over switches as standard.

Convection panels are light, usually under 6 kg, and mount on a wall. That frees up floor space and keeps the heater out of reach. Surface temperatures are lower, typically 60–70°C, which helps pass strict safety checks. But wall mounting means you need a solid wall and proper anchors. If your customer is buying for a rental property, they might not be allowed to drill. That's a real consideration.

For bathroom use, you need IP24 rating on either type. We make wall mounted convection heaters with IP24 that are safe for zone 2 in a bathroom. You won't find many oil filled radiators with IP24 because they're floor standing and pose a splash risk.

What Buyers Should Stock

Here's my blunt take after 15 years in this industry. If your market is residential and your customers care about comfort and low noise, oil filled radiators are the safer bet. They're silent, they don't blow dust, and they feel like a traditional radiator. Most of our oil filled models run at under 30 dB, which is basically inaudible.

If your market is commercial, offices, or people with limited floor space, go with convection panels. They're cheaper to ship (less weight), easier to install, and faster to heat a small room. A 1500W wall mounted convection panel will do a 15 square meter office just fine.

One thing to watch: many cheap convection heaters use a fan to push air. That adds noise and uses extra wattage. A true convection panel has no fan. Make sure your supplier isn't selling you a fan heater with a flat face. Ask for the heating element type and the dB rating.

Real Numbers from Our Line

We make both types in our own factory. Our standard oil filled radiator is 2500W, has 11 fins, and carries CE, RoHS, and ERP certification. MOQ is 200 pieces, lead time 30 days. Our wall mounted convection panel is 2000W, IP24, with a digital thermostat and WiFi option. MOQ is 200 pieces, lead time 25 days.

If you're comparing prices, expect oil filled radiators to cost roughly 20–30% more than convection panels at the same wattage. That's because of the steel, oil, and assembly. Shipping also costs more due to weight. But the retail margin can be higher because customers perceive them as premium.

Honest Takeaway

Don't stock both if you're new to the category. Pick one based on your customer's biggest complaint. If they complain about cold floors and high bills, oil filled. If they complain about bulky heaters and slow heating in small rooms, convection. And always ask your supplier for the real test data on heat-up time and surface temperature. If they can't give it to you, they're probably not making the heater themselves.