Electric heaters of any type are unsafe to leave running overnight because they carry a significant amount of risk. If a space heater falls over or becomes too hot from running for too long of a period of time, that can lead to a fast-moving fire that occurs while you are asleep and cannot act fast enough.
The best way to prevent a fire is to never leave a space heater running in a room unattended—that way, if anything does go wrong, you can take action quickly. If you have kids or pets that could knock a heater over or drape fabric on it, keep a very close eye on its operation.
The duration for which you can leave a space heater running depends on the time of day and your specific needs. During the Day: It's safe to leave your heater on for 6-8 hours if you're in the room. If you're busy or moving between rooms, consider using a timer to automatically shut it off after a few hours.
When You're Home: Feel free to run your space heater for as long as needed while you're in the room, keeping an eye on it for safety. Just ensure you're not leaving it unattended for too long, especially if you're moving to another area of the house.
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.
Space heaters usually consume between 400 and 1500 watts of electricity, and the majority use around 800-1000 watts. If an electric heater is used for 3 hours a day, then it could add up to 90 kWh of electricity to your monthly electricity bill, which could be an additional 5-10% of your total monthly electricity cost.
Electric heaters of any type are unsafe to leave running overnight because they carry a significant amount of risk.
Oil filled radiator space heaters are some of the safest on the market. 1500W is all the juice an outlet will provide (Roughly 5,000 btus).
Risk of Overheating: While modern heaters come with built-in safety features, there's always a small risk of overheating, especially if the heater is placed near flammable materials like curtains or blankets. Increased Electricity Usage: Running a heater throughout the night could lead to a spike in electricity usage.
Never leave a space heater unattended due to the risk of fire. Even if it's so cold you're afraid your pipes will freeze, you're better off unplugging the heater and leaving the water running (a stream about the size of a pencil lead should keep the pipes from freezing).
On average, you can expect to pay about 20 cents per hour to run a typical space heater that's 1,500 watts and can heat a standard room such as a home office or bedroom. If you run it for eight hours per day, you'll pay about $1.60 per day or $48 per month.
Never leave a space heater running for long periods of time, and especially not overnight; it is best to use them intermittently; depending on your situation, a suggested practice would be to turn it off/unplug it for 10 minutes every hour if you depend on its use for longer periods.
Electric space heaters can be used safely, but they are not the safest option for staying warm when the temperature drops. According to the National Fire Protection Association (NFPA), space heaters account for 43% of home heating fires and 85% of home heating deaths. They can also be a hazard in the workplace.
You don't want to waste money, but at the same time, you want to make sure your vehicle starts in the morning. One thing that most can agree on is that the maximum amount of time you should leave the engine block heater plugged in for is four hours.
Electric blankets should never be left unattended when turned on. But, can you leave an electric blanket on all night? We don't recommend sleeping with an electric blanket on all night and a thermostatic control or timer should be used if you choose to leave your electric blanket on.
Don't leave the heater unattended for long
Always remember to switch off and unplug the appliance before leaving the room or going to bed. Prolonged usage of heaters in closed rooms can be dangerous as it can create carbon monoxide poisoning which can cause headache, dizziness, nausea and weakness.
There have been many reports from doctors that sleeping with the heating on all night can cause your body to overheat much more quickly. The Sleep Charity advises that an ideal bedroom temperature is 16-18 degrees celsius. Temperatures over 24 degrees celsius can impact your sleep and cause restlessness.
Fire Hazards
Running a space heater overnight increases the risk of fire. If the unit is left unattended or placed too close to flammable materials, such as curtains or bedding, it can ignite and lead to a devastating fire.
It's a Fire Hazard
Leaving your electric heater on all day is also a fire hazard. If you are not home to monitor the heater, it could overheat and start a fire.
What is the safest heater to leave on overnight? While it's not recommended to leave any space heater on if you're not monitoring it, oil-filled, radiant space heaters are considered safer than ceramic convection (hot air) types, according to Roberson. Both of these options are safer than open-coil heaters.
Using a space heater 8 hours per day will use about 84 kilowatt-hours of electricity per week. It costs an average of $51.65 to run a space heater for a month and $258.26 to run for a year.
Example (you can use an electric heater running cost calculator below for different wattages/kWh prices): If we assume the price of electricity is $0.1319 per kWh, a 1,500-watt electric space heater will cost; $0.20 to run per hour. $4.80 to run per 24 hours (day). $11.20 to run per week (8h/day).
Old windows and drafty attic spaces with air leaks are common culprits behind unusually high electric bills. Invest in new energy-efficient windows with better seals and glass, and make sure attic and basement spaces have proper insulation. The investment today will save you money on your bill down the road.