Oil Filled Radiator vs Convection Heater: A Factory Buyer's Guide

We've been building electric heaters since 2009. If there's one question that comes up in almost every meeting with a new distributor, it's this: should I stock oil-filled radiators or convection panels? Both sell. Both have loyal customers. But they solve different problems, and if you get the mix wrong, you'll be sitting on inventory that doesn't move.

Let's break it down from the production floor up.

How They Actually Work

A convection heater pulls cold air in at the bottom, runs it over a heating element, and pushes warm air out the top. It's simple. Heats up in seconds. Most wall-mounted panels and portable convection units work this way. No moving parts, no noise, cheap to build. That's why they're everywhere.

An oil-filled radiator works differently. The element heats diathermic oil inside sealed fins. The oil holds heat, and the metal fins radiate it into the room. It takes 10–15 minutes to feel warm, but it keeps giving off heat after the thermostat cuts power. That thermal mass is the whole point.

Where Each One Wins

Convection is better for fast, targeted heat. A wall-mounted electric heater in a bathroom or a small office gets the job done in minutes. They're also lighter and cheaper to ship, which matters when you're importing containers.

Oil-filled radiators are better for steady, silent background heat. If a customer needs a silent electric heater for a bedroom or a home office they'll use for six hours straight, oil is the safer recommendation. No fan noise, no dry air blast, no clicking relay every few minutes. Just even warmth.

We see this split in our order data. Distributors in Northern Europe order more oil-filled units. Buyers in warmer markets, or those selling to rental properties, lean toward convection panels because the upfront cost is lower.

The Real Numbers Buyers Ask About

Running cost is the question every procurement manager eventually asks. Here's the honest math: a 2000W heater running at full power for one hour uses 2 kWh. At €0.30 per kWh, that's €0.60 per hour. A 1000W unit costs half that, but it also heats half as fast.

The trick with oil-filled radiators is that once the oil is hot, the thermostat cycles the element on and off. In a well-insulated room, that duty cycle might be 30–40%. So the effective running cost can be lower than a convection heater that blasts at full power the whole time. But in a drafty room, oil loses that advantage fast. Don't let anyone tell you oil is always cheaper to run. It isn't.

If a buyer asks for an energy efficient electric heater, the real answer is: match the wattage to the room size, and add a thermostat. A 1500W heater with a good thermostat beats a 2500W heater with a bad one every time.

Certifications and Sourcing Reality

For Europe, you need CE and RoHS at minimum. UKCA if you're shipping to the UK. ERP compliance is non-negotiable for anything with a plug. We build all our units to these standards, but not every factory does. Ask for test reports, not just certificates. Certificates can be bought. Test reports show the actual unit passed.

MOQ for private label electric heater runs is typically 200 pcs per model. Lead time runs 15–45 days depending on whether you need custom packaging, custom controls, or a new mold. If you want a wifi smart electric heater with your own app, add 30 days for firmware and app testing. That's not a sales pitch, that's just how long it takes.

What I'd Stock If I Were You

Don't pick one. Stock both, but weight your order based on your market. If you're selling to Amazon buyers who want a cheap to run electric heater for a bedroom, oil-filled with a 7-fin or 9-fin design and a mechanical thermostat sells well. If you're supplying contractors or property managers, wall-mounted convection panels move faster because they're cheaper and easier to install.

One more thing: don't ignore the 12v electric heater for RV campervan market. It's small volume, but the margins are better and the competition is thinner. We've seen buyers build entire private-label brands around that niche alone.

The Honest Takeaway

Oil-filled radiators and convection heaters aren't competitors. They're tools for different jobs. If you try to sell one as the answer to everything, your customers will figure it out and your returns will climb. Stock the right mix, be straight about running costs, and make sure your factory can back up the certs with real test data. That's what keeps a B2B account alive past the first order.