Half the House Has No Power: What It Means and What to Do

When a room or two goes dead while the rest of the house works, the cause is usually a tripped breaker or GFCI. When half the house goes dark at once, or the dryer, electric range, central AC, or electric water heater quits, the problem may be on the wires that bring power in: FPL says a damaged service lead, such as a broken connector or wire, can leave only the 120-volt outlets working, while 240-volt appliances may not run until it's repaired. This page calls that a lost leg. Lights that brighten in some rooms while others dim are the most urgent case.

If the whole street is dark, see what to do when the power goes out. If one breaker keeps tripping, see breaker keeps tripping, and if a bathroom, kitchen, or garage outlet is dead, see GFCI won't reset.

Most Likely Causes

1. A tripped breaker. The dead outlets and lights cluster in a room or two, and the range and dryer still work. The ESFi notes a tripped handle can rest close to ON, so look closely. Big appliances have their own breakers: Whirlpool says an electric dryer uses two, one for the drum motor and one for the heating element, and if one trips, the dryer may not heat.
2. A tripped GFCI. The ESFi says a GFCI outlet protects everything in that outlet and downstream on the circuit, so one trip can kill several outlets with no breaker tripped; a GFCI breaker protects the whole circuit.
3. A problem on the street. If the neighbors are dark or dim too, the outage is the utility's. A quick blink is different: EWEB, the Eugene, Oregon, utility, calls flickering lights a complete, momentary outage, often from a tree or branch contacting a line. Con Edison asks customers to report dim, partial, or flickering lights even if they think a neighbor already has.
4. A lost leg on the incoming service. Half the rooms die at once with nothing tripped, or the range, dryer, water heater, or AC won't run. It can follow a storm: FPL lists tree limbs on the line serving a home and blown fuses on its transformer among the reasons one house loses power when its neighbors don't, and Santee Cooper, South Carolina's public power utility, says storm damage can affect individual services and transformers. If a service lead is the problem, FPL says its crews repair it.
5. Lights that get brighter and dimmer. EWEB says that if lights "suddenly get really bright in part of the house and dim in another part," you might be experiencing partial power. FPL says swings of more than six volts from the 120-volt standard can make lights dim or brighten, and that unprotected computers and other sensitive electronics are susceptible to damage from power quality disturbances. Eaton's Type CH combination arc-fault and ground-fault breakers trip at 160 volts or more, and Eaton's instruction for that trip is to "investigate utility power for imbalance in the phases or loss of neutral." The CPSC adds that lights flickering when the wind blows can come from bad contacts where the service entrance cable meets the service drop. Treat all of these as urgent.

Lights that dip for a moment when a big appliance starts are a separate, less urgent pattern. FPL suggests checking whether sensitive equipment shares a circuit with large appliances or motors, and the ESFi lists lights that often flicker or dim momentarily among the reasons to have a qualified electrician inspect the house.

What You Can Do Safely

If any lights are brighter than normal, do steps 2 and 6 first.

1. Ask the neighbors. SCE says checking whether they have power helps tell whether the cause is inside or outside your home. If they're out too, see our outage guide.
2. Protect the electronics. SCE says to unplug computers, televisions, air conditioners, and other large appliances to prevent damage, and FPL says that when lights stay dim for an extended period, turn off major appliances and call. Con Edison suggests leaving one lamp on so you'll know when power is back.
3. Reset a tripped breaker once. Follow our breaker guide: SCE says to turn off the lights and unplug appliances in the affected rooms first. Open only the panel's hinged door, find the handle in the middle or at OFF, and push it fully OFF, then ON. Boston's emergency management office says never to touch a breaker with wet hands or while standing on a wet surface. If it trips again, leave it OFF and call an electrician. Check the breakers for the range, dryer, water heater, and AC, and any main breaker or disconnect outside near the meter (Santee Cooper, FPL); FPL says not to touch the meter itself. The Red Cross is the most cautious: in an outage, it advises having an electrician inspect tripped breakers before turning them on. If you smell burning or hear buzzing at the panel, don't touch it; the CPSC lists both among electrical warning signs.
4. Press RESET on every GFCI, with dry hands, after unplugging what's on it, as our GFCI guide describes. The CPSC says to test every GFCI after a power failure.
5. Run the 240-volt test. For power in only part of the house, Santee Cooper's next step after the breakers is to check whether the oven or dryer, both 240-volt appliances, work properly: turn on an oven element, or run the dryer on heat for a minute. If either doesn't, it advises turning off the power at the main breaker to prevent further damage to appliances and equipment. If both work and a breaker has tripped, it says the problem is inside the house and needs an electrician. With a gas range and dryer, try the electric water heater or central AC, which FPL lists among 240-volt appliances.
6. Call the utility's outage or emergency line and say "partial power." Santee Cooper asks callers to describe the problem, such as partial power or dim or flickering lights, and anything else, like a downed line or loud noises. Con Edison and Cleveland Public Power ask for a call right away about dim, partial, or flickering lights.

Should you switch off the main? Utilities differ. FPL says it is safe to use the outlets that still work while you wait for an electrician or its crew. EWEB says that if power doesn't come back after you reset breakers, turn off the main breaker and call, and Santee Cooper says the same when the 240-volt test fails. If any lights are brighter than normal, take the cautious route: with dry hands and a dry floor, switch the main OFF (our emergency shutoffs guide shows where it is) and call.

Utility or Electrician: Who Fixes What

The dividing line is the connection point on your house. Eversource maintains the poles and wires up to the connection point just after the service drop, plus the meter; the weatherhead, the meter socket, and the wires into the house are the owner's, and Eversource says a licensed electrician repairs them. Dominion Energy says it repairs service only up to the point of connection, and storm damage from the weatherhead down to the meter base must be fixed by an electrician before it can reconnect power. FPL says electricians may not work on its lines from the pole or transformer to the house.

An inspection may come before power does: after an electrician's repair, Eversource says to contact the town's wire inspector, and Santee Cooper waits to hear from the building authority. Don't open the meter, the panel's inner cover, or a junction box to hunt for the problem; our open junction box guide draws the same line.

When to Call a Pro

Call the utility's outage or emergency line now for:

• Half the house dead with nothing tripped, or 240-volt appliances that won't run (FPL, Santee Cooper).
• Lights brighter than normal anywhere, or lights that stay dim (EWEB, FPL).
• Lights that flicker when the wind blows, or sparking at the wires to the house (CPSC).
• A tree or limb on or leaning against the service wires (FPL, Con Edison). For a line on the ground, call 911 first.

Call a licensed electrician for a breaker that trips again (SCE); a burning smell or buzzing at the panel, which the CPSC lists among warning signs; storm damage to the weatherhead or meter socket (Eversource, Dominion Energy); a 240-volt test that passes while a breaker has tripped (Santee Cooper); or damage a utility crew finds on your side, which Santee Cooper says the owner must have a licensed electrician repair. In a house wired between 1965 and the mid-1970s, the CPSC counts flickering lights and circuits that don't work among the signs of failing aluminum wiring connections; see our aluminum wiring guide.

Running a Generator While You Wait

If you bring out a generator, the CPSC's rules apply: outdoors only, at least 20 feet from the house, with the exhaust directed away from the home and other buildings. Never plug it into a wall outlet: the CPSC says that backfeeding can electrocute utility workers and neighbors served by the same transformer, and Santee Cooper warns it can send electricity toward line workers, possibly the crew fixing your service. Plug appliances into the generator itself; OSHA says connecting one to a home's wiring takes a transfer switch installed by a qualified electrician. See our generator guide and generator size calculator.

Prevent It

• Map the panel. The ESFi suggests a circuit map: switch off one circuit at a time and note every outlet and fixture it serves.
• Test GFCIs monthly and after every major electrical storm (ESFi) or power failure (CPSC).
• Watch the service wires. The CPSC warns that trees or parts of the house rubbing against the service equipment can cause damage that leads to sparking, and Con Edison asks customers to report trees leaning against wires or poles.
• Use surge protectors for electronics, as the Red Cross and Con Edison recommend.
• Get an inspection if the house is 40 or more years old, you're its new owner, or the lights often flicker or dim; the ESFi lists all three as reasons to consider one.

Frequently Asked Questions

Why does half my house have no power when no breaker tripped?

Check the GFCIs and look for a breaker resting near ON. If neither, run Santee Cooper's 240-volt test: an oven or dryer that won't work suggests the incoming service, which FPL says can leave only 120-volt outlets working. Call the utility.

Why does my dryer tumble but not heat?

Whirlpool says one of an electric dryer's two breakers runs the motor and the other the heating element, so if one trips, the drum can turn while the dryer doesn't heat. Reset that breaker once. If the range, water heater, or AC is out too, suspect a lost leg and call the utility.

Why are some lights brighter and others dimmer?

Treat it as urgent: EWEB calls it partial power, and Eaton points to imbalance or a loss of neutral on the utility power when its breakers trip on high voltage. Unplug electronics, switch off the main if you can do it safely, and call the utility now.

Who fixes it, the utility or an electrician?

Utilities such as Eversource and Dominion Energy repair up to the connection point on your house, plus the meter; the weatherhead, meter socket, panel, and wiring inside are for a licensed electrician.

The Bottom Line

Check the neighbors, unplug electronics, reset a tripped breaker once with dry hands, and reset the GFCIs. If half the house is still dead or the 240-volt appliances won't run, call the utility and say "partial power"; if lights are brighter than normal, switch off the main if it's safe and call right away. Stay back from downed lines, keep the panel's inner cover on, and run a generator only outdoors, at least 20 feet from the house, never through a wall outlet.

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