Oil Filled Radiator vs Convection Heater: What to Source

If you're sourcing electric heaters for a market that gets real winters, you've probably stared at two product categories and wondered which one your customers actually need. I've been building both since 2009, and the answer isn't as simple as one being 'better.' It depends on the room, the usage pattern, and what your buyer expects when they open the box.

Let's get one thing straight first: oil filled radiators and convection heaters both run on electricity. Both are 100% efficient at converting electricity to heat, so the difference isn't about energy use per watt. It's about how they release that heat and how the room feels.

How Each Type Works

An oil filled radiator heats a sealed metal body filled with thermal oil. The oil holds heat long after the thermostat cycles off. That's why it feels warm to the touch for 20-30 minutes after you switch it off. It radiates heat directly to objects and people, and it also creates a gentle thermal current that warms the air.

A convection heater (wall-mounted panel or baseboard style) pulls cool air in at the bottom, passes it over a heating element, and pushes warm air out the top. It heats the air quickly, but there's no thermal mass. Turn it off, and the room cools down fast.

The Real Differences Buyers Care About

Room coverage and heat distribution

Convection heaters are better for heating a whole room evenly, especially if you mount them on a wall. The air circulation keeps the temperature consistent from floor to ceiling. Oil filled radiators take longer to warm up a room, but once they do, the heat feels more stable and less 'blowy.' For a large room like an open-plan living area or a workshop, a convection panel with a fan (if it has one) will get the air moving faster. Without a fan, convection still works, but it's slower.

Heat retention

Here's where oil filled radiators win. Because the oil holds heat, the heater doesn't cycle on and off as often. In a well-insulated room, that means the room stays warm longer after the thermostat kicks off. For a buyer who wants a cheap to run electric heater for a bedroom that's used overnight, oil filled is often the better call. The thermostat doesn't kick in as frequently, so the compressor (well, the thermostat) cycles less, which some customers interpret as 'energy saving.' Honestly, it's not magic—it's just thermal mass.

Safety and surface temperature

Oil filled radiators have lower surface temperatures than most convection heaters. The metal skin usually stays below 85°C, which is safer for homes with kids or pets. Convection panels with exposed elements can get hotter on the grille, though many of our wall-mounted units use a finned element that stays under 95°C. For bathrooms, you need IP24 rating regardless of type. We make both oil filled and convection heaters with IP24 for bathroom use.

Speed of heating

Convection heaters win on speed. A 1500W wall-mounted panel can raise a 15m² room by 5°C in about 15 minutes. An oil filled radiator of the same wattage might take 30 minutes to feel the same difference. If your customer wants a heater for a garage that they only turn on when they're working, convection is the obvious choice. For a living room where they want it warm before they sit down, oil filled is fine if they use a timer.

What to Source for Your Market

If you're a distributor or Amazon seller, you need to think about what your end customer complains about in reviews. The biggest complaint we see on oil filled radiators is 'slow to heat up.' The biggest complaint on convection heaters is 'room cools fast when I turn it off.' Neither is a defect—it's physics.

For private label, consider this: oil filled radiators are heavier and more expensive to ship. A 2000W oil filled unit weighs about 15kg. A 2000W wall-mounted convection panel weighs 4kg. Shipping costs eat into your margin, and freight issues are a pain. If you're selling on Amazon, the lower weight of convection panels means lower FBA fees and fewer damaged returns.

On the other hand, oil filled radiators have a longer track record in Europe. They're a known quantity. Buyers trust them for bedrooms and nurseries because they're silent and don't dry the air as much. If you're targeting a market like Germany or the UK, oil filled radiators are a safe bet.

A Real Comparison Number

Let's take a typical 20m² room. A 2000W convection heater will heat it to 20°C in about 20 minutes. An oil filled radiator at the same wattage will take about 35 minutes. After you switch both off, the convection room drops 2°C in 10 minutes; the oil filled room drops 2°C in 25 minutes. That's the trade-off.

Which One Should You Source First?

If you're new to electric heaters, start with wall-mounted convection panels. They're cheaper to produce, cheaper to ship, and they cover the most common use case: quick warmth for living rooms, offices, and bedrooms. They also fit the 'slim, modern' design trend that sells on Amazon.

If your market is Northern Europe or you already have a customer base that asks for 'oil filled radiator vs convection heater'—and they often do—then add a couple of oil filled SKUs to your lineup. They're a higher-ticket item, and the profit per unit is better, even after shipping.

Quick Tips for Buyers

• For a bedroom, choose oil filled with a thermostat. Set it to 18°C and let it cycle.
• For a garage or workshop, choose a convection heater with a fan. You want fast warm-up, not heat retention.
• For a bathroom, check the IP rating. IP24 is the minimum for zone 2.
• For a large room, don't just look at wattage. Look at the BTU output and the air circulation design.

The Honest Takeaway

Neither type is 'better.' Convection is faster and lighter; oil filled is slower but holds heat longer. If you source both, you cover more of the market. If you have to choose one, look at your shipping costs and your customer's climate. For mild winters, convection is enough. For harsh winters, oil filled will get you fewer returns. And if you're asking me what I'd build a factory around—I'd build both, but I'd sell more convection units.

That's the truth from the line, not from a brochure.