Why Does My Electric Heater Keep Tripping the Breaker

Josh Mitchell

Written By

Josh Mitchell

Expert Reviewed By

Holly Curell

Last Updated On

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Key Takeaways

  • Make sure that the circuit is not overloading. The circuit can overload if more devices are connected to the same circuit and also if the amperage of the breaker is lower than that of the space heater.
  • Faults in your heater unit such as short circuits, broken elements, overheating can cause the circuit breaker to trip.
  • A bad circuit breaker can also be the cause of tripping. To remedy this try your space heater out on a different circuit and replace the breaker if necessary.

It can be so frustrating to have a heater that keeps tripping the electricity - especially in winter when you want fast heat.

I work with a variety of portable and fixed electrical heating systems and know the issues that can crop up.

In this guide, I'll explain the most common reasons for your space heater tripping and show you how to fix the problem quickly.

10 Common Reasons Why Electric Heater Can Be Tripping Breaker (Includes Fixes!)

Heaters are high-wattage appliances that can easily overload your circuit breaker.

However, they don't trip for no reason -  and you need to understand the issue before you can resolve it.

1. The Circuit is Not Designed to Handle The Amps

Every circuit in your home has a specified amperage (or current) it can handle.

If your heater draws more power than your circuit amperage, it causes an overload that trips the breaker.
Solution

Ensure your heater is on an appropriate circuit that can handle the amperage of the appliance.

You can check the amperage rating on the circuit breaker itself. Typically, domestic circuits are 15-20 amps, but your home will have some larger ones.[1]

Important Note:

Most circuits are designed to handle only 80% of their total amperage. Meaning a 20 amps breaker is designed to support a max of 16 amps. The rest is for safety.

If the circuit breaker is too small, you can do one of the following:

  • Move your space heater onto a larger electrical circuit that can handle more amps/voltage. You can also move your space heater onto a dedicated circuit so it can draw more power from one outlet.
  • Have your circuit upgraded by a professional electrician to increase the amperage so it can manage the electrical load of your space heaters.
  • Downsize your space heater to a model with fewer amps, voltage, and wattage that won't overload the circuit breakers. Unfortunately, a lower-wattage model may provide less heat.

TL;DR: If you use your heater on a circuit that is not designed to handle the rated amps of the space heater, it will naturally trip. 

2. Too Many Other Devices Sharing the Circuit

Even if your space heater is below the amperage of the circuit breaker, other devices can cause an overload.

If too much current is collectively drawn by home appliances, it can lead to tripped circuit breakers that stop the flow of electricity.
Solution

Move other appliances to different circuits away from the space heater.

Using a dedicated circuit and a different outlet for your heater will reduce the amps to a lower level and stop the space heater tripping your circuit breaker.

TL;DR: Space heaters are recommended to be used on a dedicated circuit. If too many devices are connected to the same circuit, then it can trip due to overload.

3. The Cable is Heating Up

A hot cable is usually a sign of a fault with the electrical wiring in your space heater. This is typically caused by:

  • damage to the cables or wires
  • corrosion due to moisture
  • loose connections caused by vibrations
  • undersized wires that are unable to handle the electrical energy

The wires get hot because there's too much resistance, and your space heater draws more electricity to compensate.

This overcurrent causes overheating and causes the circuit breaker to trip to prevent electrical fires.
Solution
  • Secure the connections: The first thing to do is straighten out the space heater power cable to help lower the resistance. Inspect the connections for any loose wires and use electrical tape to hold them in place and stop the current from tripping the breaker. Tighten any screws holding the wires in place.
  • Check for any visible damage. The cable needs to be replaced by an electrician if you notice any significant damage to the cable insulation or wires.
  • Check the wire gauge (size). The wire size needs to be the proper gauge for the draw of the heater. If the wires are too small, it can cause a dangerous short circuit. Have an electrician replace the wire with the appropriate size to stop the electric heater tripping breaker.

TL;DR: A bad wire cable that is heating up can overload and trip the circuit breaker.

4. There is a Short Circuit In Your Heater

A short circuit happens when electrical energy travels along the wrong route.[2] It can be caused by:

  • damaged wiring
  • insulation failure
  • manufacturing defects - particularly in the heating elements
A short circuit will usually cause a burning smell to come from your space heater.

Important Note:

In the event of a short circuit, your circuit breaker trips to prevent electrical fires from breaking out. Do not attempt to leave the breaker on if short circuit is the cause.

Solution

Short circuits can be dangerous, so it's important to deal with it quickly:

  • Start by unplugging your space heater and letting it cool. Wear gloves for protection against the heat.
  • Test the heat system on a different circuit and plug it into a different power outlet (ideally a dedicated circuit) to see if it trips the system. If it doesn't, there might be an issue with one outlet in your home - not the heater.
  • Inspect the wires for any damage, burns, or loose connections. I also recommend using a multimeter to test the different components.
  • Identify and replace any damaged parts. You can use electrical tape for loose connections, but I recommend contacting a technician to carry out any electrical repairs safely.

Electrical repair work can be expensive.

If you have a portable space heater, it may be more cost-effective to replace the appliance rather than try to fix it.

TL;DR: A short circuit is always a bad news. If your heater is bad and it is short circuited then the breaker will trip.

5. You Have a Broken Heating Element

The heating element is essential for warming the air. If it breaks, it can cause the space heater to short circuit and lead to electricity current spikes.

Eventually, this can cause the space heater to trip the circuit.

You will likely notice broken heating elements before they trip the circuit breakers because the space heater won't function properly, leaving you with hot and cold spots in your home.

Heating elements in a space heater can break due to natural wear and tear, physical damage, manufacturing defects, and overrunning.

Solution

Start by confirming that the heating element is the issue by opening the space heater to inspect the heating element for visible damage.

You can also use a multimeter to check the resistance of the heating elements and see if the readings align with the specs of your space heater.

If it is a broken heating element tripping your circuit breaker, it needs replacing.

If you have a more sophisticated heater, I recommend calling a professional because the repair work can become complicated, but this is an easy DIY job for simple space heaters:

  • Unplug the heater and let any residual heat dissipate.
  • Disassemble the outer housing to access the heating element.
  • Carefully pull out the heating element, using wire cutters to disconnect if needed.
  • Install your new heating element in the same position and reconnect the wires with electrical connectors.
  • Secure the wires in place with electrical tape.
  • Put the space heater back together and test it on the same circuit for 15-30 minutes.
  • Let it cool, then recheck that the wiring connections are still tight.

TL;DR: Broken heat elements can raise the amperage usage thus overloading and subsequently tripping the breaker. 

6. The Gauge of the Extension Cord is Not Sufficient

Using space heaters on extension cords can be a safety hazard if they aren't the correct size.

Extension cords have different sizes of wire, expressed as American Wire Gauge (AWG).[3]

Domestic extension cords are typically available as 10, 12, 14, 16, or 18 AWG; the smaller the AWG, the thicker the wire.

Thicker extension cords can carry more electricity, further.

If your extension cord has the wrong AWG, it can't handle the amperage your heater draws.

This can cause short circuits and create a potential fire hazard - so the circuit breaker will trip as a safety feature.

Solution
  • Plug your heater directly into a wall outlet and stop using an extension cord. Alternatively, upgrade to a heavier gauge extension cord that can handle more current. Ideally, it should exceed the amp draw of your space heater.

ACLAB Note:

I recommend limiting the number of appliances on one circuit on the extension when it's in use to prevent overcurrent and tripped circuit breakers.

Having a dedicated circuit is best for most heaters to stop them from tripping the circuits in your whole house.

TL;DR: Always size the cables appropriately particular when using the heater over an extension cord. A smaller than required wire gets hot which would eventually trip the breaker.

7. There is Too Much Stress On The Blower

Many electrical heaters use a fan to circulate warm air. Still, the blower can't function properly if the blowers are dirty or damaged.

Your heater will try to work harder, drawing more electrical current to compensate. This puts extra stress on the blower and can lead to it tripping the circuit breakers.

Solution
  • Unplug the heater from the power outlet and let it cool so you can safely handle it.
  • Open the heater to inspect the blower and ducts. Clean any dust, dirt, and debris to improve airflow and reduce the electrical resistance.
  • Clean or replace the dirty air filter and other internal components to help prevent an electrical overload.
  • Check the fan blades, blower mechanism, and air filter for damage, and replace any broken parts.
  • Plug it back in, reset the power, and ensure it works.

TL;DR: A dirty blower or a blower that is under stress draws in more electricity to work. This can lead to overload and tripping of your breaker.

8. It’s Overheating

Your space heater can overheat if you set it up incorrectly or overrun it.

If it gets too hot, the circuit breaker will trip to shut it down and prevent an accidental fire.
Solution
  • Remove obstructions around your heater to improve the airflow. The unit should have a full 24-36 inches of clearance in all directions in the room so it doesn’t overheat.
  • Remove any curtains, blankets, clothes, or fabrics covering the heater that can stop airflow to the unit. This will help to prevent the space heater from overheating and tripping the breaker.
  • Check the specifications to see if it has a max run time. Many space heaters will work 8-12 hours, but others will need to cool down more frequently, or the heat can cause them to trip. Limiting the run time will reduce the electrical demands and will stop it from overheating.

If none of the above work, contact a professional for their assessment.

TL;DR: If your heater does not have ample ventilation and if it is overheating due to obstructions, then that can cause the breaker to trip.

9. Heater’s Thermostat is Malfunctioning

A malfunctioning thermostat can cause your cycle on and off too frequently.

It's typically due to a mechanical fault, electrical issues, or dirt and debris in your heater.

It can also be a software issue in some modern space heaters.

A malfunctioning thermostat will strain the heating elements and electrical connections, leading to spikes and surges that can trip the breaker.

Solution

If you notice fluctuations in the heat generated from your appliance, it’s likely the thermostat. Here's how to fix it:

  • Power down your heater and let it cool. Make sure it's disconnected from the power outlet.
  • Open up your heater to check the wiring and clean any dirt and debris from the thermostat.
  • Use electrical tape to secure loose connections.
  • Update any software if you have a smart thermostat.
  • If your space heater is still tripping the breaker, replace the thermostat.

Replacing the thermostat in a simple heater is a straightforward DIY job:

  • Disconnect the wires.
  • Lift out the thermostat.
  • Reconnect the new one in the same place.
  • Seal it up.

Important Note:

If you have a more complex smart thermostat or integrated heating system, I recommend you contact a professional.

TL;DR: A malfunctioning thermostat can put stress on the heating element and may lead to electrical spikes resulting in your breaker tripping.

10. You Have a Malfunctioning Breaker

Circuit breakers are a safety precaution to protect you and your home by interrupting the power to electrical devices and preventing electrical fires.

However, your circuit breaker can malfunction if the electricity trips too frequently. This can lead to it tripping your electrics for no reason.

Solution

Replacing the circuit breaker without solving any underlying electrical issues won't fix anything, so start by making sure the issue is with the circuit breaker:

  • Look for any visible damage around the circuit breaker and take note of any burning smells.
  • Unplug your space heater from the power outlet and test an appliance with a lower load on the same circuit - if it works, the breaker isn't the issue. If the circuit breaker trips, it's probably the breaker, not the electrical load.

If your circuit breaker is the issue, you must hire a professional electrician to replace it safely because they must rule out any other causes of the circuit breaking.[4]

TL;DR: A bad breaker can be the culprit. Test your space heater on a different circuit. 


Commonly Asked Questions (FAQs)

What Size Breaker is Best for 1500-watt Electric Heaters?

A 15 amp circuit breaker is generally best for a 1500W electric heater.

Will 220V Heater Trip Breaker?

A 220-volt electric wall heater is unlikely to trip the breaker if it's properly sized.

However, it can still trip if the wattage is too high. Ensure it's plugged into a wall outlet that can handle the current it draws.

Is it Bad If a Breaker Keeps Tripping?

Yes, this is typically a sign that something is wrong with an appliance, and the circuit breaker is stopping the flow of electricity as a safety precaution.

Plug your heater into a different power outlet, reset it, and try it on a lower setting to see if the issue persists.

If it's still not working, check for short circuits or overloads - this may mean hiring a professional for help.

References: 

  1. https://www.wikihow.com/Determine-Amperage-of-Circuit-Breaker
  2. https://www.exploratorium.edu/snacks/short-circuit
  3. https://en.wikipedia.org/wiki/American_wire_gauge
  4. https://www.osha.gov/laws-regs/standardinterpretations/2001-11-19-0
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Josh Mitchell

Founder

Josh Mitchell
My name is Josh and I am obsessed with home appliances. From portable AC units to heaters and air purifiers, I enjoy testing, learning and using these devices to improve the air quality inside my family home.

My Favorite Home Appliance?

Midea U Shaped Window Air Conditioner

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