What you need to know before you start

Replacing a breaker switch means opening your electrical panel and swapping out the old breaker for a new one. This is different from resetting a tripped breaker — which you can do safely from outside the panel — because you will be working inside the panel itself where live electricity is present even when the main breaker is off. Most jurisdictions require a licensed electrician to do this work, and many building codes prohibit homeowners from opening the panel at all. Before you touch anything, check your local electrical code or call your city's building department to confirm whether you can legally do this yourself.

If your local code does allow homeowner work, you will need to turn off the main breaker, use a non-contact voltage tester to confirm the panel is de-energized, and work methodically to avoid contact with live parts. If you are uncertain at any point, stop and call a licensed electrician. An error inside the panel can cause electrocution or fire.

Key Takeaways

  • Most jurisdictions require a licensed electrician to replace a breaker; check your local building code before proceeding.
  • You must turn off the main breaker and use a non-contact voltage tester to confirm the panel is de-energized before opening it.
  • The breaker you buy must match the amperage and type of the one you are replacing — usually 15, 20, 30, or 50 amps, and either single-pole or double-pole.
  • The cost of a new breaker is typically $15 to $50, but labor from a licensed electrician usually runs $150 to $300 for the replacement.

Identifying the breaker you need to replace

Open your electrical panel and locate the breaker that is tripped or faulty. A tripped breaker will be in the middle position (not fully on or off) or will have a red or orange indicator visible. If the breaker keeps tripping, do not simply reset it and move on — something is drawing too much power on that circuit, and resetting it repeatedly is a fire hazard.

Write down the amperage and type of the breaker. Look at the number printed on the switch itself — this is the amperage, usually 15, 20, 30, or 50 amps. Also note whether it is a single-pole breaker (controls one circuit, takes up one slot) or a double-pole breaker (controls two circuits, takes up two slots). You must buy an exact replacement. Do not guess at the amperage or type. Take a photo of the breaker and the panel label if you are unsure.

Buy the replacement breaker from an electrical supply store or home center. Bring the photo or the old breaker with you. Breakers are brand-specific — a Square D breaker will not fit a Siemens panel — so you must match the panel manufacturer as well. The panel label is usually on the inside of the door.

Turning off power and testing the panel

Locate the main breaker at the top or bottom of the panel — it is usually larger than the other breakers and controls all power to the house. Switch it to the off position. This cuts power to the individual breakers but does not fully de-energize the panel; the main lugs (the large terminals where power enters the panel) remain live.

Use a non-contact voltage tester on the breaker you are about to remove. Hold the tester near the breaker switch and the bus bar (the metal rail it connects to). If the tester beeps or lights up, power is still present and you must stop. Do not proceed. If the tester shows no voltage, test it again on a known live circuit (like an outlet or light switch in your house) to confirm the tester is working. Then test the panel again.

Even with the main breaker off, assume the panel is dangerous. Work quickly, keep one hand in your pocket or behind your back to avoid creating a path across your chest if you accidentally touch a live part, and do not touch anything except the breaker you are replacing.

Removing the old breaker

Locate the wire connected to the breaker you are removing. It is usually a black or red wire screwed into the terminal on the breaker. Loosen the terminal screw and pull the wire free. Keep track of which wire goes where — take a photo before you disconnect it if you are unsure.

The breaker itself is held in place by a clip or latch at the bottom. Push or pull this clip (the direction depends on the manufacturer) to release the breaker from the bus bar. The breaker will slide out toward you. Set it aside.

Inspect the slot where the breaker was. If you see corrosion, burn marks, or melted plastic, the panel itself may be damaged and you should stop and call an electrician. Do not install a new breaker in a damaged slot.

Installing the new breaker

Take the new breaker and align it with the empty slot. The breaker has a clip or latch at the bottom that must engage with the bus bar. Push the breaker firmly into the slot until you hear or feel a click. The breaker should sit flush with the others and not rock or move.

Loosen the terminal screw on the new breaker. Insert the wire you removed from the old breaker into the terminal and tighten the screw firmly. The wire should not move if you pull on it gently. Do not over-tighten; you are looking for snug, not maximum force.

Double-check that the breaker is fully seated and the wire is secure. Close the panel door. Turn the main breaker back on. The new breaker should be in the off position; switch it to the on position. Test the circuit by plugging in a lamp or device to confirm power is flowing.

When to call a licensed electrician instead

Call an electrician if your local code requires it, if you are not certain the panel is de-energized, if the panel shows signs of damage or corrosion, if the breaker keeps tripping immediately after replacement, or if you are uncomfortable working inside the panel at any point. An electrician can also diagnose why the breaker was tripping in the first place — often a sign of an overloaded circuit or a short in the wiring.

If you live in a rental, contact your landlord or property manager before attempting any work. Most leases prohibit tenants from opening the electrical panel, and the landlord is responsible for repairs anyway.

Frequently Asked Questions

What is the difference between resetting a breaker and replacing it?

Resetting means flipping the switch back to on after it has tripped. You can do this safely from outside the panel. Replacing means removing the old breaker and installing a new one, which requires opening the panel and working with live electrical components. If a breaker trips once, reset it. If it keeps tripping, the circuit has a problem and resetting it repeatedly is unsafe — call an electrician to diagnose the issue.

Can I use a different amperage breaker than the original?

No. The amperage of the breaker must match the wire gauge of the circuit it protects. Using a higher amperage breaker can allow too much current to flow through undersized wire, causing overheating and fire. Always use the exact amperage of the original breaker.

How long does it take to replace a breaker?

If you are experienced and the panel is accessible, 15 to 30 minutes. If you are doing it for the first time, allow an hour and work slowly. A licensed electrician typically charges $150 to $300 for the job, including diagnosis and testing.

What if the breaker slot is damaged or corroded?

Stop and call an electrician. A damaged slot means the panel itself needs repair, and installing a new breaker in a bad slot is unsafe. This is not a do-it-yourself fix.

Do I need a permit to replace a breaker?

Requirements vary by location. Some jurisdictions require a permit and inspection for any panel work; others allow homeowners to do it without a permit. Call your local building department or check their website before you start. If a permit is required and you skip it, you may have trouble selling the house later.