Informational Guide

Why Do Space Heaters Keep Shutting Off

I love space heaters but not when they keep shutting off. Learn why this can occur and how to easily fix it yourself.

by Josh M

Space Heater with a Remote Control SampleSpace heaters are powerful heating tools that work well to heat small rooms quickly.

They work well in small spaces like apartments, or you can get specialized space heaters for larger rooms.

The only problem is that if you run them for longer periods, they can start to switch off, which makes them completely ineffective.

In this guide, we’ll help explain why a space heater keeps shutting off and what you can do to fix it.

A properly functioning space heater shouldn’t shut off on its own, and it’s usually a sign that something is wrong with the unit. The most common issue is a blockage of some sort within the machine, but other issues can stop your space heater from working properly. Here’s a quick breakdown of the key issues and what you can do to sort them:

Defective Or Insufficient Power Source

Space heaters rely on a steady source of power to operate, and on average, they need about 1500 watts to run. This is more than you think, so if you have a dodgy or unreliable power source, then it will cause it to cut out while it’s on.

Look for browning stains on the heater’s prongs, as this is a tell-tale sign of damage in your plug socket. Rather than trying to sort this yourself, you need to consult a professional electrician because it can be dangerous to tamper with your home’s electrics yourself.

Dirty Air Filter

The most common reason for your space heater shutting off is a dirty and blocked air filter. This prevents ventilation and cooling air from being drawn into your device to the heating elements within.

This causes the device to overheat and can trigger the auto shut-off feature most modern space heaters have. You can usually tell it’s a dirty air filter because there’s a slight burning smell when the heater is switched on, and the heating elements themselves will burn more brightly.

To remedy this problem, you first need to switch the heater off and let it completely cool down. Then wipe down the heater with a cloth to remove any visible dust. You can then spray the filter with compressed air to remove any built-up dirt or grime that can build up over time.

Next, use your vacuum to suck up any remaining dirt from the filter. This should completely clean the filter, but bear in mind that some space heaters have removable filters, so you’ll need to slide it out of the device first.

Faulty Heating Elements

Your heating elements within the space heater can be faulty, which will mean they aren’t regulating the temperature properly within the device. This, in turn, can trigger the automatic shut-off feature and stop it from working continuously.

The best thing to do is to see if your warranty still covers your device and look to get a replacement. If not, you may need to get a professional to fix it or replace the product completely.

Blown Fuse

You may find that the space heater is turning off or can even cause the main circuit to trip, which will switch off other devices in your home. This can be caused because the circuit is overloaded, and you have too many devices which the circuit can’t handle.

You should first try to unplug some of these and see if it starts working again when you switch the main breaker back on.

If the problem persists, then you may have a blown fuse. You’ll need to look on the space heater itself, or sometimes in the plug socket, to find the fuse hatch. Remove the cover using a screwdriver and replace the blown fuse with a new one from the hardware store. Make sure you get the right size fuse; this should be clearly labeled on the heater.

Bad Thermocouple

Gas Space Heater Replacement ThermocoupleThermocouples are used in gas heaters as a safety precaution to prevent any excess gas from being emitted from the device. The thermocouple controls the flow of gas, only allowing it to flow into the heater if there is a heat source to burn it up.

If your thermocouple has become damaged or faulty, then it can trigger the shut-off, so your heater shuts off.

If you notice your flame is on but the gas supply keeps shutting off, then you will need to replace it. Thermocouples are generally quite easy to replace, and you can find them in most hardware stores.

You will need to turn off the gas supply completely, remove both ends of the thermocouple, and attach the new one. Make sure everything is secure before turning it back on.

Broken Thermostat

If your thermostat is broken, it will mean it’s sending a signal to your space heater that the appropriate temperature has been reached and that it should shut off. This is frustrating, and you will need to experiment by setting your thermostat on a number of different settings to see if it stays on or shut off.

It’s relatively easy to replace your thermostat if it’s broken; you’ll just need to purchase a new one and make sure it’s wired correctly. Most thermostats come with instructions on how to do this. Just make sure your power is turned off before you start the work.

Malfunctioning Auto-Safety Shut-Off Feature

Most space heaters have an auto shut-off feature triggered when they overheat or when they tip over. However, if your device is on slightly uneven ground, it may activate this feature, or if there’s a malfunction in the machine, this can be triggered too frequently.

Start by moving the device, so it’s on perfectly level ground. Ensure that your device is clean and not overheating and that no other factors are causing it to shut off. If the problem persists, you may need to replace the unit or have a professional replace the auto shut-off system.

Short Cycling

Short cycling is where your heater thinks it’s done the job, and it’s switching itself off very quickly. This can be caused by any of the reasons above, but if you can’t seem to solve it, then you should consult a professional for help.

How To Prevent The Space Heater To Keep Shutting Off?

We’ve talked through some of the ways you can troubleshoot the most common problems, but what’s the best way to fully maintain your device? Well, it all comes down to regular maintenance and keeping a close eye on the overall condition of your space heater.

Safety is the number 1 priority when it comes to space heaters, so you should carefully examine it before you switch it on. Every month you should also open it up to check on the inside of the device and make sure everything is where it should be.

There are a few key things you should look out for:

  • Electrical Issues
    Check the cords coming from the space heater as these contain your wires. If there are any exposed wires, this can be a safety risk as they could spark and cause a fire. If you notice anything out of the ordinary, you should replace the wiring as soon as possible.
  • Plug
    Check your plug for any visible signs of damage, as this could indicate there’s an issue with the power source. Remember, space heaters should never be plugged into extensions or multi-plugs; they should only be plugged directly into the wall.
  • Remove Flammables
    Before you switch it on, you should always remove any flammables around the space heater. This will help protect your device and limit any risk of a home fire.
  • Check The Surface
    Ensure your space heater is on a flat, level surface; otherwise, you may trigger the automatic tilt shut-off feature.
  • Check For Dirt
    The number 1 cause of space heaters shutting off is blockages. Dirt and debris will block the machine, so look for any dust or other debris that needs to be wiped from the device.

By taking the time to properly examine and maintain your machine, you will not only stop it from shutting off, but you’ll also help extend the overall life of the heater by ensuring it keeps functioning correctly for longer.

Space Heater Shut Down Prevention Tips

Other Issues of Space Heaters

Your space heater shutting off can be a real issue, but there are some other issues that can happen alongside this and stop your space heater from being effective:

Cannot Be Switched On

If your space heater won’t switch on, it’s most likely an issue with the power source. You’ll need to check to ensure everything is connected correctly and that your device is plugged in directly to the wall, not through an extension cord.

Check the socket by connecting other devices and make sure power is flowing correctly. Finally, check the fuses to see if they need to be replaced. If your device still doesn’t switch on, you’ll need to contact the manufacturer or a professional for help.

Not Giving Off Any Heat

If your device is turning on but not generating any heat, it’s most likely a problem with the heating coil. You’ll need to open up the heater and remove the heating coil to see if there’s any visible damage or other issues.

If you can’t get the heating coil hot or glowing, you will need to contact the manufacturer or look to replace the coil, but this can be slightly complicated, so you might need professional help.

How To Fix a Broken Space Heaters (Troubleshooting Guide)

If your space heater won’t start or isn’t working correctly, you need to find out the problem. You can do this by testing different sections of the space heater until you find the problem and resolve it. Here are the steps you should follow:

Firstly, you should get the following equipment:

  • Rubber gloves
  • Screwdriver
  • Pliers
  1. Switch Off The Space Heater
    Start by turning off the space heater and leave it for at least an hour, so it’s fully cool. Wait until the exterior casing is completely cool before you look to open it up.
  2. Remove Electrical Leads
    Use your pliers to pull out the knob and remove the electrical leads one by one. Mark each of them with colored tape, so you know where they’ll need to be reattached.
  3. Remove Thermostat
    Use the pliers to loosen the retaining nut holding the thermostat. This will allow you to gently remove this from the heater.
  4. Disconnect The Power Switch
    Remove any clips or screws around the power switch and gently remove the wires around it. Make sure you mark them all so you can rewire them as needed.
  5. Check The Components
    Now you’ve successfully separated the main components of an electric space heater, you can examine them to see if there’s any visible damage. If anything is broken or needs to be replaced, you can do it now and then replace all the parts within the space heater.
  6. Reassemble
    Reassemble your space heater piece by piece, making sure to replace any faulty parts. You can do this section by section if you still think there’s an issue.
  7. Clean The Heater
    Wipe down the heater and clean the filter to remove any dirt or debris that might be impacting the heater.
  8. Turn It On
    Turn the power supply back on and test the heater. If it’s all working correctly, then your job is done. If not, then the next step is to consult a professional or replace the heater.
Space Heater Wiring Diagram for Troubleshooting

People Also Ask (FAQ)

Is my space heater supposed to smell?

No, but it is fairly normal to have a slight burning dust smell when it first turns on. If this persists, it could mean there’s an issue or blockage within the space heater.

Why does my space heater smell like it’s burning?

This is probably due to a blockage in the air filter, and you should look to clean it as soon as possible. However, this could also be due to a fault in the electrics or the heating coil, so you should turn the heater off and examine the components.

Why does my electric heater smell like rotten eggs?

This could indicate a natural gas leak from the space heater, and you need to take action right away. Turn off the device fully and make sure the natural gas supply is no longer flowing. Check all your pipes and connections and, if needed, ask a professional to look over the device.

Can an electric heater make you sick?

Electric heaters shouldn’t make you sick, but they can dry the air out, making some people feel a bit lightheaded or uncomfortable.

Do space heaters use a lot of electricity?

Space heaters can use a lot of electricity and can be expensive to run compared to central heating. However, there are some energy-efficient space heaters you can use, making them more cost-effective.


Space heaters are a fast and effective way to heat a small space during the cold months. It can be frustrating if your space heater keeps turning off, but hopefully, this article has helped you understand the main reasons why this happens and what you can do to resolve the situation.

Last Updated on November 21, 2021

Josh M

My name is Josh and I am obsessed with the HVAC industry. I created this website to help HVAC techs of all levels get the best out of their heating & cooling systems. I have spent thousands of hours studying air conditioners, heaters and home air products so you can learn & buy with confidence. Learn more about the team here.