Can You Leave An Oil Filled Heater On All The Time? (Explained)

I don’t tend to leave my oil filled heaters on constantly (I use a timer).

But occasionally I come downstairs on a cold morning and the living room is much warmer than I expect. And I know that I’ve left the heater on all night!

Thankfully, my only worry is the extra heating bills. Why? Let’s get into the details.

Is It Safe To Leave An Oil Filled Radiator On All The Time?

Good quality oil filled heaters typically have overheat protection and tip-over safety measures. They can be left on as long as you take sensible precautions such as:

  • keeping flammable material away from the heat
  • standing the heater on a flat surface
  • ensuring that the cord isn’t damaged or frayed
  • having safe electrical power and sockets

Overheat protection means that the radiator automatically shuts down if the temperature gets too high. Your heater shouldn’t overheat in normal usage.

This safety feature guards against the consequences of electrical or hardware faults.

Tip-over protection means that it also shuts down if it falls over. Of course, you should never stand your heater at a tilted angle.

As oil filled heater do last a long time, you might have an older model without these safety features. Personally, I wouldn’t leave one on and unattended if it didn’t have these protections.

Tips When Leaving An Oil Filled Heater On

Extra tip from experience

The next section has a picture of a timer. When I was taking the pic, I sat on the couch and pulled my radiator towards me. One of the wheels fell off and the radiator suddenly tilted to the side.

I was holding the heater with one hand, so I managed to right it before it hit the floor. But the tip-over feature kicked in! I saw the red power light go off for a second, and then go back on again.

The wheels are the flimsiest part of the radiator and may drop off when you’re moving it from room to room. Don’t be careless about putting them back in position securely.

Should I Leave My Oil Filled Heater On All Night?

We’ve established that quality oil filled radiators are safe when used sensibly. And you probably don’t need to keep your heater on 24/7. But what if you just want it on all night?

With the usual safety features, there should be no problem with this,  apart from the extra cost of electricity. So I suggest that you manage your costs by using a radiator with an in-built timer.

I use the timer to turn on the heater an hour before I get up in the morning. Sometimes two hours in very cold weather.

Extra tip from experience

I’ve already admitted that sometimes I mistakenly leave the radiator on all night. So, If I’m so clever with the timer, how can that happen?

Well, my preferred model has a separate switch to toggle the entire timer off and on. On a really cold afternoon, I may turn the timer off to leave the heat constantly on. And then forget to switch the setting back to the timer when I go to bed. Here’s a tip: don’t make my mistake!

Will I Damage An Oil Filled Heater If I Leave It On All the Time?

Manufacturers say that their radiators should last for fifteen to twenty years. I’ve never had one that lasted that long, but I tend to break them in some way!

We have a separate article that examines how long oil-filled electric heaters really last under normal usage.

So, it’s reasonable to wonder if leaving one on constantly would affect the typical lifespan. I’m not aware of any long-term study that tested this. So we’ll have to speculate.

We know that the heating element is a metal coil encased within the oil. Metal deteriorates over time, and the deterioration will increase under high temperatures. So, this is my conclusion:

You won’t cause short-term damage to an oil filled radiator by leaving it on all the time. However, a prolonged high temperature will reduce the typical lifespan of the appliance.

Keeping The Costs Down

You can easily calculate the cost of running your oil filled radiator for 24 hours.

Let’s say that the heater is 2 KW, or you choose that setting. Your electricity provider should have the domestic rates on their website. The average rate in the U.S. is about 12 cents per kilowatt-hour (it varies from state to state).

So a full 24 hour day will cost you:

                2 X 24 X 0.12 = $5.76

And if you just leave it on all night? Let’s say your night is 10 pm to 8 AM. That works out at about $2.40.

No, it’s not cheap. On the other hand, it’s more cost-effective than some other heating options.

Cost-saving tip: a thermostat

I always get radiators with a built-in thermostat and multiple heat settings. These models may be more expensive, but I save in the long run.

The thermostat dynamically switches the heater off and on to keep a regular temperature. This avoids the experience of walking into an overheated and stuffy room.

It also cuts your heating bills.

Oil Filled Radiator On All The Time 1

Tips When Leaving An Oil Filled Heater On

Here are my top tips:

  • Never leave clothes drying unattended near the heater
  • Keep the heater away from sofas and beds (i.e. furniture with flammable material)
  • Set to a low heat (a hot stuffy room is as bad as a cold one)
  • Make sure pets can’t bump and tip it over (most likely a large dog)
  • Ensure that the electrical cord can’t overheat (don’t run it beneath the heater)

If you also leave teenagers unattended in your house, drum these tips into them!

Many parents give their older teenage kids a checklist if they’re going to be alone in the house overnight.

I suggest you remind them either to plug out the heater at night or to be sure it’s running on the timer settings.

My Preferred Oil Filled Heaters

A thermostat is almost a standard in modern radiators, and I wouldn’t buy one without it.

Here’s a tip you mightn’t think of: if you’re going to move the heater from room to room, take a good look at the wheels.

If they’re really flimsy, you may knock your heater over when placing it back on the ground. I’ve broken the entire unit this way.

There are many good brands but you can’t go wrong with a DeLonghi. I usually want multiple heat settings and a timer. These options are on higher-end models, but the cost savings in electricity are worth it to me.

If you don’t intend to leave the heater unattended, then you don’t need a timer. You’ll usually find that models without this feature are cheaper.

If you are into the aesthetics of ceramic heaters, then Pelonis is a reliable brand. Their appliances are no longer manufactured in the U.S., but they still have repair facilities.

You’ll find more details in our article that checks if Pelonis is an American company.

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Dean Casey
About Dean Casey

Hi, I'm Dean Casey, the founder and chief editor of

With over 15 years of experience in the HVAC industry, my passion is helping homeowners achieve optimal comfort and energy efficiency in their living spaces. As a certified HVAC technician and consultant, I have developed a deep understanding of home heating systems, insulation, and energy-saving practices.

I started this blog to provide well-researched, practical advice to homeowners looking to improve their home's heating performance and reduce energy bills. Whether it's comprehensive guides, hands-on product reviews, or expert tips, my goal is to share valuable information with you, my readers.

I enjoy spending time with my family and exploring the great outdoors when I'm not busy writing and researching. I'm also an avid DIYer, always eager to tackle new home improvement projects and share my experiences with you.

If you have any questions or comments about home heating, please don't hesitate to reach out through the contact page on the website. I'm always happy to help!

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