Are Oil Heaters Safe? Can You Leave Them Unattended?

Oil heaters are some of the safest types of heaters to consider using in your home. In fact, due to their safety, reliability, and durability, they’ve become quite popular among people. So, this begs the question of whether they are safe to leave on all night or night.

The answer to this question is yes. Oil heaters have a heating element encased in a metal body, making them safe to touch and unlikely to burn or overheat any parts of your home. Therefore, if you have an oil heater working properly with a functional thermostat, you shouldn’t worry about leaving it on all night. However, you have to ensure that you keep away flammable items from the oil heater.

The fact that it’s safe to leave your oil heater on all night makes it even more suitable to use, especially during the cold winter season. This means that the heater can remain on for the whole night and keep you warm as you sleep. But, it’s important to note that there are some reasons why you shouldn’t leave the heater all night.

Check them out below.

Reasons Why You Might Not Want to Leave Your Oil Heater On Overnight?

  • Catch fire/explode – Unfortunately, an oil heater is not immune to catching fire or exploding. Therefore, this is one reason you need to avoid always leaving your unit running for long hours. But in most cases, an oil heater can catch fire if it’s close to combustible items.
  • Carbon monoxide poisoning is a proven fact that burning oil produces carbon monoxide and other harmful gases. Although these poisonous gases are produced at low levels, it’s still important to ensure your space is well vented when using an oil heater. Therefore, you shouldn’t leave your oil heater overnight if your home doesn’t have proper ventilation. You can also install a carbon monoxide detector to give you additional protection and peace of mind.
  • Dry the air – It is crucial to note that oil-filled heaters dry the air similar to other resistance-based heaters do. An excellent solution to this problem would be to invest in a humidifier with water to vaporize the moisture in the space. However, having warm air replaced with colder outside air can lower the humidity in your space. Hanging some wet towels in your space can also help to add moisture.

How Long Can I Keep an Oil Heater On – If You Want to Leave the Unattended?

An oil heater takes a significant amount of time to heat your room when it’s cold. Therefore, that means you can use the heater for many hours if you want – even overnight. You can leave your oil heater for hours unattended if you’re sure it functions properly and doesn’t encounter any glitches as it runs.

However, it’s usually recommended to avoid running the oil heater for long due to some of the dangers that it poses, such as an increase in carbon monoxide, dry skin, and allergy.

If you want to leave your oil heater running for long hours unattended, you need to ensure that it has safety features. These safety features include overheating protection, tip-over protection, and installing the carbon monoxide detector in your house to sound an alarm if CO levels get too high.

You can choose to run your oil heater for several hours and then shut it off and continue to enjoy the warmth because it takes a few hours for the unit to cool off due to diathermic oil.

This is the oil that is used to transfer heat in the surrounding. The slow cooling process of an oil heater allows you to enjoy warmth long after you had shut it off, which even helps you save electricity.

Regardless of whether you want to leave your oil heater for long hours unattended or not, it’s important to note that just like all other appliances, every type of oil heater comes with its drawdowns. It’s up to you to conduct thorough research and find out the best option to consider choosing depending on your needs.

3 Best Oil Heaters that You Can Leave On Overnight

1. De’longhi Oil-Filled Radiator Space Heater

The De’longhi Oil-Filled Radiator Space Heater is designed to offer you peace of mind, thanks to its thermal shut-off that prevents overheating and also an anti-freezing feature that automatically turns the heater on to help prevent frozen pipes. This means it’s an ideal heater to use since you can leave it on overnight without having to worry about anything.

Another good thing about this oil heater is that it is durable and maintenance-free. It is designed with a high-quality, patented steel assembly and permanently-sealed oil reservoir that will never require any refilling.

It also offers personalized comfort since you can customize the unit to your heating needs, plus it also has a timer, an adjustable thermostat, and three heat settings.

The De’longhi Oil-Filled Radiator Space Heater is also intuitive and efficient. It features an ECO function that automatically saves energy by automatically adjusting heat and power settings to offer you comfort and economical warmth.


  • Durable
  • Efficient
  • Intuitive
  • Easy to use
  • Maintenance-free
  • Personalized comfort


  • Noisy
  • Awful fumes
  • Not durable enough

2. Homeleader Oil Heater

If you’re looking for an oil heater with multiple settings, then the Homeleader Oil Heater is the right option to consider. Coming from a reputable brand, this oil heater offers 3 settings suitable for medium to large rooms and is quite convenient to move around. Its portability comes from the fact that it has a carry handle and four heavy-duty caster wheels.

The Homeleader Oil Heater also has a compact design and plastic stirrup that allows you to roll up the power cord, enabling seasonal storage. Additionally, this oil heater is safe to use in your home since it includes safety features such as tip-over protection and an overheat auto-switch.

When it comes to energy consumption, you won’t have to worry about an increase in your electricity bill because this Homeleader Oil Heater only heats the room you’re in.

Therefore, this helps to lower your household thermostat and energy bills. You can use it in your bedroom, study, living rooms, and even office.


  • Quiet
  • Portable
  • Convenient
  • Adjustable thermostat
  • Safe for family
  • Multiple settings


  • Too slow
  • Terrible heating
  • Questionable durability

 3. Kismile 1500W Oil Filled Radiator Heater

The Kismile 1500W Oil Filled Radiator Heater features 3 operation modes and an adjustable thermostat that makes it ideal to use. When searching for a good oil heater that you can leave on for long hours or even overnight, it’s important to check whether it has the safety features to allow this. Luckily, this unit is designed with an automatic overheat protection system that shuts it off when the parts overheat.

Another exciting and safety feature included in the Kismile 1500W Oil Filled Radiator Heater is the tip-over protection that also shuts off when the unit is tipped forward or backward.

There’s also a cord storage that allows you to keep the wire after using the oil heater properly. It also includes universal wheels that make it easier for you to move the unit from one place to another.

It also features a built-in door handle that adds to the portability of the unit. Therefore, this means that it’s quite a portable oil heater. With the Kismile 1500W Oil Filled Radiator Heater, you can enjoy warmth anytime and anywhere the way you want.


  • Quiet
  • Portable
  • Convenient
  • Cord storage
  • 3 heating modes
  • Universal wheels
  • Tip-over protection
  • Modern sleek design
  • Adjustable thermostat


  • Cheaply designed
  • Not durable enough

Safety Features to Consider when Choosing an Oil Heater

  • Tip-over protection – This feature is ideal because it shuts off the oil heater when someone tips it forward or backward. It helps to prevent fire outbreaks and keeps your home safe.
  • Overheat protection – When you have an oil heater with overheat protection, you won’t have to worry about leaving it unattended for long hours. This is because this feature helps to turn off the unit when it heats up too much.
  • Thermostat – This is a device that regulates the temperature of your oil unit and keeps you safe. It’s ideal to buy an oil heater with a thermostat to help you know when you need to turn the heating on or off.
  • Timer – Another safety feature is the timer because it allows you to set the amount of time you want the oil heater to run. Once that time elapses, the unit will automatically turn off.

Safety Precautions to Take when Using Oil Heater

  • Ensure that you only burn approved and safe substances in your furnace.
  • If you have an oil heater that needs proper installation, hire a qualified technician to do that for you.
  • Do not store or use gasoline or any other combustible item near your oil heater.
  • All the oil lines must be made of copper, brass, steel, or copper components.
  • Ensure your oil heater encompasses all the recommended safety features.

Other Frequently Asked Questions About Oil Heaters

Are Oil Filled Heaters Safe to Leave Unattended?

Yes, it’s safe to leave oil-filled heaters unattended, but you have to ensure that they have the safety features included. For instance, if your oil heater has a timer, tip-over, and overheat protection, it can work fine even when you’re not monitoring it. Another thing is that these units tend to heat up slowly, and this allows you to leave them unattended.

Do Oil-Filled Radiators Give Off Fumes?

No, oil-filled radiators do not give off fumes. This is because you need combustion to produce fumes, and there isn’t any burning of oil in oil heaters.

Do Oil Heaters Make You Sick?

Yes, oil heaters can make you sick if your space is not well vented. This is because oil heaters produce gases such as carbon monoxide, which is dangerous and brings symptoms such as dizziness, fatigue, headache, nausea, drowsiness, and even chest pain. It can also be harmful to people with heart disease, the elderly, and young children. Therefore, it’s important to ensure your space is well ventilated when using oil heaters.

Are Oil Heaters Supposed to Make Noise?

Yes, it’s normal for oil heaters to make popping and crackling noises. This happens as the oil and metal warm up. If you have your oil heater turned upside down, it might produce a gurgling noise when you set it upright since the oil will be settling into the channels again.

Should My Oil Heater Smell?

Yes, an oil heater tends to smell since the heated oil produces a distinct odor. The good news is that this scent tends to disappear on its own. However, if the scent proves to be adamant, you can use a contaminant to mitigate this issue.