Can You Leave Electric Heaters on All Night? Benefits vs Risks

If you have an electric heater or are considering buying one, you may be wondering if you can use it to keep warm at night. There are both risks and benefits to doing so, and it's important that you're fully aware of them all before leaving your electric heater on overnight.

In this guide, you’ll find out whether you can leave electric heaters on overnight or not. We’ll also cover the risk and benefits of leaving your electric heater on overnight, as well as some alternatives. 

You might also useful to read our guide on everything you need to know about portable electric heaters. 

Understanding electric heaters

Before we look at the benefits and risks of leaving electric space heaters on all night, we need to delve into the different types and how they work.

Types of electric heaters

here are many different types of electric heaters, but we're going to focus on the four most popular options. These are fan heaters, oil heaters, ceramic heaters, and infrared heaters.

Fan heaters

If you're looking for a relatively cheap heater, then fan heaters might be the best choice for you. A fan heater simply uses a fan to push air over a heating element. The air heats up as it passes over the element, and this warm air then heats the room.

As they're fairly basic, they tend to be the most affordable option when compared to other modern space heaters.

Ceramic heaters

Ceramic heaters are also considered one of the most cost-effective types of electric heaters to run. They work by passing an electric current through a ceramic conductor to generate heat.

Ceramic is a great thermal conductor and provides heavy resistance to the current. This results in more energy being produced and creates an efficient system.

Infrared heaters

Infrared heaters work in a very different way from the other types of electric heaters. 

Instead of emitting warm air into the space, they use infrared rays to heat objects in the room. This allows an infrared heater to heat the room very quickly. Typically, it only takes a couple of minutes for the desired room temperature to be reached.

Oil heaters

Oil radiators or heaters work by heating a reservoir of thermal oil inside the unit with an electrical heating element. They're often fitted with an automatic shutoff feature which means they'll turn off automatically if you leave the heater unattended. This makes an oil-filled heater relatively safe to leave on at night.

How electric heaters work

So, you now know about the different types of electric space heaters, but how do electric heaters work in general?

Electric heaters work by heating a single room rather than by heating the whole house simultaneously as a central heating system does.

These heaters use two main methods to achieve this, which are radiation and convection. Convection heaters, like fan heaters, draw in air, heats it and then releases the hot air into the room.

Electric heaters that use radiation to emit warmth, like infrared heaters, rely on heating surfaces and people directly rather than through air volume.

Energy efficiency of electric heaters

An electric heater is essentially 100% efficient. This is because all of the electricity it uses is converted into heat. Due to this, electric heaters are much more energy-efficient than oil or gas central heating systems. Even A-rated boilers waste around 10% of the energy they use.

Benefits of leaving electric heaters on all night

There are many reasons why you might want to leave your space heater on overnight. Perhaps you're using a portable electric heater in an attic room that gets very cold at night. Or, maybe your boiler has broken, and you need to stay warm until it's fixed.

Whatever the reason, there are some benefits to keeping your space heater on during the night. Let's take a look at them.

Comfortable sleep temperature

The most obvious benefit of leaving your space heater on overnight is that it will keep the room at a comfortable temperature while you sleep. This is particularly beneficial if you sleep in a room that has poor insulation and doesn't retain heat very well.

In these types of rooms, the heat that accumulates during the day will be lost quickly, making it uncomfortable to sleep in at night.

Reduced risk of frozen pipes

Electric heaters are also very useful for gently heating pipes which prevents them from freezing. During winter, it can be beneficial to leave an electric heater on near pipes in the coldest areas of the house, such as the attic.

Electric heaters are ideal for this, as they usually have settings that allow you to control the level of heat they produce. Cold pipes need to be heated gently to avoid the risk of them bursting. So, space heaters are the perfect choice for this job.

Risks of leaving electric heaters on all night

While there are some benefits to leaving electric space heaters on all night, there are certain risks. In fact, the risks tend to outweigh the benefits. This is why it's generally not recommended that you leave your space heater on overnight.

Let's take a look at some examples of why this is the case.

Fire hazard

Fires are one of the biggest risks associated with leaving electric heaters on all night. If an electric heater has frayed wiring or malfunctions, then there is a high chance of it igniting.

Electric heaters also make the air in the room really dry by conducting a lot of heat. This makes it more likely for items in the room to catch fire if they malfunction.

Carbon monoxide poisoning

Most electric heaters don’t produce carbon monoxide. But if you have an electric propane heater, then there is a risk of carbon monoxide leakage. If you own a propane heater, you should definitely turn it off before you go to bed.

If you're using something like a fan or ceramic heater, there is no risk of carbon monoxide poisoning.

Higher electricity bills

Another downside of leaving your electric heater on all night are the running costs of an electric heater. Although off-peak tariffs can bring the costs down, these heaters are generally more expensive to run than gas, as the average cost of electricity is higher than gas. 

Alternatives to leaving electric heaters on all night

So, it's clear that there are more risks to leaving an electric space heater on all night than there are benefits. Fortunately, there are plenty of things you can do to prevent the need for leaving your heater on all night.

Use of blankets and layers

If the room you sleep in gets very cold at night, then the simplest way to stay warm is to use layers and blankets. Try sleeping in socks and a jumper, as well as your pyjamas. You can also layer two or more blankets on top of your duvet to keep the heat in.

This way, you shouldn't have to rely on using a space heater at night.

Programmable thermostats

Consider using an electric heater with a programmable thermostat. This means that you can program the heater to turn off at a certain time of night.

For example, let's say you usually go to bed at 10 pm. You could use the programmable thermostat to schedule the heater to turn itself off at 1 am. Doing so means that the room will be warm when you get into bed and as you fall asleep, but you won't have to worry about the risks associated with leaving the heater on all night.

Other heating options

If using layers and blankets isn't enough and you don't have access to a heater with a programmable thermostat, there are other heating options for you to try.

You could invest in an electric blanket or a heated mattress pad. Electric blankets lie on top of you and are heated using electricity. They often have timers so that they turn off automatically during the night. They don't require much electricity, making them a cost-effective option.

Heated mattress pads are similar but are placed underneath you. They're very effective at keeping you warm as you sleep.

Another option is to use a programmable thermostat for your central heating system. This means you can leave your radiators on when you go to bed and schedule them to turn off during the night.

In conclusion, electric space heaters are a great alternative to using a central heating system. However, they're best used for short periods, and it's generally not recommended that you leave them on overnight.

The risks of doing so outweigh the benefits, and you should try different ways of keeping warm at night instead. Consider investing in an electric blanket or wearing more layers of clothes in bed. These options eliminate the risks associated with leaving electric heaters on at night and will save you money on your electricity bills.

Frequently asked questions about electric heaters

What is the most cost-effective space heater?

Infrared heaters tend to be the most energy-efficient and cost-effective electric heaters to run. As they heat the room using infrared technology, every watt of energy is converted into usable heat. Therefore, no heat energy is lost through air escaping from the room.

Are oil-filled heaters energy-efficient?

Yes, oil electric heaters are considered to be very energy-efficient. In fact, they can be up to 99% energy-efficient. The reason for this is that all of the electric energy they use is converted into heat energy.

Why have electric heaters become so popular in the UK?

The main reason that electric heaters became so popular during the winter was the rising cost of gas. As gas prices soared, people in the UK looked for alternative ways to heat their homes other than using their central heating systems.