By [AUTHOR NAME, TITLE], Kelley Electrical Contracting. Published 2026-10-16. Last reviewed [DATE]. Educational information, not a substitute for an on-site inspection.
Why only half?
Most U.S. homes are fed with two hot lines that together supply 240 volts and individually supply 120 volts to different circuits. If one of those lines is lost, about half the circuits go dead while the rest still work. Some 240 volt appliances will not run at all.
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Check these first
Look at your main breaker and any tripped breakers. See whether neighbors have partial or full outages. If it is a neighborhood-wide or utility-side issue, report it to your utility (PG&E serves most of Fresno and Madera).
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Why it can be dangerous
Problems with the service connection or neutral can cause voltages to become unbalanced, which can overheat or damage electronics and appliances. Lights that are unusually bright or dim, or appliances behaving strangely, are warning signs. Shut off sensitive equipment and call for help.
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Who fixes what
If the problem is on the utility side of the meter, the utility handles it. If it is the meter base, service conductors on the house side, the main breaker or the panel, you need a licensed electrician, and often a utility coordination for disconnect and reconnect.
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Frequently asked questions
Is half the house losing power an emergency?
It can be, especially if lights are abnormally bright or dim or you smell burning. When in doubt, shut off the main breaker and call your utility or an electrician.
Can a bad breaker cause this?
Yes. A failed main breaker or a loose connection at the panel can drop one leg of power.
Will my appliances be damaged?
Unbalanced voltage can damage electronics. Unplug sensitive devices until the problem is diagnosed.
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Sources and further reading
Need an electrician?
Licensed California electrical contractor, license #1111378. Serving Fresno and Madera.