What is an Oil Filled Radiator?

A Comprehensive Look at Oil Filled Electric Radiators

As temperatures begin to dip, the search for efficient and reliable heating solutions becomes a top priority. Amidst various options, one stands out due to its unique features and benefits: the oil filled electric radiator.

What is an Oil Filled Electric Radiator?

An oil filled electric radiator is a type of heating device that uses oil as a heat reservoir. Despite what the name suggests, it does not burn oil to produce heat. Instead, it employs electricity to heat thermal oil contained within the unit. This heated oil then circulates around the radiator, evenly dispersing a warm, comforting heat.

How Does an Oil Filled Electric Radiator Work?

How an oil filled electric radiator works is quite straightforward. Below is a more detailed explanation of how these heaters work:

1. Powering On: When you switch on the oil-filled radiator, electricity starts flowing into the resistive heating element located inside the unit. This heating element is usually made of a wire or coil and is designed to resist the flow of electricity, which generates heat.

2. Heating the Oil: The heat generated by the resistive element is then transferred to the thermal oil enclosed within the metal columns or fins of the radiator. This oil has high specific heat capacity properties, meaning it can hold and store a lot of heat energy without changing its temperature drastically.

3. Circulation of Heat: Once the oil is heated, it starts to circulate around the columns of the radiator due to the principle of convection. Hot oil rises while cooler oil sinks, creating a natural circulation that ensures equal distribution of heat throughout all the columns.

4. Radiating Heat: As the oil circulates, it transfers its heat to the metal casing of the radiator. This heat is then radiated from the surface of the radiator into the surrounding environment, warming up the air in the room. The process continues until the entire space reaches the desired temperature.

5. Thermostat Regulation: Most oil-filled radiators come with a built-in thermostat that helps regulate the temperature. Once the room reaches the set temperature, the thermostat switches off the heating element. When the temperature falls below the set level, the thermostat turns the heating element back on, ensuring a consistent room temperature.

It’s important to note that despite the oil being heated, it never reaches a boiling point or burns. This is because the heating element regulates the temperature, ensuring the oil stays within a safe range.

Benefits of an Oil Filled Electric Radiator

Oil filled electric radiators offer numerous advantages over other types of heaters:

  • Good Thermal Retention Capacity: Due to the high specific heat capacity of oil, these radiators retain heat exceptionally well, continuing to provide warmth even after being switched off.
  • Steady Warm Heat: They emit a steady, constant heat similar to central heating radiators, creating a comfortable environment.
  • Lower Running Costs: When used with a thermostat, they can be more cost-effective than electric heaters without thermostats.
  • Silent Operation: Unlike some heating devices, oil filled radiators operate silently, making them ideal for bedrooms or study areas.
  • Variety of Wattage Outputs: These radiators come in a range of wattages, allowing you to choose the right level of heat output for your space.
  • Portability: Most models come with wheels or handles, making them easy to move from room to room.
  • Safety Features: They are safe to use, with many models featuring overheat protection and cool-to-touch exteriors.

Do Oil Filled Radiators Use a Lot of Electricity?

The amount of electricity and cost to run on an oil-filled radiator depends on its wattage, which generally ranges from 500 to 2,500 watts. The higher the wattage, the more electricity it uses. However, oil-filled radiators are known for their efficiency.

Unlike some other types of heaters that constantly draw power while turned on, oil-filled radiators heat the oil inside them and then use this stored heat to warm a room, allowing them to cycle on and off while maintaining a steady temperature. This means that even though they might have a high wattage, they don’t use that amount of electricity continuously.

For instance, if you have a 1,500-watt radiator, and you run it at full power for an hour, it will use 1.5 kilowatt-hours (kWh) of electricity. But if the thermostat is set to a comfortable room temperature, the heater won’t operate all the time. It will cycle on and off, possibly operating only half the time, effectively using around 0.75 kWh.

So, while oil-filled radiators can use a substantial amount of electricity, their efficient operation often results in less overall energy consumption compared to other heating options. However, the exact energy usage will depend on factors like the size of the room, how well it’s insulated, the outdoor temperature, and how long the heater is running.

As with any appliance, to save on energy costs, it’s recommended to use the heater responsibly – only when needed, and at the lowest comfortable setting.

Do You Have to Refill Oil Filled Radiators?

No, oil-filled radiators do not require a refill of oil. The oil in these heaters is not used as fuel, but rather it serves as a heat reservoir. It is heated by the electric element and circulates within the radiator to emit warmth. This oil does not burn off or evaporate while the heater is in use.

The radiators are designed to be permanently sealed, meaning there’s no need to replace or refill the oil throughout the lifespan of the unit. This makes oil-filled radiators virtually maintenance-free, apart from regular surface cleaning.

So, despite what their name might suggest, you won’t have to worry about refilling oil-filled radiators, making them a convenient and efficient option for home heating.

Will an Oil Filled Radiator Heat a Large Room?

Yes, an oil-filled radiator can effectively heat a large room, but it largely depends on the heat wattage output of the specific model you choose. The power of oil-filled radiators is usually measured in watts, and typically, models range from 500 to 3000 watts.

Here’s how it works: The higher the wattage, the more heat the radiator can generate, and consequently, the larger the room it can warm up. For instance, a 3000-watt radiator, which is on the higher end of the spectrum, can effectively heat most large rooms, actual performance can vary based on factors like how well-insulated the room is.

Now, if we’re talking about a very large room – say, over 200 square feet – you might find that one oil-filled radiator isn’t sufficient, especially in colder weather or if the room isn’t well-insulated. In such cases, using two oil-filled radiators strategically placed at different ends of the room could be a more effective solution.

An oil-filled radiator can heat a large room, but depending on the size of the room and the specific heating needs, you might need more than one unit or a unit with a higher wattage. As always, it’s a good idea to assess your specific needs before determining what size oil filled radiator you need.

Who is an Oil Filled Electric Radiators Suitable For?

Oil filled electric radiators are suitable for almost everyone, from homeowners looking to supplement their central heating, to tenants in apartments where installing permanent heating solutions may not be feasible. They are also an excellent choice for offices and other workplaces due to their silent operation and portability.


In wrapping up, it’s clear that oil-filled electric radiators stand as a powerful contender in the realm of heating solutions. They offer a unique combination of efficiency, ease-of-use, and adaptability that sets them apart from many other heating options available in the market.

Firstly, their efficiency is unparalleled. The high specific heat capacity of oil ensures that these radiators retain heat for longer periods, even after the unit has been switched off. This means they consume less energy while still providing a consistent source of warmth, making them a cost-effective choice for many households and businesses.

Moreover, their convenience is another significant advantage. These radiators are typically designed with user-friendly features such as adjustable thermostats, timer functions, and in some cases, remote controls. Their silent operation also adds to their appeal, as they can be used in bedrooms, offices, and other spaces where noise could be a disturbance.

The versatility of oil-filled electric radiators is yet another compelling attribute. They come in various sizes and wattages, allowing you to select the most suitable one based on your specific needs. Whether you’re trying to warm a cosy study room or a spacious living area, there’s likely an oil-filled radiator that’s just right for your space.

Not to forget, these radiators are generally safe to use, with built-in safety features such as overheat protection and cool-to-touch exteriors. They also offer the benefit of portability, with most models equipped with casters or handles for ease of movement.

Oil filled electric radiators are more than just a heating solution; they are a smart investment towards comfort, energy conservation, and convenience. Regardless of your heating needs, there’s a high chance that an oil-filled electric radiator can serve as the perfect solution, delivering reliable and steady warmth whenever you need it.