Is it safe to keep an electric fan on all night?

Electrical safety

I’m a qualified and time-served electrician and during the last two weeks of gloriously hot weather, I’ve had my trusty desktop fan firmly placed on my bedside cabinet, pointing directly at my head all night long. It’s the only way I can stay cool enough to get a good night sleep.

To be honest, it’s not just over the past two weeks either. My bedroom fan is a permanent feature and it keeps me cool as I sleep on many a stuffy night.

So why is it, that when you google “Is it safe to keep an electric fan on all night?” the majority of results advise not to do it?

Well, it’s one of those ‘Risk Assessment’ questions that doesn’t really have a straight forward answer. It’s a bit like asking “Is it safe to drive my car?”

On the one hand, you can sight factual truths like “cars can crash” and “roads can be dangerous” and “there were 1,580 reported road deaths in the UK 2019/20”, which logically conclude that it’s not safe to drive your car.

Then on the other hand, there’s the factual truth that most people who drive cars, do so perfectly safely and arrive at their destination without incident every single time.

Ultimately, it’s all about making rational ‘risk assessment’ decisions, and acknowledging that in a world of ‘liability’ and ‘ever increasing caution’, the people and institutions who issue official advise will always lean towards the ‘better-safe-than-sorry’ approach.

They would never put themselves in the position of saying... “It’s perfectly safe to keep your fan on all night”, for the same reasons they will never say… “It’s perfectly safe to drive your car”.

So where does that leave the average person, who just wants to know whether or not it’s OK to leave their fan on all night?

Well the truth is, you just have to use your own judgement, but I will try as best I can, to describe the factors that I take into account when I make my own decision.

1. Is the electric fan on its last legs?

Have a good look at the plug top, the lead, the body of the fan and the blades. If the plug top is cracked, damaged, scorched, loose, or in any way looks a bit dodgy, it’s probably not safe to use at any time. Likewise, if the lead is badly dented, cracked, split, frayed or damaged, then simply don’t use it at all.

Any dents, cracks, scorch marks or obvious damage to the body of the fan, increases the likelihood that the motor inside is not in perfect condition and it would be unwise to leave the fan running when unattended.

If the blades are loose or rattling or making contact with anything when spinning, this can put extra strain on the motor and again, it would be unwise to leave it running when unattended.

2. Does the motor run smoothly?

An electric fan motor in good condition will emit an even, low level, almost silent hum. In fact, the noise of the air being blown by the blades should almost drown-out the sound of the motor (that said, larger ‘floor-standing’ fan motors will be louder than smaller ‘desk-top fan’ motors).

If the motor seems excessively loud or emits an uneven or pulsing noise, then it’s likely that the motor is not in the best condition and could be prone to over-heating. It would not be wise to leave a dodgy-sounding fan running when unattended.

3. Does the fan smell?

An electric motor in good working order will not emit any noticeable smell whatsoever. If there is any kind of smell coming from your fan when it’s turned on, especially that very distinctive ‘electrical burning’ smell, then it’s time to by a new fan and most certainly not wise to have it running when unattended.

4. Are there any potential obstructions?

Is there anything near the fan that could potentially get tangled in the blades or obstruct it from turning? Anything that could prevent the fan from running freely could put extra strain on the motor and cause it to overheat.

Make sure your fan is far enough away from curtains or hanging materials, and if it has a side-to-side turning action, make surer it can turn freely without hitting against anything.

5. What’s the quality of manufacture?

Look for a label on the fan that has the CE Mark. This is normally on the underside of the base but could be anywhere, and is probably on a label that contains other information or marks.

The CE mark means that the manufacturer or importer affirms that the fan complies with relevant health, safety and environmental standards.

If an electric fan does not have a CE Mark, there’s no way of knowing whether or not it complies with safety standards and it would not be wise to leave such a fan running when unattended.

6. Is the fan plugged into an RCD Protected Circuit?

An RCD (Residual Current Device) is an electrical safety device that is capable of detecting common electrical faults and will automatically cut the power to the circuit if your fan becomes faulty, and will do so incredibly quickly, usually within 0.04 of a second.

RCDs can take many forms, but are usually situated in your main fuse box (consumer unit). They will normally be marked “RCD” or “RCBO” or “RCCB” and will always have a small button on them marked “T” or “Test”.

Push this “T” or “Test” button and see if the power to your fan has been tripped off. If it has, then you can be confident that your fan is plugged into an RCD protected circuit and will automatically trip off if it develops an electrical fault.

7. What’s the worst case scenario?

Ask yourself… “If the fan does overheat, and burst into flames, how much damage will it cause?”

Not foregoing all other considerations, there is additional comfort to be gained from ensuring that, if the worst ever did happen, your entire house won’t burn down.

Consider where your fan is positioned, and if it ever did catch fire, how likely it is to spread?

Having an electric fan close to combustible materials (books, papers, clothes, curtains, flammable liquids etc.) will increase the likelihood of any potential fire quickly spreading.

Think carefully about where your fan is positioned and what could happen in a worst case scenario.

8. Do you have smoke detectors?

A well placed and good quality smoke detector will quickly sound if an electric motor starts burning or combusts into flames. If you have a smoke detector nearby, and it’s in good working order, it can offer a little extra peace of mind.

So when I comfortably go off to sleep with the nice cooling breeze from my fan, I do so in the knowledge that it’s in good condition, it runs smoothly, it doesn’t smell, it’s clear from obstructions, it’s compliant with regulations and it’s protected by and RCD.

Admittedly, it sits on a wooden bedside cabinet, but flames spread upwards far quicker than they spread downwards, so I’m not overly concerned. It’s deliberately located far away from any other combustible materials, and my smoke detector is in good working order.

I’ll often turn my fan on an hour or so before going to bed, so that it’s had plenty of time to circulate fresh cool air, but when I leave the house I turn off. Even though, in my circumstance, I consider the risk to be negligible, there’s really no point in taking any risk at all if I’m not there to receive any benefit. Also, it would be a frivolous waste of electricity to keep it on needlessly.

Remember that electric motors are designed to turn and provided that they’re not overloaded, obstructed, worn or otherwise damaged, that’s exactly what they should do, without incident.

Of course there are always risks, as there are with everything. It’s down to us to make our own risk assessment, take all factors into consideration, judge the likelihood of anything bad happening and then decide for ourselves.

Electric fan safety