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A heater that keeps tripping the breaker can be incredibly frustrating, especially when you need quick warmth during winter.
Before you call in a professional, or buy a new space heater, there are a few simple steps you can try to resolve the problem yourself. In this guide, I’ll walk you through the common causes and share practical tips to get your heater back on track.
Key takeaways
Common reasons why electric heater can be tripping breaker (includes fixes!)
Heaters are high-wattage appliances that can easily overload your circuit breaker.
Reason one: 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.
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 considered a safety cushion.
If the circuit breaker is too small, you can do one of the following:
Reason two: Too many other devices are 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.
In general, follow this guide I've created to determine whether your appliance needs a dedicated outlet based on the wattage, which will be included on the packaging.
Appliance Wattage | Is a dedicated outlet recommended? |
|---|---|
0 - 500 watts | No |
500 - 1000 watts | No (if shared with low powered devices) |
1000 - 1500 watts | Yes |
1500 - 2000 watts | Yes |
2000 - 2500 watts | Yes |
Above 2500 watts | Yes (and requires a 240 volt circuit) |
Reason three: The cable is heating up
A hot cable is usually a sign of a fault with the electrical wiring in your space heater or outlet. It is not normal, and should be addressed immediately. This is typically caused by:
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
Reason five: There is a short circuit in your heater
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:
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.
Related article: Best space heaters for large rooms
Reason six: 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:
Reason seven: The gauge of the extension cord is not sufficient
The Electrical Safety Foundation recommends never using an extension cord with a space heater.
This is because 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).
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
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.
Reason eight: 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
Reason nine: It’s overheating
Your space heater can overheat if you set it up incorrectly or over-run it.
If it gets too hot, the circuit breaker will trip to shut it down and prevent an accidental fire.
Solution
If none of the above work, contact a professional for their assessment.
Reason ten: The 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:
Replacing the thermostat in a simple heater is a straightforward DIY job:
Important note:
If you have a more complex smart thermostat or integrated heating system, I recommend you contact a professional.
Reason eleven: 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:
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. It's best to contact a licensed electrician.
