Space Heaters

Do oil filled radiators need oil refilling or replacing?

Heating Trends, last updated on November 17, 2022

Find out everything about how oil radiators generate heat, what kind of oil they use and how safe are they.

#oil radiator#electric

Do oil filled radiators need oil refilling or replacing?

How do oil radiators work?

Oil radiators, like all heaters, work on the principle of converting electrical energy into thermal energy. What is specific about oil radiators compared to radiators, infrared heaters or convectors is the way they distribute heat in the space.

Oil radiators heat the space with a combination of radiation and convection heating and provide uniform and pleasant heat. Oil radiators are made of metal inserts with cavities, and inside there is a tank of thermal oil in which an electric heater is immersed. When we turn on the radiator, the heater starts to heat up and the heat is transferred to the surrounding oil which ultimately heats the body of the radiator. Once the radiator is sufficiently heated, the heat begins to radiate and flow by convection and eventually heats the space.

Our readers also liked

How much does it cost to run a 1,500 watt heater for 24 hours?

Type of oil in oil radiators

Oil radiators are factory-filled with diathermal oil, which is a type of mineral oil. Diathermal oil is used because it has a high boiling point that is three times higher than the boiling point of water and a high specific heat capacity, which allows this oil to retain a large amount of heat before its temperature rises.

This means that due to this type of diathermal oil, the radiator will continue to radiate heat even when it is turned off and will ultimately provide a pleasant and uniform heat in the room.

Why thermal oil and not water?

The combination of the previously mentioned characteristics - high specific heat capacity and high boiling points, allow the oil radiator to store a larger amount of heat, without boiling. Diathermal oil, unlike water, has excellent thermal stability. It never reaches the boiling point, does not evaporate, and therefore does not expand so much and does not create critical pressure inside the radiator housing.

Diathermal oil is a heat transfer liquid, and has a high boiling point at atmospheric pressure, at least 308°C (586°F), and a low freezing point.

Is it necessary to refill or change the oil in oil radiators?

The thermal oil in the oil radiator is filled at the factory, the oil is permanently sealed and never needs to be filled up or changed! The heat produced by the oil radiator is the result of the heating of the heating element which is immersed in the diathermal oil and eventually heats the body of the radiator. The oil never burns and is not combusted.

Can an oil radiator run out of oil?

As we mentioned earlier, the diathermal oil inside the body of the radiator is factory filled and permanently sealed, and the radiator cannot run out of oil. The only case in which an oil radiator may lack oil is due to an oil leak as a result of damage. In this case, for safety reasons, it is not possible to repair the radiator and it is necessary to get a new one, and dispose of the damaged radiator in an environmentally friendly way.

If you are not sure if your radiator is leaking, make a visual inspection and check if there is corrosion on the metal parts. If you see corrosion, cracked parts or even cracks, it is possible that your radiator is defective and you should not continue to use it.

Oil radiators require almost no maintenance at all, and if a problem occurs - it is usually a malfunction of electronic parts such as connections on the wiring, faulty switches or a faulty heater. You can easily identify problems with the electronics by the fact that the radiator does not produce heat, so it is best to take it to an authorized electrician for repair.

Oil radiators safety

Oil radiators are quite safe, and they are safer compared to other types of heaters because they do not produce high temperatures to heat the space, so you will not be able to burn yourself if you touch the body of the radiator. The heater, thermal oil and other electronic parts are located inside the radiator and therefore do not pose a risk of burns or ignition of things located near the radiator. These characteristics are ideal for households with children and pets.

It is also important to emphasize that during the operation of an oil radiator, oil does not burn, so you do not have to worry about the quality of the air in your household, or whether dark spots will appear on the walls as a result of the heating. Almost all oil radiators on the market have a built-in thermal protection. The inside of the radiator is protected from overheating, which could cause damage to electronic parts. Because inside the oil radiator there is quality diathermal oil with a very high boiling point, these radiators are safe to use.

Also, some portable radiators are equipped with a tip-over shut-off function.

Are oil radiators eco-friendly?

We can say that oil radiators are quite eco friendly. Although they are not as efficient as technological solutions that have the potential to deliver 2, 3 or 4 kW of heat energy for 1 kW of electricity consumed, oil radiators do not waste electricity. In the context of electric heaters, it can be said that they are energy efficient.

Since the oil inside the radiator does not burn and does not evaporate, there are no harmful emissions inside the household. The oil never leaves the radiator and does not produce greenhouse gases.

And very importantly, most oil radiators have a lifespan of 10 years and even up to 20 years, which means that they will serve you well for a long time and less often end up in the waste. In a sea of electronic waste, this really makes them eco friendly.