Half the House Lost Power
When half the house loses power, the cause may be a utility leg issue, a main panel or service problem, or a failed main breaker or service connection.
Quick Answer
Losing power to half the house is usually more serious than losing one room or one outlet. It can point to a utility supply problem or a service issue inside the home.
Common Causes
- One utility leg may be down or unstable.
- There may be a problem in the main panel or service equipment.
- A main breaker or service connection may have failed.
- A dangerous partial outage condition may be affecting only part of the home.
What to Check First
- Check whether neighbors also seem to have power problems, which can point to a utility issue.
- Check the main breaker area only visually and reset a branch breaker only if one is clearly tripped.
- Notice whether some 120V circuits work while others do not.
- Pay attention to lights that look much brighter or dimmer than normal.
Quick summary
Losing power to half the house is usually more serious than losing one room or one outlet. It can point to a utility supply problem or a service issue inside the home. If lights seem unusually bright or dim, or appliances start acting strange, treat it as a condition that deserves quick professional attention.
A multimeter can help narrow down whether a circuit is actually carrying power where you expect it, while a voltage tester is a safer first check before touching anything.
Common causes
One utility leg may be down or unstable.
There may be a problem in the main panel or service equipment.
A main breaker or service connection may have failed.
A dangerous partial outage condition may be affecting only part of the home.
A loose service or main connection may be causing unstable voltage.
Safe checks homeowners can do
Check whether neighbors also seem to have power problems, which can point to a utility issue.
Check the main breaker area only visually and reset a branch breaker only if one is clearly tripped.
Notice whether some 120V circuits work while others do not.
Pay attention to lights that look much brighter or dimmer than normal.
If you're checking this yourself, having the right tools makes troubleshooting much easier. View recommended electrical tools →
When to stop and call an electrician
- Stop immediately if lights are unusually bright or dim, appliances behave strangely, or the outage affects large sections of the home.
- Do not open the electrical panel beyond resetting a breaker, and do not work on live wiring.
- Call the utility or a licensed electrician right away if the outage is widespread or appears tied to the main service.
Still not sure what's causing it?
If the problem keeps happening, feels unsafe, or you're not comfortable checking it further, it may be time to talk to a licensed electrician.
Find a licensed electrician near youNext step
For step-by-step troubleshooting, see When to Call a Licensed Electrician.