Half Your House Has No Power: Likely Causes

When part of your house has no power, the most likely causes are a tripped breaker, a tripped GFCI outlet or a blown fuse. If those check out, the problem may be a broken connection on the wires that bring power into the house, at the meter or in the main panel. The utility is often the right first call.

First, is anything burning or getting brighter?

Check these before you start troubleshooting. If you see sparks, smoke or flames, get everyone out of the house and call 911 once you are outside. Don't go back in until the fire department says it is safe (Ready.gov).

If a power line is down outside, stay away from it and anything touching it. The Electrical Safety Foundation International (ESFI) says to move away from the line, never try to move it, and call 911 if someone is in contact with it (ESFI).

Call the utility right away if:

• Some lights are brighter than normal while others are dim. The Circuit Detective describes this as a sign of an open neutral, which can damage electronics, and recommends calling the power company (The Circuit Detective).
• Lights stay dim for a long time. Florida Power & Light says to turn off major appliances and call the utility right away when that happens (FPL).

If the panel, the floor near it or any outlets are wet, stay clear and don't touch them.

Why does half my house have no power?

Florida Power & Light says a partial outage may be caused by a tripped circuit breaker, a blown fuse, or a broken connector or wire at one of the service leads to the home (FPL). Here are the common causes, listed roughly from the most common and easiest to check to the least common.

1. A tripped breaker

A tripped breaker is the most common reason an outlet or room loses power, and the easiest to fix (This Old House). One breaker can feed several rooms, so one trip can look like a bigger outage than it is.

A tripped breaker doesn't always look fully off. Bob Vila says it often sits in the middle, between on and off (Bob Vila).

2. A tripped GFCI outlet

A GFCI outlet, the kind with test and reset buttons, can protect other outlets further down the same circuit. When it trips, those outlets go dead too (Bob Vila). That can knock out outlets in rooms that don't have a GFCI of their own. Check bathrooms, the kitchen, the garage, the basement and outdoor outlets. Our guide to a GFCI outlet that won't reset walks through this.

3. A blown fuse

Older homes may have a fuse box instead of breakers. A fuse doesn't trip; it melts. Bob Vila says a blown fuse may show residue or cracks in the glass (Bob Vila). Replacing fuses is something to ask an electrician about if you aren't sure of the right type and size.

4. An outlet controlled by a wall switch

Sometimes a "dead" room is really a switched outlet. Bob Vila suggests looking for a wall switch that controls the outlet and flipping it (Bob Vila). It is a simple check, and worth doing before anything else.

5. A broken service connection

Power comes into your home through service wires from the utility. Florida Power & Light lists a broken connector or wire at one of these service leads as a cause of partial outages (FPL). The Circuit Detective says that when about half the lights are dead, and may come on dimly at times, a main wire is likely open somewhere between the power company's line, the meter, the main breaker and the panel (The Circuit Detective).

Some of that equipment belongs to the utility and some belongs to you. You can't tell which from inside the house, and none of it is safe to touch. This is why the utility is often the right first call when breakers and GFCIs check out.

6. A main breaker or panel problem

The main breaker or the panel itself can fail. Fixr notes that burn marks on a panel point to a serious malfunction, and that some older panels, including Federal Pacific panels installed between 1950 and 1980, are known fire risks (Fixr). A panel problem can also show up as lights that flicker across the house or breakers that keep tripping.

7. A problem on the utility's side

Sometimes the problem is on the utility's lines, and the neighbors have it too. Florida Power & Light says to start by asking whether your neighbors are affected (FPL). If they are, report it to the utility.

Are your neighbors having the same problem?

This is the quickest way to narrow it down.

• Neighbors have the same problem: likely the utility. Report it to them.
• Only your house: Florida Power & Light says to check your circuit breakers and main breaker before calling an electrician or the utility (FPL).
• You live in an apartment or condo and only your unit is out: Florida Power & Light suggests calling your building's maintenance staff first (FPL).

What can I safely check myself?

You can do these steps without touching any wiring:

1. Check for safety first. No burning smell, no smoke, no water near the panel, no lights getting brighter.
2. Map what is out. Walk through the house and note which rooms, lights, outlets and appliances work and which don't.
3. Flip wall switches in dead rooms, in case an outlet is switched.
4. Reset GFCI outlets. Press reset on every GFCI you can find, including the garage, bathrooms and outdoors.
5. Check the panel. Open the panel door (not the cover behind it). Look for any breaker that is off or sitting in the middle. Push it fully off, then back on, once. Don't remove the panel cover.
6. Check the main breaker. It is usually the large breaker at the top of the panel. Florida Power & Light lists it among the things to check (FPL).
7. Ask your neighbors and check your utility's outage map.
8. Turn off big appliances in the meantime, especially if anything is running oddly.

If a breaker trips again right after you reset it, stop and leave it off.

What if resetting breakers doesn't help?

If your breakers and GFCIs look fine, or you reset them and the power is still out, the problem is likely upstream of your circuits. The Eugene Water & Electric Board, an Oregon utility, says that if your power doesn't come back on after resetting your breakers, you should turn off your main breaker and report a partial outage (Eugene Water & Electric Board). Your own utility may have different steps, so follow what they tell you when you call.

Many utilities let you report a partial outage separately from a full outage. PG&E lists partial power among the problems it investigates. It says a field worker checks the service and may leave a recording meter for a few days to collect voltage data. If the voltage turns out to be within its guidelines, the problem likely sits on the customer's side (PG&E).

Should I call the utility or an electrician?

Usually the utility first, then an electrician if the utility finds the problem on your side.

Call the utility if:

• the neighbors are out too;
• breakers and GFCIs look fine, but half the house is still dark;
• some lights are brighter than normal, or lights stay dim;
• you see damage to the wires running to your house or the meter.

Call an electrician if:

• the utility says its side is fine;
• a breaker trips again right after reset;
• the panel, a breaker or an outlet is warm, buzzing or discolored (see warm or buzzing outlet);
• your panel is an older brand known for problems;
• recent electrical work was done. Florida Power & Light suggests calling the electrician who did the work so they can correct any problem (FPL).

If you'd like to see the likely causes before you call, you can check my electrical. It asks a few questions and shows typical costs and what to ask a local company.

What should I do while I wait for help?

A few simple steps protect your home and your things while you wait for the utility or an electrician:

• Unplug sensitive electronics like TVs and computers in the rooms that still have power. The Circuit Detective notes that a main wiring fault can damage electronics (The Circuit Detective), and Florida Power & Light says computers and similar equipment are the most sensitive to changes in electricity (FPL).
• Turn off big appliances that are running on the side that still works.
• Don't run extension cords from working rooms to dead ones to keep things going. That can overload the circuits that still have power.
• Keep the panel door closed and the area around it clear and dry.

Can I use a generator?

Be careful. ESFI says never to connect a portable generator directly to household wiring, because power can feed back along the utility's lines and electrocute anyone working on them, including line crews. It says a permanent, high-powered generator should be installed by a licensed electrician to meet local code (ESFI). If you use a portable generator, ESFI says to plug appliances into it directly, use extension cords rated for the load, keep it dry, and never run it in an enclosed or partly enclosed space, because it can produce deadly carbon monoxide very quickly.

What will an electrician check?

A pro will usually:

• confirm which circuits are out and whether they share anything;
• check each breaker and the main breaker;
• check the panel for heat damage, loose connections and its brand and age;
• check the connections where the service wires enter the panel;
• measure voltage to see whether power is coming in properly on the service wires;
• work with the utility if the problem is at the meter or on the service lines.

How much does it cost to fix a partial power outage?

As of 2026, these are national ranges from cost guides. The cost depends a lot on where the problem is. If it is on the utility's side, ask the utility what, if anything, falls to you. We couldn't find a published cost for repairing a service lead connection.

• Electrician visit: typically $176 to $327 per visit (Fixr).
• Urgent night or weekend call: adds at least $100 to $200 to the standard fee (This Old House).
• Replacing a circuit breaker: $150 to $250 (Fixr).
• Replacing the main breaker: $200 to $300 with parts and labor (Fixr).
• Rewiring an electrical panel: $500 to $4,500 (Fixr).
• Replacing the electrical panel: $1,500 to $4,500, with a national average of $3,000 (Fixr).
• Permit for panel work: $50 to $300 or more (Fixr).
• Installing or replacing a GFCI outlet: $150 to $350 (Fixr).

What changes the price?

• Where the fault is. A tripped GFCI costs nothing to fix. A failed main breaker or panel is a bigger job.
• Who owns the equipment. Problems on the utility's side are handled by the utility.
• Timing. Nights, weekends and holidays usually cost more.
• Permits. Panel and main breaker work usually needs a permit and inspection.
• Your panel's age and brand. An older panel may need replacing rather than repairing.

Questions to ask

Ask the utility:

• Is the problem on your side of the meter or mine?
• Did you find a problem with the service wires or the meter?
• Is there anything I need to have fixed before you can restore full power?

Ask the electrician:

• What caused part of the house to lose power, and how did you confirm it?
• Is this the utility's problem or something inside my house?
• Does the main breaker or the panel need replacing, or can it be repaired?
• Will this need a permit?
• Is there a service-call fee, and does it go toward the repair?
• Can I get the price in writing before you start?
• Is your work guaranteed, and for how long?

How can I be ready next time?

• Label your breakers so you can find the right one quickly.
• Know where every GFCI outlet in your home is, and test them monthly, as the NFPA recommends (NFPA).
• Keep a flashlight near the panel.
• Save your utility's outage reporting details somewhere easy to find.
• Florida Power & Light suggests noting patterns: time of day, the weather, nearby construction, and any new appliances (FPL).

Half a house without power is unsettling, but the cause is often simple. When it isn't, the utility and an electrician can sort out whose side it is on. When you are ready, you can check my electrical to see likely causes and what to ask a local pro.