A space heater can be a convenient and efficient way to warm up a room, but it can be frustrating when it keeps turning off unexpectedly. Not only is it uncomfortable to be left in the cold, but it can also be a safety hazard if the space heater is not functioning properly.

In this article, we will explore the common problem of space heaters turning off unexpectedly and the importance of fixing the issue.

We will also provide a preview of the causes and solutions to be discussed, which include a damaged power cord, a dirty air filter, a faulty heating element or circuit board, an overloaded circuit, a weak power supply, and an uneven or soft surface.

By understanding these causes and solutions, homeowners can ensure that their space heater stays on and provides reliable warmth during the cold winter months.

Reasons For Space Heater Shut-off

Now, before you decide to lock horns with this issue and tackle it with some much-needed enthusiasm, you must first understand the collection of reasons as to why your heater switches off on its own repeatedly.

Check Your Power Supply

A faulty or inadequate power source is one of the root causes behind an uncompliant space heater. Most of the time, power sources are overlooked in favour of internal problems with the heater.

But sometimes, it is a simple case of a power socket being damaged or faulty and in need of dire repair. The average space heater uses up to 1500 Watts (W) or 1.5 kW (kilowatts) to operate and generate heat at optimal efficiency.

Although this number is highly dependent on the size of the space heater in concern, the power consumed by the device you own needs to be taken note of.

A space heater with a good power cord.

In some scenarios, the voltage (V) and wattage (W) of the space heater are not compatible with the electrical socket the heater is plugged into.

In other cases, the socket itself has most likely been damaged – lookout for any signs of charring or brownish ‘stains’ around the socket’s prong-shaped outlets. If you see any signs of discolouration, immediately unplug your space heater and consult an experienced electrician.

Simple human carelessness may also play a role in space heater issues. It is widespread for us to forget about plugging in a heater into an electrical socket before attempting to turn it on.

This is why you must always double-check if your space heater is plugged in, and most importantly, plugged incorrectly.

A heater that is plugged in loosely or improperly might contribute to its failure to start, let alone work. Always check the power cords of your heater for any signs of wear and tear damage or even fraying from time to time.

A damaged electrical cord is dangerous because it can present a shock hazard to anyone who accidentally comes into contact with it. This mainly caters towards pets or young children who tend to wrap a sticky little finger or brush a paw against an exposed electrical wire out of curiosity.

Do You Have A Blown Fuse?

Most modern space heaters come equipped with thermal fuses nestled carefully within the confines of their tough plastic casing.

A thermal fuse is a tiny device that protects the heater from overheating, and either blows out or melts to preserve the rest of the components located inside the heater from doing the same.

A standard thermal fuse usually has a rated voltage of 120 to 250 Volts (V) and a rated current of 10 to 15 amps (A).

A fuse

When a space heater malfunctions in any form, the thermal fuse located inside the heater is usually the first barrier of protection to prevent total equipment failure.

A blown fuse can also result in the inability of your space heater to be switched on at all.

If you suspect you have a blown thermal fuse inside your heater, you might first need to disassemble your heater using a set of proper tools such as adjustable pliers and screwdrivers with multiple heads to remove and detach any clips, fasteners or screws that hold pieces of your heater exterior and interior together.

Once the disassembly is complete, locate the thermal fuse and check it to see if it is burnt, melted, damaged or broken. A blown fuse will need to be replaced with a new fuse with the same specifications as its original compatriot.

Has Your Circuit Breaker Been Tripped?

Various households scattered around the globe use circuit breakers instead of fuses. The modern home usually comes equipped with a single grey box that houses a series of switches aligned neatly in rows, with a single primary breaker located at the very top.

The primary circuit breaker is the central control point for power to your home.

As for the smaller breakers, each switch corresponds to a dedicated electrical grid found in a specific area of your house, such as the bedroom, living room, kitchen and so on.

A circuit break

Sometimes, an entire breaker would be devoted to a specific power outlet that feeds a single appliance or an electric-based device.

If a breaker ‘trips’, this immediately cuts off the power supply to the electrical loop in the designated area under the breaker’s purview.

A tripped circuit is usually caused by a surge of electricity through the primary grid of the house – such as following a severe thunder or lightning storm.

The tripped breaker acts as a silent protector to prevent more electricity from flooding the grid and ruining any device or appliance that might be anchored to an electrical socket in a particular room or area.

If the circuit breaker trips, you will be unable to start your space heater. If you do manage to switch on your space heater, the device will most likely shut itself off again.

To draw electricity back into the room to supply power to your space heater, you must manually open the breaker box and flip the tripped breaker back to its original position.

If the breaker keeps ‘tripping’ or is burnt or damaged in any way, you will need the expertise of a proper electrician to replace the switch and reconnect the circuit.

What About Your Thermocouple?

You might need to check your thermocouple if you are unable to detect any problems with your thermal fuse or your circuit breakers.

Unlike a circuit breaker, which is located externally and coordinates the power supply to an entire house or building, a thermocouple is a small device located within the space heater itself.

A thermocouple

The thermocouple is responsible for shutting the device off but functions the same way a circuit breaker does.

If it ‘trips’ or detects an abnormal surge of electricity flowing through the space heater, it turns the device off every time you attempt to switch it back on and keeps it off until the internal problem can be located and corrected.

In most cases, the thermocouple is triggered into action when the space heater overheats. If this happens, you must give your heater sufficient time for it to cool down on its own before nipping the more profound issue in the bud.

Therefore, a thermocouple is merely a secondary warning system to another bigger problem that needs tending to.

Is Your Thermostat Working?

Just like a thermocouple, the thermostat is also located inside your space heater. Unlike its compatriot, however, a thermostat serves as a temperature regulator for the heating system and is usually set to your preference.

However, the thermostat can switch off automatically if the space heater overheats, or if the core temperature of the heater exceeds its manufacturer’s designated temperature range.

Although space heaters are incredibly sturdy by nature, much of the internal components and wiring are sensitive. They are unable to tolerate excessive heat beyond a specific range to operate safely.

A space heater that is left to overheat can either explode or set off in a fiery conflagration of melted elements and plastic. It is not worth taking a such risk, you may avoid it by ordering one.

Since space heaters have been responsible for the majority of the household fires in the United States every year, this can pose a severe health and safety risk.

Therefore, a melted, damaged, or broken thermostat might very well be the only thin lifeline that saves you and your loved ones from harm.

Sometimes, a thermostat might be jostled loose from its contact points, either as a defect of the product itself or if you knock over your heater by accident.

In this case, the space heater will keep shutting off unless you disassemble your heater and readjust the position of your thermostat back into its proper place.

Any damages acquired by the thermostat will require a replacement of the thermostat itself with a new one.

How About Your Auto-Safety Shut-Off Feature?

Old-fashioned space heaters did not put much priority into safety as compared to its modern-day successors.

With space heaters leading as the primary contributor of all household-related fires across the world as compared to other heating devices, the question of safety has become a significant issue that has been volleyed back and forth across boardroom tables for decades.

To combat this, the recent models of space heaters all come equipped with an auto-safety shut-off feature. What does this feature do?

It is simple. When a space heater tips over or overheats, or malfunctions in any form or manner, the tiny sensors wedged between the internal components of the space heater will immediately be set off to turn off the device.

If your space heater stands on an uneven or too-soft surface, the tip-over safety button gets triggered once the heater is tilted by more than 60% and that causes the automatic shutdown.

A tip over button of a safety heater

This button is released when the heater is tilt by more than 60%, triggering an automatic shutdown

You can test the stability of the space heater by checking for any wobbling or instability when gently nudged or by using a level tool to ensure the surface is flat.

If you identify an uneven or too soft surface, it is recommended to move the space heater to a flat, stable surface or use a solid base or stand to support it.

Is Your Air Filter Dirty?

A dirty or unclean air filter can also cause your space heater to shut off repeatedly without warning. An air filter that has been clogged with dust or debris will off exude a rather foul or unpleasant smell.

The odour alone is the first tell-tale sign that it is time to clean out your air filter.

Filthy air filters will often reduce the amount of airflow that oscillates through the heater, thus decreasing the internal capability of the device to cool itself down during and after use.

A heater that cannot cool down sufficiently will quickly overheat, and this will trigger the internal sensors to go off – thus causing a medley of other issues, including a failed thermostat and an activated built-in safety shut-off.

Therefore, it is highly recommended that you clean out your air filter every bimonthly before it even begins to produce any disgusting smells.

A dirt clogged air filter of a heater

Is Your Heating Element Working?

Most space heaters, especially electric-based devices, contain heating elements that help to preserve and generate heat inside the heater to produce warmth to a nearby area, person or even object.

In the case of oil-based space heaters, the heating element often has a greater surface area to produce heat as compared to a ceramic or mica thermic electric-based heater.

A nichrome based heating element

This works in your favour because these types of space heaters are less likely to pose a fire hazard since the oil reservoir is usually not heated up enough to trigger a fire.

Also, the heating element is completely enclosed and therefore, better protected and much safer to use.

However, if the heating element becomes cracked, damaged or discoloured in any way, it will malfunction and need to be repaired. A broken heating element usually reduces the surface area in which heat is produced.

This dramatically increases the risk of the heater overheating and therefore poses a safety risk towards its user.

Faulty heating elements will usually cause the heater to shut off, even if you attempt to turn the heater on multiple times.

A quick way to test and see if your heating elements are in mint condition is by switching on your heater and taking a quick peek at the items themselves.

A heated-up element at its optimal condition will glow bright orange, like the glowing embers of a dying flame. If the items do not burn or glow very faintly, there is a possibility that the elements might need to be replaced.

How a Damaged Power Cord Can Cause Your Space Heater to Shut Off

A damaged power cord can cause your space heater to shut off unexpectedly due to overheating.

When a power cord is damaged, it can create resistance in the damaged portion of the cord, which can cause the cord to heat up. Over time, this can cause the cord to melt or catch fire, leading to a safety hazard.

A damaged power cord of a space heater

Additionally, a damaged power cord can also cause electrical shock if touched.

Importance of Regularly Checking Your Power Cord

To prevent these safety hazards, it is important to regularly check your space heater’s power cord.

This ensures that the cord is in good condition and identifies any potential issues before they cause problems.

If you notice any visible damage, such as cuts or frayed wires, this is a clear indication that the cord is damaged and needs to be replaced.

How to Test Your Power Cord

To test your space heater’s power cord, you can use a multimeter to test for continuity and voltage.

If you’re not comfortable using a multimeter, you can also visually inspect the cord for any visible damage. Look for any cuts, frayed wires, or melted sections of the cord.

Solutions for Fixing or Replacing Your Power Cord

If your space heater’s power cord is damaged, it is important to have it fixed or replaced by a qualified electrician or professional repair service.

Attempting to fix the cord yourself can be dangerous and may lead to further damage or safety hazards.

It is also important to avoid using your space heater until the power cord is fixed or replaced to prevent further safety hazards.

If the power cord is in good condition, it is still important to regularly check it for any signs of damage or wear and tear. This can include inspecting the cord for any cuts or frayed wires, and avoiding bending or twisting the cord too tightly.

A Loose Contact In The Wall Outlet Resulted In The Space Heater Shutting Off

A loose contact in a wall outlet can cause a space heater to shut off unexpectedly, interrupting the flow of electricity and potentially increasing the risk of electrical shock or fire hazard.

It is important to regularly inspect wall outlets to ensure the safety of your space heater and identify any potential issues before they cause problems.

A loosely connected power plug in a wall socket.

You can test the wall outlet by using a voltage tester to check for proper voltage and visually inspecting the outlet for any visible damage or wear and tear.

If you identify a loose contact in the wall outlet, it is important to have it fixed or replaced by a qualified electrician to prevent any safety hazards.

Additionally, to avoid overloading the circuit with too many electrical devices, it is recommended to limit the number of devices plugged into a single outlet or circuit.


Thus, these are simply a fraction of a myriad of reasons behind the noncompliance of your space heater.

If you have looked through everything listed above and still encounter the same issue of your heater shutting off on its own repeatedly, then you either have a defective unit on your hands, or you might need to get a heater service member to take a look at your device.

Remember, if you do not feel comfortable or are not confident enough to tackle any of these problems alone, you can always request for the aid of someone with more experience than you. Always unplug your device before you begin to fiddle around with it or disassemble it – it is still better to be safe than sorry!