Oil Filled Radiator vs Convection Heater: What to Source

You're sourcing heaters for a market that's tired of returns. The question I get most from buyers is oil filled radiator vs convection heater, and the answer isn't about which one is "better." It's about which one your customer should have bought in the first place.

We've built both since 2009, and I've watched distributors kill their margins by stocking the wrong type for their climate and room profiles. Let's cut through the marketing.

How They Actually Heat

An oil filled radiator heats oil inside a sealed metal fin. That oil holds heat and radiates it outward. The surface gets hot, the air near it warms, and the room warms slowly. When the thermostat cuts the power, the oil keeps throwing heat for another 20 to 40 minutes. That's thermal mass doing its job.

A convection heater pulls cold air in at the bottom, passes it over a heating element, and pushes warm air out the top. No fan, no oil. The air heats quickly and rises, setting up a natural circulation loop. The surface stays cooler, usually under 60°C, which matters if you're selling into homes with kids or pets.

Real Numbers for Your Buying Decision

Take a standard 1500W model of each. In a 20m² room with average insulation:

• Oil filled: reaches target temperature in about 35 minutes. Holds temperature with a duty cycle of roughly 40% after that.
• Convection: reaches target temperature in about 18 minutes. Duty cycle sits closer to 55% because there's no heat storage.

That means for continuous use over 8 hours, the oil filled unit uses less electricity in the steady state. But if your customer only heats a room for an hour in the morning, the convection heater finishes the job faster and shuts off. It wins on short bursts.

That's the honest tradeoff. No model is universally cheaper to run.

Where Each One Fails

Oil filled radiators are heavy. A 2000W unit weighs 15 to 18 kg. Your freight cost per unit goes up, and your customer's wall might not hold it. They're almost always floor-standing for that reason. They also take longer to heat a garage or workshop where the door opens often.

Convection heaters are light, typically 4 to 6 kg, and most of our wall mounted electric heater models go up in ten minutes. But they drop temperature fast when the air moves. In a drafty room, they run longer. And if your customer is looking for a silent electric heater, convection wins because there's no oil gurgling as it heats and cools.

For bathrooms, you need IP24 rating. We make both in IP24, but convection panels are easier to mount high on a wall, away from splash zones. Oil filled units often sit low and take up floor space, which is a problem in a small bathroom.

What Buyers Actually Ask Us

Most private label brands come to us with a vague idea: "I want a heater for bedrooms." That's not a spec. I ask them three questions:

1. How many hours per day will it run continuously?
2. Is the room drafty or sealed?
3. Does the end user want instant heat or steady heat?

If they say 6+ hours, sealed room, steady heat, I point them to oil filled. If they say 1 to 2 hours, bedroom, quick warm-up before sleep, I point them to convection. That's how to choose electric heater for real use, not from a spec sheet.

One distributor from the UK made the mistake of stocking only oil filled units for a housing association contract. The tenants wanted a quick warm-up in the morning before work. The heaters were fine, but the tenants complained constantly. He switched half his order to convection panels with programmable thermostats, and the complaints stopped.

Manufacturing Realities You Should Know

Our MOQ for either type is 200 pcs per model. Lead time is 25 to 35 days for oil filled, 15 to 20 days for convection panels, because the press line for oil filled fins is slower and the oil filling process adds a step.

CE and RoHS are standard for Europe. UKCA is required if you're shipping to the UK now. ERP compliance affects the standby power and thermostat accuracy, and we've had to rework a thermostat design once because it drew 1.2W in standby, over the 0.5W ERP limit. Check that before you commit to a cheap supplier.

Oil filled radiators also need a pressure test on every unit. We do a 1.5 bar air test before oil filling. If a unit leaks in the field, it's a fire hazard and a recall. Convection heaters have no such risk.

The Cost of Running Argument

Customers search for an energy efficient electric heater or a cheap to run electric heater. The truth is, both are nearly 100% efficient at converting electricity to heat. The difference is in how long they run.

A 1500W convection heater running 4 hours a day uses 6 kWh. An oil filled running the same 4 hours might use 5.2 kWh because it cycles off more. At $0.15 per kWh, that's $0.12 per day difference. Over a 5-month heating season, that's about $18. Not nothing, but not a reason to choose one over the other.

The bigger cost is if your customer buys the wrong type and leaves it running longer because they're cold. That's a behavioral problem, not an efficiency problem.

Sourcing Advice from the Factory Floor

Don't ask us for the "best" heater. Ask for the best heater for your specific market's habits. If you're selling to northern Europe, oil filled radiators sell well for living rooms. If you're selling to the US South, where heating is intermittent, convection panels move faster.

Infrared heater vs convection is a different comparison, and I'll cover that another time. But know this: infrared heats objects, not air. It feels warmer faster, but it doesn't keep a whole room even. That's a niche play, not a volume play.

For your first order, don't mix too many models. Pick one oil filled 1500W and one convection 1500W with a mechanical thermostat. Test them in your own office or home. Measure the time to heat a room and the duty cycle. Then you'll know what your customers will feel.

We can send you sample units at production cost. That's not a sales pitch, it's just smart buying. You can't judge a heater from a photo.

The Takeaway

Oil filled radiators win on steady, long-duration heating and lower running cost over 6+ hours. Convection heaters win on speed, weight, and wall-mount convenience. Your job is to match the heater to the room and the usage pattern, not to the marketing brochure. If you do that, your returns stay low and your reorders come naturally.

That's how you keep a product line alive for ten years. We've done it since 2009, and we'll still be doing it when the next trend fades.