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

If you sell electric heaters in Europe or North America, you've probably had a buyer ask you the difference between an oil filled radiator and a convection panel. It's not a trick question. The answer decides what you stock, what you pay in freight, and what your customers say in reviews.

Both are popular. Both are safe. But they are not the same machine, and if you source the wrong one for your market, you'll eat the returns.

The Short Version

Oil filled radiators heat oil inside a sealed metal body. That oil holds heat and radiates it slowly into the room. Convection heaters pull cold air in from the bottom, pass it over a heating element, and push warm air out the top. No oil, no fan, just natural airflow.

One heats like a slow cooker. The other heats like a kettle with a draft.

Neither is wrong. But they fit different rooms and different customer expectations.

Heat Feel and Comfort

Oil filled radiators give off radiant heat. You feel it on your skin, like standing near a warm wall. The surface temperature stays lower than a convection element, so it's less harsh. The room warms up gradually, but the heat lingers after the unit shuts off. That's why people say an oil filled radiator is a cheap to run electric heater for a bedroom if you use the thermostat correctly. You set it at 18°C before bed, the oil stays warm, and the unit cycles less during the night.

Convection panels heat the air directly. The room feels warm faster, especially if the unit is wall mounted and placed low. But the air cools quickly once the heater stops. No thermal mass. So for a living room you use all evening, a convection heater will cycle on and off more often. That's not necessarily more expensive, but it feels different.

If your customer is comparing oil filled radiator vs convection heater for a bedroom, oil is usually the safer bet. For an office or a workshop where people come and go, a convection panel responds faster.

Running Cost and Efficiency

Here's the blunt part: both are nearly 100% efficient at converting electricity to heat. That's physics. The difference in running cost comes from how you control them, not the heating element itself.

A 1500W oil filled radiator running flat out for eight hours uses 12 kWh. A 1500W convection heater does the same. Same bill. But the oil unit holds heat, so with a good thermostat, it might only run for five of those eight hours. The convection heater loses heat when it shuts off, so it runs closer to six or seven hours.

So yes, oil filled radiators can be more energy efficient electric heater options in practice, mainly because they hold temperature better. But that only works if the heater has a proper thermostat, not just a dial that clicks on and off.

We build both types at our factory. For oil filled radiators, we fit a capillary thermostat with a 0.5°C differential. That's tighter than most cheap units, which swing 2°C or more. Tighter control means fewer cycles and lower running cost. If you're sourcing private label electric heater units, check the thermostat spec. It matters more than the wattage.

Safety and Certifications

Oil filled radiators run cooler on the surface, usually around 60-70°C on the fins. Convection panels with exposed elements can hit higher surface temps. For homes with kids or pets, that's a real consideration.

Both types should carry CE and RoHS for Europe, UKCA for the UK, and ERP compliance if you sell into the EU. We test every batch. Our oil filled models also pass the 45-degree tilt test, which is required for some insurance policies in Europe.

If your target market is bathrooms, neither type is ideal unless it has IP24 rating. We make a wall mounted electric heater with IP24 for bathrooms, but that's a convection panel, not an oil radiator. Oil radiators are not sealed for wet zones. Don't let a buyer push you into selling oil filled units for bathrooms. It's a liability.

Lead Times and MOQ Reality

Our standard MOQ for oil filled radiators is 200 pieces per model. For convection panels, it's the same. But lead times differ. Oil filled radiators take longer because of the filling and welding process. Expect 30-45 days. Convection panels are simpler, so we can ship in 15-25 days.

If you're an Amazon seller launching before winter, that difference matters. A 15-day delay in October can kill your Q4. Plan your PO dates accordingly.

Which One Should You Source?

I'll give you a straight answer based on what we see from our buyers.

If your customers are in northern Europe or Canada, where winters are long and rooms are small, oil filled radiators sell better. They feel warmer, they're silent, and people trust the technology. The phrase "oil filled radiator vs convection heater" gets searched a lot in those markets because buyers are trying to decide between the two for a bedroom or a small living room.

If your customers are in milder climates, or they're buying for offices, garages, or workshops, convection panels are lighter, cheaper to ship, and heat up faster. They also mount on walls, which saves floor space. A wall mounted electric heater in a garage is a common search. That's a convection product, not an oil radiator.

One more thing: freight. Oil filled radiators are heavy. A 1500W model weighs around 15-17 kg. A convection panel of the same wattage weighs 4-6 kg. If you're shipping a container from China, you'll pay roughly double the freight per unit for oil. That eats into your margin. Some buyers still choose oil because the retail price is higher. But don't ignore the landed cost.

The Honest Takeaway

There is no single best electric heater. There is only the best fit for your customer's room, your shipping budget, and your sales season.

If you want a product that feels premium and holds heat, source oil filled radiators. If you want faster heat, lower freight, and easier wall mounting, go with convection.

Just don't mix them up in your catalog. And if a supplier tells you one is "more efficient" than the other, ask them to explain the physics. If they can't, walk away.