Reviews of the Best Oil Filled Heaters – Buyers Guide

When purchasing a space heater for use in your house during winter, one of the most popular options in the market is the oil-filled radiator. Thanks to their effectiveness, energy efficiency, and safety, oil-filled radiant heaters are more desirable than other options such as water heaters or bar heaters. But what makes them so effective and convenient?

Let’s take a look at how they work and what models are considered the best.

Quick Take: Best Oil-Filled Radiant Heaters

These are the top oil-filled heaters on the market:

  1. Delonghi TRH0715CA 1500W Safe Heat Portable Oil-Filled Radiator
  2. Delonghi TRD40615ECA Dragon Digital Full Room Radiant Heater
  3. NewAir AH-450B Electric Oil-Filled Space Heater

Find out more as you read one!

How Do Oil-Filled Radiant Heaters Work

Oil heaters consist of metal columns with cavities. Inside the body and fin of the heater is diathermic oil, which flows freely around the heater. The oil is not used as fuel, but instead serves as a heat reservoir, so it never gets used up. It just continues circulating through the heater for as long as you use it.

When it is plugged in, electricity is consumed by a resistor inside the heater to generate heat. That heat is absorbed by the diathermic oil that is enclosed in the heater. As the oil in the heater warms up, it begins to circulate through the fins and columns. As the oil is slow to lose heat, the unit only switches on occasionally to keep the liquid at the right temperature. Some basic models have high, medium and low settings, but others offer timers and precise thermostat temperature controls.

As the oil moves, it transfers heat into the metal of the heater’s fins, creating an even surface temperature. One of the advantages of an oil-filled heater is that they operate so silently. This is because most models don’t have built-in fans to distribute hot air. As the metal fins heat up, they begin to radiate heat into the room. This heat is circulated throughout the room by natural convection in the air.

Unlike traditional radiators, oil-filled radiators are mobile and can be moved around almost everywhere. They connect to your household electricity with an ordinary wall plug, and most have carrying handles. Larger models have wheels for easy repositioning.

A common concern from buyers is about the need to refill the oil. Because the oil is not burnt but is instead used as a heat reservoir, you don’t need to refill the oil. The high specific heat capacity and high boiling point of the oil means that your heater can store a lot of heat without the oil getting hot enough to boil. This makes the design of the system much simpler.

How Much Heat Can An Oil-filled Heater Give Off?

Typical oil heaters range in power consumption/output from 300 to 2400 watts, and their length and number of columns is roughly proportional to their power rating. A 2400 watt oil heater is usually approximately 3.5 feet in length. Multiply the wattage of your unit by 3.41 per watt to calculate BTU. A standard 1,500-watt electric heater produces 5,115 BTU per hour.

All electric resistance heaters are 100% efficient, with operating costs determined by their wattage and the length of operating time. A 500-watt heater will take twice as long to reach the same thermostat setting as a 1000 watt unit; the total consumption of electricity is the same for both.

Heater sizes of 1,000 watts/3,410 BTUs are suggested for rooms under 100 square feet, a 1,500-watts/5,115 BTUs for rooms measuring 100 to 150 square feet, and a 2,500-watt/8,525 BTUs for rooms between 150 and 250 square feet.

The Good and The Bad

Like any product, oil filled radiant heaters have their advantages and disadvantages. Here are some of the good points:

Quiet operation

Whereas a traditional space heater with an exposed heating element uses a fan to blow hot air into the room, oil-filled heaters are almost entirely silent. The most noise it makes is some clicking as the thermostat adjusts itself.

No dryness

Since the heater does not use a fan, the air in your room won’t dry out.

Energy efficient

Electric heaters are almost 100% efficient, which means that all the energy used is converted directly to heat. An oil-filled heater doesn’t even have to provide power for a fan motor.

Slow to cool

Oil heaters keep radiating heat even after the power has been turned off.

Long lasting

The lack of moving parts, besides wheels on some models, means that the heater will last a long time if well-maintained.

Thermostat controlled

Once the area or room reaches a comfortable temperature, oil-filled heaters will automatically cycle on and off to maintain that warmth, instead of running continuously, saving you money while preventing overheated rooms.

Low maintenance

The oil isn’t used as fuel, so there’s no need to replace it, ever.

Compact and portable

Oil-filled heaters are lightweight and easily move from place to place.


Oil-filled heaters are some of the safest space heaters available. Most models include overheat protection and tilt-switches that turn the heater off in case of a problem. The heating element is sealed inside the heater, so there’s no chance it will encounter anything flammable.

Non-scorching surfaces

The metal surfaces get warm to the touch, but never hot enough to burn if brushed against accidentally.

No vents required

An oil-filled heater is entirely enclosed, so there’s no need to worry about dust or debris getting inside or fingers poking through an exposed grille. Also, there’s no concern about blocking air flow through intake and outtake vents. Since they don’t burn oil or gas, they don’t produce carbon monoxide and are safe to use indoors.

One of the disadvantages of oil-filled heaters is that they take a little longer to heat up than a fan-forced heater, since they have to first heat the oil, then warm the air around them. They can also leak oil if they are not well built.

Safety Principles

Some basic precautions should be observed for safely operating the heater. First, avoid having any object within three feet of an oil heater. Using an oil heater to dry clothes is not recommended by any modern manufacturer, as there is a risk of fire. Similarly, don’t keep fabric and clothes too near the heater to prevent risk of fire.

It should also be noted that some oil heaters contain strong warnings to avoid operation in damp areas (such as bathrooms or laundry rooms) because the moisture and humidity can damage components of the heater itself.

Quick Comparison Chart of the Best Patio Heaters


Our Rating


Delonghi TRH0715CA 1500W Safe Heat Portable Oil-Filled Radiator ​

DeLonghi TRH0715 Oil Filled Radiator

Delonghi TRD40615ECA Dragon Digital Full Room Radiant Heater ​

Frigidaire FFRS1022R1 10000 BTU 115-volt Slider/Casement Room Air Conditioner with Full-Function Remote Control

NewAir AH-450B Electric Oil-Filled Space Heater 

NewAir AH-450B Electric Oil-Filled Space Heater, Black

​Honeywell HZ-789 EnergySmart ​

Honeywell HZ-789 EnergySmart Electric Oil Filled Radiator Whole Room Heater

Pelonis NY1507-14A Digital Radiator Heater 

PELONIS NY1507-14A Digital Radiator Heater with Remote Control

Reviews of the Best Oil-Filled Heaters

Now that you know how an oil-filled heater works, it’s time to check out some highly rated heaters and see whether one of them is the right one for you.

Delonghi TRH0715CA 1500W Safe Heat Portable Oil-Filled Radiator

DeLonghi TRH0715 Oil Filled Radiator

Among the best available on the market, the DeLonghi oil-filled radiator heaters are the most popular and best rated. Plus points for the TRH0715 include its simple controls that allow temperature adjustments and has three temperature settings. A thermal cutoff prevents overheating, and the heater never requires refilling. It is also energy efficient and made from durable rust-resistant metal, so it will last a long time.

Anti-freeze technology automatically turns the unit on when the temperature drops below 42 degrees, preventing frozen pipes. The heater has no moving parts, providing consistent, silent warmth. The unit features snap-in wheels, requiring no tools for assembly or set-up. The cord wraps around the front plate, so moving and storing the unit is easy.

Disadvantages include that it gets quite hot so people especially small children can burn themselves on contact with the surface. And like most oil-filled heaters it takes time to warm up a room after starting. It does not have a remote control.

Delonghi TRD40615ECA Dragon Digital Full Room Radiant Heater

Frigidaire FFRS1022R1 10000 BTU 115-volt Slider/Casement Room Air Conditioner with Full-Function Remote Control

The Dragon model is designed for large spaces like your bedroom and features easy-to-use digital controls. The 24-hour programmable timer is convenient for programming it to operate at the right time. It has three heat levels and the Eco function automatically sets the most appropriate power level for your room, helping to reduce bills. It comes with wheels that let you easily move the heater.

One the downside, it has no remote control.

NewAir AH-450B Electric Oil-Filled Space Heater

NewAir AH-450B Electric Oil-Filled Space Heater, Black

The NewAir AH-450B is packed full of useful features that make it a popular choice. For starters, it can heat spaces up to 150 square feet, making it ideal for dorm rooms, dens and small offices. For safety, it has an overheat protection feature and a tip-over switch. It is easy to move around using its four casters and carrying handles. Other helpful features include a 10-hour timer, a remote control, three heat options and five temperature settings.

Honeywell HZ-789 EnergySmart

Honeywell HZ-789 EnergySmart Electric Oil Filled Radiator Whole Room Heater

The HZ-789 heater comes with digital controls and a 12-hour timer, adjustable thermostat and three heat settings. It’s convenient for small spaces, which it heats up very fast. It has a large handle and wheels for mobility. For safety it has a tip--over switch, overheat protection, 3-prong grounded plug and a heavy duty power cord. It does not get too hot to the touch, so is generally safe for children and pets, although care should still be taken during operation.

It does not have a remote control.

Pelonis NY1507-14A Digital Radiator Heater

PELONIS NY1507-14A Digital Radiator Heater with Remote Control

The NY1507-14A has a digital display and comes with a remote control for adjusting the thermostat for personal comfort. Durability is assured with heavy gauge steel construction and a rust-free enamel finish. The oil never needs refilling or replacement. It has a handle and casters that make it easy to move. The cord can be wrapped convenient storage during the off season.


When you need to heat up a small, enclosed space or you need a heater to supplement your existing heating in certain rooms, an oil-filled heater can be very helpful.

Their robustness, ease of use and efficiency make them popular with homeowners and businesses alike, and with new features like programmable timers and remote controls, the latest models can truly make staying warm a convenience rather than a hassle.

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