Can You Leave An Electric Fan Heater On All Night? (Explained)

I have occasionally fallen asleep leaving an electric fan heater on all night.

In general, I try to avoid doing this. But because it sometimes happens accidentally, I also take precautions.

This article has my best tips to follow if you’re likely to leave your appliance running overnight.

Is It Safe To Leave An Electric Fan Heater On Overnight?

Leaving an electric fan heater on all night will not be safe if:

  • the model doesn’t have an overheat safety cut-out mechanism
  • the unit is near flammable material
  • the unit is standing on an unstable surface
  • the plug or cord gets hot to the touch with prolonged use

Let’s get into these points in more detail.

Check if your model has overheat protection

Overheat protection means that the unit automatically shuts down if the temperature gets too high.

An undamaged appliance shouldn’t overheat in normal usage. This safety feature protects from electrical or hardware faults that override the thermostat settings.

But how do you know if your model has this feature? The unit is unlikely to have markings to tell you. And you probably don’t have the box that the appliance came in.

The easiest way to check is to look for an online sales page for your exact model.

Check the description or sections titled “specification” or “benefits”. You should see something like below:  (that’s the text for my cheap model).

Overheat safety cut-out protection

If you don’t see anything to suggest that the feature exists, then you likely have a very cheap unit. My advice is that you get rid of it and buy an appliance with this safety feature.

Make sure that the appliance isn’t near flammable material

Do you have a pile of unwashed clothes on the floor of your bedroom? Keep the heater well away from it.

Some people use these heaters to dry shoes or clothes. That’s not a problem as long as the unit is attended (and you’re awake).

Be sure not to use the heater for drying anything if you’re about to fall asleep.

We also recommend that you don’t leave the fan heater on all night in a tent (read the linked article for some tips).

Keep the appliance flat and on a stable surface

The marketing material for my model lists one of the benefits as being able to have it flat or upright. If you’re not sure what I mean by flat, the picture above shows the two positions:

If there’s a possibility that you could leave the appliance on overnight, my advice is to have the unit always in a flat position.

This is the most stable position. The unit is unlikely to fall off a table into an unsafe position.

Check the cord and plug periodically

One common problem with the cheaper appliances is that the plug overheats.

In some cases, people have reported that the plastic has melted with prolonged use.

Below is an example of an obvious problem. Be sure that you don’t let your plugs get to this point without noticing.

You should periodically touch the plug and cord to ensure that they aren’t getting too hot. They shouldn’t be uncomfortable to touch.

But what if you find that it is too hot? If the appliance is outside of the warranty, I would simply dispose of it.

Heater plug

Will A Fan Heater Get Damaged If Left On Overnight?

Take a look at this schematic diagram of the inner workings of a fan heater:

There is a metal heating element that is in a coil or mesh shape. Metal deteriorates over time, and the deterioration will increase under high temperatures.

With prolonged use, your appliance will eventually stop working. However, I wouldn’t expect that to happen within the warranty period.

If you are experiencing issues where you’re not actually getting heat, check out our article on reasons why your fan heater is only blowing cold air.

I’ve already mentioned issues with the plug and cord overheating. This can cause some deterioration of the plastic casing or fraying of the cord.

If you leave the heater on all night, you should check the plug and cord for any overheating issues.

How Much Will Overnight Usage Cost?

Have you woken up with the heater running? Wincing about the impact on your wallet?

It’s not difficult to calculate the cost of running your appliance for eight hours while you slept.

Let’s say that the heater is 2 KW.

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).

Eight hours will cost you:

                2 * 8 * 0.12 = $1.92

So, that’s a little under two dollars. It’s not a disaster. But you are still consuming more energy than you probably need.

If you want a more details, check out our full article on how much it costs to run an electric fan heater.

Keep the appliance flat and on a stable surface

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.

If you keep to the lower setting, you will cut your heating bills.

When I’ve accidentally fallen asleep with the appliance on, I tend to wake up with a dry mouth. That’s nothing that a long drink of cool water can’t fix!

We have a separate article on whether these fan heaters dry the air that explains the effects on the immediate environment.

The room is also uncomfortably stuffy. You may be wondering if the heater has burned the oxygen in the air. But you don’t need to worry about that (read the linked article to learn why).

I’ve also been asked by campers if these appliances are a good choice. Check out our article on whether you can use an electric fan heater in a tent.

Alternative Heaters For Overnight Use

In general, my advice is to avoid leaving your fan heater running overnight.

However, there is a different type of heater where the only disadvantage should be the similar costs I’ve mentioned above.

Check out our article on whether you can leave an electric oil-filled heater on all night. I explain why I’m far more positive about using these appliances in this way.

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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